LCEC – Lee County Electric Cooperative

Are your windows and glass upping your energy usage?

September 22, 2020 – You may be surprised to learn that upwards of 30 percent of your cooling costs is attributed to glass and windows. Even though today marks the start of fall, the weather in sunny Southwest Florida is hot pretty much year-round. Consider the following tips from our energy experts about your home’s window and glass to potentially cut down on your electric usage:

• Significant air-conditioning savings can be attained by blocking solar heat before it reaches the windows, or by using special heat-reflecting glass or heat-reflecting glass coatings (residential window tint).
• Reflective glass or reflective glass coatings should be rated to reflect at least 65 percent of all solar heat to be considered efficient in Southwest Florida.
• Internal window coverings trap solar heat between them and the window glass until the heat energy warms the air in that space. The heat-laden air flows up to the ceiling, where it waits for the air conditioner to cycle on and draw it in through the filter. This creates an illusion of efficiency when, in fact, the load on the air conditioner has not been altered.
• Awnings, storm shutters, shade trees and porch or lanai roofs are all very effective in blocking solar heat. To be 100 percent effective, the exterior shading device must never allow direct sunlight to touch the window’s surface.
• East or west windows are the main source of intrusive heat. It is recommended to use shading devices and tint on east and west windows since they experience many hours of direct sunlight.
• South-facing windows experience a great deal of direct sunlight in the winter months when the sun rides lower in the sky. In the summer, south-facing windows are largely shaded by the overhanging soffit of the roof.
• Skylights experience many more hours of direct sunlight than any vertical window and should be avoided if possible.
• It is difficult to utilize shading devices to block the sun from entering skylights. Existing skylights can be tinted, covered, blocked or shaded to lessen their load on the air conditioner.
• When upgrading windows, consider energy-efficient features such as double-pane, low-E glass as well as type of frame material.

For more ways to save on your energy usage, visit lcec.net.