Keeping Heat Out- Stay Cooler

Yesterday I talked a little bit about why staying cool in the summer is largely due to keeping heat out of the house more than it is about pumping cooler air into the house. If you really want to stay cool in the Atlanta summer, you have to keep your home well insulated year round.

I thought I’d take just a minute to go a step further with some heat gain 101. And to understand heat gain better, it helps to understand how heat functions and how your windows can slow heat from coming into the house.

Heat is active. And it warms the areas that it is effecting by two means; Radiation and Convection.

It’s gonna get a little bit like science class in here so hold on. But in this post we’re only going to talk about…


You don’t have to get our your yellow nuclear jump suit, Marty. Not all radiation is going to kill you. For our purposes we’re gonna stay focused on radiation in general terms. Without getting into all the very technical descriptions, the most basic definition I can give you is that it is how heat is transferred between two substances that are not in contact with one another.

With that in mind, the best way to fight off radiant heat is to reflect the heat back to its source. Once an uninsulated window is heated by radiant heat, it has a high emissivity factor. That’s why you’ll hear of windows that have “Low-E” or “low emissivity”. These windows with the “low-e” coating (a film that is actually coating the glass in a double paned glazed window) are reducing the heat transference by reflecting radiant heat back to where it came from.

So for starters, keeping your house cooler starts with windows with Low-e that will reflect heat back to its source and cut down on heat infiltration.