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Is there an efficient way to bring the solar hot air from my second floor to my basement?

GBA Editor | Posted in Energy Efficiency and Durability on

I have a saltbox — south facing, well insulated house, 1.5 floors over a full, very well insulated livable basement. In the winter, the solar gain on a sunny day brings temps to the high 80’s on the second floor. Should I try a blower to blow the heat down 2 floors? I heat (usually only in early mornings) with a kerosene Monitor heater on the first floor.

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  1. Riversong | | #1

    Good passive solar design, with the proper ratio of south glazing to floor area (7%-12%) and sufficient thermal mass, prevents such overheating problems.

    If the solar gain is entering mostlyh through the first floor windows and the air temperature is stratifying that much, then you have a leaky house and need to consider air tightening. If the problem is too much insolation into the second floor, then you could add some thermal mass, either to floors or walls (even doubling up the drywall can help), and you might want to actively move some of that warm air downstairs - but that requires a return air path to complete the cycle. An open stairwell will work if upstairs doors are 1" above the floor to allow air movement.


    Adding mass upstairs is a good idea. We've done built in book cases under the windows with three inch concrete countertops 18" deep for this in the past.

    I also think a duct and fan pulling warm air down to your basement has promise. My sense is that you don't have a forced air system perhaps you could run a galvanized 8" duct to the basement with an efficient squirrel cage blower at the top of it. I don't think a panasonic bath fan with a six inch vertical duct would move enough air to be effective and I'm not knowledgable enough with high efficiency blowers to recommend one specifically.

  3. Riversong | | #3

    I would recommend Fantech inline fans, such as the FR or FG series:

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