Entry Door Glass Options

R-Value reflects properties of the glass only. Center of glass calculations are based upon software from Lawrence Berkeley National Laboratory.

While R–value measures resistance to heat transfer, U–value measures the rate of heat transfer. The lower its U–value, the better the product’s ability to resist heat conduction. In simple terms, U–value is the mathematical reciprocal of R–value; that is, U = 1/R and R = 1/U. Energy Star windows must have a U-Factor of .27 or lower. Entry doors with no glass must have a U-factor of 0.17 or lower.

Doors with half glass or less must have a U-Factor of 0.25 or lower. Doors with more than half glass require a 0.30 U-Factor or lower.

Depending on the region in which you live, you’ll want door glass that keeps cold out and prevents heat from leaving your home in winter and keeps heat out and air conditioning in during the summer. 

Our entry door Warm Edge Glazing System is designed to do just that. Combined with a high R-value, double- or triple-glass unit, insulating chambers filled with Krypton or Argon gas and Super Spacer®, glazing improves the comfort and energy efficiency of entry doors. Our glazing system is available in seven options, including high-performance Low-E glass and increased UV protection. All Windows Pittsburgh entry doors with DLA-UV glass packages are ENERGY STAR qualified for all climate zones in the United States.