How to Stay Cool (on the cheap)

A couple of weeks ago things got pretty hot here in Vancouver Washington, with temperatures hitting the low 100s. I was really tempted to go out and buy an air conditioner, but it only gets really hot for maybe two weeks here and after that the proper use of fans does the job fine. So it was hard to justify spending the money on air conditioning only to end up using it for maybe two weeks out of the year. But when it’s 100+ degrees outside a fan isn’t much help. It was hot and I needed some relief, so I put to use some basic science – heat rises. Fortunately my house is on a raised foundation and even better the access to the underside of the house is in my closet. I pulled the access cover from the floor and immediately realized that my idea was golden – the temperature was easily 15-20 degrees cooler under the house than it was inside the house, which makes sense because –

• Heat rises so it makes sense that it would be cooler under the house than say above it
• There is no significant amount of sunlight that gets under the house so even on really hot days it’s nice and cool under the house

To test my theory I took a box fan and stuck it over the opening, turned it on and was greeted with air that felt like it was refrigerated – at least compared to the 100 degree air in the room. The other bonus was that there were no strange odors coming up from under the house. There were a few things I needed to still work out though –

• I needed something more beefy than a box fan
• I needed to direct the air out of the closet and into the room
• I needed to still be able to walk into my closet without falling into the hole

To solve the fan problem I went and got a Patton industrial fan which I knew would provide sufficient air flow. I then used some cardboard and duct tape to make a duct-work that forced the air to flow up from under the house and into the room. I used some boards to cover the hole and folded the carpet back so that only about 8” of the hole was exposed.

All said and done if I kept the blinds closed during the day and started the fan early enough in the morning the room stayed comfortably cool. Opening the window a crack helped to evacuate hot air if the fan had not been turned on early enough. As well as it worked though there are some caveats –

• You need a house that is on a raised foundation
• You need a hole in the floor of the room you want to cool
• It’s basically a one room system, unless you cut a hole in the floor of all your rooms, or you came up with some kind of whole house duct-work to circulate the air throughout the house
• It’s loud – this is mostly due to the fan I used, even on low Patton fans are loud
• It takes up closet space, at least in my case
• There are houses where you would not want smell the air from under the house, fortunately I didn’t run into this issue
• It’s ugly - I didn’t spend much time on aesthetics

I unfortunately didn’t take any temperature measurements when it was still hot but I can say that if the outside temp was 100+ degrees and I started the fan early enough (to keep hot air from getting trapped the room), and kept the blinds shut I’d guess that the room stayed around 70-75 degrees. Now that the temps have mellowed out as long as I keep the blinds shut I don’t need to start the fan in the morning and only run it if I feel hot.

Basically my only cost was $40.00 for the fan, the cardboard and tape I already had. An air conditioner sufficient for my room would be about $200.00+ $600.00 plus wiring a separate outlet for the unit (1000+ Watts @ 10 Amps - needs its own circuit.)

(click on thumbnail for full image)