Hot air

[john8750]

Seems like a lot of hot air in the attic. Any way to use that energy?
I remember some talk about a solar though. A fluid is passed through a parabolic collector and then through a heat exchanger to produce steam and power a turban generator. The problem was a lot or collector is required to make it feasible. A normal house is not enough.

John Smith

[DamonHD]

Paint your roof white and/or better insulate above the top floor to help avoid it (and your top floor) getting too hot in summer time in the first place might be a better saving overall (eg from reduced A/C and fan demand in the house)!

Rgds

Damon

[tanner0441]

Hi

If you really want to use it. Build an air to air heat exchanger and pre heat your fresh air into the building, or duct it to the bottom of the house.

As others say I would want to know if the heat is being lost from the lower floors or solar gain, both are unwelcome and indicate a need for better insulation it is poor insulation under the rood itself or if it is coming from the lower floors then you are paying for it and the insulation over the ceiling on your top floor.

If it is unwelcome solar heat through the roof painting it white though it would help would probably upset your local council. I would go for PU foam with aluminium foil on one side which you put against the roof to push the heat back out and fit the bats up between the joists.

Brian

[john8750]

Some great ideas guys. I have a white rubber sort of roof. Right below that is a 2 inch thick type of foam, foil on the inside and some hard under layer, like plywood. The attic is well insulated. It is a mobile home so I'm sure it is some sort of composite material.  Also, I have an attic fan. The hot air coming from that fan on a hot day seems like a waste. There surely must be a way to use it.
Any ideas??

BTW- inside the house is kept well under control with central air, ugh the electric bill....


John Smith

[tanner0441]

Hi

Mobile homes are renowned for being difficult to keep comfortable. (I lived in one for 4 years, and I fitted an AC unit designed for a small computer room) You could dig a hole insulate it, fill it with rocks, put a lid on it, and duct the air down into it.  Then on a cool evening you could return the air from round the warm rocks back into the mobile home. Depending on the temperature of the scavenged heat you could put it into stored water, air to water heat exchangers are easy to come by, car radiators. Without doing tests and measurements so you know exactly how much heat there is. Like wind because it feels like a good blow doesn't mean it is, likewise because it feels uncomfortable to your body doesn't mean there is enough waste heat to do anything with, apart from getting you to sweat a bit.

Brian