Whole House Fan vs Central AC

Old 06-11-16, 05:42 AM
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Whole House Fan vs Central AC

I was at the big blue box (BBB) store today. The vendor (contracted through BBB) told me to avoid investing into a whole house fan because there is no economical advantage over the new generation of ACs.

Is this true or were they throwing a sales pitch? AC (1 stage system) for 8K. The whole house fan is only $400. We have about 3 hot months and about 1/2 humidity month.

They kept saying that the whole house fan is worthless compared to the new type of AC. When I asked them for the comparison of amp usage, the vendor avoided to share the amp usage for their Lennox system. Red Flag.

Right now, it is not hot yet in California. The nights are cold and the days are warm. Wouldn't a Whole House Fan be the ideal candidate or am I missing something here?
Old 06-11-16, 07:21 AM
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There really is no comparison, as you are talking a $7.6k price difference.

Whole house fans work well. If it is cool and dry at night, you can seal up during day and get away with no AC.

If it is humid, a whole house fan will do nothing for it.

One ventilates and one conditions the air.

With AC you get filtration and dehumidification. Ventilation and you get whatever it is outside. It is all up to if you can handle hot days. If it gets cool at night and is dry, the whole house will help greatly, while using very little power compared to an HVAC system.

I always remind people the HVAC, as well as a fan is also an improvement on your home. It adds to its value if the time comes to sell.

I would install whole house, since it would be good to have even with AC. Then see how it works. Its a $400 gamble to maybe save $7600. And there will be many times you can save electric and run the house fan. The fan, depending on your energy rate, will probably pay itself off if you decided to add AC, by taking run time away from the system at night and cooler days. over 10-15 years, those days/nights add up. Not only less electric, but less hours on the equipment.

It's 1 larger fan motor vs 2 fan motors plus compressor. If I can run a fan to do the work of the compressor, I will take the fan. It all depends on your climate.
Old 06-11-16, 07:25 AM
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"Wouldn't a Whole House Fan be the ideal candidate or am I missing something here?" As you have discovered, opinions vary, but the advice you were getting may have been clouded by the desire for a sale :NO NO NO: , it happens.
Using a WH fan is very much a personal choice and dependent upon the local climate. If you were pulling in lots of humidity it might not be good, but when to use it is a user's choice. In my experience, NJ, they make short work of that hot air in an attic allowing the house to cool down more rapidly, assuming it exhausts into the attic.

When you enter the hot, hot season it is probably best to stay with just the ac so it isn't playing catch up with daily humidity, but again, that is something you decide.

My climate is much different, but my activities vary from closing the house up tight to retain as much of the overnight cooling, to opening all of the windows and doors (screens required), to running a large 3 speed window fan in the evening. In about 30 minutes the house is cool after the sun goes down.

I vote for adding the WH fan.

JJ, I'm slow, but looks like we agree .

Last edited by Bud9051; 06-11-16 at 07:26 AM. Reason: slow
Old 06-11-16, 07:31 AM
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Likewise, we have seasons that really don't dictate heat, nor cooling. Sort of a limbo period when nothing runs to condition the air. That's where the WH fan comes in nicely. Exchange of fresh air makes things just feel nicer. Of course, in the South, we have summer and winter, making conditioned air imperative for creature comfort. Unlike Chicago which has "winter" and "the 4th of July".
Old 06-11-16, 07:51 AM
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If I were you, I get both. Problem solved no matter where you live.
Old 06-11-16, 12:09 PM
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For the most part I don't need central A/C here although I do use a window unit in the bedroom during the hotter weather. In the past I have set up a 20 inch box fan in the window on one end of the house (block off the parts not covered by the fan with cardboard) and then open a window on the other end of the house. As long as the relative humidity is fairly low (most of the time) this does a very good job of cooling my house after the sun goes down and outside temperatures are lower than indoors. However, when the RH is high it will make the indoors absolutely miserable.

The down side is that you have to have the windows open and the airflow brings in any smells, noise and DIRT in the air.. The latter, even with regular window screens, is significant. Leaving the windows open will usually negate using an alarm system as well. If you don't leave the windows open the whole house fan is practically useless.
Old 06-11-16, 12:11 PM
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Ahhhh! Thank you to everyone, especially the long detail replies.

I actually already have an AC. But it is 20 years old. It still works just not efficient.

I agree. We turn AC on days which are humid because fans will do nothing for humidity. But humidity here is only 2-3 weeks worth.

I will proceed to get the Whole House Fan.
Old 06-11-16, 01:03 PM
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In my experience, in NJ, they make short work of that hot air in an attic allowing the house to cool down more rapidly, assuming it exhausts into the attic.
I'll second that. I only use my A/C when it's really hot out. We do get spells of high humidity and the fan is useless in those conditions.

I have a 40"-42" gable mount with a powered louver. I have the louver set up to open automatically without the fan if the attic temperature gets over the outside temperature.

They do add to the dust content of the house as the fans draws in outside air. If you have allergy problems the fan would not be a good choice.
Old 06-11-16, 02:46 PM
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We have four bedrooms upstairs. Two bedrooms have vaulted ceilings. Will the whole house fan be able to remove the heat build up at the top point of the ceiling for these two bedrooms?
Old 06-11-16, 02:57 PM
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Not likely. If you were to run ceiling fans in those rooms to circulate the air you might have a better shot.

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