I thought I’d take a close look at these insulating window shades today that Zero Energy Design is referencing in their energy model. There are a lot of cellular shades that are made up of one, two or three layers of honeycomb fabric with air in between the cells that makes the shade act as an insulator. From what I found, most shades can increase the R-value of a window by anywhere from 2.0 to 4.8 depending on the number and size of the cells and the material used. This is pretty significant since most energy star, double pane, low-e windows still have an R value of around 3.0 or less.
The first thing I thought when I heard insulating window shades was whether or not they would be ugly in a modern interior. After seeing some, I don’t think they look too bad. Look how happy the people are with their installed shades! The bottom line is that in the city most are going to install some type of window covering for privacy, so why not give them a nice white shade that is custom made for their windows and save them some cost and hassle?
Zero Energy recommended looking at both Bali and Hunter Douglas brand shades. Long story short, Hunter seems to have the slightly better brand in terms of quality and R-values in their shades. They also offer one of the only triple-cell shades I could find.
There are a whole bunch of window shade sites out there but most of their pricing seems to be the same. I’ll use blinds.com for reference here as they seem to be a larger site. I priced a double cell shade in white that is semi-opaque to still let in light and for our 2′ x 5.5′ windows, they will cost $90 each. This has an R-value near 4.35 and the jump in price for the triple cell version is over $50 for only 0.45 increase in R value. Not really worth it in my opinion.
So we still have the question of whether this is a good investment toward improving the energy efficiency of the home. We will spend a little over $1,000 on the window shades which will decrease our energy costs by about $80 if the homeowner uses them properly and religiously year round. The other option is to spend more for the better Thermotech windows which guarantee a thermal improvement of almost $100 per year no matter how the homeowner uses them. The cost will be at least double the $1,000 premium for the better quality windows, but the labor costs will not increase. I would imagine the window shades will cost a couple hundred dollars to have installed in the overall budget.
What are your thoughts? Shades and the Pella windows or no shades with a superior Thermotech window?
Source Link: Great link on window shading options to improve energy efficienty. If you really wanted to go nuts you could probably bring your windows to a similar R-value as your existing walls by installing cellular shades internally in your windows, installing a roman shade over the window and then adding some heavy drapes outside of that. http://www.theblindspot.biz/energy-efficiency.htm
If you enjoyed reading this post I can promise you'll love our new writing over at Postgreen Homes. Yeah, we know that's the same thing your favorite band said and their new album is nowhere near as good as their early stuff, but seriously, we are actually still getting better.
There also isn't much conversation to be had here . . . at least not with us. So come on over to the Postgreen Homes Blog and tell us what you think of our new(ish) digs and crazy ideas. We will be sure to tell you what we think of your opinion.