When cold weather sets in, the owners of old houses usually feel the effects first. Owing to the seasoned construction, these houses lose a lot of heat through infiltration – the movement of air through cracks and joints, and some through conduction – transfer through materials. The best way to make your windows more energy efficient and comfortable this winter is by limiting the occurrence of these losses.
Weatherization seeks to improve the “enclosure” around your home. With regard to your windows, this includes sealing leaks and/or upgrading your windows. Many old homes constructed before the 1980 energy codes were enacted have thin, leaky windows with a single layer of wood between the controlled interior environment and the harsh outdoor climate.
By sealing any leaks or upgrading your windows, you improve the comfort level inside your home while reducing energy use. Weatherizing your windows offers several benefits, including:
- Warmer winters because heat is trapped inside
- Increased comfort because of reduced drafts and cold surfaces
- Increased energy efficiency and reduced bills
- Increased value of your home when looking to sell
Try to find out how cold drafts are getting into your home so you can fix it. Outside air usually seeps in around the glass panes in the sash, between the sashes, or around the window frame. Depending on the source of air intrusion, there are a number of ways to weatherize your windows, including:
If you notice air getting into your rooms around the outside of your window frames, you can easily stop this by applying high quality silicone caulk. First, you need to remove the old caulk and clean the area properly. Then, caulk all the joints between your window frame, as well as the surrounding structure.
For wide or deep gaps, you should fill as much of the space using foam rope to reduce the amount of caulk used. Also check for air intrusion at the point of contact between the wood molding and plaster wall and fill it with caulk.
- Replace the glazing
If you notice gaps around the glass panes of drafty windows, you should consider replacing the glazing compound used to fix the glass to your windows. The glazing tends to harden with time, which in turn causes it to break easily and form gaps around the window frame.
Old glazing can be easily removed using a putty knife and replaced with fresh glazing. Use a glazing tool to smooth the compound evenly to create a neat seal. You should note that packed glazing material has a fairly short shelf life, so it is not advisable to use the compound that remained from the previous year, or even save some for the next cold season.
Many homeowners report a lot of air intrusion from between and around the window sashes. There are several short-term solutions for this to get you through the cold season, including:
- Attaching weatherstripping to the frame
- Installing rope caulk between the lower and upper sashes, as well as around the frame
- Covering the whole window with plastic “shrink wraps” using a hair dryer to create an air seal
With these techniques, you will need to remove the material in spring for easy operation of your windows.
- Low expansion spray foam insulation
For homeowners with double-hung windows, a common source of drafts is the cavity holding the sash cords. Even when considering new replacement windows, it is important to add insulating material to the sash cord cavity to keep the cold air out.
- Use storm windows
Storm windows are largely used to protect the main window from harsh forms of precipitation, though they also reduce heat loss by creating a dead-air space in between the two windows. For them to provide effective insulation, they should be tightly installed around the window frame to prevent air movement.
However, you should leave a small weep hole to allow moisture vapour to escape. Loosely installed storm windows are ineffective insulators, plus they increase the risk of frost on the indoor window surface. Also, the sashes should be tight enough to keep frost from forming on the storm window.
Many modern homes take advantage of new technologies, such as double- or triple- glazing, proper selection of the window frame material (fibreglass or vinyl), use of argon-filled double-paned glass, and the use of special coatings to achieve better insulation during the cold weather.
Regardless of the weatherization techniques used, homeowners should also take advantage of their shades and curtains to control the level of comfort inside the home. During cooler weather, you should open your curtains during the day so the sunlight can warm the inside of your home, and close them at night to retain the heat.
You should also ensure that the drapes fit tightly at the bottom and sides when closed to prevent cold air from behind the curtains mixing with the warm inside air.