Windows are problematic when it comes to energy efficiency. We have long used a shutter or a blind to help keep a room cool or warm, but does this really help.
I was giving a talk on the topic of improving your home’s energy and water efficiency, when I mentioned that replacing windows should be the last thing that you do. Many homeowners start with replacing windows, and I do not suggest that this should never be done, but other projects will be more beneficial when starting down a path to improve the home. This prompted someone to ask if there is anything we could do to improve the efficiency of a window. I mentioned that there are solar screens that can help There are films that go onto the window to improve their efficiency. Finally, I mentioned having appropriate window treatments.
My wife and I installed wood blinds on a window by our front entrance, and this did help, but it is not the best. I had seen plastic blinds. I was not too happy with the quality of construction or the material. These are great if you are installing shutters on every window in the home though. Te wood shutters felt better, looked better, and might be more energy efficient (in the sense of stopping the transfer of heat better than glass). Wood does allow for thermal bridging, so wood shutters are better than nothing. When we decided to install shutters on another front facing window, we were planning on a wood shutter again. This is when we discovered a product that helps stop the thermal bridging of a solid wood shutter. There are shutters with wood exteriors, but the internal sections are composed of foam insulation. Shutters with this construction qualify for the energy efficiency tax credit on your Federal returns. The product looks and feels like my wood shutter, and is great for the window, since that room obtains a good deal of afternoon sun.
We wanted new blinds for another room, so we explored our energy efficient options. Blinds may not achieve the same efficiency that the foam/wood shutter does, so I do not know of a blind that qualifies for a tax credit (I would be interested to hear if there is one). What we settled on was a blind that some call a Persian blind. These are blinds with a honeycomb pattern. Some of these are made with lighter weight materials. Some of these blinds come with both a lighter material to bring diffused light into the room, along with heavier material. My wife wanted a material that would be a screen (concern over a neighbor looking into our windows). We ended up with on off the shelf model that needed to be cut to length. This blind has a light colored cloth for the exterior and a darker cloth inside. The blocked sun light cannot heat the room, and the space feels cooler. Thermal bridging is not happening too fast.
Windows will always be a weak point in our energy efficiency efforts. Eventually, I will install triple pane windows, I do not want shutters on all of my windows, so the Persian blinds may be the option. I want my windows, since I do not have to turn on the lights, which is why I may be adding more windows to the home.