Scheme for a 100% Passive 100% solar house for a cold climate
house may heat itself in a cold climate without purchased energy.
Although shown as 100% passive, in practice the house would have a fan
to blow hot air into the house from the heat store, and a thermostat to
control the fan for automatic temperature regulation of the habitable
space. Manually operable dampers on suitable openings between the heat
store and the habitable space would allow for manual temperature
regulation during a failure of fan power.
The design of a suitable thermal mass for the heat store may be seen at Free-standing column of stones for a heat store without fans.
The house has only one set of dampers on the air heater side, at the
bottom of the air heater. These passive plastic film dampers prevent
back flow of cold night air into bottom of the heat store. No
dampers are necessary at the upper opening into the heat store
from the air heater. The heat trapping structure of the upper opening
will prevent leakage of the hot light air above into the cold heavy
night air below, as long as the air heater, or the house, or both, are
reasonably air tight.
Upper dampers, if present would swing into the heat store during
operation, where their operation would be inconvemient to verify, and
would allow only awkward access for repair. The lower dampers swing
into the air heater, where they should be easily visible, and allow
easy access for maintenance, if the air heater is large enough for easy
entry. The lower opening into the heat store from the air heater is via
a cold trap, so that air on the inside of a damper made cold at night
by conduction through the thin plastic film will not slide across the
floor of the air heater and onto the floor of the inhabited space.