Keep out the Heat part 1: Solar Screens

Solar Screens: Before and After

There are three main ways to lower your energy usage due to air conditioning in the summer:

Insulate your home so cool air doesn't leak out
Program your thermostat so the AC doesn't have to come on as much or stay on as long
Keep solar heat out in the first place!

I've been thinking a lot about the last one lately since the front of my home faces due South and receives sunlight almost all day. In order to prevent my house from heating up like an oven, I somehow have to find a way to limit the solar radiation that enters the home. There are several methods to do this including:

Solar Screens
Window Tint
Awnings
Shading

I was stumped last month when my uncle asked:

What are the pros and cons of Solar window screens vs solar film? What are the best products? What is more cost efficient?

Quite frankly I had no clue! And I could understand his confusion after I did some searching on Google and couldn't find a comparison. Most of the sites are selling product, not giving objective analysis.

An example of a Solar Screen can be seen in the images by the company Insolroll and their energy-efficient SilverScreen. Insolroll states that their SilverScreen solar screen "gives the best view retention, glare control, and heat reduction". Insolroll's solar screens install from the inside, but from what I can tell, solar screens are most affective when they are mounted outside the windows (like in the image at the top of the post). This way any heat the screen absorbs is given off outside the home, and not in the home's interior. I like what the eHow on "How to Save Money with Solar Screens" says about mounting interior vs. exterior:

Decide whether you want your screens on the inside or outside of your windows. While screens may be installed on the inside of the window, the most efficient solar screens install on the exterior of your home. With the screens on the exterior, the heat that is not immediately deflected will be absorbed by the screen while a major portion is dissipated into the surrounding atmosphere. Solar screens on the exterior also eliminate the need for covering windows in the winter time as the insulating techniques work year round. The installed screens help to hold the heat that is generated in the interior of your home.

Based on some preliminary research, it seems that solar screens are extremely popular in Texas. This fact was re-itereated by the energy audit recommendations from the City of Austin, TX, which has a requirement that many homes have energy audits (my uncle who asked the solar screen vs. film question and my father -in-law who informed me about the Austin energy audit both live in TX). Statesman.com reports the following findings from the first year of the Austin energy audit city ordinance:

In the first year of a new city ordinance, energy audits were completed for 4,862 homes. Here are the most common issues uncovered during that year:

58 percent needed window shading (solar screens on windows).

Nearly 80 percent needed more attic insulation (another 10 inches, on average).

About 68 percent needed duct repair work in attics. (On average, 22 percent of the air conditioning in older homes leaks into the attic, Austin Energy says.)

78 percent needed weatherstripping, sealing or caulking around windows, doors and other openings

If you don't mind the aesthetics of them, solar screens seem like a great solution. And if you really don't mind the aesthetics of them (an off-grid cabin maybe?) check out project 16 of the Home Energy Projects Guide, which shows you how to build your own solar shade screen!

I'm still looking to see how they perform vs. window tint. Does anyone have any experience out there? We'll look closer at window tint and other solutions in later posts in our Keep out the Heat series.

Join the forum discussion on Solar Screens vs. Solar Film!

Tags:

Insolroll silverscreen

solar screens

solar screens vs. solar film

Comments

Anonymous (not verified) Mon, 06/27/2011 - 19:22

We went with the solar screens, made the house looks better and kept out way more heat than the tint we had up.

Anonymous (not verified) Tue, 08/16/2011 - 20:03

Hey All, The company I work for has recently started offering our product lines (Solar Screens, replacement screens, screen doors and grilles) direct to consumers and contractors via <a href="https://www.screenitagain.com" rel="nofollow">screenitagain.com. Because I'm thinking about installing solar screens on my house, I decided to do some research and found that Paul and Henrietta are both correct. Keeping the sun (heat) out of the house completely is the best course of action and that films can be a big help. <em>Read about solar screens & keeping the sun's heat outside @ <a href="https://www.screenitagain.com/solar" rel="nofollow">screenitagain.com/solar.aspx</em> After <em>reading around</em> I'm thinking I'll be going with the solar screens option. They seem to be able to block just as much sun but are typically cheaper than the high-end films. Just my $0.02

