return to As Built
What are earth tubes?
The earth tube is a passive heating and cooling technique that uses the near-constant temperature of the earth to pre-heat incoming air in the winter and pre-cool it in the summer. Air is drawn through tubes buried under the earth before bringing it into the building envelope.
Why use earth tubes?
By code, we have to bring fresh air into the building for indoor air quality so we wanted to use earth tubes to precondition the incoming air. In our case, we ran into a water main, the result being the tubes lost their slope. Losing slope caused a section of the pipe to hold water and dirt that we are not able to clean out. So we repurposed the earth tubes to serve our earth room (helping the earth room maintain a temperature range in which the Altherma heat pump, normally located outside, operates more efficiently.)
When should earth tubes be used?
- Best in climates with extreme heat and cold. The high difference between the ambient temperatures and the required indoor temperatures create the best opportunity for the earth tubes to produce valuable results.
- Need available land to accommodate the length of tubes.
- Avoid areas with high water tables.
- Great opportunity to place them under the building floor when constructing a new building.
How are they working?
- Earth Tubes Our design page for the earth tubes.
- Earth tubes/ground coupled heat exchanger Definition and description of earth tubes. Source: Wikipedia