For June, here’s another tip to help you keep cool without cranking on the AC so much in the summer time. And just in case you think we’re well into summertime we got until June 21st before it’s official. 

This tip isn’t some task you can start performing on a daily basis. It’s more of a idea that would really help as you decide how and what to invest in in terms of your home. 

Think, insulation. 

• Siding is insulated. Is your home properly insulated with the best material for keeping heat out?
• Attics, crawl spaces, floors. Do they have the best siding available in them? Most homes will use the “pink stuff” rolled out in these areas but is it the best? With advents in insulation such as spray on foam you could be getting better energy values from newer products. 
• Insulated windows. Are your windows equipped with thermal glass that slows down heat infiltration as much as possible? Low-e, double glazed windows, with a good spacer system, foam filling, and even the use of vinyl over wood can cut down on how much heat is coming into your home everyday. 

I was in a customer’s home today looking at their front door they need replaced. As is necessary, the customer and I were walking in and out of the door looking all that needs to be replaced. It was of course a hot June day and keeping the front door open as we looked around caused the customer’s wife to finally chime in with “Shut the door. You’re letting all the heat in!”

Just as those words came out of her mouth I thought, “She gets it!”.

You see, I grew up in Atlanta hearing “Don’t let the cool air out! Shut the door!” or “I’m not paying to air condition the whole neighborhood!”. But rarely do people seem to realize that even though an open door or window will let cool air escape, heat is coming into your home at a much quicker rate than it would if the door or window was closed. 

That’s why thermal windows and doors work to not only keep you warmer in the winter but cool in the summer. Properly insulated windows allow heat to come into your home at a much slower rate. Think about what your single paned or aluminum windows are doing to keep heat out? Nothing!

So if you’re looking to cut down on the AC costs this summer, think about whether or not your windows are helping or hurting your insulation. Keeping the heat out can really help you win that battle. 

If I walked into your home and offered you $1 million house tokens to buy it from you, the first thing you’d ask is, “how much is $1 million house tokens worth in dollars?” It’s the same with a U-Value. If I tell you my window has a U-Value of .25 that number means nothing to you until you understand what a U-Value is. 

What’s the Value of “U”?

For starters, a U-Value measures how well a window insulates heat. That is, how efficiently does it keep heat out of the home in the summer and  keep heat in the house in the winter to put it more simply. The reason a lower U-Value is better than a high one is because lower numbers mean that a particular window is allowing heat to transfer at a lower rate.

Heat is always active and will escape or enter your home regardless of how well your windows are insulated. But technology in replacement windows and efforts by manufacturers to lower the rate of heat transfer have given windows great insulation value. 

Putting  It into Perspective

You may have heard of “R-Values” before. The higher this number the better. R-Values apply to things such as fiberglass insulation (or new spray in foams and other methods of insulating a home), walls, and doors. 

For example:

Your insulated walls may have an R-Value somewhere around R 10-18.

And Your floors may be insulated well enough to achieve a R 20-25. 

Your attic space may have an R-Value up to R 39-49.

So with higher being better you can get an idea of what the actual value of these numbers are in terms of “R-Value”. 

Now back to U-Values. To understand their value think of the U-Value as the opposite of the R. Since R-Values measure how well solid materials insulate heat you can’t apply them to glass. Glass in windows is designed to see through and open and no matter how well it is insulated it will let heat out at some point. So in order to understand how well a window is insulated we have to understand how well it is slowing heat down NOT keeping it in like we would want to know with an R-Value. That’s why a U-Value is the inverse, or opposite, of a R-Values. 

So, to keep the math easy…

a window with a .25 U-Value has an insulation value equivalent to a R Value of 4. 

a window with a .10 U-Value has an insulation value equivalent to a R Value of 10. 

Now it’s not safe to assume that R Values and U Values are quite as interchangeable as I’ve just demonstrated but the purpose is to give you an idea of the value of each “U” number you get as you look at thermal double paned windows.

To sum up, lower U Value means a lower rate of heat transference. The lower the U Value the better the insulation of the window. We use U Values rather than R Values when considering windows because they’re really more accurate for judging how well a window is insulated. 

Also, keep in mind, when looking at a U Value make sure you know whether or not this number is for the whole window or just the center of glass. Center of glass numbers are always going to be better than the overall U of a window and to really get an accurate comparison you want the overall U Value. 

Check NFRC.org to look up insulation ratings on windows that are thermally certified or give us a call at Atlanta Area Window and Door Co. to find out about which thermal windows we offer.