One of the energy saving measures that I grew up with was the use of a whole house exhaust fan on cooler summer nights. When I bought an old Victorian house, and didn’t yet own window air conditioners, this seemed an obvious expedient. Or a “Duh,” in the parlance of world weary (i.e: inexperienced) youths.
After a decade and a half, my first big fan wore out; a bearing seized. The big box hardware stores no longer seemed to carry such units, so I replaced it on the cheap, online. Much to my chagrin, it turns out that a) You get what you pay for, and b) There are no published ratings on consumer grade fans for how much air they move, nor how efficiently.
I did some research, and ordered a more expensive commercial grade, window-mounted, whole-house exhaust fan. So today’s Object At Hand is a 20″ Air King Model 3C614/9166. It arrived in a few days. I suspect that our UPS guy is afraid of our doorbell, and is also too shy to knock. I am usually home, yet packages regularly materialize on the porch without any annunciation from their deliverer. So far, we have discovered them before local opportunists made off with them.
But this is not the point. I bought this fan in April 2012, the start of a record hot summer. The nights last summer were never cool enough to use the fan (rarely dropping below 80 before dawn). So the fan sat in the attic in its box until this spring. That is when I found out that the western breezeway window that I’d used before was only 20″ wide; too small for this 20″ fan. My mistake was not realizing that, although a 20″ consumer fan is a fan in a 20″ box, a 20″ commercial fan means a 20″ diameter blade, plus housing.
My previous one must have been the 16″ model. Now with this post as documentation, my next one will be, too. So I had to use the larger southern window.
I ran an extension cord from one of the ceramic light fixtures reachable only by ladder, so that we can turn on the fan by by pressing the light switch at the foot of the stairs. I did have to reinforce the 115 year old, marginally maintained, double hung window frame to accept this heavy and almost too large fan. Luckily, the sash cords on this window had already been replaced by chains, so the window opens and closes fairly well.
You can see in this picture that the upper sash does not clear the fan area. What you cannot see is that I had cut away part of the metal fan frame in order to fit it lower down on the sill, rather than up in the raised sash guide area. But this monster does pull quite a bit of air from the far corners of the house.