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3 Reasons Why Older Windows Lose Heat

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With arctic chills in the air, conserving heat and energy in your home has never been more important. But, this can be a hard task with older windows which are a major source of heat loss in the winter. Read about the three major types of heat loss that older windows are often not equipped to withstand.

older windows

1. Infiltration

Infiltration is the exchange of warm air for cool air and vice versa. Losses are driven by wind and by differences between indoor and outdoor temperatures. They occur primarily through cracks in the sash, gaps between the sash and jamb, and gaps between the frame and rough opening.

2. Conduction

Conduction is the movement of heat through solid materials, like the glass and metal frame of an older window. In this process three times as much energy is lost as infiltration and 25% of total heat loss occurs this way.

3. Radiation

There are two types of radiation: thermal and solar. Thermal radiation is energy that passes directly through air from a warmer surface to a cooler one and is a major cause of heat loss in the winter from your home. Solar radiation is the transfer of heat from the sun through your windows and into a room. Once inside, objects in your home reradiate this heat at weaker wavelengths that are unable to penetrate the window glass.  As a result, a heated “greenhouse effect” occurs and causes your air conditioner to work overtime.

Installing new windows can go a long way towards lowering your heating bill and keeping your home warm and cozy this winter.

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