We will continue to charge the Solar Battery, whenever our water storage tank reaches 130 degrees. Because November and December are typically cloudy and the outside temperatures are declining, we expect the Solar Battery’s average temperature will decline slowly until it has fully discharged (about 66 degrees) in early January.

During this stage, we will not need to burn very much wood or deliver heat via hot water very often because average daily outdoor temperatures are still fairly high (varying from about 50 degrees on Nov 1 down to about 24 degrees on Dec 31). As a matter of fact, during this period we will have more of an over heating problem in the Active Area than a heating demand problem. In many passive solar heated houses the entire interior space is thermally connected. However, in our house, the Active Area is thermally isolated from the rest of the house – well insulated from the bedrooms upstairs and bedroom in the back/north side, plus, there is a 3 ½” concrete mass on the first floor that minimizes short term heat gains from moving toward the basement. On the other hand, if the basement has an elevated temperature, the hot air rises and provides some heat to the first floor or at least minimizes heat loses through the first floor.

Our strategy to minimize over heating in the Active Area will not be to open windows, except in the early fall or late spring when the “extra” heat will not be needed and is not desired elsewhere. During the late fall and winter, our strategy will be to move the heat from the Active Area to cooler areas of the house, such as the upstairs bedrooms. This will be accomplished with floor registers much like in the old farm house I grew up in, but with low wattage inline duct fans that will force first floor, warm ceiling air up and cool upstairs air down. The net effect will be a comfortable Active Area and warmer bedrooms, with no loss of heat energy. An underlying benefit will be that the outlying bedrooms are now better heated and thus the Active Area will stay warm longer with less heat loses. This process is controlled with simple non-programmable thermostats.

During this late fall period, we will have to provide heat, on a regular basis but in varying amounts to the bathrooms. This is done with warm water PEX radiant distribution of the heat stored in the 300 gallon tank and easily controlled with programmable thermostats.

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