Passive Cooling And Heating Earth Tubes
(SAFETY DISCLAIMERS - The use of earth tubes may allow dangerous radon gas to enter your home depending on your location. It is advisable to purchase a continuous radon detector for your home if you plan on installing earth tubes.
It is also important to ensure that earth tubes have proper drainage to prevent any mold growth within the earth tubes from condensation.)
The idea of using earth tubes has been around for ages, and they are currently used in large scale buildings to reduce cooling and heating costs.
The basic concept of earth tubes is to use the earth to cool a building in the summer and heat a building in the winter. This is done by burying pipes in the ground below the frost line. Once you get to a certain depth in the ground the temperature levels off and remains constant year round regardless of the outside temperature.
So the object of earth tubes is to take the outside air into the ground thus cooling or heating it to a consistent 60-70 degrees; then bringing that air back into the building.
How To Install Earth Tubes
Step 1:
Find out how deep the frost line is for your area. In many parts of the United States the frost line is approximately 42 inches.
Step 2:
Dig out a 11′ x 5′ hole below the frost line. This will allow for the 10′ x 4′ 6″ earth tubes to be inserted easily.
(WARNING – Precautions should be taken to avoid cave-ins such as proper temporary bracing of hole side walls!)
Step 3:
Fill in the hole with 6 inches of gravel to allow for any water drainage.
Step 4:
Assemble five 10 foot long 6″ PVC pipes as shown in the photo below. Set pipes onto gravel drainage base.
(TIP – Elevate one end of the pipes a couple inches to ensure any water will easily drain out through the drainage holes. This is illustrated in the last photo on this page.)
Earth Tubes Top View
(Click On Images To Enlarge For More Detail)
Step 5:
Cover pipes with backfill.
Step 6:
Cover the intake portion of the earth tubes with a screen to keep out rodents and other pest. Ensure intake pipe is angled toward the ground as displayed in the photo below to keep rain water out.
Step 7:
Connect the other end of the pipe to the house, and attach either a solar powered or electric fan inside of home to bring air into the home through the earth tubes.
Earth Tubes Side View
