Copyright © 2020 Albuquerque Journal
We recently purchased a little cabin up north. Last fall, as I walked past two windows, I felt a cold breeze blowing through them. They were about 30 years old and had once been functional double-pane windows. I used one and a half rolls of paper towels to temporarily fill the gaps. They had to be replaced this summer and it was time to do some research. This is what I found out.
Most of us are familiar with the term “R-value.” Jeremy Cook is an engineer who writes for Home Depot. He defines R-value as “a measurement, a rating, which corresponds to heat transfer through conduction. The higher the rating, the better the material resists heat transfer,” he says. In New Mexico, wall insulation should have an R-value of 19-21. But what about windows?
Windows are the weakest link in the energy efficiency of a building. They leak heat in winter and add heat in summer. The standard today is a Low E double-glazed window with argon gas between the panes. But even the best of them won’t give you much more than an R-3 value.