Building codes typically echo the administration s guidelines.
How much roof venting for 6000 cfm house fan.
This is important because air like water takes the path of least resistance.
The federal housing administration recommends 1 square foot of attic ventilation for every 150 square feet of attic space.
Let owens corning roofing help you calculate exactly how much ventilation you will need for a healthy and balanced attic with our 4 step ventilation calculator.
Having an understanding of this makes choosing the correct fan size for your home an easier process.
Here is an example.
A wind turbine catches the wind and spins a fan which pulls hot air outside.
To simplify this you can only bring in as much as you can take out.
Dangers of too much ventilation.
Attic vent fans are commonly rated from 800 to 1 600 cfm making one fans suitable for attics of up to around 2 200 square feet.
This is telling you that you would need 6 32 square feet of net free venting to properly ventilate all the air you are pulling in.
Cubic feet per minute or cfm is the amount of cubic feet of air per minute the fan moves.
With a power switch or a thermostat installation an attic fan can be turned on to let hot air from the attic out.
Use only soffit vents as fresh air intakes for powered attic ventilators.
Understanding whole house fan cfm.
Add an additional 20 cfm x 1 20 if you have a steep roof and 15 cfm x 1 15 for a dark roof.
Whole house and attic fans are also capable of pulling carbon monoxide back into the home through a damaged flue.
Determine how much net free venting your fan will require.
Take the total cubic feet per minute of air flow cfm of the fan and divide by 750 2.
Whole house fans come in a variety of sizes determined by the amount of air they circulate or whole house fan cfm.
If you divide that by 750 you get the number 6 32.
To calculate the total minimum soffit vent intake area in square inches divide the cfm of the pav by 300 and multiply the result by 144.
The two main dangers associated with too much ventilation involve roof damage and increased utility bills.
Roofing resources during covid 19 for contractors for homeowners.
The 537 cfm fan is capable of moving plenty of air.
Attic x 0 7 700 cfm minimum fan rating.
The higher the cfm the more venting area is required to keep the system working efficiently.
This will give you the amount of net free venting in square feet required for the fan you select.
