ISS Research Proposal
Development of a single-layer Aeroponics system for space-restricted areas
Names: Gabriel Teng(22), Ethan Khor(12), Koh Guofeng(13
A. Problem Statement
The world’s population is increasing very rapidly and the supply for food is not going to be able to meet demand soon. (Collins, 2013) An answer to this is to increase the rate of agriculture. However, this poses another set of problems. Lots of land will be required and the space will not be maximized to full potential. An answer to this is ways of farming. This project aims to make use of technology to make space efficient agriculture techniques.
B. Engineering Goals
To build a single-layer and sustainable aeroponics farm that can operate in space restricted urban areas.
B2 Specific Requirements
- Low-energy consumption
- Must be space saving
- Cost effective
- Time saving
- Easily manageable
Aeroponics is the process of growing plants in an air or mist environment without the use of soil. Aeroponics is a relatively new way of growing plants that is getting increasingly popular with many people because of the speed, cost and novelty. (Garderner, 2008)
Unlike hydroponics, which uses a liquid nutrient solution as a growing medium and essential minerals to sustain plant growth; or aquaponics which using water and fish waste, aeroponics is conducted without a growing medium. (Garderner, 2008)
Plants grown using aeroponics spend 99.98% of their time in air and 0.02% in direct contact with hydro-atomized nutrient solution. (Garderner, 2008) The time spent without water allows the roots to capture oxygen more efficiently. (Clark, 2008)
Aeroponics allows more control of the environment around the root zone, as, unlike other plant growth systems, the plant roots are not constantly surrounded by some medium. (Clark, 2008)
A typical aeroponics system is made up of high pressure pumps, sprinklers and timers. If any of these break down, your plants can be damaged or killed easily. (Garderner, 2008)
Most aeroponic systems are not exactly cheap. Aeroponic systems may cost many hundreds of dollars each and they use lots of energy to operate.
Hydroponics is a subset of hydroculture and is a method of growing plants using mineral nutrient solutions, in water, without soil. (Wikipedia, 2013) Terrestrial plants may be grown with their roots in the mineral nutrient solution only or in an inert medium, such as perlite, gravel, mineral wool, expanded clay pebbles or coconut husk. (Wikipedia, 2013)
No soil is needed for hydroponics. The plants are grown in other mediums. The water stays in the system and can be reused. Thus, there is a lower water requirement. It is also possible to control the nutrition levels in their entirety, which results in lower nutrition requirements. (Patterson, 2013) No nutrition pollution is released into the environment because of the controlled system. (Patterson, 2013) There are stable and high yields and pests and diseases are easier to get rid of than in soil because of the container's mobility. (Patterson, 2013) The plants grow healthier because there is no pesticide damage. It is also easier to harvest, and better for consumption.
Without soil as a buffer, any failure to the hydroponic system leads to rapid plant death. Other disadvantages include pathogen attacks such as damp-off due to verticillium wilt caused by the high moisture levels associated with hydroponics and over watering of soil based plants. (Wikipedia, 2013) Also, many hydroponic plants require different fertilizers and containment systems.
Dynaponics is an improvement from aeroponics to make it more energy and water efficient while maintaining the air environment for the plants to grow in. (Kevin, 2013) This is done by having air pumped through a reservoir under the roots of plants that are suspended in mid-air, shooting water drops at the plant roots providing the plants with the nutrients and water that they need. (Kevin, 2013)
The use of Dynaponics will reduce the amount of water used and the area needing while increasing the rate at which the plants will grow dynaponics systems are also much more energy-efficient than aeroponics systems. (Kevin, 2013)
Like Aeroponics, the roots are suspended in mid-air and the roots are oxygenated, resulting in healthier crops and better produce. (Kevin, 2013)
Dynaponics, while they are energy and water efficient, and able to grow plants much quicker and space saving, were not designed for commercial farming. (Kevin, 2013) These systems might not be able to deliver the water fast enough due to the air jets being of low pressure, and the crops may wilt and die. (Kevin, 2013)
B4. Final Solution and why
Our final solution is Aeroponics.
Why did we choose it over other solutions?
Aeroponics allows plants to have an easier intake of oxygen due to exposed roots. It is also easier to manipulate the environment of the plants due to the lack of need for a medium for the roots.
