When your window seals aren't a tight fit, they let cold air into your home and waste energy when your heating system has to work harder. That will cost you. So assess the seals on all of your windows, including bay windows, to see whether you have any problems to fix. A window clearly has a problem if you see condensation on the glass panes, a sure sign that you don't have a tight seal, but many seal issues are less obvious than that.
A simple way to test each of your windows is to move your hand around the outside borders and middle pane edges to feel for cold spots or breezes. Some experts recommend slowly moving a lit candle or incense stick around the rims of your windows, but be sure to keep curtains and sheers clear of any flame or ember as you do so. If your candle's flame flickers or your incense stick's smoke blows in a different direction, that's the site of a seal issue.
*What Causes Window Seal Failure?
Most often, age is what causes window seals to fail. Weather seals installed several years ago may have dried out and become inefficient, or they may have become damaged when you had your house siding cleaned with a pressure washer or your house painted. You may just have a buildup of dirt or leaves or a dead bug stuck in the window tracks, pushing the seal out of position.
*Cleaning Your Seals
Vacuum your window tracks and seals regularly to remove debris, dirt and dead insects. Next, spray your window tracks with an all-purpose cleaner, and let it sit for a few minutes as it works on dirt and grime. Then take a specialized window track cleaning brush (available on Amazon.com for less than $6) and scrub away all buildup. Wipe the tracks completely clean, and dry them with a paper towel before closing the window.
*Repairing Window Seals
Some seals do need to be replaced -- for example, old seals that absorb water, causing mold issues, and completely dried-out or flat stripping. As a weekend project, you can repair old or damaged seals on your windows. To do this, know which type of seal you're replacing or repairing. Do you have weatherstrips, or is it caulk? Full and complete removal of either is essential to creating a complete seal with new product.
Don Vandervort, founder of the home improvement website HomeTips, advises using a putty knife to remove any existing seal or caulk around the interior trim of the window and clean the surface. If you are removing caulk and choose to re-caulk your window edges, Vandervort says, "use a caulking gun to apply new silicone or silicone-impregnated latex caulk," which is readily available at home improvement stores.
If you prefer the look and process of weatherstripping over caulk, consider the two main types of weatherstripping used around windows:
--Self-stick tapes: Made of rubber, foam or vinyl, these strips are backed with adhesive covered with a peel-off backing. Simply cut the strips to length, peel the adhesive, place them and press them to secure them. This choice, according to Vandervort, is ideal for "metal or vinyl windows where nailing isn't an option, especially where the parts of doors or windows press together rather than slide against one another."
Vandervort says: "The highest-quality and longest-lasting of the self-stick tapes is ethylene-propylene-diene monomer rubber. EPDM rubber retains its elasticity and insulating qualities even after years of exposure to subzero temperatures. Another good choice is high-density foam, which is also durable and long-lasting. Closed-cell foam is waterproof, weather-resistant and inexpensive, but it does break down and will need to be replaced regularly. Open-cell foam can be compressed the most to seal even the narrowest of gaps, but it is only for indoor use, as it quickly degrades when exposed to the elements."
--Nail-on strips are ideal for wood windows, according to Vandervort, because they don't depend on adhesives, which can lose their sticking power over time or in heat. Where gaps are large, use a vinyl tubular gasket or rubber tubing with a metal-reinforced flange for nailing.
*When You Need Professional Help
Truly damaged or aged windows can be replaced with new, energy-efficient windows, which may qualify you for a tax credit. New and improved windows completely eliminate seal issues and, in some instances, also provide your furniture and wood floors with protection from ultraviolet rays. It's a big investment, but it saves you money in energy costs and improves your home's resale value.
If you don't wish to replace all your windows, look online to find a glazier, a professional who will replace just the glass portion of a window. Sometimes the issue is with cracks in the glass, perhaps along the pane levels.