Anonymous (not verified) Thu, 04/19/2012 - 14:40

One very important issue concerning black solar screens is that they absorb heat. That transfers heat to the space between the solar screen and the window, warming the window, which in turn warms the house's interior. Although much less heat comes in than would without the solar screen, that hot pocket of trapped air needs to be vented. An easy solution that I have used since 1990 is to drill small holes in the very outside edges of the solar screens as well as corresponding locations on the exterior window frames. Then use 2 1/2" sheetrock screws to attach each screen to the window frame. That spaces the solar screen about 1.5 inches away from the window allowing air flow between the window screen and the window, eliminating the trapping of hot air in between. The result is a big temperature reduction on the surface of the window inside the house. You just want to be very careful not to drill into the edge of the window's glass in order to avoid cracking a window.

ckmapawatt Thu, 04/19/2012 - 19:06

I like that idea a lot. You think there would be a commercial solution that would do this?

Anonymous (not verified) Tue, 06/19/2012 - 23:59

Recently we have viewed several homes on which a certain company in Colorado has been installing solar screens. There is a right and wrong way to install solar screens. This certain company is installing solar screens by replacing the bug screen on the window with solar screen and making another screen for the non opening side of the window where they attach this screen by placing screws into the actual window frame.

Anonymous (not verified) Sun, 09/12/2010 - 14:40

Greetings Every body, I thought I would place a quick post concerning the newer Ceramic films now offered through 3M and various other Window Film Suppliers to clarify a couple of things. Though conventional window films might be dyed or metallized, ceramic window films are actually created in totally different manner. They are constructed of a nano-ceramic material which will results in one of the most crucial advances in Window Films in many years. Though more costly than other dyed or metalized films, ceramic films perform drastically better in terms of infrared and heat rejection. There's a wealth of information and facts on the internet, just run a google search on for "Ceramic films" or visit the <a href="http://www.sunrayfilms.com" rel="nofollow">Residential Window Tinting</A> page at Sunrayfilms.com website.

Anonymous (not verified) Wed, 08/04/2010 - 18:52

Great post! We have both awnings and roll-down window shades -- keeping the heat outside is the right thing, to be sure. The awnings are awesome -- easily adjustable (mostly for winter/summer), but kind of expensive. The shades are ... ok -- they roll down on the outside of the house, but are not easy to manage and blow around in a breeze, plus, you can't see out. But they certainly work -- my office is our "sun room" and today it was over 90&deg;F and humid -- the office stayed comfortable, with max temperature of 82&deg;F by the afternoon (plus a fan). It's certainly true as David said in his comment -- air sealing keeps what's in in, and what's out out. We do "morning lockdown" on hot days to keep in any cool air from the evening :-). The solar shades look really cool. I'll definitely check them out. Here are some posts from my blog on roll-down shades (http://fivepercent.us/2008/06/08/staying-cool-without-air-conditioners/) and awnings (http://fivepercent.us/2009/08/02/green-review-sunsetter-awnings-keep-heat-outside/) for anyone who's curious about the details. Tom

Anonymous (not verified) Wed, 08/04/2010 - 15:01

You mentioned conduction of heat and radiation, but overlooked convection. Don't forget to seal your house so the cold air doesn't leak out and the hot air doesn't leak in. David

Anonymous (not verified) Wed, 08/04/2010 - 01:01

We have western facing windows, so we suffered from glare and heat during the summer. We found that installing window tint on these windows helped with both problems and we did not have to deal with the solar screens which we found visually unattractive. Take a look at SnapTint window tint kits, we found their pricing affordable and quick to install.

Anonymous (not verified) Wed, 08/04/2010 - 17:59

We choose the solar screens after considering our options. However if we could do it over again I would have passed on any window coverings and focused on awnings and canopies to keep the sun from reaching the windows in the first place.

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