Use warm air from loft space?

[booshank]

On sunny days the air in loft spaces tends to heat up even if the air outside is cold. I was thinking that all that heat goes to waste as it's insulated from the house by loft insulation.

While making some thermostatically controlled fans for an electronics project, the idea came to me of putting something similar into the loft to pump the warm air into the house on cold days.

Anyone have any ideas on this? Seems technically fairly simple, but maybe I've overlooked some reason why it wouldn't be a good idea...

[stoneyboy]

booshank,
Unfortunately lofts only get really hot on sunny days - days when the house underneath is warm anyway.
I guess you could try a heat recovery unit drawing warm air out of the loft and feeding it into the house but you are talking big money.
end

[solarsecurity]

I have read forum posts about this before on other forums. Some people have suggested using piping which goes from the attic to the ground floor with a bathroom extractor fan attached at one end to direct the warm air to the ground floor. Pretty simple really!

[htg engineer]

The loft only gets hot on summer days, normally when you want the house to be cooler not warmer?

In the winter when you want heating the loft will be cold. You'd be better spending money on loft insulation to prevent heat rising and escaping through the loft/roof when you have the heating on.