POLITECNICO DI MILANO

SCHOOL OF DESIGN
school year 2019 - 2020
curse: DESIGN & ENGINEERING

THESIS PAPER
GRADUATE: MICHELE POLIZIANI
SUPERVISOR: SILVIA FERRARIS

INDOOR AEROPONIC TOWER

FOR A STABLE FOOD SELF-PRODUCTION
 Index

3 -Abstract
5 -Today’s agricolture

7 Problems of nowadays agricolture

7 -water consumption
9 -pollution (fertilizer runoff, fossil fuel, long distance distribution)
10 -pesticides(trace of pesticides in food)
11 -soil erosion and desertification (degradation of the soil quality)
12 -deforestation
12 Hydroponics
12 -what is it?
12 -pro cons
14 -different hydroponics techniques
18 -how plants improve air quality
19 -plants that don’t worth them in hydroponics
23 -plants that worth them in hydroponics
29 -plant crossing datas
30 -1°st year possible harvests
33 -Market definition
37 -common elements across the mkt
38 -User definition
38 -how is the standard italian family?
40 -how is the standard european family?
42 -survey result
48 -user definition
49 -Briefing
50 -Concept
51 Physics components
51 -Water tank
51 -Tank cover
52 -Tower block
52 -Layer
53 -Water diffusor
54 -Net pots
54 -Cap
55 -Light support
56 Technologic components
56 -Cob LED
56 -Water pump
57 -Plc
58 -Plc transformator
58 -7 segments screen
59 -Sensors
60 Storyboard
62 My prototype aeroponic tower
65 Opinions and new acknowledge
66 My prototype Deep Water Culture box
68 Opinions and new acknowledge
70 Design part
70 Water tank

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70 Woodboard
72 Anti-spruts plate
73 Layer
74 Light module
74 Water diffusor
76 Final product
78 Human relation
79 Customer packs
80 Woodboard’s details
81 Web sites

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Abstract

Agricolture is one of the most ancestral activity ever practised; nowadays studies attribute
the first sign of it to 12’000 years ago simoultaneously in different areas of the Earth. When the
mankind has started to be sedentary, he started to practice agricolture and livestock because
were more reliable ways to get higher quantity of food, meat and leather, and even safer than
hunting.
In this epoque (8’000 BC) it started to be applied the most rudimental agricoltural techniques
such as irrigation, fertilization, deforestation, and to be studied the most suitable plants
and crops for agricolture purpose. This mix of circumstances is generally known as the 1°
agricultural revolotion. Plants as grain, corn, rice and mice started to be domesticated from
their original wild state and, throught artificial selection be led to a more productive and stable
form. In this way domesticated crops started to guarantee higher yields and simultaneously
grew weaker, with respect their ability to survive without our help. Thus led to produce food
surplus for everyone and lay the foundations for mankind grows, cities development and
raising of societies and cultures.

The industrial revolution, borned in the United Kingdom, delivered to the man the steam
engine, a new technology that exploited the energy contained in fossil fuels to generate a
quantity of work not even comparable to that one supplied from animals’ force. This invention
led to the 2° agricultural revolution, from now on new set of machineries were used to work the
soil faster and deeper.

Today agriculture is still the principal method to produce food and even if it seems an activity
hard to develop and implementing, it continues to change in metodologies and applications.
Due to technology and industries growth is established that the number of people all around
the world will raise of 2 billions in the next 30 years, from 7.7 to 9.7 in 2050; mankind will be 11
billions around 2100.

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All the living beings have modified themself through thousands of years, to survive to all the
different climate conditions of the World. Every single animal and plant, from the smallest to
the biggest and most impressive, are connected to each other and to the nature that surrond
them, in an active life net. When a mixed group of plants caracterized by common needs of
temperature, humidity and nutriets, grow toghether in a given region they attract different
animals that feed of them. Linked to the visible animals there are unvisible living beings, the
mycrobes, that transform compounds and “waste“ in new chemical structures. This mix of
factors create an ecosystem and there are thousand of different ones spread all around the
World, depending mainly on the climate how much water is present in the environment. Every
ecosystem has a rule: the productivity is limited by the total amuont of energy received, and
this depends on the geographic position of that environment that can has longer or shorter
summer.
All the plants are able to grow and reproduce taking advantage of the sunlight, that through
the photosintesys, excrete oxygen and store carbon to create sugar and proteins for new sets
of green structures. Then herbivorous animals eat plants for accomplishing their nutritional
requirements, thus growing, breathe oxygen and exhale carbon dioxide. They also excrete
solid and liquid waste that is nutrient for the earth, thus used by the plants. When animals and
plants died, detritivores microbes decompose them creating nutrient fertilizer for new plants.

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Sunlight is the major form of energy that constantly light and allow life on our Earth, due
to it evolution of all living beings has take place over millions of years, from microbes to the
biggest animals ever lived. Since the energy is never destroyed but transformed, even in the
processes inside living beings this appen; chemical compounds that we call waste, are in
reality a source of energy and life for other creatures. This virtuous circle of life is how nature
works from the origin of the time, and it will be like this forever.
Unfortunately cities of today don’t respect this law, they consume large amount of energy and
resources in a linear way, thus without considering the waste that is hopelessy destroyed by
incenerating. The energy contained in the used artifacts is released in the form of heat, without
providing any kind of support for a new set of objected to be produced. This is what circular
economy talks about, designing whatever we need with the keypoint of using the waste as
source of energy for other industries that can transform that material and energy in something
new , to be used again even in other form different from the original one.
The question that we should answer to is , can a city work as a natural ecosystem, and at the
same time provide an healthy and safe place for its inhabutants? We have all the technology
to provide this change and the new generations have willingness and consciousness to move
themself to a new green revolution.

TODAY’S AGRICULTURE

From the Industrial revolution on the number of people praticing farming went drastically
down, due to the movements from countries to cities. People has preferred living in city
because of the more services all in one place,the possibility to take up the dreamed job of
change it easily, the more interacions with other people and the relatively easier life compared
to the hard work in the countriside. The status of farmer has progressively shifted from
accepted to be a source of derision and mockery. People has moved to the cities but none
born within them were dreaming to go to coutries.
So nowadays we are arrived at the point that only a little part of the population own land and
work it. As this European Parliament’s report says, the total labour force in agriculture in Europe
has decreased of 30% in one decade (Figure 5), from 11.5 million worker in 2007 to 9 million in
2017. This massive labour outflow is due to: structural changes in agriculture sector, a declining
number of farms, combined with an increase attemp to pursue economy of scale(less farms,
but bigger).
Structural change of the primary sector is due to different factors: 1)technological progress, 2)

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accession to the EU, 3)income gap between different economic sectors and 4) gender gap.

Technological progress

Technological innovation is a key factor for improving agricultural productivity and

maximizing food supply through higher yields, but technological progress also increases the
productivity of agricultural labour. As technology goes on, the labour demand will decrease
concurrently with a higher need for specialized and skilled emploees. Automatization and
mechanized work can be applied in all the manual and repetitive tasks, but not in the cognitive
agricultural jobs; in this sector only the application of machine learning and AI can speed up
the workers’ productivity. Innovation through robots in the fields and AI in the informatic system
is expensive and surely raise the production costs within the farm.
The EU agricultural outlook of the European Commission (2018) predicts that labour outflow
from the agricultural sector will continue until 2030, and meantime the agricultural workforce
will decrease of 2%, till 7.7 million units. Technology oriented agriculture is possible and
will be more and more achivable due to the instruction and education of the young farmer
manager(less than 35 years). A 2018 Eurostat report says that 20% of young farmer have a
complete agricultural trainee, compared to just 2.6% of old farmers above 65 years old. These
statistics can help to explain the increase in the number of
medium- and large-size farms managed by young farmers which reached 27.5% of EU farms.

EU accession

The accession and economic growth of EU has facilitated the expansion of industry and
services, creating a big amount of new job opportunities. the European Commission (2017)
predicts that workforce outflow from the agricultural sector will continue as long as the other
sectors in the economy provide more attractive incomes.
The city offer better life opportunities due to the presence of infrastructures and services
available to the citizen; in the same way powering the third sector in rural areas will improve
the attractiveness of these place, thus a return to the agriculture.

Income gap between different economic sectors

Gullstrand and Tezic (2008) mention that economic gap between agriculture and other sectors,
plus low agricultural education are the main reason of the outflow toward better economic
sectors. There is even a great difference between income generated on-farm and off-farm, this
encrease the possibility that emploees choose to move to different economic sectors.

Gender gap

The agricultural sector is unbalance speaking in term of gender emploiment. An European

Parliament’s recent study (2019) says that:
-between 2013-17 the women unemployment rate in rural areas was higher compared to men,
7.6% vs 7.1%
-in rural areas women are more likely to get an informal employment compared to men, thus
it’s more difficult to find a long term job and social stability.
-women in rural areas have less potential in becoming farm owner compared to men.
Franić and Kovačićek (2019)remind also that this gender gap is present not only in agriculture
but in all EU economic sectors with an average gross earning per hour 16.3% below those of
men. (Estonia has the higher earning gap 25.3%; Romania the lowest 5.2%)

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Eurostat (2018) provides data about the men undispute managment of farms: 71% are male
farm manager, 58% of those are more than 58 years old (Figure 10).

PROBLEMS OF NOWADAYS AGRICOLTURE

Today’s agricolture is responsible of a huge series of problems connected to the environment.

The traditional production methods, as the intensive harvesting of single crops, have created
serious problems in the surroundings of the fields. Here is a list of the main ones:

Water consumption
Food production is the most expensive human activity, in term of water consumption. Around
70% of the water taken from lakes, rivers and underground springs goes into irrigation, 10% is
for domestical uses and 20% for industry.
Since the 60’ the global demand for food started to raise, pushed by the economic growth
after the war. The increase in food production was possible thanks to high yield crops, intensive
ground exploitation and new chemical fertilizer to feed the plants.
What agriculture produces is driven by consumer demand, and changes in consumer
preferences have an influence on the water needed for food production. For instance cereals
today represent 56% of the whole amount of calories, and is foreseable to stay around 50%
of the all food consumed in the future. A big part of the cereals harvested are for cattle
consumption, and this is why meat production require around 20 times more water, than
vegetables. In the table we can see how much water is required for some of the main foods in
our diet.

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Pollution
Todays agricolture is responsible of earth and water pollution, due to fertilizers runnoff in the
underground springs, rivers and lakes. One strong examples of a past destructive runnoff in
California, since the 50’s. In a region of this state, known as Central Valley, the first types of high
yield farms started to appear,and together with the diary industry, created a $65 billion market.
This region has a very hot climate, around 43° C, one of the driest zones of the States. The
crops produces were of all kinds , from tomatoes to nuts, every vegetables and fruits, all plants
that require high amount of nutrient and water to survive.
After 30 years of these methods,even with more developed and strond fertilizers, ponds
started to appear everywhere. The earth was completely full of runnoff from the fields, that the
contamined water welled up from the aquifiers. Soon a lot of wild animals and birds died, and
there weren’t any clean water springs to irrigate the crops. In 2009 Steven Chu decleared that,
the entire California agricolture risk to fall and become obsolete, due to the high salt levels,
pesticides and heavy metals in the underground waters.

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Other source of pollution are related to the fossil fuel consumption, both in fields and during
transport of the earth’s products, from countries to the cities.

