Most homes over 25 years old have inefficient windows that let too much hot and cold air transfer through them. In an effort to save money homeowners are taking advantage of the window replacement tax credits available through EnergyStar. Choosing windows is not a task to be taken lightly as they have the potential to be the biggest heat loss source in your home.
Window Comparison Guide
There are a few things you should do when comparing different types of replacement windows.
First you should gather some specifics about the windows you need to replace. Sizes, window positions, desired lighting, siding, and possible weather conditions are a few of the items to consider. Does a side of the house face high winds, excessive rain, or other unusual circumstances?
To build a few starting ideas you should next go on the internet and do a little background research. This information can quickly help you identify starting questions and possible problems.
Next you should go to one of the larger home improvement stores such as Home Depot, Menards, or Lowes to see what they have. This gives you a chance to actually see and examine windows. Larger stores often have a wider selection of replacement windows on display
Now, if there are any in your area, you may wish to compare windows by going to a home show and looked at the window displays and talk to the window installers. This gives you a chance to actually talk to a professional to get some of those pesky questions answered from a source often more reliable and comprehensive than online sources. For example, at a Remodelers Expo I met John Kooiman from Sandau Construction Co, Inc. John’s company has been installing windows for 2 decades and he shared some very helpful tips with me about windows and website resources where I could get more information. A special thank you goes out to John who helped get me started on this article.
The Expo also gives you a chance to make a few decisions about installers while you talk with them. Don’t assume that you’ll be dealing with the same person if you have them install your windows. Ask them if they specifically will be doing the work. Also ask about guarantees, especially written guarantees. While you’re there examine each window and check out its structure as well.
The next step is to take the information gathered at the show and go back to the internet. This can give you more information about the window quality and other manufacturers and double-check the information that you gathered. Was it correct? Are the prices reasonable? Are there other, possibly even better, solutions for your specific situation?
When comparing replacement windows look for the following important information:
- Is the window NFRC rated? The National Fenestration Rating Council has a labeling system for certifying energy efficiency of windows, doors and skylights. They have an extensive database for almost every window manufacturer with all the rating information by model. www.nfrc.org NFRC labels attached to windows have energy performance ratings which measure U-factor and solar heat gain coefficient and additional performance ratings which measure visible transmittance and condensation resistance of the window.
- Does the window meet Energy Star performance guidelines for a tax rebate? A window needs to meet the ENERGY STAR qualification based on U-factor and SHGC ratings. Check out the details www.energystar.gov Don’t forget to visit the Energy Star rebate finder or rebate locator. Just put in your zip code and check to see if there are any special offers, rebates or recycling incentives in your area. www.energystar.gov There are 4 climate zones for ENERGY STAR qualification visit the ENERGY STAR Climate Zone Finder to find out yours.
- What type of glass does the window have? Low-E4 glass blocks about 85% of UV rays, typical clear glass only blocks 40%, but a window system of Low-E4 glass and special solar control gas can block up to 99.97% of UV rays.
- Strong stable frame? Think of how many times you open your windows in a year and how easy they are to clean. You want to look for a stable frame that will take the opening and closing several hundred times a year and not chip, crack, bend or bow.
- Warranty items? Is the warranty easy to understand? Does it cover everything? (frame, sash, glass seal, hardware, screens) Does the warranty transfer to the next homeowner if you sell your home? Pick a company that has been around for a while and is not in financial difficulty. You want to make sure that if you should have a problem in a few years that the company is still around to service your warrantee. For an example Anderson windows offers a 20 year glass warranty and a 10 year component warranty.
The NFRC Window Label Summary
- U-factor is the measurement of thermal performance. The lower number the better thermal performance.
- SHGC Solar heat gain coefficient is the measurement of the products ability to block heat by sunlight. Ratings are between zero and 1. The lower the SHGC number the better.
- Visible Transmittance measures how much light comes through the window. Ratings are between zero and 1. The higher the VT numbers the better.
- Condensation resistance measures the windows resistance to condensation on the glass. The higher the CR number is the better.
Window Frame Comparison
A window is usually measured by U-factor but we are just comparing window frame materials and R factors are used below. Higher R-factor means less energy loss through the window frame (The higher the number the better the R-factor):
- Aluminum window frame – less than 1
- Steel window frame – less than 1
- Solid vinyl window frame – less than 1
- Wood window frame – 1.41
- Polyurethane window frame – 7.14
Window Glass with Gas
For increased energy efficiency high density argon gas or krypton gas is used between the layers of sealed glass to lessen heat and cold pass through as well as block sound pass through. This is particularly handy if you live near a busy street or your neighbor loves to use power tools outside. The gas they use is stuff already found in the atmosphere and is harmless but when used in a window system with low-E4 glass it is a much more efficient window. Another advantage to the low-E4 glass and gas window system is that it reduces ultraviolet rays that fade carpet and furniture. Look for the symbols Ar (argon gas) or Kr (krypton gas) on window spec sheets.
Always ask about options or if they come with the window as these can also add up if you don’t factor them in. Ask if insect screens are included or are available. 2 more important questions to ask are how many choices of hardware are included and how many color options.
I hope that this window replacement guide has been helpful in answering a lot of your questions. Feel free to print it off and take it shopping with you so you remember all the questions to ask. You may want to take a note book to scribble down your notes so you can compare the different features when deciding which window replacement best fits your needs.