On Monday, July 15, 2013 9:41:58 AM UTC-4, Home Guy wrote:
" wrote:



A vent fan still needs fresh air to come from somewhere, just like

a ridge or any other vent. In fact, one of the main arguments

against power fans is that they can pull cold air from inside

the house up into the attic.



Better that than having ridge vents (or other passive vents) that have

NO ability to ventilate an attic.


The vast majority of roofing and building experts say you're wrong.
Also, if ridge vents were not good at venting attics, all the shingle
manufacturers would not allow them to be used per their warranties.
Yet, all shingle manufacturers say ridge are either preferred or
OK. In fact, many of the shingle manufacturers sell ridge vent products.
Who know more, the manufacturers standing behind their hundreds of
years of experience and warranties, or you?







In other words, if the attic is so air-tight that a power fan can create

a negative pressure such that the only air being moved out of the attic

is being replaced by air coming from inside the house, then I'd rather

see that situation rather than the attic cook itself.



It's not that the attic has no venting. It may not have venting adequate
to support the big honking fan. Yet, the venting could be perfectly
adequate. Also, a power fan is a point ventilation exhaust. A ridge
vent can exit air uniformly across the whole attic.




But the fault in that situation is a lack of intake / soffit vents, not

the fault of the power vent fan.



Anyone interested can do some googling and find that most experts

today recommend ridge vents over power vents.



Because roofers are not electricians. They don't want to mess around

with having to provide power for vent fans.

I said experts, not roofers. There are research labs, universities,
construction experts that have actual data showing ridge vents work.






On the hottest days of the summer there will be very little wind, and

your ridge vent will do **** for you. That's why the power vent pays

off.

You of all people should know that hot air rises.