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Old 09-06-11, 05:35 PM   #9
MN Renovator
Less usage=Cheaper bills
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I'll chime in on this. I've seen others do this and so tried it earlier this summer. I didn't use the furnace because at the time it used a motor that sucked about 800 watts or so, I just ran a fan from the basement up to the next level and another from there to the top floor. The basement was about 60 degrees, upstairs about 80, after about 6 hours the house was a uniform temperature, the next morning the basement was 65 and upstairs was high 70's, ran it again and then soon enough the basement was 70 and the upstairs was still hot. The cycle continued until I realized that it wasn't going to work out too well. I usually spend time in the lower level and decided that it was better just to be in the lower level of the house(not the basement) for using the computer, reading the paper, etc. So I let the upstairs be 82 degrees while downstairs was 75 or so and comfortable enough and didn't bother firing up the A/C. I have a guest room downstairs with a bed and ended up sleeping down there and it cut the A/C usage down to days where it was 85 degrees or higher. I also only ran the A/C when the house was going to get above 40% humidity and on the cooler days I'd let it get to close to 50% and allow it to run constantly until humidity was in check again.

I later did a radon test and learned you really shouldn't be sucking basement air into your living areas, especially if you are using a furnace blower to do it, by putting the basement under negative pressure you are sucking air through the small cracks in your basement, the drain tiling, and pulling in air through the soil which is a great way to not only introduce radon into your basement, since you are sucking that basement air throughout the house you are putting that radon everywhere. Western Wisconsin is in an area where if you are doing what you are doing, you really should check your radon levels. My living area including lower level doesn't have much radon but I wouldn't sleep in my basement and I won't be running any fans to push that air upstairs either.

Since hot air rises, I've also been thinking of going the window A/C or mini-split inverter heat pump route too as my A/C is from 1986 and probably in the 10-12 SEER range. I swapped out my shaded pole blower motor for one that is a split-capacitor design and went from 6.6 amps or so to 3.3 amps at air conditioning speed(800 CFM blower at 1/5 HP). More savings at the slower furnace speed when comparing both motors. Either way a window A/C uses so much less power and only cools the area we want it to cool so I think you are going the right route.

Problem is that I don't have the up/down sliding windows, mine are tall side-to-side sliders and I can't find a window A/C to fit them so I'd have to go for a wall A/C which takes me out of the $200-400 or so 10.8 or better EER A/C unit market.
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