Five Percent: Conserve Energy

Climate Change Is Important: Energy Conservation is the First Step

June 8, 2008

Staying Cool without Air Conditioners

It’s hot here in Boston — mid-90s Saturday through Tuesday. But we’re cool so far here in our house. 95 outside, low-70s insideHere are my thermometer readings from yesterday.

No energy was used to keep the house this cool. And today, it’s still cool and comfortable. And quiet. I am very comfortable.

We have no air conditioners.

Or should I say we have the most efficient air conditioners: our house is well insulated. Roll-up Exterior Window ShadesIn particular, we installed Cooleroo window shades on our little sun room. We covered 8 windows with four shades, at about $70 per shade. They will last for years, and they roll up, out of sight, when we don’t need them.

Over the years, gradually, we have made changes like this that make our house tight and comfortable, both winter and summer, including:

  • Insulating the exterior walls (and attic and basement)
  • Attic exhaust fan, peak vent last time we got a new roof
  • Whole-house fan
  • Ceiling fans for several rooms
  • Storm doors
  • Turn off lights and reduce appliance use
  • Use the bathroom and kitchen fans to exhaust heat/humidity
  • Replaced windows with double-pane

Insulating a house, especially one like ours that was built in the 1920’s would seem like a lot of work. We had the blown-in cellulose insulation installed the second year we lived here, after we realized the old boiler we had couldn’t keep the house warm. Blown-in insulation is far from perfect; they tend to miss spots, you pretty much have to get your house repainted (they remove siding from the exterior, then replace it), and it settles over time. Another option for retrofits is an expandable, spray-in foam, which seems like it would be more effective and have less impact on the house exterior.

Of all the things you can do to save energy in your house, insulating is almost always the most effective and has the quickest payback. Don’t forget to seal around windows with caulk to prevent drafts, too; this is a one hour job that can make a huge difference.

We actually do own several room air conditioners. Over the last few years, as we gradually introduced all the changes I noted above, and as we gradually became more aware of energy conservation, we found we needed the air conditioning less and less. I think we may have turned on the air conditioners once or twice last summer. Maybe we can go all summer without turning them on this year.

In 2005 I said I would be a hypocrite to suggest not using A/C. But I have to say, it seems very doable. And even if I do go ahead and turn them on, it the need for cooling will be a lot less; it’s not all or nothing.


  1. In the spirit of full disclosure, I have an update. We just suffered through a 4-day heat wave, with temperatures reaching 95 to 100 degrees each day. It was humid and terrible, and mercifully, it’s over now.

    The first day, our well-insulated house did great. By the second day, the house was in the mid-80s, and it was a little cooler than that outside. So we turned on the whole-house fan. By the third day, we both really wanted to put in an air-conditioner, since we hadn’t gotten much sleep in the last few days. We didn’t, but we will if it gets that hot again.

    So, I just wanted to point out that considering using an air conditioner does not count as having impure thoughts.

    The point of Five Percent is that we can make a huge difference reducing our consumption in a lot of little ways that add up. We don’t necessarily need to go “off the grid” or “cold turkey”, we just need to learn and make sensible choices in how we use resources.


    Comment by Tom Harrison — June 12, 2008 @ 10:34 am

  2. […] shades on our windows for years, and lately have been using them. Several years ago, we installed Cooleroo Shades over the exterior of some of the south facing windows — while not perfect, they do their job […]

    Pingback by Cool and Comfortable with No AC | Five Percent: Conserve a Little Energy — July 31, 2009 @ 2:54 pm

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