Copper pipes have many drawbacks like the oxidation and corrosion. They do not tolerate high
temperature amplitudes and they are not elastic. The cost of repair and start-up are relatively high
compared to PVCs. Oxidation and corrosion are very dangerous for the fish and plants because those
chemical reactions release toxins, something we should avoid. We also want a material which is elastic
and easy to fix. We should be aware that all pipes around should be insulated with proper thermal
insulator which cost about $2.00 /ft. of pipe. The Table 5 compares two types of pipe
Oxidation Corrosion Temp
Tolerant
Elastic Price / 10ft
PVC* No No Yes Yes 3.23 $
Copper Yes Yes No No 9.55 $
PVC stand for Polyvinyl Chloride. prices HomeDepot.com. assumed ½ inch diameter of pipe.
http://www.engineeringtoolbox.com/pipes-tubes-d_347.html
Table 5. Comparison of different piping materials
In conclusion the best material for the pipes is PVCs. It is pretty obvious that has major advantages than
its counterpart. PVC pipes are almost universal in water flowing systems and aquaponics.
2.3.2.3 Water Temperature
Since we are going to build a greenhouse and the aquaponic system in the very cold climate of New
England the heating of the water tank and the greenhouse is indispensable. The factors we have to take
in considerations are the efficiency and the cost of the system .First we have to determine the type of
energy source for the system. The two most used and easier to find sources of energy are electric and
natural gas. These two technologies are easy to access but they are costly for heating. Firewood is
cheaper but the available fuel is limited. Solar is free and available but is really dependent on the
location. Natural gas and firewood have the greatest environmental impact because they burn and
release different greenhouse gases, very harmful for the environment. On the other hand electricity
does not have a direct impact on the environment only if it is produced by renewables sources like wind
or solar (Wiser, 1999).The energy sources can give us an idea on what heaters we should use. We have
electric heaters, gas heaters, firewood heaters and solar systems. All of the heaters but the solar have
some risks related to the fire. Electrical heaters have the risk of short circuit, the natural gas heater uses
high combustible fuel and firewood the firewood heater because it operates as a basically controlled fire
that can be problematic if it gets out of control. The table below shows a clearer picture of the different
fuels.
Availability Environ. Impact Hazards Efficiency Cost/BTU
Electricity High Low /Passive Fire 98 % 35.17 $
Natural Gas High Medium/Active Fire/Explosion 78 % 16.35 $
Firewood Medium High/Active Fire 70 % 12.99 $
Solar Depends None None 100% 0 $
Sources: US Department of Energy (http://www energy.com). Prices: US Energy Information Administration.
http://www.eia.gov. One BTU is the heat required to raise 1 lb. of water by 1 F degree,
Table 6. Comparision of different heating sources.
When choosing a heating option it is important to consider reliability and safe fail over, as well as
efficiency. The majority of cold weather climates rely on gas heaters. Electric heating is also used, but