Whole house Fans.

[Mark42]

Re: Whole house Fans.

Got a $200 bill for AC alone the other month. I will be adding a whole house fan in the ceiling of the second floor hallway. My last house had one and in the evening, it would pull cool air into the house and blow it into the attic, cooling the entire house. The next day the AC would not come on until much later in the day after the cooling affects of the fan wore off.

I read where the belt drive models are quieter than the direct drive models.

A two or three speed model will also work well in the evening where you don't want strong breezes coming throught the windows and the noise level is much lower.

Also a good idea to get some 1.5" or 2" rigid foam insulation and make a box to go over it for the winter time so cold attic air doesn't leak down through the louvers and waste heating dollars. Rigid pink foam panels cut very nicely with box cutters and glue together very well using Gorilla Glue. The 1.5" pink foam has an R- value of about 7.

 

[jlinder]

Re: Whole house Fans.

While attic fans are great during those times in the fall and spring where the outside is cooler than inside there are drawbacks.

In the hot summers we run the A/C. During the cold winter we need to heat. Any loss of roof insulation caused by the fan can offset the advantages.

For controlling costs in the summer I have become a big fan of the roof ridge vent.

This is a vent that runs the length of the peak of the roof. Fairly simple to get installed and since it is at the top of the peak it really draws out the heat out of the attic in the summer.

 

[Mark42]

Re: Whole house Fans.

While attic fans are great during those times in the fall and spring where the outside is cooler than inside there are drawbacks.

In the hot summers we run the A/C. During the cold winter we need to heat. Any loss of roof insulation caused by the fan can offset the advantages. .

" Also a good idea to get some 1.5" or 2" rigid foam insulation and make a box to go over it for the winter time so cold attic air doesn't leak down through the louvers and waste heating dollars. Rigid pink foam panels cut very nicely with box cutters and glue together very well using Gorilla Glue. The 1.5" pink foam has an R- value of about 7."

If you need more than R7, just double up on the thicknesss. If you don't want to make one, they sell them at Depot for about $70-90.

For controlling costs in the summer I have become a big fan of the roof ridge vent.

This is a vent that runs the length of the peak of the roof. Fairly simple to get installed and since it is at the top of the peak it really draws out the heat out of the attic in the summer.

I have a ridge vent on my house. In the summer it is still 120* up there on a hot day. And I have a power roof vent too that was added with the central AC.

If you really want to cool the attic, a power gable end vent is the way to go.

 

[zach103]

Re: Whole house Fans.

we have one. its kinda loud.. but its really old.. like stated its nice when its colder outside.. ours can be removed in winter.. we just move it to the joists in the attic and put an insulated panel in its spot.. my dad hasnt complained about that set up and he does everything possible to keep the house draft free and energy efficient.