How Many Cfm Attic Fan Move

Ft of attic space for example 20 x 50 to be effective.

How many cfm attic fan move.

The most powerful box fan available is the lasko 3723 which has 2500 cfm. 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. The quietcool afg pro 3 0 attic gable fan can help cool and ventilate your attic for just pennies an hour. According to the home ventilating institute hvi powered attic ventilators need to move a minimum of 700 cubic feet per minute cfm for 1 000 sq.

The afg pro 3 0 is possibly the most powerful residential attic fan on the market today. For a 20 box fan the cfm can range from around 1000 cfm up to 2500 cfm. Most fans are rated from 50 to 110 cfm. Box fan cfm can vary depending of the size of the fan.

For proper cooling and efficient operation any whole house comfort ventilator requires adequate unobstructed outlets in the attic through soffit vents grilles or louvers. So as another example moving to a 2500 cfm fan would cut the air exchange time to roughly 7 minutes 17 600 2500. Attic x 0 7 700 cfm minimum fan rating. Another way to look at this is to calculate how many air exchanges are performed in an hour for a fan with a certain 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. Next multiply the square feet of attic space by 0 7 to get the minimum number of cubic feet of air per minute that the fan should be rated to move. Fans are sold on the basis of diameter or the cfm of air they move. For bathrooms 50 square feet and smaller it is recommended you purchase a bath fan designed for small rooms which will typically have a cfm range of 50 79.

Whether exhausting air or bringing fresh air into a structure the calculation produced should help to figure out the size of fan s required to accomplish the air exchanges needed. A 30 inch fan will move 5 700 cfm. For example a typical 36 inch diameter whole house fan will move 6 900 cfm of air. Attic vent fans are commonly.

Attic fan size calculation. Running at 250 watt and moving over 2860 cfm this fan uses less power than typical attic fans that move half the amount of cfm. For bathrooms that are larger select a fan that can move at least 1 cfm per square foot of room. The formula above gives an approximate value of the cfm needed for an attic fan.

High cfm fan buying guide. To facilitate faster air exchange would necessitate choosing a fan with a higher cfm. Many are solar powered and require no other wiring so they don t cause any additional charges on your electricity bill at all. Below we list the top box fans cfm.