As temperatures start dropping, the first thing you will notice is a cold breeze blowing through your windows. A draft through the window panes, a chill in the corner where your couch sits, and the rising cost on your heating bills are all clear signs of heat loss through your windows. The best thing about it is that you won’t have to replace your old windows to get the job done.
This article provides you with the most efficient methods for insulating your windows throughout the winter months.
Why Do Windows Leak Out So Much Heat?
Even high-quality windows are thinner and more susceptible to heat loss than walls. The three major mechanisms through which heat is lost via windows include heat transfer via conduction through the glass and its frame, air leaks through the cracks, and the radiant heat loss from your room to the cold environment outside. Single-pane windows with poor seals, along with poorly insulated windows, are the major culprits.
However, according to the U.S. Department of Energy, windows may be responsible for about 25 to 30 percent of heat energy lost by your home.
Step 1: Discovering Where the Air Leakage Is Coming From
Before investing in new equipment, determine how the air is leaking in. Here are a few quick and simple tests that will give you answers:
- The hand test. On a windy day, run your hand around the window frame and sash at a slow pace. Moving air means you found a gap.
- The candle/incense test. Light an incense stick and place it around the window edges. Smoke movement indicates air leakage. Do not place it near any curtains.
- The paper test. Put a strip of paper in the closed window. If it is easy to pull it out, there is a weak seal.
- Visual inspection. Check cracks in caulk, worn-out weather stripping, cracks or gaps where the frame meets the wall and any loose glazing compound.
Write down all the trouble areas. They will come in handy later.
Step 2: Plug Gaps Using Caulk
It is the least expensive solution and can be very effective for sealing stationary gaps between the window frame and the walls or trim.
- Remove the existing caulk using a utility knife or scraper.
- Wash the surface with a wet cloth and allow it to completely dry.
- Use the caulk gun to apply a bead of paintable, exterior-grade silicone or acrylic latex caulk.
- Smoothen it with a wet finger or caulking tool.
In case the gap is wide, insert a backer rod first and then caulk it. Do this on days that the temperature is above the minimum application temperature of the caulk, which is about 40 degrees F.
Step 3: Installing Weatherstripping
While caulking seals the joints that do not move, weatherstripping seals the parts of the window that can move. Here are some examples of what you can use:
- Adhesive foam tape is very affordable and easy to use, although it will last for just a few seasons.
- V-Strip, which is also called a tension seal, is made of plastic or metal and is used on sliding and double-hung windows.
- Rubber or silicone bulb seals are more long-lasting and great for tight windows.
Measure all sides of your window precisely, clean the area, and install the weatherstripping firmly. Make sure that the window closes and locks after installing it. A proper seal will compress under pressure of being closed but won’t make the window difficult to close.
Step 4: Installing Window Insulating Film
There are many options for winterizing, but installing window insulation film is one of the most commonly used methods. The film is a clear plastic material which is applied to the window frame using double-sided tape. Then, the plastic is heated with a hair dryer to make a sealed layer of air between the plastic and the glass of the window.
This air provides additional insulation and helps reduce drafts and heat loss through the window. In order to do the job properly, you need to:
- Clean the window frame to ensure proper application of the tape.
- Apply the tape to the window frame, leaving the tape backing intact.
- Cut the film a little bigger than your window size and apply it to the tape while stretching it slightly.
- Warm the plastic film with a hair dryer set at medium temperature.
It becomes almost invisible when mounted properly, costs just a few dollars per window, and can be taken down during spring. It makes an ideal option for renters as it will not ruin the window frame.
Step 5: Install Thermal Curtains and Honeycomb Shades
Thick and insulating window coverings will serve as an additional barrier between your room and chilly glass. Thick-lined thermal curtains can help prevent the escape of a lot of heat, especially if they are hung close to the window and hang below and beyond its edges. Ideally, they should be installed near the wall on a curtain rod and hang up to the floor or the windowsill.
Honeycomb shades are more efficient because they have air pockets providing insulation. In addition, their sides fit snugly into the window frame. They should be opened on sunny days to benefit from free solar energy and closed after the sun sets to keep the warmth inside.
An easy regimen can be very effective: opening window coverings on south-facing windows during the day and closing all of them after sunset.
Step 6: Add Some Fast and Cheap Extras
If you’re looking for an instant improvement or just want to pinch some pennies, there are some little extras that can make a big difference:
- Draft stops. Simply roll up a towel or a draft snake under the bottom of a window or door, blocking out cold air that gets through the sill.
- Bubble wrap. Simply spray water on the glass surface and stick some clear bubble wrap on top; it will adhere to the window surface. While it’s not very attractive, it provides surprisingly good insulation.
- Rope caulk. Rope caulk fills spaces in and around the window sash and comes off easily in the spring.
- Reflective film. Applying low-e glass film to the glass surface helps reflect heat back inside the building while letting the light in.
Long-Term Improvements
In case your windows are extremely old or you will live in your place for some time, it is wise to think about some long-term improvements.
The addition of another window to the existing one from the outside or from the inside is called a storm window. Such a measure reduces heat loss up to 25 to 50 percent. It is much cheaper than the installation of new windows. Magnetic or compression storm windows can be taken out easily.
The most effective choice would be to replace your windows with the ones that have double or triple glazing, low-E coating, and insulated frames. The product should have the ENERGY STAR label and low U-factor. It is expensive at first but the benefits will pay off later.
Things to Watch Out For
Here are some mistakes you may make:
- Not cleaning the surface. Any dust or moisture prevents the adhesion of tape and caulk.
- Sealing everything. Gas appliances and fireplaces need some air in order to function properly. Seal all the windows, not the vents.
- Missing the condensation. Moisture between the film and glass means that there is too much humidity in the room.
- Don’t forget the bedrooms and basements. Smaller, rarely used windows usually have the biggest leaks.
Closing Words
Window insulation need not be a big project. Begin with pinpointing where the leaks occur, then plug them up using caulk and weatherstripping. Install insulating film or thick curtains on top to ensure added insulation. If you would like to go the extra mile, install storm windows or new windows altogether.
Plan a weekend to complete the task before the winter arrives. By winter, you will be very happy with your decision to do so.