I’ve written a few times about our decision to start replacing the windows on our house with double-pane energy-efficient ones. Now that we’ve had one (yes, only 1 of 16 windows has been replaced so far) for the duration of an entire summer and most of fall, I thought it would be appropriate to make some preliminary observations.

First, I noticed that the act of replacing that one window (which sits at the center of the south wall of our house) provided some relief to the load on the A/C through the summer months. We were able to turn off the A/C at sundown, and not turn it back on until around dawn the next morning, most of the time. Not having to run the A/C at night did wonders for our total electrical bill, and that isn’t a joke.

But, just as interesting is an observation that I’ve made since the start of October. We’re STILL running the A/C in the afternoons, and most of the time we have not turned on the heater at night. Even with overnight lows in the range of +40F degrees, it has not been necessary to turn on the heater to stay warm.

Anyhow, we have placed the order for window #2, and the guy who measured that window also measured the rest of the windows on the south side of the house. I think we’re going to be able to maintain the pace of 2-3 windows per year, but we’re absolutely going to replace them all.