How Much Roof Venting For 6000 Cfm House Fan

Determine how much net free venting your fan will require.

How much roof venting for 6000 cfm house fan. A minimum of one square foot of inlet area for every 300 cfm of hvi certified fan capacity is required for proper fan operation. 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 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.

Attic x 0 7 700 cfm minimum fan rating. Use only soffit vents as fresh air intakes for powered attic ventilators. Having an understanding of this makes choosing the correct fan size for your home an easier process. Whole house and attic fans are also capable of pulling carbon monoxide back into the home through a damaged flue.

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. So at 3000 cfm you ll want six square feet of venting. This will give you the amount of net free venting in square feet required for the fan you select. Roofing resources during covid 19 for contractors for homeowners.

If you divide that by 750 you get the number 6 32. 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. To simplify this you can only bring in as much as you can take out.

Whole house fans come in a variety of sizes determined by the amount of air they circulate or whole house fan cfm. Here is an example. 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. 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. The federal housing administration recommends 1 square foot of attic ventilation for every 150 square feet of attic space. This is important because air like water takes the path of least resistance. Cubic feet per minute or cfm is the amount of cubic feet of air per minute the fan moves.

Dangers of too much ventilation. With a power switch or a thermostat installation an attic fan can be turned on to let hot air from the attic out. Building codes typically echo the administration s guidelines.