PESTICIDES (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2984095/)

The term pesticide covers a wide range of compounds including insecticides, fungicides,
herbicides, rodenticides, molluscicides, plant growth regulators and others. A pesticide must
be lethal to the targeted pests, but not to every other species, including man. Unfortunately,
this is not the case, so the controversy of use and abuse of pesticides has surfaced.
Noone is completely safe from an exposure to pesticides, that can cause serious health
diseases. Around 1 million people are affected by pesticides intossications, every year
worldwide. The group exposed to the higher hazards are the workers in the pesticides
industries, and the farmers during the use and application of these chemical compounds.
Organochloride is kwown to be responsible of pollute the tissues of every forms of life, from
the undergrounds to the seas and lakes, birds included.
DDT compounds are responsible for impairing the birds’ eggshell, it thins the structure
heading to premature born and all problems related to this situation.
Chemicals that term as Endocrine Disruptors, are responsible for antagonising natural
hormones in the body; their long-term, low-dose exposure is connected to immune
suppression, hormone disruption, diminished intelligence, reproductive abnormalities and
cancer.
Other studies on the exposure of pesticides to humans, were conducted in Italy after the
Seveso disaster in 1976. The local chemical industry, dealing with dioxine pesticides, had fail,
and consequently a large amount of this chemical was released in the surroundings.Scientists
declared that a link between the dioxine exposure and cardiovascular diseases and cancer
was established.
Other problems caused by pesticides are that they pollute the fruit, infact traces of chemicals
were found in small percentages in quite every vegetables in which they are implied.
Pesticides once released in nature, not just hunt down the target insects, but they are harmfull
to every form of life, plants and erbs even if they are not the designated target.

Pesticides contaminate the majority of watercourses; an american study conducted by the U.S.
Geological Survey in the 90’ revealed that 90% of all the water and fish samples, from the major
rivers and lakes of the States. Urban streams are more polluted than the agricoltural, with
pesticides and insecticides that overcome the laws on acquatic life.
Heavy treatment of soil with pesticides can cause populations of beneficial soil
microorganisms to decline. According to the soil scientist Dr. Elaine Ingham, “If we lose both
bacteria and fungi, then the soil degrades. Overuse of chemical fertilizers and pesticides have
effects on the soil organisms that are similar to human overuse of antibiotics. Indiscriminate
use of chemicals might work for a few years, but after a while, there aren’t enough beneficial
soil organisms to hold onto the nutrients”.
A wide variety of microorganism (mycorrhizal fungi, bacteria) transform the atmospheric
nitrogen into nitrate, that can be absorbed by the roots. Most herbicides reduce the presence
of these living beings, thus result in a more sterile land (triclopyr, glyphosate, 2,4-D).

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Soil erosion

Terrain is constituted by different layers, called horizons, standing on the bedrock, the most
inner rocky level. Soil is the outer layer of terrain.
Soil erosion is a complex process that depends on soil properties,ground slope,vegetation, and
rainfall amount and intensity. It mean that due to rainfall and wind, the earth becomes dust and
is literally blow away by the wind. If this process is too fast, it thins the soil layer, full of nutrients,
microorganisms and fungi, and in a few generations the land becomes sterile, and starts the
desertification.
Other effects linked to soil erosion are the advanced lost of soil in country and mountain
slopes, that creates landslides, till the complete terrain fail. The eroded land flyes to the valley
and reduce the efficiency and flow rate of the waterstreams.
Soil erosion is a relatively new fenomenon, studied since the 30’ in USA, especially in the
region known as Dust Bowl, that comprend territories of New Mexico, Texas, Colorado, Kansas
and Oklahoma. After just some decades of conventional agriculture the rate of soil loss was so
high, that for 10 years several dust storms happened in the Dust Bowl. The territory became
sterile and the result was thousand of farmers family forced to leave the area.
The harder practice that the earth withstand is the plowing, a mechanical break of the soil
that soften it and incorporate air and oxigen underneath it. In that period started many studies
about the soil erosion, the first comparisons were made between tilled filds and no tilled ones.
These studies are hard to put in comparison , because the erosion rate is strictly related to
different caracteristics of the land, temperature, amount of rainfall, vegetation, and slope. That
is why all these observations end with very different datas, but in general we can synthetized
that no-till practises can save 2.5-<1000 times more soil; hence, a no-plowed fild is completely
in line with the soil production rate.

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Deforestation

Everyday around 50 000 acres of forest are cleared by farmers and loggers worldwide.
Considering just the Amazon Basin we lose around 10 000 football fields everyday. The main
reason of deforestation is connected to animal agriculture, and is strictly related to greenhouse
gases uprising, disruption of water cycles, increased soil erosion and excessive flooding.
The constant destruction of our forests threatens biodiversity, decreases carbon absorption,
magnifies natural disaster damage, and disrupts water cycles.
Animal agriculture and livestock are the main reason of deforestation: the global meat demand
raises, so do the number of cattle to feed and graze.
Nearly 60 percent of the world’s arable land is used for beef production alone, which requires
large amounts of land used for cattle grazing and cultivating feed crops like soy. This crop has
doubled in production in the last 20 years, for satisfying the major meat demand. Around 80%
of all soy harvested is destined to cattle feed.

Hydroponic Techniques

Under the Hydroculture dom there is the hydroponics techniques. Plants can grown without
soil, by using nutrient mineral solution dissolved in water. This enriched water is sprayed
directly on the roots exposed in air. The plant can be supported in a inert medium such as
perlite,rockwool or coco fibres, just for support a little bit the vegetable mass. The nutrients
used in hydroponic can come from different sources: fish excrement, chemical fertilisers or
cattle manure. These techniques represent an improvement to the traditional agriculture in soil
for many reasons.

Pros

We can gain many advantages from an hydroponic production, especially if we link these
techniques with a controlled and safe indoor environment.

-Year-round crop production: in a traditional outdoor field we can harvest crops only in certain
periods of the year , associated to the right seasons. Adverse weather conditions as night
frost, abundant rainfall,floods, hail, strong wind, snow, or on the opposite, drought and high
temperatures, are strong enemies that reduced or sometimes totally destroy the crops. As the
climate change these natural phenomenons are more popular, and usually jeopardize the yield
in the last week of the harvesting time.
If we practise hydroponic techniques in an indoor, safe and controlled environment, the
farmer doesn’t have to worry about the weather and sudden climate change conditions. Every
crops can be produced everywhere and year-round, without losing time waiting for the right
temperature, or letting the earth rests.

-No agricultural runnoff: is the biggest problem in traditional agriculture. The USDA indicates
the agricultural runnoff as the main source of pollution in the USA. If we want the maximum
yield from a field, we must give more water that the amount obtained from the seasonal
rainfall. Moreover we have to furnishing more nutrients than the natural ones embedded in the
soil. Runnoff are unpreventable and in a traditional field it contains: silt, fertilizers, herbicides,
pesticides, fungicides, insecticides, heavy metals, high nitrogen levels, minerals in crystals.
All these compounds flow to the rivers or waterstreams, till the sea; that’s the reason why
the USA are forced to import nearly 80% of its seafood.
Many problems are caused by these chemicals, as contaminate fresh water springs, or
creating dead zones for every of water living beings.

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-Allowance for ecosystem restoration: hydroponic cultivation are usually grown in indoor
conditions or in an outdoor massive contest, in which layers of irrigated pots or pie are kept in
a relatively little yard. If a conversion between traditional agriculture and hydroponics system
was done, it would allow a natural restoration of the past outdoor fields. The environment
is much more resilient than what we think, and if left wild it’s completely able to restore its
natural equilibrium, decontamination from chemicals and going back to be a wood. For
istance, after the Chernobyl disaster all the surrounding areas were contamined by high levels
of radioactivity. The wild life never left the region and start to increase in number , even the
plants and trees started to grow in the middle of the abandoned cities. The nature gradually
but without interruptions takes again the territories that were used and exploited by human
activities.
Costa Rica is another example of how the nature is strong and recovers itself. As the number
of farm increased, portions of tropical forest were replaced with sugarcane, coffe and other
crops plantagions. From 2000-2005 the cattle industries endured a lower production, due to
the USA beef market that was more concorrential. As outcome many fields and pastures were
abandoned, and turned into forest again.

-Saving water: The traditional agriculture use 70% of all fresh water to irrigate crops. In an
hydroponic system the water circulates in the system and is collected again without losses.
In this way farmers manage to save around 70-80% of water compared to traditional in-soil
methods. Aeroponics techniques use nozzles and sprayers to wet the roots, and can save up
to 95% of fresh water. Horticulture methods are used even in the space by NASA and ESA, to
produce fresh vegetables and plants directly in orbit.
Plants can colonize volcanic islands that have no soil at all, thanks to hydroponic technique. In
this way plants help to create soil: the roots crack large stones in smaller ones till it becomes
new soil.
The problem of irrigation in the traditional fields is huge; the world population is growing
toghether with life expectancy, thus a lot of people to feed for many years. Hydroponics
systems circulate and collect water, are the only way to increase food production without
damage or pollute as the traditional in-field methods.

-Reduction in food miles: hydroponics methods are very suitable in urban contexts because
they don’t require arable land. Following this logic farmers from the countries can move
back to the cities and cut down a lot of prices related to the land working, transport and
refrigeration. Talking about a huge hydroponic urban production it’s possible to establish a
solid trust relation between customer and producer; the first can see directly with his own eyes
where the product comes from and how it’s done.
In a private production these values are still valid, the grower will acquire experience and sets
up a new relation with the nature; he also can save money on food expenses and totally cut
down the transport from the field to the dining table.

-More controls, food safety and security: in an hydroponic system we can check and set up
the best mineral and ph values of our crops. We can decide what fertiliser is the best, and
evenually change it, at any time by flushing the water reservoir. In an urban context the user
will totally avoid herbicides and pesticides because the number of hazardous insects are less
than in a traditional country field. In addition the urban grower uses no pesticides or herbicides,
because in an hydroponic environment the lack of soil doesn’t allow the spread of insects and
bacterias that live in the earth.

-Higher growth rate: hydroponic system gives to the roots all the nutrients that are required for
growing health, taste better and increase the production.
In the traditional agriculture the plants are holded up by the soil , a solid medium that provides
all macro/micro elements and traps the water.

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In a system like that, the plant spends energy to grow the roots into the soil, and that is a
reason why farmers plow the fields, they try to soften it.
In an hydroponic system the roots are free to grow without effort, in a controlled and inert
ambient, thus the plant has more energy for the vegetative phase and for increasing the
production.

CONS

-System failure threats: an hydroponic system uses water and electricity to run, and these
components work for several hour per day. If some component is broken is important to
individuate and replace them as soon as possible. Hydroponics techniques are able to pump
the root system and speed up the plant’s growth, but as downside is very fragile and even a
failure or disfunction for some hours can compromize all the crop.

-Experience : running a hydroponic system require a dose of knowledge and experience for
avoiding the errors and failures in crop’s growth. Concepts as water electro-conductivity, ph,
what plants can be grown or what is the best fertiliser, must be studied and investigated to find
the right balance of the system.

-Initial expenses: the system represent the biggest initial expense, but it’s not the only one,
the user need to buy seeds or directly plants, the right fertiliser, acidity corrector and replace
everyting that get broken. Is an investment that needs to be payd off.

DIFFERENT HYDROPONICS TECHNIQUES

There are several hydroponics techniques that rather differ one from another. The more
suitable method depends upon the space that the grower wants to occupy, and the
experience that he has on hydroponic.

