When I was a young boy living in the South, believe it or not, there were only a few people that had air conditioning. I remember that my parents had an AC window unit in their bedroom, but I didn’t live in a house with central air conditioning until 1968. How did people stand the heat? Well for one, they had no choice. Second, few people then lived in new housing developments with lots of concrete and asphalt and no trees. And third, many houses had shady porches and attic fans.
So what is an attic fan? If you start looking on the internet, you will see lots of talk about attic fans that are used to cool your attic and how that will save money when trying to air condition the house. That may be true, but that’s not what we were looking for. O.K., so I learned that you need to search for “whole house” attic fan.
What is a Whole House Attic Fan?
An attic fan is a large fan, usually 24-36 inches that is mounted in the ceiling of the top floor in your house. When the fan is turned on, it pulls cool fresh air in through open doors and windows and pushes hot air out of the house into the attic and out through the ventilators in the roof or the gable ends.
Most attic fans were coupled with automatic louvers that opened when the fan was on and closed when the fan was turned off. These fans were great for cooling the house, especially at night when it was cool outside, but still hot inside.
We looked at several options for a “whole-house” attic fans. I even crawled up into the attic and measured the spacing of the rafters to see where I could cut a hole in the ceiling. I had already made plans for the framing and the wiring for an attic fan. Then we found the Air King whole house window fan.
Table 1. Comparison of Air King Whole House Window Fans
Air King makes two models; 16 inch (model 9155), which they call a window fan and the 20 inch (model 9166), which is the whole house window fan. Both models have 3 speeds and are reversible, but the table below shows only the data for the high and low power settings.
|Blade Size||20 Inch||16 Inch|
|Window Height||26.25 in||22 in|
|Window Width||27.0-38.0 in||26.5-34.5 in|
The 20 inch model can move between 2,510 and 3,560 cubic feet of air per minute (CFM) at using between 115 – 170 watts of electricity. The 16 inch moves between 1,360 and 2,470 CFM at 52 – 90 watts. Both fans are rated for noise at 64 decibels (dB) at high speed and the 20 inch is 50 dB at low speed and the 16 inch is 47 dB at low speed.
The only advantage of the 16 inch fan we can see would be the fact it costs less. The 20 inch fan moves 44% more air at high speed than the 16 inch fan, so we recommend getting the 20 inch fan unless your windows are too small. We went with the 20 inch fan.
Advantages of Window Mounted vs Ceiling Mounted Whole House Fan
- Simple installation with four screws for window mount vs new construction – cut hole in ceiling, framing, wiring and possible building permits
- Temporary vs permanent installation – since the window mounted fan is only needed in Summer, it can be easily removed
- A permanent mounted ceiling fan would have to be insulated in the Winter
Air King 9166 Whole House Window Fan Advantages
- Mounts inside the window frame so the window can still be opened and closed
- Simple installation with just four wood screws, all you need is a screwdriver! Air King 9166 Manual (pdf file)
- 3 speed motor – moves between 2,510 – 3,560 Cubic Feet of air per minute
- Cost less than 2 cent per hour to run at high power (170 watts X 1 hour/1000 = 0.17 kw hr X 11.54 cent per kw hr = 1.96 cent
- Reversible motor will pull cool air in or exhaust hot air out
- Metal frame and blade construction (yes, some people complain that the dust cover is plastic, but that doesn’t matter to us)
- One year Warranty
Air King Whole House Window Fan, Model 9166 Review
Air King Whole House Window Fan Negatives and Solutions
There are a few negative points about the window mounted whole house fan. First, the Fan permanently blocks the view from our bedroom window during the Summer. There is nothing we can do to get around the fact the fan blocks the window. Either we have a window fan or we have the view, but we can’t have both. Luckily we have two windows in our bedroom. Let’s face it, you will not see photos of anyone’s window fan in Better Homes and Gardens Magazine. But the look on our faces when the cool breeze is coming into the house – Priceless!
As I mentioned in the table above the fan can be somewhat noisy. It varies between 50 and 64 dB from low to high power. For a comparison, the noise level at the library is around 40 dB, the average home conversation is about 50 dB. The average office or restaurant runs about 60 dB and a vacuum cleaner is about 70 dB. There is simply no way around it, a fan will make noise, even natural wind makes noise; 40 dB at 13 mph and 85 dB at 62 mph. We get around the noise issue since the fan is mounted in an upstairs window away from our TV room. We open windows in the rooms that need to be cooled and the cool, fresh air pours in and the noise remains upstairs. We can sleep in the room with the fan if needed, but it usually cools off here before we’re ready to sleep and we turn the fan off.
