Help with Attic Exhaust

[Joseph Meehan]

Good point.

[Tom Baker]

I think you would find the Building Science Corporation web site helpful. The information is from building researchers. Climate specific problems are addressed. I and other architects refer to it, if you want recommendations. Tom Baker

[xrongor]

ridge vents are totally the way to go if you ever have a say in the matter, such as when its time to re-roof.

randy

[George E. Cawthon]

[George E. Cawthon]

First, I hope you have openings to let air into the attic when the fans are running, e.g., soffit vents or other gable openings. Second, you are right it will suck in the hot air, and the attic can never be cooler than the outside temperature. However, if the fan lowers the temperature in the attic to 10 degrees over the outside air temperature, it will significantly reduce heat buildup in the house.

[George E. Cawthon]

[Travis Jordan]

Unless of course you have a tile roof and live in an area that requires product approval on ventilation products. There are currently no ridge vents approved for use under tile in the State of Florida.

[Travis Jordan]

Yes, but. If the attic is insulated with R-30, only 3% of that 10 degree difference gets to the ceiling side of the insulation. (Thermal conductivity [U factor] = 1/30 = 3.3%).

[Travis Jordan]

Only if the attic is poorly insulated.

[Travis Jordan]

/snip/

R-30. Anything more than that gets into the law of diminishing returns.

You probably should just have some more loose fill (sounds like you currently have perlite) blown in. Laying bats over the top of loose fill is problematic because of the voids created in the process.

White tile is a good choice over any other color for a Florida roof since white's greater solar reflectivity means significantly lower temperatures for the roof deck (and therefore, it is probable that the underlayment will last longer). Of course, you have to clean the algae off it every so often....

[CAStinneford]

I don't know how well they work but there are a number of sites with insulating covers you put in the attic above your fold down stairs. Here's one link.

[BinaryBillTheSailor]

You can get any color or material you want in CT. My roofing is light gray asphalt shingles. One neighbor has a tan asphalt roof and another neighbor has a green, metal, standing seam roof. There are several homes in my area with Spanish style red clay tile roofs, not to mention the many who have slate or cedar shingle roofs.

BB

[Steve B.]

I think you are trying to keep it overly cool in the attic. Most of these type fans are set to come on at 120 degrees. On mine I did block the vent with plastic on the end of the house with the fan. Fan generally comes on around noon and cuts off right around sunset.

Steve B.

[Drummer of The Vibe]

I'm not sure if anyone else picked up on this, but what TIA bought was a gable end vent fan. The purpose of this device is to create a negative pressure inside the attic to draw outside air in through either OTHER gable end vents or soffit vents. By the way, what TIA is calling gable vents are really soffit vents (since the run the length of the home). Getting outside air into the attic helps keep the temps closer to the outside temp which is important in both the summer (keeps roofing from overheating and helps to stop it from warming living space) and winter (stops ice damming).

I suspect that what TIA REALLY wanted to buy was a whole-house-fan. This device is used to draw air out of the living space and into the attic where it can be vented through either a ridge or gable vent. Of course, you have to open all your windows to make it work, and again you're still at the mercy of the outside temp. This is only effective during seasons when night time outside temps are much lower than in the inside (where daytime heat has built up). Eventually, in summertime, it's just too hot inside and out to do any good. I had one of these fans and it ran for maybe 20 days out of the whole year.

Bobby in NJ

[Drummer of The Vibe]

I'm not sure if anyone else picked up on this, but what TIA bought was a gable end vent fan. The purpose of this device is to create a negative pressure inside the attic to draw outside air in through either OTHER gable end vents or soffit vents. By the way, what TIA is calling gable vents are really soffit vents (since the run the length of the home). Getting outside air into the attic helps keep the temps closer to the outside temp which is important in both the summer (keeps roofing from overheating and helps to stop it from warming living space) and winter (stops ice damming).

I suspect that what TIA REALLY wanted to buy was a whole-house-fan. This device is used to draw air out of the living space and into the attic where it can be vented through either a ridge or gable vent. Of course, you have to open all your windows to make it work, and again you're still at the mercy of the outside temp. This is only effective during seasons when night time outside temps are much lower than in the inside (where daytime heat has built up). Eventually, in summertime, it's just too hot inside and out to do any good. I had one of these fans and it ran for maybe 20 days out of the whole year.

Bobby in NJ

[Drummer of The Vibe]

I'm not sure if anyone else picked up on this, but what TIA bought was a gable end vent fan. The purpose of this device is to create a negative pressure inside the attic to draw outside air in through either OTHER gable end vents or soffit vents. By the way, what TIA is calling gable vents are really soffit vents (since the run the length of the home). Getting outside air into the attic helps keep the temps closer to the outside temp which is important in both the summer (keeps roofing from overheating and helps to stop it from warming living space) and winter (stops ice damming).

I suspect that what TIA REALLY wanted to buy was a whole-house-fan. This device is used to draw air out of the living space and into the attic where it can be vented through either a ridge or gable vent. Of course, you have to open all your windows to make it work, and again you're still at the mercy of the outside temp. This is only effective during seasons when night time outside temps are much lower than in the inside (where daytime heat has built up). Eventually, in summertime, it's just too hot inside and out to do any good. I had one of these fans and it ran for maybe 20 days out of the whole year.

Bobby in NJ

[Lost-In-Translation]

Dear Bobby in NJ

Thanks for weighing in on this.

Just for reference, TIA isn't a name, it's USENET speak for "Thanks in Advance"

Have a great weekend!

message news:...

[Oscar_Lives]

Yes, Tia is a name, dumbass.

[Tom]

Lost-In-Translation mighta wrote:. > Just for reference, TIA isn't a name, it's USENET speak for "Thanks in

So Oscar wrote:

Also, just for reference, it means "aunt" in some languages, like Spanish... bitch! : ) That's like... my third emoticon, ever. Sorry. Tom Someday, it'll all be over....

[Lost-In-Translation]

Not the way I used it . . .asshat!