I live in a mediterranean climate in Southwestern Oregon where average high temperatures during the peak of summer are 90 degrees, and average lows are 58. Our house is on a southwestern facing slope, and it has limited shade. Thus, it’s fully exposed to the sun, and the air conditioning system needs to work overtime during late spring, summer, and early fall to keep the house at a comfortable temperature.
At night, I have turned off the central air, opened the windows, and hoped that the cool air from outside would transfer to the inside. However, as I’ve experienced in other houses, only a few degrees of cooling occurs using this method–and I’ve had many nights with restless sleep because of a warm bedroom. This is because simply leaving the windows open does not actively cool the thermal mass of the house nor distribute cool air throughout the house. Therefore, once the sun rises, it doesn’t take long before the central air needs to be turned on again. Using the central air overnight is certainly an option to keep the house cool overnight, but the energy used to do this is significant.
I’m not the “greenest” person on the block, but I do like to be aware of and explore environmentally friendly options for most of our purchases. So I set out to learn more about ways to keep our house cool in an energy-efficient manner. First, I investigated purchasing solar panels that would power our central air, ideal because of our ample exposure to the sun. I spoke to a local resident that has solar panels, and they had very favorable reviews. However, when I did the math, it was going to be too costly of an initial investment unless we planned to live in our house for 30 years, which we don’t. Additionally, some of the tax credits associated with solar panels have gone the way of the dinosaur. The idea still intrigues me, and I hope to be able to invest in solar panels in the future. It just makes sense. The second option I explored was a whole house fan. Our neighbors told us about their whole house fan which cools their house rapidly in the evenings once temperatures drop into the 70s. They did mention that the fan, although only on for 5 or 10 minutes to cool the house off, was very loud.
So, to make a long story short, I weighed the options and decided to get a quiet, energy-efficient whole house fan installed. I had an Airscape 2.5e whole house fan installed in my 2000 square foot house. I talked to a few people who had these specific energy-efficient fans installed to get a decent idea that they would do the job. The concept behind these newer fans is that the user leaves them on all night, allowing the structure of the house, or thermal mass, to cool off sufficiently to maintain cool temperatures during the next day. I’ve added a post of pros and cons to the fan now that I’ve used it for a couple months. Overall, the investment was not exorbitant, I’m very pleased with the fan’s performance, and I know it’s using significantly less energy than if I just used our central air. This results in cost savings, and since energy prices will likely not be going down anytime soon, the money I save should increase year to year.
In addition to the whole house fan, I had a solar attic fan installed, which works primarily during the day to cool off the attic space, thus keeping the hottest air away from the adjacent living spaces. It uses no electricity, was recommended highly by a neighbor, and it has performed well to our knowledge.