They can cool your home in less than an hour.
How do you measue for a attic fan.
I know the dimensions of my attic space.
Find the overall air volume of your home.
Measure the length of one blade from tip to base.
And then add insulation if your attic does not have the recommended levels.
Attic fan size cfm 0 7 x sq ft area of the attic formula 1 the size of an attic fan is calculated in terms of cfm.
Ceiling fans come in a variety of sizes ranging from 30 inches for small rooms to 70 inches for larger rooms.
Measure the length and width of each floor of your home with the tape measure.
Next multiply the square feet of attic space by 0 7 to get the minimum number of cubic feet of air per.
You can also view my blog post about attic air sealing here as well as a great article from a well respected professional in the home performance industry about power attic ventilators here.
More importantly though you ll need to choose the right size ceiling fan according to the size of the room.
A typical fan can t do both the work of an attic and the whole house fan but a whole house fan does both.
Attic fan size calculator step 1.
Multiply length times.
Its a matter of personal preference.
You can check the recommended levels of insulation for your region on the energy star website here.
Fans that measure 52 inches are the most commonly used.
For heating and air conditioning airflow or for other exhaust fan situations see our airflow calculator.
Then enter the height at the highest point.
They can cool your home in less than an hour.
You want to make the ceiling plane is as air tight as possible.
One of the most asked questions we get is what size whole house fan do i need.
Multiply the blade length by two and add that measurement to the hub diameter from step 3 to determine your total fan diameter.
Be sure to measure from just above the blade root as shown or from where the blade meets the hub in an assembled fan.
You can size a whole house fan for either a moderate flow or the breeze effect.
How to size a whole house attic fan.
Then click on calculate.
Calculate the required cfm air flow.
To determine the size of your attic multiply the width by the length of the attic floor in feet.
Multiply the total air volume in cubic feet by 30 which represents a complete air change every 2 minutes.
For open blade fans see our ceiling fan calculator.
Enter the length and width of your attic or ceiling crawl space.
How to size attic exhaust vent fans for your home attic size.
The formula above gives an approximate value of the cfm needed for an attic fan.
Option 1 moderate flow efficient cooling 1 5 2 0 cfm of air flo.
Finding the right sized whole house fan for your home.