TRADITIONAL WHOLE HOUSE FAN SIZING VS WHAT WE HAVE DISCOVERED!

The traditional whole house fan is sized by taking a home's total square footage and multiplying it by 2 or 3.  The number you arrive at, should equal the flow rate of your fan in air flow (CFM).  Using this formula, a 2,000 Sq. Ft. home would require a fan that is rated at 4,000 - 6,000 cubic feet per minute of air flow!  Although this formula does work - There Is A More Efficient And Effective Formula That is Better...

TRADITIONAL WHOLE HOUSE FAN PROBLEM #1:  Most Homes Don't Have Enough Roof Vents!

A 6,000 CFM Whole House Fan Requires - 8 Square Feet Of Unobstructed Roof Venting.  Almost All Homes In Existence Today - DO NOT HAVE THIS MUCH NET FREE VENTING!  You Could Always Add More Vents and Venting - But That Could Get Expensive.  Furthermore, Do You Really Want To Put More "Holes" In Your Roof Than Are Already There? 

TRADITIONAL WHOLE HOUSE FAN PROBLEM #2: Do You Like Mold?  What About Ice Dams?

The Traditional' Whole House Fan, Leaves A Large Uninsulated Hole In Your Ceiling!  Especially In Colder Climates - Heat From The Home Will Travel Into Your Attic.  Where It Will Meet With Cold Surfaces And Condensation Will Form. 

(If You Have A Whole House Fan That Does Not Automatically Seal When Not In Use, Be Sure To Cover It During The Off Season Or Duct The Exhaust Directly To The Outside!)

NEXT: A MORE EFFECTIVE SIZING METHOD >>>