Our Great City

We just got our first electric bill since it's been winter cold, and it was a Doozy ! ! ! So that made me think about heating systems and insulation issues. Insulation is not usually a problem area on home inspections around here. We don't have a lot of older houses, and when I say older I mean over 50 years old. But even though most of our houses are well insulated, there are still a lot of ways for heat to escape in winter, and get in during the summer.

Heat travels by conduction, convection or radiation. Insulated walls, floors and ceilings are pretty good at preventing all three. On cold winter days houses lose most of their heat through the windows. Windows transfer heat by all three methods. This can work in your favor on the sunny side of the house, but on cloudy days or on the shady side it's best to have some good shades or curtains. Windows also conduct heat, which in winter causes their surfaces to be cooler than the inside air temperature. This in turn cools the air near the window, making it heavier and causing it to fall, convective cooling as the newly cooled air is continuously replaced with warmer room air. Windows are unique since they can transfer heat in all three ways.