I hope someone can clear this up for me.Has anyone installed an attic fan in Ontario, Canada? from what I have read, they really help in cooling down a house at a fraction of the cost of AC. I have not found any information related to our climate and the HVAC people I spoke to had nothing good to say about them (then again, they make $$ from installling/fixing AC....).Also, I'm in a 3 year old house. Apparently the house is too 'tight' for these to make a difference (per the HVAC guys....). Costco has a solar powered one for $199 that I'm thinking about, so any help would be much appreciated. Thanks!