January and February are typically the coldest months we see in the San Jose area. Evening temperatures can sometimes get down below freezing. Relatively speaking, the San Jose area has pretty mild weather year-round—especially when you compare it to other parts of the country that see sub-zero temperatures in the winter—but the inside of your home can still get pretty cold at night in the winter.
Usually when we talk about the energy efficiency of replacement windows and doors, we are talking about keeping your home cooler in the summer, but good windows and doors can also keep the inside of your home warmer in the winter.
If you have older single pane windows, you’ve probably noticed that the interior side of the glass is very cold to the touch when it’s cold outside. This might not have surprised you too much. Glass is not a very good thermal insulator. Just like when you pour a cold liquid into a drinking glass and the glass itself gets cold, an old single pane window will get cold on a cold day. Not helping matters any is the fact that many older windows use aluminum frames around the glass. Aluminum, being a metal, is also a good conductor that does very little to keep cold or heat from coming inside your home.
The good news is, with every year that passes, new technology comes out that helps make new windows more and more energy efficient. For example, most of the replacement windows sold today use vinyl frames. Vinyl is a poor conductor of heat transfer, which is a good thing. It does a good job at keeping heat and cold from coming into your home.
Replacement windows have also seen improvements to the glass when it comes to energy efficiency. The windows we sell at Custom Exchange use insulated glass, which has a special transparent coating on them that reflects infrared light, keeping your home warmer in the winter and cooler in the summer. The coating also protects your furnishings from fading, since it keeps out UV rays.
In between the two panes of glass in dual pane windows is a special type of gas (either Argon nor Krypton) that further minimizes temperature transfer and makes the window units more energy efficient.
Depending on the specific technology involved, some replacement windows sold in San Jose are more energy efficient than others. So, how do you know if you are purchasing the most energy-efficient replacement windows for your San Jose home? Look at the U-Factor.
The U-Factor rating is a standardized rating within the replacement window industry. Every replacement window manufacturer should publish their windows’ U-Factor ratings on their websites and/or their product brochures. U-Factor measures how good a window is at keeping a home insulated from outside temperatures. This number is determined by an independent nonprofit testing agency called the National Fenestration Rating Council (NFRC).
With U-Factor ratings, the lower the number, the better a window is at insulating your home. U-Factor numbers for most replacement windows range from 0.20 to 1.25. In San Jose, you don’t need the lowest U-Factor number possible, since it doesn’t get extremely cold here. A replacement window with a U-Factor rating around 0.30 is perfectly adequate in San Jose.
You don’t have to spend another winter with a cold, drafty house. Contact us at Custom Exchange to learn more about energy-efficient windows and doors, or to have us come out to your house and give you an estimate on new replacement windows and doors.