The importance of windows on the energy efficiency of a home is often underrated. According to the U.S Department of Energy, windows can account for 25% or more of the energy use needed to heat or cool a home.
The NFRC conducts voluntary window energy efficiency testing, included on all Energy Star certified windows. The performance ratings it generates reveal a particular windows' air leakage, the amount of solar radiation it admits, and how well it conducts non-solar heat, among other things. Depending on the local climate, different ratings and values are more or less important, so the ratings aren’t one-size-fits-all.
Heritage Construction Co. – an established Texas based construction company with an expertise in roofing and insulation – states various other factors can influence a window’s overall effectiveness, including the state of its caulking, how well insulated it is, and what added features or accessories it has. They took the time to discuss all of these causes and share their expertise on energy efficiency.
How Often Windows Should be Inspected
Heritage Construction Co. recommends inspecting and testing the efficiency of windows at least once every year. Alternatively, if homeowners notice a sudden spike in their air conditioning costs without a change in weather, they should consider looking for the potential source immediately, with poorly insulated windows being a likely culprit.
Testing Windows for Air Leaks
According to Heritage Construction Co., using thermal imaging cameras is a great way to check the heat/cold loss patterns of windows. Not only will these cameras show how severe the overall problem may be, they can also pinpoint exactly where air leaks are located.
An inexpensive option for those without thermal cameras is to conduct a smoke test. Close all windows and doors in the home and turn on any exhaust vents in the kitchen and bathrooms. This will create a negative air pressure environment inside the house, causing more outside air to be drawn in through any available openings. Now take a lit incense stick and slowly move it around the window, checking for any disturbances in the smoke that would indicate a draft.
Caulking and Insulating Windows
In the case of new homes, windows should be re-caulked after one year due to the natural settling process that occurs which can cause the caulk to separate from the wall joints. Otherwise, Heritage Construction Co. states window caulking should be completely replaced every five years, with touch-ups being done as needed.
During the winter when windows are unlikely to receive much if any use, weather stripping can be applied around the window’s movable parts to further insulate it. Larger gaps around the frame can be plugged with spray foam, while draft stoppers can be used to fill any gaps between the window frame and the bottom of the sash.
Other Energy Efficient Window Upgrades
Interior window treatments can also prove highly effective at insulating windows and blocking light, including side-hung drapes and pleated blinds. For homeowners who don’t want their windows blocked all the time, window films are a great alternative that limit UV exposure and solar heat gain while still enabling them to see out the window.
Exterior blinds or awnings are an added alternative that can limit or completely block light, heat and/or radiation from reaching windows in the first place. Exterior storm windows can also greatly reduce air leakage and heat transmission.
About Heritage Construction Co.
Heritage Construction Co. is a construction management contractor service that operates in several neighborhoods throughout the state of Texas. Founded in late 2009 by Jake Brydon and his two brothers, Heritage Construction Co. has evolved into an industry leading, trusted, household name in the storm restoration industry. Heritage Construction Co. develops creative solutions and pride themselves on outstanding customer service, transparency with clients, and their ability to ethically complete any job.