How to pick energy efficient windows
February 27, 2014
Old windows can create a variety of problems for your home. But the solutions are in your control! Let's take a look at two common issues associated with old windows and how you can fix them:
- Non-insulated glass. Your windows give you natural light, yes, but did you know they also account for almost 30% of the year-round energy (both heating and cooling) you consume? If you're losing energy through your windows, you may be paying the price in your utility bills. Glass alone is not a good insulator, and if you have old windows, you may not have any of the energy-saving options you could get today. For example, if you have a three foot by five foot single-pane, non-insulated window, you can lose up to 850 BTUs per day. Your furnace would need to run for about three hours to generate that much energy.
- Air infiltration. If you have problems with air getting into and out of your home, then you might have loose-fitting windows. Even if there's only a 1/16" inch crack in each window, those seemingly small amounts add up and you're left heating and cooling a home with that collectively-sized hole in it.
So how do you fix these problems?
The answer, of course, is energy efficient windows. To start, look up your Energy Star zone if you don't already know it. This can help you decide exactly which upgrades to invest in for windows in your area, which, in turn, can help save you money. You'll need to make decisions on:
- Sash and frame fittings. A tight sash and frame ensure all the air both inside and outside your home stays where it's supposed to. Look for a sash with very low air infiltration test results (something with less than 10 cfm/ft - which is 10 cubic feet per minute per square foot - is a good start).
- Window frame materials. Look at multi-chambered vinyl (you can ask to see a cut piece of this - generally, the more chambers the better), thermally enhanced aluminum, and wood window frames. These materials conduct less heat and cold than some others on the market.
- Glass. There are many, many glass variations to choose from, and you'll choose yours based on how much sun your home gets. Two important measurements to look for are the u-value, which measures the heat flow through the glass, and the Solar Heat Gain Coefficient, which tells you the amount of the sun's energy entering the home through the glass. For both measurements, lower is better. The Energy Star zone map can help you decide just how low you should go. Aside from these measurements, also check the zone map for low-e glass recommendations. Low-e glass has a metallic coating on it that reflects radiant heat.
By doing a little research and knowing which questions to ask your window dealer, you can solve your window problem and start seeing energy savings. Get in touch with a window contractor now to get started by filling out the form at the top of this page.