Energy Efficient Windows: Your Questions, Answered (part 2)

In a previous post, we answered some of the most common questions we get about energy efficient windows. Today, we’re going to dive deeper and answer even more questions. The more you know about windows and energy efficiency, the smarter a consumer you’ll be.

We’re here to help you get the best energy efficient windows to save you money and make your home your comfortable.

If you haven’t read it yet, read Energy Efficient Windows: Your Questions, Answered.

What is light-to-solar gain (LSG)?

In addition to SHGC (solar heat gain coefficient), VT (visible transmittance), air leakage, and the U-factor, you might see this energy performance factor on a window.

LSG is the ratio between the SHGC and VT. What does this mean? This number tells you how efficient the glass is at letting in light without also letting in lots of heat. Like the SHGC, you should talk to a window expert about what number to look for here.

What window type should I choose?

When choosing an energy efficient window, the operating type matters. Certain types are more efficient than others, which means that you should take this into account when getting new or replacement windows. Let’s take a look at them.

  • Awning. This type has a hinge at the top and opens outward. It typically has less air leakage than sliding windows.
  • Casement. This type has hinges on the sides. Like awning windows, it generally has lower air leakage than sliding windows.
  • Hopper. This type has a hinge at the bottom and opens toward the inside of your house. It is similar to awning and casement types in terms of air leakage.
  • Fixed. This window type, when installed correctly, has no air leakage whatsoever. If you’re looking for maximum energy efficiency and don’t need to open the window, this is a good bet.
  • Single and double-hung. This type of window slides vertically. It has more air leakage than windows with hinges (awning, casement, hopper) and fixed windows.
  • Single and double sliding. Instead of vertically, this type slides horizontally. It is similar to the single and double-hung it terms of air leakage.

Why does window orientation matter?

The answer to this question is pretty intuitive: the sun moves throughout the sky throughout the day, while your home doesn’t. Depending on the season, some windows are going to get more sunlight and solar heat than others.

You can affect the energy efficiency of your home through “passive solar design”—choosing windows with performance ratings to maximize heat gain in the winter (saving you on heating costs) and minimize heat gain in the summer (saving you on cooling costs).

North-facing windows get a lot of indirect light, while south-facing windows get a lot of direct light. The amount of light and heat east- and west-facing windows get varies during the year: they get a lot of direct light in the summer and little in the winter.

All this means that you can’t just choose one energy efficient window for your whole house and be done with it. You may need to choose different windows for each side of your house.

What does a proper installation involve?

We talked before about how important installation is: if your energy efficient window isn’t installed correctly, it defeats the purpose of replacing your windows. In addition, an improperly installed window can let in water and pests and cause all sorts of other problems.

There are a few ways to tell that you have hired a window installation company that will do the job right:

  • Ask for references and pictures of the company’s previous work.
  • Ask about the company’s training procedures and how often the installers do window replacement.

After the installation, check to see that the sill is level and the frame is square. Make sure that the window is easy to open and close. Look at the caulking to see if it is tidy. Good installers will make sure that even the smallest details are right.

If you have more questions, we’d be happy to answer them. Contact Jack’s Glass today at one of our three convenient locations–Elsmere, Covington, or Dry Ridge, Kentucky–to learn how we can help you choose and install the best energy efficient windows for your home.