Why Place Baseboard Heaters Near Windows?

HOME CLINIC: Why are electric baseboard heaters always placed underneath windows? Don't they use more energy that way? F.P., Seattle

DEAR F.P.: Windows are the coldest surfaces in homes. Placing the heat source under the window helps even out the hot and cold spots.

Cold windows cause cool air currents in the room. The air next to the window cools more rapidly than the rest of the air in the room. This cold air is more dense, so it sinks to the floor.

As the cool air sinks it draws more warm air to the windows, cooling this air. As you can see, a continuous flow of cold air is created. This cold air moves across the room, making occupants uncomfortable.

Placing a baseboard heater right under the window can reduce drafts. The warm air from the heater will rise and heat the cold air flowing down from the window. No more cold draft across the floor.

Another good thing happens with the heat source below the window. The heater warms up the inside surface of the window. Heat always radiates from warm to cold. Your body, 98 degrees warm, will now radiate less heat to the warmer windows, making you more comfortable.

Do you use more energy that way? Probably not. Yes, there will be more heat loss out the window. But you won't have chilled air flowing across the room. You'll be heating the window more, but the room less.

Installing more energy-efficient windows and insulating walls, ceiling and floors are the best way to use less energy.

In a well-insulated, more energy-efficient home, you can usually place the heat source elsewhere in the room with little comfort penalty.

Written by Mike Nuess from the Education and Information Network of the Washington State Energy Office. This information can be made available to accommodate people with disabilities; please call 1-800-962-9731. (Voice and TDD).