This year at my house, we have been on a quest to make our attic more energy efficient. I think we realized just how much this unseen area contributes to our overall comfort —not to mention what we pay to heat and cool the house.

The first thing we did was install more insulation this winter. In addition to the tax credits we'll be able to claim, there were several incentives available from our state and utility that made it a great time for us to make this improvement. Following the installation, we noticed an immediate improvement in the overall comfort of our home and the furnace seemed to kick on a lot less often.

We also figured that the extra insulation would help us feel more comfortable in the summer, and it definitely has. We get a lot of direct sun at our house but the air conditioner doesn't usually turn on until around 3 or 4 pm. In addition to the extra insulation, there are probably several reasons for this:

  • We keep our thermostat set at 78°F in the summer—when we're home. It's set higher when we're away all day. This is the upper edge of comfortable for some people, but we keep ceiling fans on when we're in the room and it actually feels several degrees cooler.
  • We are diligent about opening windows at night. Luckily, the temperature here in Colorado cools considerably at night, and with the windows open, so does our house.
  • In the morning, we shut all windows and blinds to keep in the cool air.

The insulation and these daily steps have kept us pretty comfortable, but we still felt that our attic could use some improvements. We knew that it was getting extremely hot up there and that it was still contributing heat to the house, so we started looking at our options for ventilation. Our contractor initially recommended looking into both whole house fans and attic fans. Several friends and family members have attic fans and have reported great success with them, and after further checking out the house, our contractor also recommended going this route. The attic fan pushes hot air out of the attic and is appropriate for our house, since it is well-sealed and has adequate ventilation.

We just had the attic fan installed a few days ago so we're still assessing how well it works for us. So far, though, it does seem to be helping. One day in particular we noticed that the house managed to stay pretty cool in spite of having to keep the windows shut the previous night (due to torrential downpours). Normally, this would result in high indoor temperatures early in the day and the air conditioner running much more than usual, but it was still only 78°F inside late in the day (when it was over 90°F outside), and the AC had yet to turn on. The usually stifling garage also seems to be a bit cooler. We'll be pretty happy if the air conditioner rarely turns on and the house stays cool!

How are you keeping your home cool this summer? What steps have you taken to improve the efficiency of your attic? Check out DOE's Guide to Durable AtticsPDF for more ideas.

Allison Casey is a senior communicator at DOE's National Renewable Energy Laboratory, which assists EERE in providing technical content for many of its Web sites.