Skip to Main Content Skip to Footer Content

Glass Doctor Blog

DIY Project: Test to See If You Need New Windows

A window

Now that mild fall temperatures have given way to bitter winter weather, you might be on the lookout for ways to keep your heating bills down. Your windows are some of the most effective places to check because air leaks could be wasting a significant amount of heating dollars. Plus, winter is the perfect time to look for signs you need new windows because the temperature difference between indoor and outdoor air is so striking.

Here are a few DIY tests you can do to see if you need new windows.

The Flashlight Test

The purpose of this test is to pinpoint leaks around your windows that are large enough for light to shine through. Wait until the sun sets. Then, go outside while a second person shines a flashlight around the edges of the window from inside the house. If you can see pinpricks of light shining through the frame, you have a problem. After all, if light can pass through, so can air.

Fortunately, a flashlight test reveals merely that you have a leaky window. As long as the panes are in acceptable condition, all you need to do is seal the leaks with caulk. This simple improvement can make a big difference to your energy bills in all seasons.

The Smoke Test

While some problems are big enough to spot with the naked eye, other leaks are so small that you need to conduct a smoke test to see them. To do this, close all the windows and doors in your house and turn off the furnace. Next, turn on all kitchen and bathroom exhaust fans to negatively pressurize your house, which forces air to be drawn in through any gaps in your home's external envelope.

Now, check for leaks by lighting an incense stick and holding it close to exterior doors and windows. Watch how the smoke swirls around in these areas to help you spot leaks and drafts. If you have already sealed visible holes with caulk, but the smoke test reveals more problems with your windows and doors, this could be a sign you need new windows.

The Infrared Camera Test

With a little help from technology, you can see how the ambient air temperature differs throughout your home. Wait until a particularly cold day. Then, break out the infrared camera, go outside, and aim it at your house. As you do this, keep in mind that hot areas register as white, red, orange, and yellow while cold spots appear green, teal, blue, and black.

Ideally, the windows panes should appear yellow to green on the infrared camera to indicate minimal heat loss. Glass is a poor insulator, but double-pane windows have a pocket of air between the panes to improve insulation.

If your windows appear orange, red, or even bright white on the infrared camera, you are losing large amounts of heat through inefficient, most likely single-pane windows. This is a clear sign you need new windows with modern features to make your home more energy efficient.

Upgrade to Double-Pane Windows

Far too many homes today still have outdated single-pane windows. Others are so leaky around the edges that they waste energy as badly as single-pane windows. If you don't already have them, this winter could be the time to upgrade to double-pane windows. If the frames are still in good condition, Glass Doctor® can replace just the glass to save you money on this important home upgrade.

Contact Glass Doctor today to speak with one of our team members and discover how double-pane windows can contribute to your home's energy efficiency.

Let Us Call You

Service Type*

By checking this box, I agree to opt in to receive automated SMS and/or MMS messages from Glass Doctor, a Neighborly company, and its franchisees to the provided mobile number(s). Message & data rates may apply. Message frequency varies. View Terms and Privacy Policy. Reply STOP to opt out of future messages. Reply HELP for help.

QA Common - By entering your email address, you agree to receive emails about services, updates or promotions, and you agree to the Terms and Privacy Policy. You may unsubscribe at any time.

About Glass Doctor

Established in 1994, Glass Doctor® is a global franchise organization providing electrical installation and repair services. Recognized by Entrepreneur magazine among its “Franchise 500,” Glass Doctor franchisees provide these services to both residential and commercial customers at almost 200 locations worldwide. Glass Doctor is a subsidiary of the Neighborly® family of service franchises.
Learn More

Find a Glass Doctor Near Me

Let us know how we can help you today.

Choose a Glass Type:*

*Indicates a required field

Call us at (833) 974-0209
Glass Doctor van with a location pin in the background.