Choosing Windows for a Sun Space
LESLIE: Now we have Mitch from Texas who’s got a question about a window in a sunroom. What can we do for you?
MITCH: In regard to … we’re thinking about adding on a sunroom. Some windows are better than others as far as thermal efficiency and …
TOM: Absolutely. I mean in a climate like Texas, you want to be very, very careful what kind of glass you put in the sunroom. Because if you don’t have energy efficient glass, that’s going to become such a hot space you won’t be able to use it four or five months of the year.
LESLIE: Well, low-e glass seems like a good solution for this space.
TOM: Absolutely. What you want is Energy Star-rated glass. That’s going to have several components to it; most important of which is what Leslie just mentioned, low-e glass. And that stands for low emissivity. And basically, what happens with low emissivity glass is the ultra-violet rays of the sun are reflected back out. It’s as if the sun is hitting a mirror and that heat doesn’t penetrate the glass into the sunroom. The other thing, of course, you want is thermal pane glass. That is glass that’s made with two layers of glass with a gas in between. Generally, it’s krypton or argon gas. It’s a high insulating value to that kind of gas.
So, if you use low-e Energy Star-rated windows, then you’re still going to be OK. Even though, if you do, remember that you also need to consider how much HVAC you might want in that space. It’s possible that you may want to add additional air conditioning to cover that.