GAF Intake Booster

I am still in the process of getting ready to have my roof done - the contractor I have selected is going to install the Smart Vent product since I have no soffits and use a ridge vent for exhaust. The problem is he suggests that I put the ridge vent the full length of the roof, but the area of Smart Vent that I can add will only equal about 3/4 the amount of intake for the. I am wondering if I was to add the GAF Intake Booster which is 500 cfm if this could help me give overcome not having enough intake.

The only reason I ask this is because everywhere I have read says that exhaust should not exceed intake.

Any thoughts and comments would be appreciated. Thanks!

The true ratio shouyld be 60 intake 40 exhaust. As far as using a power vent cause thats what that really is for an intake. I would not do it. A power vent will only work correctly for a long period of time with intake. The motor will burn out if there is zero intake. I know that sounds funny but it is my exp. that have have noticed this. I would still use a drip vent or smart vent before using a power vent for intake. Those are my 2 cents

Just because you have more exhaust than intake, does not mean your attic will not be ventilated. It just means, under laboratory conditions, your exhaust will only equal your intake.

Thanks for the quick replys - just to clarify I am wanting to use the GAF intake booster along with the Smart Vent.

Why both??? You will have enough intake with the smart vent. And using the intake boster will only turn the smart vent into an intake itself bringing in water, snow and dirt. I would NOT do that period.

Hi Gtp1003,

I think you may not be talking about the same thing. Although I agree that the Smart Vent will be enough intake. With the fans you would need to install at least 2. They are also not eye appealing.

The intake fan works tha oppisite of an exhuast fan. It is designed to push air into the attic. It is installed down at the eaves.

Once again thanks for the replys. I am afraid that either I am getting confused or I have miscommunicated something.

Here are my numbers

Attic dimension = 27’ x 29’ = 783 square feet

Net Free Area required = 783/300 = 2.61

2.61/2 = 1.31 square per intake/exhaust request

1.31 x 144 = 188.64 required area

Total Ridge length = 56’
Area per foot of ridge vent = 14"
Total Vent Area = 56 x 14 = 784 square inches

Total available length to install Smart Vent = 44’
Area per foot of Smart Vent = 9"
Total Intake Area = 44 x 9 = 396 square inches

If I have done this correctly I believe I am short 388 square inches. So what I am asking is would using the intake booster along with the Smart Vent for intake help me achieve the required 784? If not, what risk is there if I have exhaust that exceeds the intake.

According to your math, and I believe it is correct, you should have enough of both.

If you have more exhaust than intake, you can only figure the amount out equals the amount in.

SmartVent can be used as a ridge vent, too! You will gain the proper flow of air. At 9 NFA your exhaust would be closer to the 1/300 you are looking to get and be closer to your intake vent. If you use it at the ridge, put the lifted side towards the East/SouthEast. When the wind blows it will suck hot attic air at 100% efficiency!

PS: you may want to check your roof plan because 56’ ridge/44’ intake seems that you have roof structures that may need other ventilation products that also offers.

Good Luck!