-STATIC SOLUTION CULTURE: plants are grown in a container of nutrient solution, depending
on how much we want to scale the system, we could deal with food jar, pots, buckets, tubes
or big tanks. The water is constantly checked to assure the right values, and is flushed and
replaced once in a week, or depending on the dimensions and number of plants.
In the top of the reservoir ther’s an inert solid panel, made of plastic, rubber, wood or
polystyrene. This represents the support that holds all the crop, the grower will cut circular
holes for each plant. The panel float on the reservoir and let the roots to be always plunged
in the nutrient solution. For aerating the roots, an air pump raises the oxygen levels of the
solution.

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-NUTRIENT FILM TECHNIQUE (NFT): the roots are constantly wetted by a nutrient film of
water, flows inside a PVC pipe. The tube should be large enough to contain the adult root mass
of every plant, and has a slope around 1:30-1:40 to avoid ponds in local depressions or defects
of the material. Once the water has flow along the pipe is collected in a tank, where it’s easy to
check the values and correct them.
The key goal of this techniques is that the plant is exposed to all 3 elements to grow healthy:
adequate nutrients, oxygen and water.
The recommended water flow is 1 L/min, with a maximum of 2 L/min; above or below this
gap crop will have nutritional problems. It has been tested that pipes longer than 10-15 m
shown depressed growth rate in the last meters. If the grower want a NFT line longer than
15m he should place another water reservoir in the middle of the system to enrich again the
waterstream.

-AEROPONIC: in this technique the roots are kept continuosly or not, in an environment with
100% of humidity, created with high pressure nozzles or sprayer, that emit fine drops of nutrient
solution.
The advantage of aereoponics compared to the other hydroponics techniques are several:
every plant can be grown in this way because is easy to control the microenviroment.
Aeroponic use 65% less water and about 1/4 less nutrient than the other systems. NASA
research has shown that aeroponically grown plants have an 80% increase in dry weight
biomass (essential minerals), and receive 100% of the available oxygen and carbon dioxide.
Aeroponic is studied and used by NASA because a mist is easier to handle than a liquid in a
zero gravity environment.

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-EBB AND FLOW (FLOOD AND DRAIN): there’s a water reservoir full of nutrients, and a tray
that contains the plants. A timer switches on the water pump that fills the tray, after that the
water drains back to the main tank. This cycle of flood and drain allow the roots to absorb
both nutrient and oxygen from the air. During the drain time the medium keeps humidity and
fertiliser, to prevent the roots get dry.

-DEEP WATER CULTURE: in this method plants are kept in a nutrient solution enriched with
oxygen. An air pump and a porous stone assure that water is constantly saturated with oxygen,
in this way the grower cuts the growing time. This technique diffear from the static solution
culture because there’s a gap between the level of water and the bottom of the net pots. In
this way a part of roots are always in the air, thus absorb oxygen.
As the root mass grows and stretches out, the grower can reduce the water level, hence more
roots will be exposed to the oxygen in the air.
Another variant is instead of a sub irrigation, a top irrigation from the lid; water drips wet the
root mass and fall into the reservoir. In this way plant grows faster in the first weeks because it
has access to the nutrients since the beginning.

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-ROTARY: in this technique a circular frame holds all the plants, and accomplishes 1 full turn
per hour. In the bottom part of the circle there is the water enriched reservoir that pours the
plants once per turn. In the center there’s a high intense grow light that simulate the sun. This
frame is particularly used in indoor ambient because it provides for a light, and is a scenic
object. This is the only technique that uses the gravity force to strech the plant, infact it has
been studied a faster growth than the other methods. Depending on how deep is the structure
it can house a great number of plants.
As downside the grower can cultivate only short green leaf plants, because the weight of the
fruits will damage them during the rotation, squashing the other vegetables. If it’s not well
projected problem related to drips of water falling down to the hot bulb or to the other leafs
are common. This method is more expensive because of the material to buil the frame, and
other components as the stepper motor. It can be considered a mix between an horizontal and
a vertical system.

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HOW PLANTS IMPROVE AIR QUALITY

An aeroponic tower can grow all type of plants, from vegetables to fruits and houseplants.
Adding a bit of green is a cheap way to furnish the house. Standing on Forbes there are a
significant amount of scientific proves that being around greenery can stave off stress, and heal
the space:

-reduce stress and anxiety: a study on the Journal of Physiological Anthropology claim that an
active interaction with indoor plants (touching, watching, smelling...) reduce physiological and
psychological stress. Even being around or touching the soil works as antidepressants, infact
the earth is house of microbes called Outdoorphins, that release cytokines which then leads
your brain to produce more serotonin. Obviusly a walk in a wood is the best cause there are
more microbes in the soil , but even furnish an interior with houseplants can boost your mood.

-spruce up the air: the American Lung Association says that indoor air can be even more
polluter than the outdoor, due to a continue emission of pollutant from electrical device and
other stuff. Asbestos, mold, radon, formaldehyde, benzene and carbon monoxide are the main
pollutant that cause illnesses like dry eye, asthma or headaches.
Ornamental Plants like Peace Lily or English Ivy are able to filter out these compounds, they
absorb them through the roots and leaves. Infact plant-filled rooms contain up to 60 percent
fewer airborne molds and bacteria than rooms without plants.

-act as natural hudifier: plants release water vapour throuh the leaves in a process called
transpiration. During winter the common proble of dry air can cause different annoyances;
adding some green inside the house help in humidity regulation.

-enhance the cognitive skills: Texas A&M University and researchers at Exeter University, UK
have conducted similar studies: keeping pots around the workspace improve the creative
performance, boost the productivity around 47%, increase the memory retention up to 20 %.

-plants facilitate in healing: Kansas State University researchers found that being in proximity of
plant help to keep the calm and so healing faster from injuries. Even studies led by Texas A&M
University suggest that horticulture therapy can help patients in health facilities.

So there are plenty of reasons to full the house of pots and plants. An aeroponic tower can
produce food and vegetables more nutrient and fresher than those buoght on market, cuts
down the food miles, and heals the indoor air.
So standing on these reserches a part of the tower pots should be filled with ornamental plants
as English Ivy, Spider Plant, Gerbera, Bamboo, Palm, Peace Lily or Chinese Evergreen to take
advantage of these positive sides.

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 PLANTS THAT AREN’T WORTH THEM IN HYDROPONICS

Hydroponics is a growing technique especially used in an indoor environment, for instance

green houses or indoor farms, to cultivate all year-round.
Because hydroponics provides the right amount of nutrients, PH, and water to the plant, the-
oretically it’s suitable for all plants and vegetables, but it isn’t in practise. There are physical
limitations both in an indoor and outdoor space that don’t allow hydroponics for every crops.

Vining plants tend to expand in horizontal as grapevine, kiwi, or in vertical as ivy, or hops.
These types are not suitable both for the big roots expansion in the ground, and for the outer
space that plants take, once fully grown.

Other plants not appropriate in hydroponics are all the cucurbits that produce big fruits or
grow too much, requiring a lot of free space. Zucchini, pumpkin, watermelon and melon
literally grow for meters during summer and autumn; for these physycal caracteristics these
plants cannot be hydroponically grown, besides in single water reservoirs, outdistanced enou-
gh one from the other. In any case these crops occupy more space than other vegetables.

- 20 -
Other vegetables that don’t like hydroponics growth are potatoes of all kind, because their life
is really linked to the soil. The ground protects potatoes and matures them quickly and heal-
thily. Some hydroponics potatoes attempt is possible, but it requires more effort, energy for the
water pump and time, in change of a smaller production, compared to soil. Another reason why
potatoes are not an hydroponics crop, is because the plant produce an extensive root system
that require more space than a water tank could provide.

Roots, bulbs and tubers are another categories not very hydroponics suitable: carrots, onion,
garlic, turnips, ginger, shallot. Typically, these species will need plenty of soil for their roots to
spread out in search of nutrients and moisture, thus is not enough the artificial space provided
by a plastic container. These crops are simply not space-saving, and this is one of the main pro
in hydroponics.

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Cotton is a bulk crop, this means that only if harvest in huge quatity is valuable. The growing
season is long, around 6 months, thus just one harvest per year. Once mature it’s harvested
with specialized machineries and equipments that run on land.
Manufacturing one pair of jeans requires 680 gramms of cotton; considering that one acre
produces up to 22 Kg of cotton, it can be manufactured in 33 pairs of jeans. The only problem is
that this average is not possible in hydroponics conditions, and nowadays there aren’t machi-
neries setted to harvest from an hydroponic system.
If the grower decides to grow cotton in a greenhouse, he’ll face to very high running costs: fer-
tilisers, lighting, monitoring system.

Another crop that is not worth to be grown hydroponically is corn. This plant can be harvested
every 60 days, with a growing time in Europe from March to November, thus 4 harvest per year.
This plant reach important dimensions, especially in height, around 2.5 meters, and this is the
first reason why is not possible to cultivate in a commercial vertical farm. Corn requires large
amount of fertiliser and sunlight compared to other crops, and that a reason why it costs much
to grow in an hydroponics system rather than in open field. It simply doesn’t make sense be-
cause there are cheaper methods to grow it.

- 22 -
Rice is the highest water consuming crop and the most consumed in the world, around 1/3 of
the whole population. With the seas’ levels rising a lot of rice cultivations around the world will
be in dangerous, so it’ll be important in the future, reach a significant level of hydroponics rice
production, in order not to lose many outdoor harvest due to climate warming.
Today technology doesn’t make valuable to grow rice in hydroponic system, due to the lar-
ge amount of greenhouse space that a company should has, in order to quickly pay back the
investment.
Today most of the human labour has been cutted by using special equipment and tractors.
Growing rice in an indoor system adds a lot more costs compare to soil, as electricity, the who-
le system, sensors, lighting, fans. This is the reason why men still grow rice in outdoor fields.

Following the rice reasoning I can affirm that even the other 4 main cereals , wheat, barley,
spelt and oat aren’t economically worth in an hydroponic system.

Other seasoning crops that has no sense if hydroponically grown are all fruits and dry fruits.
Apple, pear, banana, lemon, orange, tangerine, pomegranate, ananas, peach, cerry, apricot,
persimmon tree, walnut, almond, chestnut, jujube, are trees’ fruits, some can be different me-
ters height, some other maximum 2 meters, according to the plant type. Trees are very heavy,
require stability, thus is not possible to grow them in an hydroponic tank.

- 23 -
Continuing the reasoning among ornamental plants, due to their main caracteristic of living
with a little amount of water, all fat plants are not advisable in hydroponics. These plants store
high quantity of water in their leafs and vegetable structures, usually grow really slow, and last
many years. If a fat plant such too many water it drought faster that a normal ornamental plant.

PLANTS THAT WORTH THEM IN HYDROPONICS

Main crops as five cereals, and most of tree’s fruits are not advisable in an hydroponics sy-
stem, due to physical caracteristics and living time. On the other hand vertical farms are new
economic businesses, where with sophisticated devices men grow vegetables in an indoor
hydroponic space. In these facilities technology constantly control every water parameter, pos-
sible system failures, climate, humidity, lighting and spread deseases; in this way is possible to
obtain higher yields in less time, and obviously all year-round.

Let’s see how are the most grown hydroponics crops, what are their living parameters and in
which way they are grown.

