SDR 11 HDPE Coils polyethylene pipe 500' lengths
a non-electric, passive geothermal
solar heating & solar cooling system
Earthtubing utilizes conventional, thin wall, plastic pipe to passive solar pre-heat your home's air intake. Fresh air enters a system of these pipes which are laid around the exterior and interior of your home's foundation. (Or even down the driveway!) You can let the air draft naturally through your earthtubes for a truly sustainable, non-electric, passive geothermal system or add fans and filters to supplement the home's back-up heating and cooling system. Be careful with Earthtube details, though ... while architects are warming-up to the idea, they are making very elementary mistakes, like using large concrete (cement) pipe that is impossible to clean.
Earth tubing (fresh air return tempering) is not suggested for low/zero energy, sustainable applications in humid climates where the designer is concerned about air quality. There have been numerous designs over the years that attempt to deal with the issues, but they invariably are forced to develop high-energy, mechanical systems to deal with lowering humidity and sterilize air prior to passage through the tempering earth tubes. Every low-tech passive energy system we have ever encountered fails to properly address the air quality issue. Hybrids tend to rely upon UV treatment of the air, which is sketchy, at best.
Conventional homes are typically High R value and "airtight", so all of the heating and cooling effect is stored within the air temperature (convection). If you let the air escape, you lose all your comfort.
"High thermal mass" building materials allow the heating and cooling effect to be stored within the home's walls and floor (radiant). This allows you to vent the inside air of an HTM without "losing" all your heating or air conditioning comfort. Constant venting in the winter is common to HTMs, with fresh air being pre-heated or pre-cooled before it enters the home.
HDPE Geothermal Piping System-Key Benefits
* Cost Efficient Installation- Easy to join, lightweight, and flexible to help reduce construction and installation costs.
* Tough and Durable- Excellent impact and abrasion resistance. Pressure ratings based on long term testing. Exceptional resistance to slow crack growth and environmental stress cracking.
* Ductile and Flexible- with a bending radius equal to approximately 20 times the diameter of the pipe, HDPE piping has the flexibility, that will make trench and downhole installation easy.
* Resistant to Chemicals and Corrosion- Excellent resistance to most chemical compounds and aggressive soils.
* Thermally Conductive- HDPE pipe offers high strength resin pipe material to minimize pipe wall thickness and maximize heat transfer.
* Leak-Tight Joining- Long continuous coils or straight lengths reduce joining requirements. Properly made heat fusion joints are as strong as the pipe itself and do not break.
* Superior Flow Characteristics- HDPE pipe offers high volume flows with low flow resistance. The hydraulically smooth, non-wetting surface provides excellent flow properties. A Hazen-Williams C-Factor of 150-155 is typically used to estimate flow resistance. HDPE pipe does not rust, rot, corrode, tuberculate, or support biological growth.
* Sequential Footage Markings- Coils contain footage marker indications every 2' to assist with proper depth setting in borehole installations.