Selecting the right window solution for your home is a balance of taste and experience: your taste, our experience. Our energy efficient window specialists help match your vision with the ideal long-lasting Victor’s Construction and Remodeling replacement window.
Keeping heat in (or out)
Windows lose and gain heat by conduction, convection, radiation and air leakage. This heat transfer is expressed with U-values, or U-factors. U-values are the mathematical inverse of R-values. So an R-value of 2 equals a U-value of 1/2, or 0.5. Unlike R-values, lower U-value indicates higher insulating value.
Conduction is the movement of heat through a solid material. Touch a hot skillet, and you feel heat conducted from the stove through the pan. Heat flows through a window much the same way. With a less conductive material, you impede heat flow. Multiple-glazed windows trap low-conductance gas such as argon between panes of glass. Thermally resistant edge spacers and window frames reduce conduction, too.
Windows lose heat in four ways. The rate at which a window loses heat through the combination of the four is called its U-value. It is the inverse of the R-value, so the lower the U-value, the greater the insulative value of the window.
Letting in the right amount of sun
In a cold climate we welcome the sun's heat and light most of the time. And once we capture the heat, we don't want to give it up. In a warm climate, we don't want the heat, but we do want the light. Advances in window technology let us have it both ways.
Windows that block UV-radiation reduce fabric fading. Expect to find windows off the shelf that block more than 75% of the UV-energy. Contrary to conventional wisdom, some visible light fades fabric, too. Some manufacturers use the Krochmann Damage Function to rate a window's ability to limit fabric-fading potential. It expresses the percentage of both UV and of that portion of the visible spectrum that passes through the window and causes fading. Lower numbers are better.
Keeping warm around the edges
If you've lived in a cold climate, you've seen condensation and even frost on windows. When warm indoor air cools below its dewpoint, liquid water condenses on the glass. Condensation typically develops around the edges of window glass. No surprise. The edge is where most multiple-pane glazing is held apart by highly conductive aluminum spacers.
Energy-efficient glazing reduces winter condensation. When low glass temperatures cause inside air to reach its dew point, water condenses on the window. The chart indicates the points where indoor humidity and outdoor temperature combine to cause condensation on various types of glazing.
Good frames insulate
The most widely available window frames are wood (including vinyl-clad and aluminum-clad wood frames), with 46% of the market. Hollow vinyl frames hold 36% of the market, and aluminum runs a distant third, with a 17% market share. A trickle of alternative materials such as wood-resin composites, fiberglass, PVC foam and insulated vinyl makes up another 1% of windows sold. A window's frame represents about 25% of its area. So it's important that the frame material be thermally nonconductive. For the most part, wood and vinyl are the best performers, and they work equally well (see U-values for common frame materials). Aluminum frames are typically poor energy performers.