Green leaf
Lettuce

is the most hydroponics cultivation all around the world. Many caracteristics make this green
leaf plant the most suitable in an hydroponic system, first of all the dimensions. Heigh betwe-
en 150-300 mm and width 50-300 mm, lettuce can be grown from the seed. When it become
adult, lettuce has short thin roots around 457 mm, that such fertilised water and make the
plant ready to be harvested in 45 days. Thanks to greenhouses lettuce can be grown all year
round; in these structures the climate, exposure to sunlight, humidity and ventilation are com-
puter controlled, thus is possible to grow it anywhere around the world. Greenhouse prevents
the exposure to earth living beings and diseases, so lettuce can be grown without pesticides.
In the most cases the technique used is static solution culture, with big water reservoirs and
polystyren panels that float on them; the inert panel has holes in which are arranged the crop.
The water is oxygenated with air pumps that make bubbles.
Other techinique can be NFT in PVC pipes, in this way the grower use the verticality of the
greenhouse, and avoid big water reservoirs. Even in this case air pumps are used to keep water

- 24 -
enriched with oxygen.
In a vertical farm lettuce is cultivated under LED lights that provide the optimum light
spectrum.
(https://www.producegrower.com/article/lettuce-and-leafy-greens-101-a-production-guide/)
Lettuce grows in water with pH 5.4-6.0 and an electroconductivity (EC) of 1.4 mS/cm. Day

temperatures range from 20 to 24°C and should never exceed 25°C, while night temperatures
range from 15.5 to 18° C.
Providing supplemental CO2 is a method to increase and boost the production, can be produ-
ced from oil sub-products burners or from CO2 liquid pressurized tank. The best concentration
is between 1000-1500 ppm.

Other green leaf vegetables are grown in hydroponics system as the lettuce ones. kale, swiss
chard, spinach, savoy cabbage.

Kale
It’s grown from the seed in an inhert material as rockwool or perlite. The lifetime is long, around
3-4 months. The optimum pH is between 6.0-7.0, EC 0.8-1.8 mS/cm according to the growth.
Root depth 150-300mm, height 300-450mm and width 200-450mm is bigger than lettuce and
require more space to grow. The temperature is between 15.5-18.0° C.

Spinach
Grown with the same techniques as the other; the water main value are: pH 5.6-6, EC 1.3mS/
cm. Carbon dioxide is used with concentration 1000-1500 ppm during daylight, at normal le-
vels during night(390 ppm). Temperature around 24° during day and 19° C at night.
The dimensions are:roots depth: 25-130mm, height 100-150mm and width 150-200mm.

Swiss chard
It’s grown in NFT system harvested in 35 days from germination. Optimum pH is around 6.2-7,
with an EC 1.8–2.3 mS/CM, in a temperature between 10-25°C. Growers should only harvest
partially, leaving 25–30% of the foliage for the plant to photosynthesize through the next turn.
This method can be done with quite all green leafs vegetable. Height can be 200-600 mm ,
width 230-450 mm and root depth 200-250 mm.

- 25 -
 Tomatoes

The importance of tomatoe in the occidental food is undisputed, it’s the most important crop
outside the green leafs grup that is possible to hydroponically grow.
Because of the vining nature of the plant, it’s grown in vertical, in special PVC coloumns, where
inside them water runs continuously, otherwise it’s tied to vertical supports, infact the height is
0.9-4.0 meters. Width is 600-900 mm and roots depth is 200-600 mm.
The high water quantity in irrigation for grow it is very high.
This is the main reason why it’s grown hydroponically, to save a huge amount of water. It also
require a high fertiliser amount, with an EC 2.0-5.0 mS/cm, and pH between 5.5-6.5.

This very tall plant requires stability, infact it’s grown in an inhert medium such as coco fiber or
expanded clay. A drip system conducts the fertilised water to all the plant spots, and an under-
neath pipe system picks up the liquid, and gathers it to the reservoir.
A domestic tomatoes hydroponics system used is deep water culture, using different buckets
to slot in each other. The smaller one hold the medium and the plant, the bigger bucket collect
water and sends it to the reservoir.
Tomatoe grows better in warm season, with the earth temperature at least at 12°C and the air
between 18-32°C. Outdoor it requires 50-60 days before the harvest during early season; till 80
days if planted in late season, close to automn.
Due to the vining tomatoe caracteristic, this plant requires supports to let the structure grow in
vertical.

Pepper

In the same way of tomatoe, even pepper is possible to be hydroponically grown. Buckets full
of medium provides stability to the pepper plant, that can reach 600-900 mm height. The roots
depth is 200-1200 mm, and width of 600 mm.
The optimum pH level is 5.5-6.5, with EC 2.0-2.5 mS/cm, this plant is ready to be harvested in
60-90 days. Hot peppers can take even till 150 days to reach maturity.
Pepper requires much water to produce fruits, in an open field condition, with hydroponics is
possible to cut down the water consumption.
If pepper is cultivated indoor it surely needs holders to keep the weight of brances and pepper.
The optimum temperatures are 18.3-35° C to germinate, and 21-29.5 to grow.

- 26 -
 Cucumber

Cucumber seed has a high germination rate, and it can be directly sown in the growing me-
dium choose (rockwool, stone, coconut fiber...). Warm temperature around 26.5° C speeds up
the seed propagation. Cucumber require fertilizer in moderate quantity to ultimate the propa-
gation stage. Once it has 3-4 leafs is ready to be trasplanted in an hydroponics system as the
Dutch buckets (DWC system).
Cucumber dimensions are massive: 300-2400 mm height and 300-600 width, with root depth
between 900-1200 the main tap root, and a dense root mass of 600 mm in diameter just un-
derneath the soil.
Cucumber love light and warm temperature, between 23-26.5° C during day, and around 10°
cooler at night. Besides summer it requires a proper artificial lighting to bear fruits.
Like other vining plants, also this is heavy fedders, with an EC 2.0-3.0 mS/cm, in a pH 5.8-6.0.
Cucumber maintenance foresees pruning of leafs and fruits: there should be one pepper with
one leaf, to mantain the fruit development and maximixe the light exposure. Only smaller fruits
can grow together with other little ones.
Harvest fruits frequently to avoid excessive crop loads and promote normal fruit development.
The daylife of cucumber plant is around 70 days.

- 27 -
 Strawberry

It’s a small plant with very short root depth, if cultivated in an indoor environment it produces
fruits all year round.
For commercial porpouse, strawberries are grown in greenhouse with NFT system with one le-
vel or more. Other time if the company wants to exploit the vertical space of the facility, straw-
berries are cultivated in vertical aeroponic tower.
The dimensions are suitable for a domestic space, infact the height is 200-300 mm, width 220-
300 mm and root depth less than 300 according to the plant type and plant’s wellness.
The water values to keep it alive and productive are pH 5.5-6.5 and EC 1.8-2.2, temperature
between 20-22.5° C to germinate, and around 17.5-25° C for growing.

Herbs

Basil

It’s the main hydroponics herb, with a maximum height of 600 mm, width 500-750 mm and
root depth 200-300 mm. In a single pot it can be grown decades of single basil plants. The per-
fect location is in fully sun, this plant tolerates well the hot rather than the cold, even with just
one frost night basil can die.
Water should has low fertiliser value, around 1.0-1.6 mS/cm and a pH 5.5-6.5. Higher fertiliser
will produce more leafs but with less fragrance.
For commercial purpose basil is produced in NFT and with vertical aeroponics towers. If cutted
a few cm off the top the plant is stimulated to become short bushy.

- 28 -
 Parsley

It’s a biennal herb that can be harvested multiple times, all year-round if protected during win-
ter. More seeds can be putted in one spot because of the limited dimensions of a single plant.
Height between 450-600 mm and width according to how many plants we have. Root are not
very deep, till 600mm in open soil.
The hydroponics system used for parsley are NFT, DWC and static solution culture. The level
of fertiliser dissolved in water is 0.8-1.8 mS/cm, in a pH range 5.5-6.0. The living temperature is
18-21° C , but it withstand well the colder days.
The yield is very generous, and is ready after 70-90 days after planting.

Mint

It’s a perennial invasive plant with a fresh taste, exist in many versions, mint can produce very
high yield. As all herbs even mint can be grown in group, as in an intense production. The hei-
ght depend on how do we prune the plant, but can reach 450-600 mm. The width depend on
how many plants there are in the pot. Root depth outside a pot can reach 600 mm.
The water values are pH in the range 5.5-6.0 and EC quite high, from 2.0 to 2.4.
Mint can be harvested 2-3 times in a growing season; it takes 40 days to harvest.
The methods used to grow mint are grow zip, vertical aeroponics tower and DWC.

- 29 -
 Crossing datas

In this chart I cross all the previous datas to calculate some averages. The dimensions were
refered to normal plants grown in soil. Considering them in an indoor urban space, with artificial
lighting, or in the best case (south exposure of the house) a partial exposure during daytime,
indoor plants will grow less that the above averages.

Height Width Root pH EC Days to

depth harvest

Lettuce 150-300 50-300 450 5.4-6.0 1.4 45

Kale 300-450 200-450 150-300 6.0-7.0 0.8-1.8 90-120

Spinach 100-150 150-200 25-130 5.6-6.0 1.3 40

Swiss 200-600 230-450 200-250 6.2-7.0 1.8–2.3 35

chard

Tomatoe 900- 600-900 200-600 5.5-6.5 2.0-5.0 60-80

4000

Pepper 600-900 600 200-1200 5.5-6.5 2.0-2.5 60-90

Cucum- 300-2400 300-600 900-1200 5.8-6.0 2.0-3.0 70

ber

Straw- 200-300 220-300 300 5.5-6.5 1.8-2.2 30

berry

Basil 600 500-750 200-300 5.5-6.5 1.0-1.6 50-60

Parsley 450-600 500 5.5-6.00 0.8-1.8 70-90

Mint 450-600 50-600 5.5-6.0 2.0-2.4 40

AVERAGE 521 379 408 63

I continue the reasoning about my vertical tower trying to calculate how many harvests in an
indoor aeroponic tower the user can do, in a year.

- 30 -
 Pot #1
Pot #2

Pot #4
Pot #3

Pot #7
Pot #5

Pot #9
Pot #8
Pot #6

Pot #11

Pot #17

Pot #21
Pot #12

Pot #31
Pot #13

Pot #15
Pot #14

Pot #19
Pot #18
Pot #16
Pot #10

Pot #22

Pot #32
Pot #23

Pot #27
Pot #25
Pot #24

Pot #29
Pot #28
Pot #26
Pot #20

Pot #30
Swiss chard
Spinach - mint
Lettuce

Tomato - Pepper
Cucumber
Swiss chard
Kale
Spinach

Spinach
Kale - parsley
Pepper
Cucumber
Lettuce - pepper
Tomato - Swiss chard
Mint

Lettuce
Basil
Lettuce

Parsley - Strawberry
Pepper
Kale - Pepper
Cucumber - Mint
Spinach - kale
Basil

- 31 -
Lettuce
Strawberry x2 - spinach

Cucumber - pepper
Tomato - strawberry
Swiss chard
Parsley

Pepper
1° st year possible harvests

Lettuce x2 - kale
Tomato x2 - Lettuce - Mint

Mint
Kale

Basil
Legend:

1 week
Pepper

Parsley
Tomato
Lettuce

Harvest
1 month
Spinach

Cucumber
Strawberry
Swiss chard
I’ve builded this chart taking in account the average of pots that the already on the market
products have, 32. After this, I consider every space as one week, thus I’ve marked the months,
till one year. Then I’ve casually fullfill every week, according to how much time do the hydro-
ponics crops explained earlier take to grow, from seedling to harvest. I’ve consider to plant
the same crop in 4 pots every time, in order to fill every level with one plant type. Finally once
every spot was colored, I’ve highlited in the upper part every harvest between one color and
the next.
With this random set of consequent crops I’ve obtained 48 harvests in 12 months of full activi-
ty. Every harvest correspond to 4 plants cutted if the crop is green leaf; to the fruits grow in 4
plants for the vegetables, and to 4 pots full of plants if we talk about herbs. So with this crops
series I obtain: 32 lettuces, 20 spinaches, 20 kales, 16 swiss chards, 20 tomatoes, 28 peppers,
16 strawberries, 16 cucumbers, 8 basils, 12 parsleys and 12 mints.
With this pots number, and vegetables sets, is possible to harvest maximum every 3 weeks,
but lot of time even once per week. Just the first month of activity is absent of any harvests.