While Aeroponics may be generally known to use a lot of energy and be expensive, we can overcome these problems by using a low-cost solar panel to provide energy to the set-up. We are also using cheap but effective materials such as foam boards, PVC pipes, and relatively low pressure pumps.
The disadvantage of other solutions outweigh their advantages, as Dynaponics is not practical for large-scale use, and is mostly used in small-scale experiments or as demonstrations, as it is a relatively new concept.
As for Hydroponics, the plants will be less healthy than those grown in an Aeroponics set-up, due to the roots not being able to take in much oxygen.
The Final Design
We chose this project because our country is facing restricted land space and almost all of our food is imported. We hope to be self-sustaining in terms of food.
Equipment List: QNTY
- 175 gph pump x1
- Water tank x1
- Aeroponic Spray Nozzles x2
- PVC piping (Diameter: 16mm) length:1.5m x1
- PVC pipe elbows x2
- PVC pipe T-junction x1
- Pots (Dimensions: 45cm by 45cm) x1
- Soil (Enough for the pot, roughly 14175cm^3)
- Germinated spinach plants x12
- LED lights (red and blue)(3 each)
- Aeroponic nutrients
- EPS foam board (Dimensions: 90cm, 44.2cm) x1
- Soft tube (length: 4cm) x1
- Voltmeter x1
Here are some of the designs we have come up with:
This design uses a rain-bar on top of the plants to simulate rain while the roots will remain suspended in mid air. The water will travel from the rain-bar to the sponges that keep the plant in place within the foam board. The sponges will retain water for the roots to absorb.
This system uses more of a dynaponics setup except that instead of a pool of water, air is sprayed into pipes of water and will deliver water droplets out to the plant roots and plants will ultimately absorb it.
1. Set up a glass tank with a submersible pump at the bottom.
2. Connect the pump to a network of pipes, which lead to spray nozzles, which will water the plants.
3. Cut out a part of an EPS foam board that is 2.5cm thick to fit the top of the tank.
4. Cut small holes in the foam board and plant the plants inside.
5. Turn the pump on. The water should travel up the pipe and through the spray nozzles.
6. Suspend an LED light above the tank such that the plants receive its light.
7. To eliminate any unfair variables, all plants will experience the same amount of light and be frequently watered.
8. Record the heights of all the plants throughout one week in order to test that the set up is working.
9. Find the average height of the plants in each environment.
10. Record the results in a table.
Risk assessment and Management
- Our experiment includes the use of PVC plumbing and the use of saws and other sharp tools may be required. All sharp objects must be kept track of at all times.
- Water is used in the experiment and students should make sure their hands are not wet when touching power outlets
- Hot water is used to fit the pipes and the students should handle the water properly to prevent it from spilling and potentially scalding students.
- Students must handle the glass tank with caution and not carry it too high up to prevent it from breaking, which may result in serious injuries.
Here is the set-up of our experiment:
We will have a set up built according to the procedures, containing 8 plants. This will be used to test if the set up will work and if the plants will grow.
We will test the aeroponics’ effectiveness by measuring the height of plants daily throughout one week. We will also use a sponge in the place of a plant and record it’s conductivity after 30 minutes to test if our watering system is effective.
During and at the end of the experiment, we will check the height of the plant to see if there is any growth.
We will also be using a voltmeter to measure the electrical resistance of the sponge. As the water has mineral salts and other conductive nutrients in it, the wetter the sponge, the more conductive it is. As the sponge gains moisture, we should see the resistance of the sponge decreasing.
Clark, J. (2008, December 22). How aeroponics works. Retrieved from http://home.howstuffworks.com/lawn-garden/professional-landscaping/alternative-methods/aeroponics.htm
Gardener, D. (2008, May 17). Aeroponics - benefits and disadvantages. Retrieved from www.gardeningsite.com/aeroponics/aeroponics-benefits-and-disadvantages
Kevin B, R. (2013, July 18)
. Retrieved from http://data.delos.com/spaceset/pdf7/edgewater.pdf s
Patterson, S. (2013, July 18). Aeroponics vs. hydroponics. Retrieved from http://www.doityourself.com/stry/aeroponics-vs-hydroponics
Wikipedia. (2013, July 11). Hydroponics Advantages. Retrieved from http://en.wikipedia.org/wiki/Hydroponics#Advantages
Collins, P. (n.d.). Retrieved from http://www.worldometers.info/world-population/