Attic ventilation systems?

Question

What would be better to cool down my attic? A wind turbine or a powered

fan with a thermostat? And why? My attic gets to be 100-120 degrees when it's like 80 outside? It just has regular roof vents at this time.

Answer 1

Power fan with a thermostat.  With a wind turbine if there is no breeze it will not cool.  The cooler your attic the less your air conditioning has to work to cool your house.  This will also help your shingles last longer.  Get one that moves a large quantity of air.

Answer 2

The turbine is best, it is free to operate and automatic.  A better option but more skill and labor intense is gable vents.  That is, two 2' x2' ventilation openings at each end ot the end walls, close to the ridge.

I've been in attics.  Ridge vents alone don't creat a lot of air movement.  Roof vents (the kind weaved in with the shingles) don't create a lot of breeze.  A gable vent at each end of the building creates a refreshing breeze when working in an attic.

Answer 3

There is no magic pill for attic ventilation. Most attics need to have at least 2.5 air exchanges per hour. That is to say that you need to replace the air in your attic with new air from outside of the attic at least 2.5 times every hour in the summertime. However big your attic is will determine what type of ventilation you need. This really is judged by the Cubic Feet per Minute rating or the CFM of whatever type of vent your researching.

I like using the 14" wind turbines that require no power. They will always move air, even if you have low wind outside. A fan will give you great ventilation as long as it is on. Most of these will be on a thermostat which means that when it is not hot, it will not be running. They typically costs about 2 cents an hour to run. Ridge Vents are great for moving air out of every "hot spot" in the attic but not so great for moving lots of air unless you can get a lot of ridge venting on the roof.  

Any type of roof ventilation must be added with consideration to intake ventilation as well. Most homes, even new homes, have very poor intake. Usually adding more soffit vents, or fixing the ones you have so they are allowing air into the attic, is a mandatory improvement when adding more exhaust ventilation.

Answer 4

skaz915 advise is sound no moving parts and no running costs but make sure you have soffit vents (i hope you call it a soffit your side of the pond lol) to allow the cooler air in. This will work by natural convection hot air rises and exits the roof space via the high ridge vent (exhaust) and cool air enters via the low soffit vents (inlet).  

Answer 5

Honestly dude this comes from 15 yrs home building experience, ridge vent is ur  best bet. Remember hot air rises and the ridge of ur roof is the highest point on your roof. All you have 2 do is rip the ridge cap shingles off or your roof and cut the plywood or osb back an 1 1/2" on each side of your ridge board and install the ridge vent which is a brainless installation and reapply new ridge cap shingles. Very easy fit. A lot easier than an electric fan with a thermosat or a wind turbine. Easiest fix there is by a long shot.

Answer 6

100 to 120 sounds normal.

You want to move the air, all of it.  The design should be taylord for your roof design.  The key is to move air from one side to the other just like a tunnel.

Keep in mind that your insulation effectiveness depends upon the moisture content.

Answer 7

to answer ur question, the best to use is ridge vent..... of the 2 u listed i would use the power vent, gives u more control of the heat... check in on ridge venting....

lic. gen. contractor