My Mother’s House Part IV: Installing a Passive Heating System

1 / 9
The cooling system pipes enter the house through an opening at each end of the front wall.
The cooling system pipes enter the house through an opening at each end of the front wall.
2 / 9
Elevation drawings.
Elevation drawings.
3 / 9
The building's natural air conditioning system consists of 15
The building's natural air conditioning system consists of 15" diameter PVC irrigation pipes buried deep in the cool soil.
4 / 9
The above-ground portions of the upper level are insulated with 1/2-inch polystyrene and 3-1/2-inch fiberglass for a combined R-value of over 20.
The above-ground portions of the upper level are insulated with 1/2-inch polystyrene and 3-1/2-inch fiberglass for a combined R-value of over 20.
5 / 9
The drainage lines for the foundation run through the same trenches as the
The drainage lines for the foundation run through the same trenches as the "cool tubes".
6 / 9
Gravel is spread around the drainpipes that lie against the back wall.
Gravel is spread around the drainpipes that lie against the back wall.
7 / 9
The intake ends of the cool tubes are capped with screens and shields to keep rain out.
The intake ends of the cool tubes are capped with screens and shields to keep rain out.
8 / 9
Fill dirt was added until we reached a level about 1-1/2 feet below the edge of the roof on the back of the building. We then laid a 6-foot-wide sheet of 4-mil polyethylene along the entire length of the building, to prevent water draining off the roof from running directly down along the wall.
Fill dirt was added until we reached a level about 1-1/2 feet below the edge of the roof on the back of the building. We then laid a 6-foot-wide sheet of 4-mil polyethylene along the entire length of the building, to prevent water draining off the roof from running directly down along the wall.
9 / 9
The greenhouse section of MOM's house nears completion.
The greenhouse section of MOM's house nears completion.

With winter upon us, the Eco-Village crew has been hard at work getting “My MOTHER’s House” ready to weather the coming storms. Beyond the innumerable seasonal details to be taken care of — which include installing insulation, sealing, shingling and flashing to name a few — we’ve had to finish off one component that we really won’t be needing all that much until next summer.

Because our building’s single most important energy-conserving feature is its earth berming (and, on the front half of the structure, the sod roof), we’ve been anxious to get on with the necessary backfilling and grading. But, to do so, we’ve also had to go ahead and install the natural cooling system (it consists of a pair of buried 15-inch-diameter, 60-foot-long plastic pipes), through which ground-cooled air can be drawn into the house. Now air conditioning may not be at the top of your list of concerns as the snow blows past the living room window, but the tubes had to be installed before the berming could be done. So snuggle up to your wood stove while we tell you about our passive home cooling system. 

Using the Earth For Passive Heat

Because soil is far less willing to conduct heat than is air, the temperature of the earth below the frost line remains comparatively constant throughout the year. At 25 feet down there’s essentially no change in the ground temperature, although at shallower depths the tempering effect is weaker. In general, however, the earth six feet or more below the surface will stay fairly close to the average annual air temperature for the area.

  • Published on Jan 1, 1982
Comments (0) Join others in the discussion!
    Online Store Logo
    Need Help? Call 1-800-234-3368