We did install one window unit in Miss F's room. At the end of May, it was over 90 degrees outside for four days. We had tried to use fans and leave Miss F in just a diaper, but she was drenched in sweat. In the end, it seemed better to have a happy, safe, well rested baby than to make some kind of ecological or frugal point.
*B* and I did a fair amount of research about energy efficiency and cooling our home. This site is fascinating as far as energy useage and cost goes. We always assumed that central air was more efficient than window units. We didn't know how wrong we were!
Using Fans to Cool
Fans (ceiling, box, etc) cost very little compared to running a window unit. Running a medium ceiling fan 24 hours a day - which we don't do - is 1/10th the cost of running a window unit. And that window unit is about 1/4 the cost of a central air conditioning unit. Now I know that we use more fans because we don't have a window units, and we have more window units because we don't have central air. But we would need four window units (which we don't have) to make up the cost of central air, or a whopping FORTY fans to make up that energy consumption.
We have seven fans (three ceiling, two largish size, and two small size) and one window unit that run at different times a day. All of these running 24 hours a day cost about $121 per month, compared to $286 for central air. We turn off all but one ceiling fan, a small fan, and a window unit at night, so that really is a lower number than $121. Even now, Miss F's window unit is on since she's napping, but it's on energy saver set for 73 degrees. Most of the time, that bad boy doesn't even kick on. On her level of the house, there's a ceiling fan and a small fan on because I forgot to turn them off this morning. On my level of the house, I have one small floor fan aimed at me, and one ceiling fan running.
We don't actually turn this one off during the day because it's hard to tell when you've actually turned it off or not. It takes forever to stop turning.
So here we are, in the end of June, with fans a-blazing. Part of our success, so far, is the relatively mild weather we've been having. In the last month, one day averaged in the 60s, ten days were in the 70s, fifteen in the 80s, and only four in the 90s. The other part comes from good research on air circulation.
Our front door and our back door are not quite in line with each other. We can open both doors and draw a little tiny bit of air. I wouldn't even call it a breeze. But the back door is directly across from our living room window. We put a box fan in that window, pointed outward, to draw air through the rooms. It's amazing how well it works!