Drafty windows are a sign that it might be time to do some window shopping. Energy Star ratings on windows meet strict guidelines for energy efficiency.
SPECIAL FOR the Arizona Daily Star
Question: How do I know when my windows can be replaced?
Reply: Signs that windows need replacing due to age, poor quality, or improper installation include:
- Drafty windows (slowly wave a candle around the edge of the window. When the flame flickers, hot air comes in and cold air goes out – an expensive price to pay in the desert summer).
- Windows that are difficult to open or close indicate wear on rollers and guides.
- Noises from outside are easy to hear inside (upgrading also provides more privacy).
- Daylight penetrating around the window perimeter indicates bad weather.
- Caulking (newer models do not require caulking).
Q: If my windows need to be replaced, what do I need to know before I start shopping?
A: Here are some key terms you need to know in order to make a smart decision:
- The R-value is a measure of how efficient a window is. It shows how much heat can get through the window in an hour. (This is known as “heat gain.”) The larger the R-value, the more efficient the window. Windows with a high R-value let less heat in on hot days and less heat out if you run your stove on cool evenings.
- Glazing refers to the number of panes of glass a window has. The windows are single, double and triple glazed. Single pane windows are not energy efficient. Triple glazed windows are helpful in very cold climates or when noise reduction is desired, but they are very expensive. Double windows of pain are the smartest buy for most households. They have two panes of glass and a layer of air between them. The distance between the glasses can be too small or too large – an ideal space requirement is about one centimeter. The exchange of air between the glass layers with argon gas is inexpensive and only leads to an efficiency of 10-15% in the winter months.
- Low-E stands for low emissivity. Low-E is achieved by having a thin, clear layer of silver or tin oxide on the glass that prevents heat from penetrating the glass, making the window more energy efficient. Low-E can be applied to windows two to three times during manufacture, bringing the UV reduction to 95% and the heat saving to 80%.
- Cladding – Clad windows have wooden frames on the inside and either aluminum or vinyl on the outside. Rosie’s favorite is the aluminum-clad wooden window frame. Rosie always advised never to buy vinyl windows. However, the development of the vinyl clad window has improved significantly. They have come a long way and are a common choice for replacing windows and doors in the home. Be careful not to stay away from soft pliable vinyl as it will not withstand the extreme weather and sun exposure of Arizona. Modern PVC-vinyl compounds contain inhibitors that prevent the sun’s UV radiation from softening and damaging the vinyl. Reinforced metal in the vinyl and additives in the vinyl itself are innovative improvements that have helped make this a better choice than it has been in the past. If you can afford it, Rosie says a wood-framed aluminum window will keep the most out of the desert heat and sunlight.
- Toughened safety glass crumbles instead of splintering into pieces when broken. It is required by code for certain windows installed deeper in a wall or next to a door. This upgrade is expensive and only makes sense if the upgrade requires it.
- Energy Star label. Search Windows for Energy Star Rating. These windows meet stringent energy efficiency guidelines from the US Environmental Protection Agency and the US Department of Energy.