The last downside to the window mounted fans is that the blinds do not cover the fan, so the sunlight comes through. We can opened and close the window with the fan in place, but not the blinds. Our solution is to simply hang a bath towel over the fan to block out the sun. The towel could also provide privacy if needed.
The Whole House Fan Saved Us Money
We bought our 20 inch Air King whole house window fan at the end of June last year. To see if the fan actually saved on cooling costs, I compared the previous July and August electric bills when our only cooling option was the central air conditioner to the July and August electric bills after we started using the fan, see Table 2 below. The electric bill for July and Aug. with only the AC totaled $121.26 for 58 days of service. The July and Aug. electric cost after we started using the window fan was $107.45 for 63 days of service . That is $2.09 per day without the fan and $ 1.71 per day with the fan for a savings of 39 cents per day.
But the savings is even more significant. Since it is might be unfair to compare between years without knowing anything about the relative temperatures between years, I also looked up the total cooling degree days required for July and Aug. of 2010 and 2011 to see if the cost was less because the weather was cooler in 2011. What I found was the exact opposite (also see Table 2).
Table 2. Energy Cost Comparison: Before & After Installation of Whole House Window Fan
|Cost & Use||July-Aug 1st Year||July-Aug 2nd Year|
|Per Day Cost||$2.09||$1.71|
|Cooling Degree Days||254||321|
- Our daily electric costs decreased by 18% when we used the whole house fan to cool the house at night instead of using the AC
- Even though there was an 11% increase in cooling degree days
- and we had an increase in electric costs
- Using the whole house window fan also dramatically increased our comfort level because we actually use the fan due to low cost of operation
Since the average cost for electricity in the U.S. is currently about 11.54 cents per kw hour and we pay about 12% less than the national average, your savings could actually be more than ours.
The Whole House Fan Keeps Us Cooler
How does a fan keep us cooler than central air conditioning? Because we actually use it. We use the fan because we know it only costs about 2 cents per hour to run (or about 47 cents if run for 24 hours) . Our 48,000 BTU central air conditioning costs about 55 cent per hour to run. If we run it just four hours per day for a month and that is an extra $68 just for cooling costs. There were many days that we used to be slightly uncomfortable, but we would hesitate to run the AC because we knew it would cost a few bucks. We go ahead and spend the money and use the AC when we really need it, but Yes, I admit to being cheap. But it is also about trying to use less energy so there is less dependency upon foreign oil and less pollution and all that good stuff. But every dollar we save on energy costs is a dollar we can spend on something fun.
Whole House Window Fan Demo
Air King Customer Reviews
One of the first things we did before buying our fan, was to look at the reviews left by customers. Since it has been over a year since we bought our fan, I went back and looked at the reviews again.
There are two main places to buy the Air King fans, Venting Direct and at Amazon. The 216 customers that gave reviews at Venting Direct gave the Air King fans an average of 4.6 out of 5 stars. There were only a few bad reviews, and they mainly complained about the fan not working or being to loud, but were happy with the way their problems were resolved by the Venting Direct customer service people.
Customer reviews at Amazon was as follows: 60 total reviews, 30 gave 5 stars, 11 gave 4 stars, 4 gave 3 stars, 4 gave 2 stars and 11 gave 1 star. I assumed that 4 or 5 stars meant that people liked the fan, so 41 of 60 (68%) liked it. I also assumed that one or two stars meant they did not like the fan, so 15 out of 60 people (25%) did not like the fan, and there were 4 of 60 reviewers (6.7%) that gave it 3 stars, so I guess they didn’t really know one way or the other. Seems like there is always about 10% of the people that just don’t understand the question.
These negative reviews also concerned us before we bought our fan. So we dug a little deeper and read all of the bad reviews at Amazon. A third of the people that rated the fan low (1 or 2 stars) seem to be disappointed because the fan is not made the same as it was years ago. That may be the case, but there is not much we can do about that now. Perhaps a company could make a very heavy gauge metal fan with a motor that was strong enough to suck a cat from under the bed and be so quiet you wouldn’t even know it was running, but you can bet it would cost more than $150 and nobody would buy it.
Another third of the people rated the fan low because the motor “burned out” or quit working. That is not good. So that was 5 of 60 total reviewers (8.3%). Maybe it’s a loose wire, maybe the motor really burned out, I don’t know, but either way, that is inexcusable and not what I want to hear about a product that I am considering. There seemed to be some unhappy buyers that were not yet able to resolve their problem and from my experience with products at Amazon, that seems to be very usually. But since the customers at Venting Direct seemed to get their problems solved quickly and easily, we decided to buy our fan there.