Low-E Windows VS Standard Windows

What are Low-E Windows? Low-E windows as defined by http://www.royalprime.com are windows that have two glass panes or more that selectively rejects certain energy which as a result, greatly decreases the amount of heat that transfer through the glass (window glossary, 2012). In this research paper I compare a standard egress double pane  double hung window to a Low-E double pane single hung window and explain why replacing the standard windows is a worth wild investment.

The Low-E window I decided to compare to the standard egress window was the ThermaStar by Pella 10 Series Double Pane Single Hung. This window is filled with argon gas between the glass panes to maximize energy efficiency (Thermastar, 2013). To minimize cost I decided to replace a double hung window with a single hung. I found the ThermaStar by Pella window on Lowes.com and the cost of each window is $138.00. The price to purchase the 11 standard size windows would $1518.00. This Low- E window has a U-value of .3 compared the standard window with a U-value of 1.1. (Thermastar, 2013) This is 72.7% lower than a Standard egress window. That makes a huge difference when you calculate the difference in winter heat loss and summer heat gain. For the standard windows the BTUH for the winter hear loss was 10,395 compared to the Low-E window with a value of 2,835. For the summer heat gain the standard windows has a BTUH value of 3,465 compared to the Low E windows with a value of 945. So a Low-E window heat transfer is a lot lower which saves you money spent on heating or cooling.

It is expensive to replace windows in your home but there are many benefit that help offset the cost. According to the United States Department of Energy, “New, energy-efficient windows eventually pay for themselves through lower heating and cooling costs, and sometimes even lighting costs” (U.S. Department of Energy, 2012, para. 4). For example a home owners that replaced standard double pane double hung windows with Low-E double plane single hung windows save around 126.00-465.00 a year on energy cost (Blue,N.D., para 1). Homeowners who replace their windows are also eligible for a federal tax credit which is 10% off your cost up to $200.00  (Blue,N.D., para 2). Taking all that into consideration, a homeowner who invests in new windows could recover all their money in as early as 3 year.

 As a result, replacing the 11 windows out of the 12 would be a worthwhile investment. For the fact, that down the road you will end up saving more money on your  energy cost then it would cost you to replace the windows. For this particular paper I decided to specify on Pella, but not all Low- E window manufactures are the same. Low-E windows can have many different properties, for example, the windows can be double or triple pane. They can also be filled with argon gas, and some windows can have shading or glazing. You will get what you pay for in windows, the higher the price the better the window.     

References:

1. Blue, J.(N.D.) Will Replacing Windows Save on Energy Costs? Green living. Retrieved from http://greenliving.nationalgeographic.com/replacing-windows-save-energy-costs-2217.html
2. ThermaStar by Pella 36-in x 54-in 10 Series Double Pane Single Hung. (2013) Lowes. Retrieved from http://www.lowes.com/pd_109449-1257-748171609911_4294772368__?productId=3117823&Ns=p_product_qty_sales_dollar|1
3. Windows Glossary. (2012) royal prime window specialist. Retrieved fromhttp://www.royalprime.com/windows_glossary.html
4. U.S. Department of Energy. (2012, June 18). Energy-Efficient Windows. Retrieved from http://energy.gov/energysaver/articles/energy-efficient-windows