High-performance windows with new glazing technologies reduce energy costs and make homes more comfortable as well. Another added benefit is less condensation and reduces the chance of mold and mildew.
High-performance windows create warmer interior glass surfaces, reducing frost and condensation. High-performance windows with warm edge technology and insulating frames have such a warm interior surface that condensation on any interior surfaces is significantly reduced under all conditions.
Impact of Low-E Glass and Insulating Spacers on Condensation
The adjacent images show interior surface temperature patterns of a clear double glazed unit (left) and an energy-efficient Low-E insulated glazing unit with an improved spacer (right).
Under typical winter conditions, (i.e. 20°F outside), condensation on the glass under typical humidity levels is shown by purple and blue. With a conventional clear double glazing (left), condensation occurs in a band a couple inches wide along the edge of the sightline, with more condensation along the bottom than at the top. With the energy-efficient Low-E insulated glass unit (right), condensation will be greatly reduced (a small strip less than 1″ high along the bottom).
Under extreme winter conditions (i.e. 0°F outside), condensation is shown by purple, blue and green. With clear double glazing, there is condensation over the entire unit. With energy-efficient Low-E glazing, there is only condensation on a band along the bottom and up along the edges.
Impact of Temperature, Humidity and Glass Choice on Center-of-Glass Condensation
The graph below shows condensation potential on the center of glass area (the area at least 2.5″ from the frame/glass edge) at various outdoor temperature and indoor relative humidity conditions. Condensation can occur at any points that fall on or above the curves. As the U-factor of windows improve there is a much smaller range of conditions where condensation will occur.