|Truth Of The Matter Is, Many
Consumers Are Being Misled When Considering A Whole House Fan...
When purchasing a whole house fan, there are a number of issues to consider beyond how much air it moves, how it installs, and how much power it consumes.
Alert #1: IF YOU LIVE IN AN AREA WITH A COLD CLIMATE - YOU MUST SEAL YOUR WHOLE HOUSE FAN DURING WINTER MONTHS - OR DUCT THE EXHAUST DIRECTLY OUTSIDE - SERIOUS DAMAGE TO THE HOUSE CAN RESULT!
By design a whole house fan is mounted between the ceiling and attic of your home. When the fan is not running, the hole that air moves through must be closed. Or, the air will continue to move from the house to the attic. It is like leaving a window open. In a cold climate, during the winter months - warm humid air from the house will flow into the attic. The moisture in the air will condense on the cold surfaces (just as it does on cold window surfaces), and water will drip on the insulation and mold will grow. Cover It, Seal It - Or Duct The Exhaust Directly Outside to prevent damaging your home.
Alert #2: FAN AIR FLOW IS DEPENDENT ON SYSTEM DESIGN AND INSTALLATION. SOME MANUFACTURERS PROMOTE SERIOUSLY OVERSTATED PRODUCT PERFORMANCE.
How do we know this? For years we saw manufacturer's making claims about the air flow on their fans. The flow rates were just to good to be true, but to you the average consumer - you would not know the difference!
We took several competitor's fans to a third party laboratory and had their air flow tested. The results were as we suspected, overstated air flow rates...
Flow through a fan changes as obstacles are put in the path. Grilles, ducts, and gravity dependent backdraft dampers will all reduce the amount of air a fan is able to move. In some products, such obstacles can reduce the installed air flow by 40% or 50%! Independent laboratories (such as HVI) can rate the air flow of the product as a system.
Air blown into the attic must be allowed to escape from the attic to the outside. Otherwise the air will seek other outlets like flowing back down the walls of the house and in through outlets and light fixtures. If you do not have the required net free area of roof venting, you will not only be pumping heat back into your home but the dusty, smelly attic air as well.
Divide the fan’s flow by 750 to determine the necessary, clear opening to the outside. (Insect screens are particularly restrictive to air flow.) For example, a 3000 cfm fan would require in roof venting the equivalent of a 4 square feet to the outside. If the hole is covered by an insect screen, the hole would need to be twice that size.
Alert #4: BEWARE OF "SOUND" RATINGS
Any sound rating of a fan in “sones” must be performed in a certified laboratory, if its not certified - Then Don't Believe It! Any sound rating in “sones” in the specifications of a whole house fan is only a manufacturer’s guess, unless of course they have had their fans tested and certified.
It Is Our Hope That Whole House Fan Manufacturers' as well as Distributors' Stop Fleecing Consumers With Bogus Flow Rates, Sound Levels & General Misinformation.
With Over 200 Years Of Combined Industry Experience In The Field Of Residential Ventilation, We Hope Our Expertise In This Field Has Given You A Little More Insight Into The World Of Whole House Fans. Free Expert Advice Is Always Available, M-F From 7 am - 5 pm PST At 1.888.845.6597
Alert #5: PROTECT YOURSELF FROM INSTALLERS WHO MAY OVERCHARGE YOUR FOR INSTALLATION
We recommend getting at least 3 different quotes or bids for your whole house fan installation. You should check each installers license (if applicable), as well as make sure they have liability insurance and worker's comp insurance. It is also a good idea to check referrences.
Over the years, we have heard from a few customers who were significantly overcharged for their whole house fan installation. You could expect to pay anywhere from $150-$450 for a fan installation. There are many variables that will determine the exact cost that will be dependent on the setup of your home.