Plants Full pots Fruits Total food

grown grown average weight
weight per year
(Kg*plant) (Kg)

Lettuce 32 0.15 4.8

Kale 20 1,5 50.0

Spinach 20 0.1 2.0

Swiss chard 16 1.0 16.0

Tomato 20 6.5 130.0

Pepper 28 1.0 28.0

Cucumber 16 2.5 40.0

Strawberry 16 Perennial

Basil 8 Perennial

Parsley 12 Perennial

Mint 12 Perennial

270.8

- 32 -
If the first chart I tried to predict how many plants can we grow per year, in a 32 pots hydroponi-
cs system. Now, with the left diagram I want to understand how many kilograms of vegetables
can be produced in a system like that.
“Plants grown” is the column with the plants harvested in a year; “Full pots grown“ is the dedi-
cated column to the herbs, because the user will fill the entire pots with seeds, creating a little
but perennial intensive production. “Fruits average weight“ comes from different researches
about how much can one plant produce on average; it has been the most difficult one to defi-
ne because it’s not easy to say the average food from just one plant, because it can depend on
a lot of factors, firstly the grower’s abilities and the plant’s health.
Multipling the plants that I harvest every year, by the average food that one of those produces,
I have obtained the average food production per year per crop, the last cell is the sum of food
obtained in a year with this system, around 270 Kg.
Is this amount enough for sustaining a 3 members family, for one year? The vegetables con-
sumed in every state per capita is very different, depending among a lot of factors like the
temperature, or the culture. In Europe the country that consumes the highest quantity of ve-
getables and fruits is Denmark with 255 Kg x year x per capita; followed by Spain (204 Kg) and
Italy (168 Kg).
Standing on the WHO (World Health Organisation) everyone should eat 5 portions (1 portion=
80gr) of fruits and vegetables per day, for an amount of 400 gr per day, thus 146 Kg per year
per person. In Europe the more one state is near to the Mediterranean basin, the more fruits
and vegetables consumes, accoring to the warm climate and the Mediterranean diet.
Taking Italy for instance, a 3 members family eats around 168x3= 504 Kg of fresh fruits and
vegetables per year. A vertical tower with 32 pots will produce around 270 Kg of fresh vege-
tables, that is more than half that the family needs. Always remember that WHO talk about a
quantity of fruits and vegetables to eat, instead an hydroponics system is specified mainly for
vegetables. If I consider inside that 504 Kg per family, half of fruits and the other part of ve-
getables, it can be said that a system with a production like that can cover all the vegetables
need.

Many green leafs and bulbs if A bunch of perennial herbs, Tomato reaches maturity a few
cutted can regrow always avaiable to the grower at a time, making it harvestable
for many weeks

- 33 -
Other considerations about this set of choises are about herbs and other vegetables: when
the grower harvest herbs he can just cut the amount needed and let the other grow. From the
cutted stems is possible that foliage and new branches grown again, if the plant has enough
strength to tolerate the stress. In this way is easy to mantain an herb for a lot of months, har-
versting it only when it’s needed, keeping itv always fresh.This method is possible even with
lettuce, and all green leaf vegetables: instead of chop down the plant we cut only the external
leafs that we need, and let new leafs born from the plant center. Tomatoes and strawberries
are similar to that, infact we gather only the mature fruits; once we have taken the first harvest,
new fruits will grow and become mature, creating more than just one wave.
Other plants as tomatoes reach the ripen stage a bit at a time, fruits can be harvested when
the surface change from dull to glossy. This process require at least a month, depending on
the climate conditions; in this way if the user decides to plant tomatoes, he’ll have fresh toma-
toes for at least a month, with daily harvests rate.
This reasoning are applied to all alfalfa and spyced herbs that can be hydroponically grown.
Plants as rosemary, parsley, basil, mint, watercrescion, sage, oregano are harvested in little
quantity, only when it’s needed, making these crops grows again, always fresh and perennial.

MARKET DEFINITION

These are the main industrial artefacts that exploit the hydroponics features with a vertical
dimension, the whole in an urban environment. With this market research I’ll be able to identify
the main characteristics of an hydroponic tower, in order to better define what the user may
want from his system.

TOWER GARDEN

With 2 models HOME and FLEX, the brand offers a way to cultivate fresh and nutrient
vegetable in an aeroponic system. The site houses 32 plants in a space of 1473 x 609 x 609
mm; the surface occupied by the reservoir is 0.37 m^2.
A low wattage, low pressure pump moves the enriched water to the top of the tower, here the
liquid passes through a pierced dish and fall down in drips. This cycle is alternated to a dry
period, according to the timer setting. The tank holds 50L. The HOME tower comes with 4 neon
light that allow the growing even if the system is not exposed to the daylight.

Price: 970$

- 34 -
NUTRITOWER

A revolutionary new home appliance that lets you harvest fresh fruits, vegetables, and herbs
no matter the climate or season. With its patented design and top of the line technology, you’ll
be growing enough food to harvest something every week of the year. This company pledges
to produce at least 27 Kg of fresh green leafs per year, with a bulk of 1762 x 609 x 609 mm. The
reservoir contains 13 L and the around the main coloumn there are 4 fluoreshent lamps 54W
each. It comes with 32 pots that can produce up to 1000$ worth of food per year.

Price: 845$

MR STACKY

This tower is one of a kind, single pots with cross shape are alternated one on the other till the
tower is completed. An internal drip system keeps the medium always wet and nutrient. The
reservoir holds 60L of water, 20 plant sites, and the overall dimensions are 965 x 406 x 406
mm. One strong aspect is that the customer can easily accomodate other pots, thus having a
higher tower; even the packaging is very small cause the pots can be stacked.

Price: 300$

- 35 -
AEROSPRING GARDEN

The Aerospring is a patent-pending vertical aeroponic gardening system designed for urban
home gardeners who want to grow their own herbs, salads and vegetables in limited space. A
few Aerospring units could serve as your own urban farm and allow you and your family to be
self-sufficient. The produce will be fresher, pesticide free,tastier and more nutritious than any
store bought greens that has had to travel and transit before landing
on your table. Moreover, produce is grown in a sustainable system that recycles water and
nutrients continuously.
The pack comes with a 75 L tank, 12 hexagonal hollowed sections that can house up to 36
plants. Germination kit and liquid fertiliser for 2 month are also included. The indoor model can
be closed in a hexagonal growbox, that doesn’t let the light scattering or bothering the user
during the night. The Aerospring measures 1950 x 580 x 640 mm and consume just 150W/h
(6x20W tri-band led grow light + 30W water pump).

Price: 1499$

JUSTVERTICAL

This canadian company propose its concept of vertical hydroponic system: a wood-plastic
closet that can be suited with different furnish styles. It can house 16 plants in a volume of 1770
x 915 x 200 mm. The 12L reservoir is hide inside the bucket base, and there is enough room
for other house stuff. A mobile app sends notifications when it’s time to add fertiliser or fill the
tank.The internal full spectrum white led consume just 75W/h and allow to grow even in low
sunlight conditions.
Justvertical assures 4.5 Kg/month of food production, thus around 55 Kg per year of fresh and
nutrient vegetables.

Price: 999$

- 36 -
THAI ADVANCE

One of the simplestest aeroponic system, a sort of tower gets down to the bone. These thai
company cuts on the design and offers a durable and affordable tower for both indoor and
outdoor. The object can hold 24 plants divided in 6 levels, in a volume of 2080 x 480 x 480 mm.
It comes with no electrical stuff except the pump, germination cubes and its net pots.

Price: 180$

FOODY VERTICAL GARDENS

This tower is composed by 3 sections that hold 12 plants each plus 8 spot in the base, and
a big water reservoir as base.The dimensions are 1219 x 508 x 508 mm. Inside the sections
the pump suchs and circulates water, creating an ebb and flow system. One big pro is the
possibility to add a motor that rotate all the column 4 times per hour, thus to maximise and
even out the light exposure for all the pots.
Price: 329 $

-current culture h2o

-Pineapple Tower Hydroponic System

- 37 -
GENERAL CHARACTERISTICS OF A COMMERCIAL HYDROPONIC TOWER

From this chart I can assert that the price of these towers largely depend on the lighting
system: if the company provides it, the final cost raises.
The dimensions not differ a lot from each other, quite all the towers are similar in volume.

Tower NutriTower Aerospring Mr. Stacky Just Thai Foody Vertical

Garden
Garden Vertical Advance

Height 1473 1762 1950 965 1770 2080 1219

(mm)

Width 609 609 580 406 915 480 508

(mm)
Depth 609 609 640 406 200 480 508
(mm)
Water Tank 50 13 75 60 12 45
(L)
Pots 32 32 36 20 16 24 44

Lights 4 4 6 No 1 No No

Wheels Yes No Yes No No No No

Price 975 $ 845 $ 1499$ 300$ 999$ 180$ 329 $

- 38 -
 User definition
HOW IS THE STANDARD ITALIAN FAMILY?

ISTAT is the italian institute for statistics, every year mades researches, surveis, studies and
reports about the composition and habits of italian people. I use this source to establish a
sample of the possible customer.
Italy is one of the eldest country in term of population ages, this means that the amount of
young people is restricted compare to the senior.
Elders
Youngs

The ratio between old people (over 65) and young (less than 15) is the old age index, and
synthesize well the italian age condition. On the 1 of January 2018 the old age ratio was 168.9%,
raised from the previous year, when it was 165.3%. This mean that we’ve got an average of 168
elders every 100 youngs.
Nord-west is the eldest italian region with a ratio of 179.8% against the south area that is the
youngest with 149.2% of old age people. In Europe Italy is the eldest country, followed by
Germany (158.5%); on the other side there’s the Ireland with 64.1%.
The only softening aspect that low the old age index is the residential foreign population, with
an average of 34.5 years old.

It continues to raise the number of families, due to semplifications on how to set a family unit;
but the number of components decreases. The average families, 20 years ago (1996-1997),
were 21 millions, and today it’s 25 millions. Family member passed from 2.7 in 1996/7, to 2.4
components in 2016/7. In the same 20 years period one person families are increased from
20.8 to 31.9%; on the opposite big families (5 or more members) are decreased from 7.9 to 5.3%.

- 39 -
One third of the families is composed by one person, this because there has been a deep
trasformation in the last decades of our population: less children, more people live on their
own, reduction in the family members, raise of separations and divorces, and new migratory
scenarios. The most numerous families are in the south, but even here in the last 20 years the
average decreased from 3.1 to 2.6. One person families are most concentrated in the nord-
west of Italy.

- 40 -
In conclusion the annual ISTAT survey about the italian population and its composition, draws
an old country that struggle to exit from this vortex. The family has reduced in components in
the last 20 years, till an average of 2.4 members. More one-person families and less children
born.

In a scenario like this I face to a standard family of 2 member and half, more close to 2 than to
3.
I consider to design my object for a 3 person food production. In this way I’ll cover all the 1-2-3
members families, that are the 79% of all italian families.

