In his simple and inexpensive version of hypocaust, Richard has lined up the cavities in hollow concrete blocks to create rows of small tunnels for air to travel through. Air warmed during the day circulates through these tunnels in the floor and gives off its heat to the concrete. Later, as indoor temperatures fall, heat rises up through the concrete floor into the house. Terry Komp South-facing windows provide direct solar gain. When compared to a hypothetical reference case, which reflects conventional building practices in the Jonesport area, Richard calculates that his home uses 70 percent less energy for heating.
Natural ventilation provides cooling.
The added insulation alone reduces the home's heating load by about 35 percent. Of the remaining load, about 54 percent is met by solar features, further cutting the amount of auxiliary heating that the wood stove must provide. The hypocaust system under construction. Warm air from the house circulates through concrete blocks positioned end to end, creating an in-floor heat storage system. Komp poured a concrete slab over the blocks.