How Much Roof Venting For 6000 Cfm House Fan

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.

How much roof venting for 6000 cfm house fan.

The federal housing administration recommends 1 square foot of attic ventilation for every 150 square feet of attic space. With a power switch or a thermostat installation an attic fan can be turned on to let hot air from the attic out. Roofing resources during covid 19 for contractors for homeowners. Building codes typically echo the administration s guidelines.

Understanding whole house fan cfm. 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. This is important because air like water takes the path of least resistance. Here is an example.

Dangers of too much ventilation. Use only soffit vents as fresh air intakes for powered attic ventilators. Cubic feet per minute or cfm is the amount of cubic feet of air per minute the fan moves. 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.

Whole house fans come in a variety of sizes determined by the amount of air they circulate or whole house fan cfm. A wind turbine catches the wind and spins a fan which pulls hot air outside. The two main dangers associated with too much ventilation involve roof damage and increased utility bills. Take the total cubic feet per minute of air flow cfm of the fan and divide by 750 2.

The higher the cfm the more venting area is required to keep the system working efficiently. A rule of thumb is you should have one square foot of net free venting area for every 500 cfm of airflow. If you divide that by 750 you get the number 6 32. To simplify this you can only bring in as much as you can take out.

Add an additional 20 cfm x 1 20 if you have a steep roof and 15 cfm x 1 15 for a dark roof. A minimum of one square foot of inlet area for every 300 cfm of hvi certified fan capacity is required for proper fan operation. Whole house and attic fans are also capable of pulling carbon monoxide back into the home through a damaged flue. This will give you the amount of net free venting in square feet required for the fan you select.

Determine how much net free venting your fan will require. The 537 cfm fan is capable of moving plenty of air. So at 3000 cfm you ll want six square feet of venting.