Where your heat goes
Windows are the weakest part of most walls. Even a good double-pane window insulates far less than the wall around it, and older single-pane and early double-pane windows, common across Atlantic Canada's older housing, are worse. On a cold, windy night, a window radiates heat out, chills the air beside it, and that cold air drops to the floor and spreads across the room. That is the "draft" people feel even when the window is shut tight.
In a region where many households spend more on home energy than the Canadian average, that loss adds up every winter.
What actually works
1. Cellular shades (the clear winner)
Honeycomb pockets trap still air against the glass. The US Department of Energy found cellular shades can cut heating energy use by up to 20% compared with uncovered windows. Double-cell and blackout cellular insulate the most. Cellular shades.
2. Side channels
Seal the edges so cold air cannot loop around the shade. On drafty older windows this is often the difference between "a bit better" and "I can sit by the window now."
3. Lined Roman shades
A thermal lining adds a real layer, with a soft, tailored look. Good for heritage homes where cellular would look out of place. Roman shades.
4. Motorized schedules
The best insulating shade does nothing if it is open at midnight. Shades that close at sunset and open on sunny winter mornings (for free solar heat) do the work for you. Motorized blinds.
What does not insulate much
Slatted blinds (wood, faux wood, aluminum), solar shades, sheer and zebra shades. Great products, but not for keeping heat in.
Blinds and heat pumps
Heat pumps are now everywhere in Nova Scotia, PEI, New Brunswick and Newfoundland, and they work best in rooms that hold their heat. On the coldest nights, when a heat pump is working hardest, cutting heat loss through the windows helps it keep up. Cellular shades are the natural next step after a heat pump install. Read: blinds and heat pumps.
Summer, too
The same shades that hold heat in during January keep heat out during a humid August afternoon. Close south- and west-facing shades during the hottest part of the day and the room stays noticeably cooler, which means less work for the heat pump in cooling mode.
Frequently asked questions
What are the most energy-efficient blinds?
Cellular (honeycomb) shades are the most energy-efficient everyday window covering. Their air-filled pockets slow heat loss, and the US Department of Energy found they can reduce heating energy by up to 20% compared with bare windows. Double-cell, blackout and side-channel versions perform best.
Do blinds really keep heat in?
Yes, insulating window coverings reduce heat loss through windows, especially at night. How much depends on the product and fit. Cellular shades with side channels make the biggest difference; slatted blinds make very little.
What are the best blinds for drafty windows?
Double-cell cellular shades with side channels, or an outside mount that overlaps the window frame. These trap air against the glass and stop cold air from falling into the room around the edges.
Are energy-efficient blinds worth it with new windows?
Yes, though the gain is smaller than with older windows. Even good modern windows lose much more heat than an insulated wall, and cellular shades still improve comfort near the glass and reduce heat loss at night.
Are there rebates for energy-efficient blinds in Atlantic Canada?
Window coverings are generally not included in provincial efficiency rebate programs, which focus on heat pumps, insulation and windows. Check the current Efficiency Nova Scotia, NB Power, efficiencyPEI and takeCHARGE NL programs, since offers change.
Read next: Are cellular shades worth it? · Blinds and heat pumps