Glass Doors and Energy Efficiency

Posted: Oct 01, 2012
Author: G&S Contracting, Inc.

If you have a glass door in your house, it is most likely the largest of your glass fixtures, and as such, is the most vulnerable spot for poor insulation. But it doesn't have to be. Choosing an efficient door can save you tons of money in the form of lower electricity bills, as well as being good for the environment.  Since energy efficiency is of the utmost importance when selecting the right glass door for your home, it's critical to know what to look for.

The glass part of the door is usually the most resistant to heat transfer of the entire door; the most poorly insulated parts of the door are where the glass meets the frame. However, there are options for insulating the frame as well. A strip of plastic or other less heat conductive material, thermal break, is placed in the middle of the frame to reduce the transfer of heat from one side to the other.

The glass panes in your glass door can also be made double in order to slow the transfer of heat occurring across them. The space between the two panes may even be filled with a gas, usually argon, which resists heat change better than the air in the atmosphere.

Certain labels on glass doors can be of great assistance when trying to decide which glass door to use in your home. Look for the National Fenestration Rating Council (NFRC) logo, along with the U-factor and solar heat gain coefficient (SHGC). The NFRC is an organization that monitors the energy efficiency of windows; they provide a standard by which the consumer can compare glass in either windows or glass doors. The U-factor and SHGC are both measurements telling how vulnerable the glass is to heat change; ideally, you want both numbers as close to zero as possible.