HOW IS THE EUROPEAN STANDARD FAMILY?

Eurostat is another institution that cunduct surveys and studies among the european
population. This one put in comparison the family and household composition between 2010-
2019.
The number of householder rose by 7%, however single adults householder, thus an adult
that live alone or with child but not in couple, increased much faster of 18.1%. On the other
side household made of couple with or without child registered a slow increase of 3.9%. This
survey counts even people that live with other members in the same house, a pattern not very
common in Italy except for the college students that live in group.
So in ten years the number of householder rose, but much faster among the single adult rather
than couples.

+3.9%
+18.1%

-5.7%

- 41 -
Even from this graph is clear that in the last decades every category of householder without
children rose, even by important percentage, as in the single adult coloumn.
In 2019 the EU recorded an increased of 10.8% of householder without children, and a slow
decrease in adults living with kids of 1.4%. Every country registered this increment of adults
living alone and in most cases without children.

In Europe houseolder with 1 child are the most common, especially in Portugal, Bulgaria,
Lithuania and Latvia. This trend is not really uniform across all countries, infact the northern
tend to be more positive in having cildren: in Sweden, Ireland and the Netherlands the
standard family has 2 kids.
At european level 4 families out of 10 have 2 children; 4 and a half is constituted by only child
and the rest, around 12% are big families with 3 or more children.
I want to project for more than one country, so I’ve highlighted the most populated european
states. Standing on the next chart Italy, Germany and Spain have 50% of the families with one
child, so I choose to project my aeroponic tower with a production for 3 people, in order to
cover half of the families of 3 of the biggest european states, plus all the new lonely adults that
seems to be an increasing trend, crosslinked to all Europe.

- 42 -
 SURVEY RESULTS

To better know the user I’ve done a Google form survey, directed to a public already learned
in hydroponics techniques. To reach this purpose I’ve sourced different hydroponics groups
on Facebook and joined them. Then I’ve realized my personal form both in english and italian,
according to the groups identified.
I’ve published it in all 11 hydroponics groups, 4 italian and the rest english, obtained 51 answers.
The survey is structured in 3 parts: the first is about the user, who he is, from what context
he comes from, and why he prefers hydroponics rather than soil (a question to reinforce my
hydroponics position).
The second part is about what a typical hydroponics user usually grow in his system, a list of
vegetables, herbs and green leafs to check.
The last part is about what the user wants from a commercial hydroponics system, with a list of
functionalities to check, and how much the user is ready to pay for the electricity bill.
The survey is made for people aready learned in the hydroponics world, both at an amatorial
and professional level. Many questions has given the opportunity to the interviewed to counsil
his point of view, giving advises.

Age? Età?

Starting from the age we’ve a younger public in the international survey, with 2/3 of young
people from 15 to 35. Instead in Italy we have 2/3 of adults from 26-45. In Italy we’ve more
elders over 55 practising hydroponics, and this is confirmed from the ISTAT datas about this
country’s people composition.

- 43 -
 Gender? Genere?

Where do you live? Dove abiti?

About the provenance both the international and italian survey answer with a quite sharp equal
division, 1/3 each from the city center, border and countryside. The only difference is that in
Italy more people doing hydroponics are from the countryside, thus their experience is related
to a medium big outdoor space, rather than a urban context, as I want to design.

Have you got an outdoor space to use as you Hai uno spazio esterno da utilizzare a tuo
please? piacimento?

Quite the totality of the intervieweds have an outdoor space, to use as they want.

Are you interested in growing your own vege- Sei interessato a coltivare verdura, foglia
tables, green leafs or herbs? verde o piante aromatiche in casa?

- 44 -
Are you interested in vertical hydroponics sy- Sei interessato a sistemi idroponici verticali
stem, to save space? , per salvare spazio?

What hydroponics system do you use? Quale sistema idroponico usi maggiormente?

In Italy quite the totality of the answers are in favor of the vertical hydroponics systems to save
space; in the next question again the public confirms to already use vertical systems in their
houses, with 41.7% of vertical growers.
This is an important keypoint that confirms even the fact that the dimensions are important
for a good success of this project.

Why do you prefer growing in hydroponics Perchè preferisci la coltivazione idroponica a

rather than in the soil? quella tradizionale in suolo?

The next question is to understand in deep the reasons that drive a grower to prefer
hydroponics agains soil cultivations: in Italy people prefer it for more purposes, it’s water-
saving , pesticides free, less hard, more productive, and one interviewed suggests that
hydroponics can be helpful to people with nickel allergies. This is because the enriched water
stored in the tank is protected from exterior events, as a nichel contamination.
The international survey says that growers choose hydroponics mainly because is more
productive (73%), and in equal part to save water, pesticides free and less hard, but still with
percentages lower than in Italy.

- 45 -
What green leaf plant do you most frequently Quali piante a foglia verde coltivi maggior-
grow in hydroponics? mente in idroponica?

The next questions ask what the typical hydroponics grower prefer to cultivate. The winner
among green leafs is undoubtedly the lettuce, grown respectivly with 50 and 80%. In second
place we’ve spinach and chard in both the surveys; talking about the other vegetables in Italy
there are more differentiation, growers like to experiment with quite all green leaf.

What vegetable do you prefer to grow in hy- Quali verdure coltivi maggiormente in idro-
droponics? ponica?

About vegetables, the most grown is tomato with more than half of the intervieweds that
choose it. Still here the italian side is most curious and try to cultivate all the chooses with
higher percentage than the international survey.

What aromatic plants do you mostly grow in Quali piante aromatiche coltivi maggiormente
hydroponics? in idroponica?

In the herbs question we have an inversion of behaviour compare to the previous two
questions: the international interviewees experiment more with these plants rather than with
vegetables, basil is the most cultivated followed by rosemary, parsley and oregano.

- 46 -
If you have enough space, will you be interes- Se avessi spazio in casa, saresti interessato
sed in an indoor hydroponics system? a un sistema idroponico indoor?

If you have enough space, will you grow plants Se avessi spazio in casa, coltiveresti anche
even during winter and cold months? nei mesi invernali?

Quite the totality of the people interviewed are in favour of using indoor hydroponics system,
and use them during winter months, for a year-round vegetables harvest.

What caracteristic would you like to have in an Quali caratteristiche vorresti avere da un
indoor hydroponics system? sistema idroponico commerciale?

This question is about what the user want to have, if he would buy a commercial system. The
caracteristics most appreciated are: having 2 sensors for EC-pH, having an automatic system
to correct pH and fertilization, having a quiet water pump, a generous tank, and in minor
part an LCD. The caracteristics less appreciated are about comfort of handling this device:
presence of wheels, at eyes level, automatic check of temperature and humidity.

- 47 -
How much would you pay more on the electri- Quanto pagheresti in più sulla bolletta del-
city bill, for running an indoor hydroponics la luce, per utilizzare un sistema idroponico
system? indoor?

This is the last question of my survey, a way to understand how much people are willing to
pay more for using a device like this. This is a sore point, but still people already interessed in
hydroponics have positively answered: I can consider the average of preferences around 20€
more on the electricity bill.

- 48 -
 USER DEFINITION

Less hard Water saving

Hydroponics allow to avoid all the Users like hydroponics be-
dirt carried by the soil, and all the cause it saves up to 70% of
effort for working the ground. water, and avoid the effort
and time for watering the
plants

3 members family 26-45 years old

Consume around Interested in growing

500 Kg/year of fruits plants on their own
and vegetables

Pesticides free

Indoor vegetables
are more resistent to
diseases, and they’re
without pests

- 49 -
 BRIEFING

AEROPONICS
Comfort side VERTICAL TOWER Growing vining plants

Quiet pump (<35 dB) Supports for brances

Big tank (≈70L) and fruits

1-3 members Indoor growing

family
32 pots for a stable Neon tube or LED
food production lighting system

extra pots
expansion layers

Water value Limited dimensions

check dimensioni da casa
EC sensor + pH sensor Exploit mostly the
verticality rather than
width and depth

BRIEF: an indoor aeroponic tower for growing vegetables, with a food production for 1-3
persons.The object is modular to fullfill the food needs of every user. The bulk dimensions are
thought for occupy the minimum space. The tower is for domestic purpose, with the possibility
of growing all year-round.

- 50 -
 CONCEPT

In order to keep the number of pots at 32 (11 levels of 3 pots each), the tower has to be slender,
with the high around 1700-1800 mm. The water tank is the most voluminous component with
dimensions around 650x300x450 mm for a 80L capacity; I have to play with this size, raising
the height of the tank and diminishing both width and depth, trying to mantain a 70-80L bulk.
I want to give the possibility to the user to expand the tower according to his needs, simply
buying some extra pots layers, assemble it and continue to use the gravity for bringing the
nutrient water to all the pots.
Exterior to the tower there is the lights support, a modular system that can be assembled
according to how many pots layer the user has. Above this system is possible to instal a
movable net that will be used for supporting the vining plants.
The aeroponic tower will have 3 main physical parts: the water tank, the tower and the lights
support.
The technological side can be considered devided in: sensors (pH-EC), the pump and the LCD
interface.
I’m going to examine one by one every of these aspects of the project, through researches
from the current state of the art, maching all the user’s needs that I’ve identified in the previous
sections.

- 51 -
WATER TANK

It contains the water enriched with fertiliser, to assure the stability of the chemical water value
I’ve to do it voluminous. More water means more time before the pH and EC changes, thus a
more stable system.
I’ve done some attempts starting from 50 L capacity, comes out with a 680x300x245 mm
reservoir. In order to take advantage of the verticality, I’ve decided to reduce the length from
680 to 650, and increase the height till 450. The depth is another key dimension because it
assures the right distance from the vegetables to the LEDs; I’ve set it to 300 mm.
With this water tank dimensions I’ve obtain a volume of 87 Liters; obviously the user can
choose to fill it with less water, for instance if I take in account 60 mm margin the water inside
will be 76 L, around 10 L less.

material : stainless steel

process: deep drawing

TANK COVER

The cover closes the tank, assuring that no insects, dust and dirt go inside the water. Another
function of the cover is to keep the water out of the sun rays, infact the light allow spreading of
algae, and I don’t want that.
The cover will keep the tower in place, and allow the user to reach the reservoir throught a
little door in the front. In the right side there are 2 screens that, when consulted, comunicate to
the user the water values.

material : solid wood

process: saw cutting

- 52 -
TOWER BLOCK

This component blocks the first layer to the wood cover thus holds the tower in place. This
block is mounted from the outside of the cover, and in the inner side it stops the the first plastic
level, due to the shrinkage.

material : PVC layer

process: injection molding

tank cover tower block

LAYERS

Layers are assembled each on top of the other, till the tower has the right number of pots for
a stable production. I decide to create 2 type of layers, module A and module B, I cannot just
turn one and put it on the top of the same because the male-female joint wouldn’t match. The
only difference between A and B is the position of the pots holes, to fullfill better the space of
the tower.

material : PVC
process: injection molding

- 53 -
WATER DIFFUSOR

This component provides water to the plants roots. Once the user has built the tower
according to his food needs, the diffusor will be placed to the top of the tower, it spreads the
water pumped from the tank, creating water drops that wet the pots and return to the reservoir.
The majority of the holes are in the front part of the water diffusor because the main amount of
roots exit in correspondence of the pots side.

