How to Cool Your Home Naturally – Part Two

How to Cool Your Home Naturally – Part One covered some of the larger scale things you can do to keep your home cool. You’re probably not going to make large-scale changes to your home and you might not want to invest in awnings and there’s only so much you can do with your appliances. What you really want to know is how to simply use your windows to make your home cooler. This is where window magic comes in. (And this is my favorite part!)

My version of home cooling involves using fans. You have to decide where that fits into your desire to cool your home naturally. Fans also use electricity, of course. Looking at this site, it says an A/C might be 3500 watts and a box fan on high 100 watts. Think about it, do your own math, and draw your own conclusions. You also might be looking at non-A/C options just because you don’t have an A/C, while box fans are readily available and pretty cheap. Either way, read on for tips on using your windows and fans to make your home cooler.


  • Your windows need to be able to open and close and they all need to have screens. If you’re in an older home, this might mean you have to get some tools out to scrape open windows that have been painted closed. If you’re renting a house, some states and cities require the landlord to provide screens for all windows, so that’s something you can look into.
  • My instructions use box fans. These are the large, square fans that sit nicely in most windows and cost about $10 at Wal-Mart. How many you need depends on your house layout and your preferences. If you don’t know, start with two until you know you want more.
  • I use an indoor/outdoor thermometer. This isn’t necessary, of course, but through that link you can find them as low as $10 on Amazon. This helps me find the exact right time to switch the windows.
  • One extra option is ceiling fans. Ceiling fans help move air around in your house, which is good for just a window/fan system. Also, when you’re being blown on by a fan, your temperature perception is up to 3 degrees cooler due to evaporation from your skin. This means sticking a ceiling fan (or another kind) in a room can give you 3 bonus degrees without doing anything extra.
  • You should keep your interior doors open. You want to get as much circulation in your home as possible.

What to Do With the Windows

The easiest thing you can do is this: when it’s hotter outside than inside, close all your windows. When it’s cooler outside than inside, open all your windows. Right now at the Wallow, the morning cross-over comes between 8:00am-9:00am. The evening cross-over comes between 7:00pm-8:00pm. This is where the indoor/outdoor thermometer comes in, because this is going to vary everywhere and throughout the season. Using a thermometer enables you to maximize your cooling time very precisely. If you leave your house in the morning before the cross-over time, you need to close the windows anyway.

If you’re home at the right times, and don’t mind watching the thermometer, here’s another thing that I do. Instead of waiting until it’s hotter outside than in, I keep an eye on the thermometer to find the time when the temperature inside the house starts to rise. Even if it’s still cooler outside, I close all the windows. This means I’m sealing up the house at its lowest temperature.

If you’re not going to be awake at the morning cross-over time or might otherwise not be there to make the switch, before you go to sleep or leave the house, at the very least, close up and cover the windows on the east side of the house. The moment the sun hits the east side in the morning, you’ll start to gain heat there, so these are the most important windows to have taken care of before the morning.

What to Do With the Fans

First, remember that fans only go in the window when the outside air is cooler than the inside. Otherwise, the whole house is closed up tight!

For a two story house, you want to increase the air coming in the first floor and increase the air going out the second floor. Hot air rises and you want to help it along getting out of your house. You might try putting a fan blowing in on the first floor and a fan blowing out on the second floor. Or two fans blowing out on the second floor. Experiment with your fans to find what works the best with your layout. If you have rooms that don’t get good airflow, such as a room kind of stuck back in a corner, or if you have rooms with excess heat, such as a computer room, you might add an in or out fan in that room, too, to help it’s circulation.

Our house at The Wallow has a skylight in a loft. I actually rigged up a box fan to blow out the skylight. Then we have two box fans pointing in on the second floor, one in a computer room and one near the loft with the skylight. We’ve found that due to our south facing covered porch, the downstairs stays cool enough without fans blowing in on the first floor. The right configuration will be different for you. You’ll have to experiment.

For a one story house, put one fan blowing in on one side of the house and a fan blowing out on the opposite side of the house. If there’s a breeze in your area, it might work best to only open the windows on the two sides that are the direction the wind is blowing. Then aid these windows with fans, coming in with the wind and out on the opposite side. A windsock is a very easy thing to create and put in your yard to help you determine the direction of the breeze.

What About You?

So far, using all these tips has worked wonders at The Wallow. We’ve got a lot of things going in our favor, though: the south porch, the skylight, the fact that we’re not surrounded by city, and the relatively mild outdoor temperatures overall.

Have you tried cooling your house without A/C? What things have you found that helped? How did it work out? I’d love to hear about it in the comments.