Red Seal Glazier Practice Exam

What does "Low-E" glass stand for?

1. Low energy glass, designed to minimize power consumption

2. Low emissivity glass, designed to reflect infrared radiation

3. Low exposure glass, used in hazardous environments

4. Low environmental impact glass, made from recycled materials

The correct answer is: Low emissivity glass, designed to reflect infrared radiation

Low-E glass stands for low emissivity glass, which is specifically designed to reflect infrared radiation while allowing visible light to pass through. The term "emissivity" refers to a material's ability to emit thermal radiation; in this case, Low-E coatings are applied to glass surfaces to reduce the amount of heat that is lost or gained through the glass. By reflecting infrared radiation, Low-E glass helps maintain a stable indoor temperature, improving energy efficiency in buildings. This makes it particularly beneficial for windows in residential and commercial applications, as it helps to keep heat in during the winter and out during the summer, thus reducing heating and cooling costs. Other options don't accurately describe Low-E glass: the first option refers to energy consumption but does not capture the specific property of emissivity. The third option suggests an application in hazardous environments which is not a characteristic of Low-E glass. The last option implies it has a low environmental impact due to recycled materials, while the primary purpose of Low-E glass relates to thermal management rather than material sourcing.