material : PVC
process: injection molding

- 54 -
NET POTS

The pots are already provided in the components of the aeroponic tower. This net pots are
standard, with a diameter of 50 mm. If the user buy new layer the relative pots will be included
in the purchase. To keep the plant in place inside the pot a neoprene spong disk is provided
too, one each pot. Even this part is standard and already used in growing activities as scion
production. The fact that the plant are disposed horizontally is not a problem infact plants
naturally grow toward the light, no matter in what position it comes from.

material : PVC
process: injection molding

CAP

It’s the upper part of the tower that close it, slotted in the water diffusor. The cap has both the
aesthetics and functional purpose, infact it prevents dust, insects and dirt to reach the fertilised
water, keeping it cleaner and limiting the spread diseases.

material : PVC
process: injection molding

- 55 -
LIGHTS SUPPORT

The lighting system is foundamental for an indoor growing. In my project I’ve to make it
modular to adapt itself to every configuration that the user apply to the tower.The modules are
assembled one on the top of the other throught a joint that assure the electrical continuity to
all LEDs.
The outer shape reminds to a plant with lateral branches to the sides. Even in this case we
have 2 modules LEFT and RIGHT. There are 2 LEDs each piece, one in the central body and the
other situated on the lateral branch; in this way the light support illuminates all the tower till the
top.

material : stainless steel metal sheet

process: laser cut

- 56 -
COB LEDs

I want to use lighting parts easy and cheap to replace. In this category, relate to the market
we have neon tubes or LEDs: the first are easy to be replaced but less aesthetics and more
expensive than LEDs; the second are definitely the cheapest.
Among LEDs I can choose between strip LED or cob LED: the strip is a sequence of single
diodes, the cob (cheap on board) is the latest evolution of the single diodes, a chip on which
decades of diodes are already assembled, creating a square emitting area. Cob LEDs exist in
different wattages: 20W, 30W, 50W, working at 220V, thus no transformator is needed. These
elements are connected through 2 wires, positive and negative, in series along the light
support.
Because of the high density of diodes in a limited space this device becomes soon hot, and
need a proper aluminum heat sink in the back, for working at a proper temperature and last
longer.
There are 2 cob LEDs on each segment of the light support, connected in series directly to the
socket; in case of replacement the user unscrews the LED’s screws, break the welded point
and wire the new one chip again.
40

60

Cob LED - 50W - 220V

WATER PUMP

The aeroponic tower work with a normal acquarium water pump that move the water from the
tank to the water diffusor on the top of the tower. This system doesn’t have to work constantly,
infact by definition in an aeroponic system the roots are exposed both to enriched mineral
water and air. These 2 cycle are ruled by a timer that switch on and off the pump.
This element work with 220V and consume 35W, moving 2000 L/h. I assume a working cycle
of 15 minutes out of an hour, thus 6 hours per day, the pump will absorb 35W x 6hours= 210
W*day x 365 days = 76650 W*year. The cost of the electricity is 0.052 €/KWh, so the pump will
cost 76,650 (KW*year) x 0.052(€/KWh) = 3.98 €*year
Along the tower will flow 2000 (L/h) / 3600 (sec) = 0.55 L/sec; in 15 minutes of work the roots
are wetted by 495 liters of water. All this moving liquid enter in contact with the oxygen of the air
during the falling, absorbing it; in the same way the roots capture oxygen during the dry cycle.

- 57 -
 Sunsun pump CHJ-2000, 35W, 220V, 2000L/h

ARDUINO MINI (PLC)

This chip has a programme written inside that when started it opens the relay that closes the
electronic circuit of the pump, switching it on. Once passed 15 min the Arduino chip opens the
pump’s electronic circuit for 45 min, and so on.
The other programme inside this chip read the value from the water sensors in entrance, and
gives back the relative numbers to the 7 segments screens.
Using this components allow me to control the pump, the sensors and the screens in one time,
with a price around 1€.
Arduino mini is fed with a 5V continuous current, so it’s needed a transformer 220-5V; this
component costs around 0.5€ and is very small.

Arduino mini 5V

- 58 -
 Ac-Dc 5V 700mA for Arduino Mini

7 SEGMENTS SCREEN

This type of screen is very famous and can communicate through C language to Arduino. One
screen is for pH value and the other for the electroconductivity value. The sceens are switched
on by the user only during the lecture moment; Arduino constantly reads the state of a button
next to the screens, if it has been pressed the pcb will switch on and off the screens.

- 59 -
ARDUINO pH-EC SENSORS

These are 2 separate sensors that once sink in a liquid they communicate back the 2 pH-EC
values to arduino. The sensors are fixed to the side of the tank at a proper high in order to
touch the water. These components require a dedicated driver before Adruino mini.
The company is Grove and the pH is 16€, instead the EC sensor is 30€.

Grove EC sensor Grove pH sensor

Grove EC-pH driver

- 60 -
STORYBOARD

This is a sequence of actions that the user

does for starting and mantaining a new set
of vegetables.

- 61 -
- 62 -
MY PROTOTYPE AEROPONIC TOWER

I’ve experiment during summer about hydroponics, in order to be more deep inside this
argument, trying to see directly on the field.
In order to do so, I’ve buildt a personal aeroponic tower, made entirely in PVC. The water tank
has been bought as a clothes box, or a box for olding stuff in general, I’ve cutted the cirlcolar
hole in the cap for hosting the PVC pipe of the tower.
A timer switch on and off a 12V, 60Amps high pressure water pump, a quarter per hour. The
liquid reac every pot from the top to the bottom, all connected in series.
Inside the pots I’ve placed expanded clay for retaining more moisture and water, every plant
has it’s original topsoil from the greenhouse, surrounded by clay.
Every nozzle could be adjusted in flow, by screwing the red cap; the first had to be tighten
more in order to distribute better the flow across the tower.
I’ve used this tower for 2 month and a half, correcting everyday the water values and taking
note of them.

16 Pots

Water in
Aeroponic
tower
Pump

Water out

Water tank, 18 L

- 63 -
Inside view of the tower Water falls in the reservoir and on the pots below

Lettuce Basil

Lettuce Canasta lettuce

- 64 -
Water tank, 18 L EC value at 1400 mS/cm

optimal pH value ph value after 8-10 hours

residues of fertiliser in the nozzles rudimental water filter

- 65 -
OPINIONS AND NEW ACKNOWLEDGE

I’ve cultivate this set of vegetables from july to september in outdoor condition, the tower was
under the shadow of a fig tree.
As vegetable I’ve choosen all green leaf: 2 types of lettuce and some basil.
During this first try I’ve taken sign of the pros and cons that I’ve seen.

The first cons of my prototype was that the tank was under estimate, the 18 L tank didn’t
provide a stable and relailable system, infact the I’ve had to adjust and check the water values
twice per day.

Other problem observed was that the roots expel a sort of gelatin that was captured by the
pump and injected through the nozzles that, after one week clearly had lower flow. I’ve had
to adjust the flow of the cleaner nozzles to balance the pressure, till I’ve had disassemble and
clean every single dirty nozzle more times. Due to this problem I replaced the water once
every 10 days, to get rid of the dirt water.

For some reason the roots in general didn’t grow very much, thus the plant stayed relatively
small, but alive, vigorous and colourfull.

Due to the nature of the lettuce leaf, these plants should never stay in full sun, but under non
direct sunlight.

The main pro was that I havn’t to irrigate and I have used much less water compared to an
open field growth.

Regulate the amount of fertiliser is very easy, and with this number of plants the EC value
remained mainly stable.

The plants’ reactions to the events is very fast, you can clearly see if the plants has passed
good times or not very much. This is a double edge sword, the user can easily save the
cultivation choosing to take a specific action to bring wellness to the plants, or soon loose
every vegetable.

As soon as the lettuce grown, the tower became a sort of spot for insects, spiders, flyes, and
so on, that have an effect one on each other, creating a sort of micro habitat. Despite the
presence of parasites the plant hadn’t show sign of bites or pricks from the hosts; the plants
apart the fertiliser hadn’t got external treatments to help the leafs’ growth.

- 66 -
MY PROTOTYPE DEEP WATER CULTURE BOX

After the conclusion of the aeroponic tower first approach I have experiment in another
technique, the deep water culture.
The system is composed by a big plastic box that contain the fertilised water, the horizontal
wood plane hosts the pots, at a fixed distance from the water. The roots are directly sink
into the water, and a pump moves the water making it produce bobbles, thus creating an
oxygenation process. The pump is comanded by a timer for 15 minutes/hour.
In this system I’m growing 11 plants of Romana lettuce.
Every pots is made from a single-use coffe plastic glass, with holes in the bottom to let the
roots grow and reach the water.

I’ve experiment during summer about hydroponics, in order to be more deep inside this
argument, trying to see directly on the field.
In order to do so, I’ve buildt a personal aeroponic tower, made entirely in PVC. The water tank
has been bought as a clothes box, or a box for olding stuff in general, I’ve cutted the cirlcolar
hole in the cap for hosting the PVC pipe of the tower.
A timer switch on and off a 12V, 60Amps high pressure water pump, a quarter per hour. The
liquid reac every pot from the top to the bottom, all connected in series.
Inside the pots I’ve placed expanded clay for retaining more moisture and water, every plant
has it’s original topsoil from the greenhouse, surrounded by clay.
Every nozzle could be adjusted in flow, by screwing the red cap; the first had to be tighten
more in order to distribute better the flow across the tower.
I’ve used this tower for 2 month and a half, correcting everyday the water values and taking
note of them.

Side view Top view

- 67 -
Roots view Water pump in action

Roots view Water pump in action

Roots view Water pump in action

- 68 -
 Roots details

OPINIONS AND NEW ACKNOWLEDGE

This set of Romana Lettuce is still ongoing, starting on September it has still one month to be
harvested. It’s cultivated with natural autumn sunlight outside, and spends the night inside the
garage. Due to the grade of the autumn sung rays, the system can be exposed directly to the
full sun, with the green leafs that still are hard and turgid.

This system is more stable thanks to the huge amount of water compared to the other, around
50 L; with this volume the change in water values are slwer, giving to the user more time
before going in values too much unsuitable.

This system is definitely more quiet, infact the pump is a normal acquarium pump 220V, only
5W with a flow of 320 L/h.

The plants are grown much more compared to the aeroponic tower, with a quantity of water
used very little compared to an open field condition, around 60L in one month.

Despite the little free space between a lettuce and another, they are all grown significantly,
with improvements day by day.

- 69 -
The roots system is grown outside the pots, and is visibly he althy, clean, quite white and
always wet.

The corrections of the water values have to be done every 4-5 days, much more compared to
the twice times per day of the tower prototype.

This set of vegetables as the past are pesticides free, with a set of insects and hosts that live
on that, but still without any damages or bites from them.

There aren’t any specific cons, except by the fact that is hard clearly see if the wat er touch
the roots.

- 70 -
DESIGN PART

In this section I introduce the design choises related to the single components of the
aeroponic tower. For each piece I’m going to explain the why it has that shape, the machining
process and the material.

WATER TANK

It’s the base part, it contains all

the water and works as the foun-
dation of the aeroponic tower.
The design characteristics are re-
lated to the durability of this part
mostly against the corrosion. The
fertilised water swings between
acids and basics values, from 5.5-
8.5 pH. This is a critical condition,
thus only strong materials can be
choosen. Summed to the corro-
sion there’s the fact that the tank
holds 80 L of water, a big amount
if it’ll be scattered inside the house. The tank has to be resilient to resist to blows, and not loo-
sing the shape due to the water mass, over the years.
The material more appropriate is sheet stainless steel, thickness of 2 mm, it’s deep drawed in
an appropriate die, obtaining the final shape. After this it’s important to cover the material with
painting, both inside and outside, to better protect the surface from te water.

WOOD BOARD

- 71 -
The wood board will cover the tank is the place of more interaction with the tower,
because it gives the water values and act as a working plane, for leaning garden
objects as scissors or fertiliser bottles.
The criticality of the board is that the tower works with water, and the wood is not in
favour of that, both because it absorbs the water, and because under the board there
will be the main electrical devices and wires.
To accomplish these aspects, the board has a plastic border that runs across the enti-
re perimeter, the border is screwed from the bottom to the wood board. The right part
of the border isolates the LCD with its relative button, from the working plane. The
LCD is posed in the front part of the tank, thus to stay away from the water fall inside
the tower, and even being comfortable to the user.
In the left side the wood board has a trapdoor to access to the tank underneath; this
hole is used by the customer to reach the water and decides what to do, if adding
more fertiliser, adding the pH corrector, empting the old water and filling with new
one. In case of water falls outside the tower, the plastic border contains the missed
drips, that can be absorbed with a sponge and putted back through the trapdoor to
the water reservoir. The trapdoor is a
stainless steel metal sheet, with a pie-
ce of plastic boarder too, that comple-
te the perimeter.

- 72 -
 ANTI-SPURTS METAL PLATE

To protect the wood board and electrical stuff from water spourts I’ve decided to use a metal
plate, of the same material of the water tank; in this way the liquid is completely close up in
stainless steel.
This metal plate is bended in the edges to create the perfect join with the tank underneath. 2
holes are cutted on its surface, the biggest holds the layer tower and the little is for the trapdo-
or. In the center there are a couple of arms that keep in place the light support, and allow it to
slide away from the tower, to regulate a proper light distance.
The material is the same steel of the water tank, laser cutted in the holes and then pass in a
bending machine. After the machining the metal is protected as the tank, by a paint layer.

Wood board

Tower block

Anti spurts plate

Tank

- 73 -
 LAYERS

The layers constitutes the height of the aeroponic tower, depending on how much food does
the user want to produce. The module is one, with the 3 pots holes asymmetric in order to
fullfill the inter-spaces along the tower, infact the layers are assembled alternatively rotated
of 180°. the upper and lower borders have half female, and half male join, thus to be always
stacked one on the top of the other, after being frontally rotated.
The material is PVC, injected in its proper mold; the plastic is already white, to seems like the
house wall.

Female Male

Male Female

- 74 -
 WATER DIFFUSOR

The water diffusor is posed on the top of the last layer, it holds the pipe from the water pump
and divides the liquid into drops. In this way the water reaches every pots, that in turn hit the
lower pots. The holes are distributed in the same way both in the front and back of the layer to
let the water reaches the small and young, and the bigger and older roots.
The material is the same of the layer, PVC injected in a mold, same thickness and finishing.

In the same way I’ve modeled a cap to close the internal tower part from external agents and
parasites. The convex part is just aestetical, to break from the squared shape of the rest of the
tower.

LIGHT MODULE

- 75 -
The light modules are 2: left and right; they’re mounted one on the top of the other till all the
tower height is covered with lights. Every module has

- 76 -
 FINAL PRODUCT

Wood board assembly

Tank Anti-spruts plate Border Base support

Light support assembly

0.1 0.2 0.3.1 0.4.1

Trapdoor Right

Right module ass.

Trapdoor ass.
0.3.2.1 0.4.2.1
Border COB
0.3.2.2

0.3.2
0.3 0.4.2.2

0.4.2
0.4
ISO 7045 M3x5 ISO 7
0.3.2.3 0.4.2.3

ISO 4
0.4.2.4
PCB cover
PCB ass.

0.3.3.1 Wire
0.3.3

0.4.2.5
PCB
0.3.3.2 Conn
0.4.2.6
5V transformer
0.3.3.3 Conn
0.4.2.7
LCD
0.3.3.4

Button Left m

Left module ass.

0.3.3.5 0.4.3.1

ISO 7045 M3x10 COB

0.3.3.6 0.4.3.2

0.4.3
ISO 7045 M3x10 ISO 7
0.3.4 0.4.3.3

Wire ISO 4
0.3.5 0.4.3.4

Wire
0.4.3.5

Conn
0.4.3.6

Conn
0.4.3.7

- 77 -
This tree diagram explains how the final Green Wall is born, talking in a pro-
duction context. I’ve manage to unify different components in assemblies
so to arrive all together to the customer, for being assembled in the final
product.
The main assemblies are 2, the wood board and the light support. Then
there are other single components outside subassemblies, as the water
tank or the anti-spruts plate. Following the tree I’ve assigned a number part
to every component, that says at what level of assembly the part is.

- 78 -
 Man 50° percentile Woman 50° percentile

Man 50° percentile

2022
1755

1626

817

650
Man 50° percentile Woman 50° percentile
1107
1904

1029
1770

1370

751

POSIZIONE LIV. PEZZI CODICE DENOMINAZIONE MATERIALE - DATI TECNICI PESO NOTE
Part Reference Level Qty Part number Part name Technical data, designation Unit kg Notes
A termine di legge l'Autore si riserva la proprietà del presente disegno vietandone
la riproduzione e la comunicazione a terzi senza la sua autorizzazione scritta. Rev App'd Date
TIPO DI DOCUMENTO Disegno di produzione
This document is property of Creator and it shall neither be copied nor reproduced
Document type
nor disclose any third party without authorization in writing from Creator. ........................................................
AUTORE VERIFICATO DADATA DI EDIZIONE 01
Created by Approved by Date of issues
Michele Poliziani
Silvia Deborah
Ferraris
PROGETTO
2020.12.01 Project Green Wall
......................................................... 02

STUDENTE DOCENTE INSIEME 03

Assembly Green Wall assembly
........................................................
04
Michele Poliziani Silvia Deborah Ferraris GRUPPO
/
Sub-assembly drawing ................................................
CODICE - Part
SOTTOGRUPPO
/
Sub-assembly drawing ................................................
number

POLITECNICO DI MILANO PARTICOLARE SCALA

Part / Scale
...................................................................... 1:5
Scuola del Design DIS. N. - DWG. N. Rev. FOGLIO
Corso di Laurea in Sheet
Design & Engineering
A.Y. 2019/ 2020 - Thesys 01.03 00

I’ve created specific technical draws that describe the relations between Green Wall and the
customer; all the dimensions are related to the 50° man-woman percentile, thus the most
common that we can find in the world population. Both the aeroponic tower and the maniquins
are in scale 1:1 in the original drawing file, to assure the most realism in the comparison.

The object has an height of around 2 meters, according to how many layers we add. It seems
too much comparing to the man’s height but it’s reasonable, because the user has to interact
with the heighest layers just when it’s time to harvest the vegetables. Obviously if the customer
use less than 10-11 layers there isn’t this problem.

- 79 -
Green Wall will be sold in 3 main user pack, according to how many member family the user
has:
3 members: comes to the user with 11 layers, 33 pots, 8 light modules for a total of 16 LEDs
2 members: the height is 1500 mm for a total of 21 pots, enlighted by 8 LEDs
1 member: the smallest, has 12 pots, 4 LEDs, with an height of around 1 meter

3 people pack 2 people pack 1 people pack Man 50° percentile

33 pots 21 pots 12 pots
16 LEDs 8 LEDs 4 LEDs
2099

1755
1499

1049

Because the object is modular it’s sold separately single lights modules (left-right), and layers
with already the necessary net pots. The limit height is undefined, if not for the user or the ro-
of’s height.

POSIZIONE LIV. PEZZI CODICE DENOMINAZIONE MATERIALE - DATI TECNICI PESO NOTE
Part Reference Level Qty Part number Part name Technical data, designation Unit kg Notes
A termine di legge l'Autore si riserva la proprietà del presente disegno vietandone
la riproduzione e la comunicazione a terzi senza la sua autorizzazione scritta. Rev App'd Date
TIPO DI DOCUMENTO Disegno di produzione
This document is property of Creator and it shall neither be copied nor reproduced
Document type
nor disclose any third party without authorization in writing from Creator. ......................................................................
AUTORE VERIFICATO DADATA DI EDIZIONE 01
Created by Approved by Date of issues
Michele Poliziani
Silvia Deborah
Ferraris
PROGETTO
2020.12.01 Project Green Wall
........................................................ 02

STUDENTE DOCENTI DI STAFF INSIEME 03

Assembly Green Wall Assembly
........................................................
GRUPPO 04
Sub-assembly drawing /
........................................................
Michele Poliziani Silvia Deborah Ferraris
SOTTOGRUPPO CODICE - Part
Sub-assembly drawing /
........................................................ number
0
POLITECNICO DI MILANO PARTICOLARE SCALA
Part /
........................................................ Scale 1:50
Scuola del Design DIS. N. - DWG. N. Rev. FOGLIO
Corso di Laurea in Sheet
Design & Engineering
A.Y. 2019/ 2020 - Thesys 01.01 00

- 80 -
The wood board is the main working plane that the user has, it’s possible to put on garde-
ning stuff as scissors and fertiliser bottles. The teak is treated with gloss that prevent the wa-
ter to damage the upper part. The PVC border is thinked to not let eventual water fall into the
ground; if it happen the user can easily absorb it with a sponge, or convey the water back into
the reservoir, throught the trapdoor.

- 81 -
The LCD is protected in its own border, the user can switch it on and off throught the button,
and it instantly communicate the pH and Electroconductivity of the water.

- 82 -
WEB SITES

https://en.wikipedia.org/wiki/Hydroponics#Techniques
https://www.forbes.com/sites/nomanazish/2018/02/10/think-you-dont-need-houseplants-
science-says-different/#160626633595
(https://rurallivingtoday.com/hydroponics/what-cannot-be-grown-hydroponically/#Worst_
Plants_for_Hydroponics)
(https://hydroponicsspace.com/hydroponic-cotton-is-it-achievable/
(https://hydroponicsspace.com/can-you-grow-rice-hydroponically/)
(https://gardeningtips.in/growing-kale-hydroponically-plant-care-yield-guide#Hydroponic_
kale_fertilizer_and_nutrient_solution
https://veggieharvest.com/vegetables/kale.html
(https://www.plantgrower.org/uploads/6/5/5/4/65545169/cornell_cea_baby_spinach_hand-
book.pdf)
(https://growguru.co.za/blogs/hydroponic/ph-ppm-ec-water-for-hydroponic-plants)
Vegetables
(https://homeguides.sfgate.com/cucumbers-shallow-roots-85473.html#:~:text=Root%20
Structure,8%20inches%20of%20the%20soil.)
(https://veggieharvest.com/vegetables/strawberry.html)
(https://veggieharvest.com/herbs/basil.html)
pepper : https://krostrade.com/blog/how-many-bell-peppers-per-plant/#Do_Bell_Peppers_
Keep_Producing
tomatoe: https://www.gardeningchannel.com/how-many-tomatoes-do-you-get-from-one-
plant/#:~:text=For%20example%2C%20a%20Roma%20tomato,who%20will%20eat%20the%20
tomatoes.
lettuce: http://www.etruriaroyalfruit.it/images/prodotti/pdf/lattuga.pdf
cucumber: https://homeguides.sfgate.com/many-cucumbers-produced-plant-53146.htm-
l#:~:text=Generally%2C%20a%20healthy%20pickling%20cucumber,6-ounce%20cucumbers%20
per%20plant.
(https://ec.europa.eu/eurostat/statistics-explained/index.php?title=Household_composition_
statistics)

- 83 -
- 84 -