Simple Skylight Shading
 

Hi Folks!

I love my 1500 square-foot modified Cape Code, including two skylights, one in the kitchen, and one upstairs.

However, in the summer, they turn into solar death rays, heating the house.

I had bought some "solar window screen" at the home improvement store a few weeks back. The skylight in the upstairs cranks open. The one in the kitchen does not. (Also, the upstairs one is in easy reach, whereas the kitchen one is in a vaulted ceiling.)

The upstairs skylight is a little larger than 3 feet square. The solar screen I bought is 3 feet wide. I cut a length off the roll a little less than three and a half feet.

I opened the skylight, feed the material through, and then shimmied it up over the glass by grabbing it with one hand on either side. I then cranked the skylight shut, pinning the screen in place.

Immediately, I could feel the difference. Essentially, I was now in the shade instead of the sun!

I'm just doing this as a test, but wow, feels better already.

Later, I had to climb up on the roof (for a totally unrelated reason) but I snapped a photo of the outside of the skylight.

The trim and glass are both already dark colored, and the screen seems to blend right in. From the ground, the neighbor's house, or the road, it doesn'y look bad at all!

http://300mpg.org/wp-content/uploads...55-640x480.jpg
http://300mpg.org/wp-content/uploads...56-640x480.jpg

For orientation, I am crouching on the roof, uphill of the skylight. There is a several inch gap on the TOP of the skylight which isn't covered by the window screen. This is actually good, because it makes the difference between full sun and "sun through the screen" really obvious. (Sort of built in A/B testing or control and experiment.)

In case you are wondering why the screen is on the OUTSIDE of the window, it's to keep the heat OUT. A screen INSIDE the window will also block light, but it will absorb (and then release) the heat INSIDE the house. Let's keep heat OUT of the house in the first place during the summer.

I originally just thought I would do this as a test, and then build some sort of fancy wooden frame, but it really doesn't look bad at all right now. I don't know how wind and rain will effect it. Guess I'll just wait and see.

I would also like to screen the kitchen skylight, but that is much larger, needs to be done from the outside, and I can't just open the window and pinch the screen in there. It will need some sort of framework.

Nice work Ben. I bet that'll help a ton this summer. I'd definitely get one for the kitchen.

Here's a couple of photos from the inside, so you can see the difference between the skylight with and without the solar screen.

(Yes, the window is dirty.... I know already, jeez!)

http://300mpg.org/wp-content/uploads...64-640x480.jpg

http://300mpg.org/wp-content/uploads...65-640x480.jpg

It's a SIGNIFICANT difference in brightness. Unlike regular bug screen, this solar screen is more material than holes!

Call me crazy if you'd like but when I reroofed my house, I decided that roof glazing was a terrible idea. In the summer you get too much light and way too much heat. My bathroom figuratively felt like an oven in the house. In the winter, the bathroom became the coldest room in the house. I realized this thing is hurting my energy usage and comfort in a significant way.

I had the skylight in my bathroom removed when I reroofed my house. Initially with the reroof I shoved a chunk of R10 XPS in the gap and used temp caulking around the foam to create an air seal. That winter I was comfortable in the bathroom and whenever I took a shower in the winter, I wasn't getting water condensation dripping down the floor. Fun thing I found is that the drywall shaft around the skylight had a product called Thinsheath or some similar name to that, stamped with R6 on it. It it isn't obvious, this big shaft facing the highest point of the house, including the attic was not helpful in the extreme heat or extreme winter. Heat exchange was high and I'm glad I got rid of the skylight. With an 8 watt LED in the bathroom providing plenty of light, I can't see the advantages of using a skylight, even the 'light tube' types, especially since they are rarely installed with insulation.

I guess in the end, if you have one, you are stuck with it until you reroof if you don't have spare shingles that are available or if you don't know how to do the work properly. I prefer to produce my own light with efficient means because daylighting has a high cost of heat when you don't want it and when you want warmth you are exchanging the indoor heat with the outside through the glass. Skylights are even worse because they face the sun in the summer and boil you out. In the winter they are covered in snow and useless a majority of the time. I don't miss mine, I now have a comfortable bathroom.

I put 5 skylights in my house and I have no regrets, other than the fact that I put two in the kitchen, when one would have been just fine. The light that streams in has completely changed the character of the house for the better. Winter time in Western Oregon means long periods with overcast skies, so having light coming in from above has a brightening effect on the soul.

Also, an untended benefit of the skylight in my bedroom is that it just so happened that light from the path of the full moon sweeps across my bed at night. This often wakes me up, and reminds me of my position as a humble observer in this parade that we call life.

I have my house insulated to such a degree that the skylights, for the most part don't drag the house out of the comfort zone. All of the skylights open but one, and they play an important part in summer ventilation.

Our winters usually feature a week or so of being hit by a 'Blue Norther', when temperatures plummet. I have temporary, fitted foam blocks for particular windows, on those exceptional days.

However, the two in the kitchen do face south and there is summer heat gain that I'd like to reduce.

I like bennelson's approach, easy cheap & safe.

I don't know if other opening skylights work this way, but all of mine have a pin that can be pulled out that allows the window to open up enough for me to squeeze my body through and sit on the skylight ledge, where I can clean or do other tweaks as required.

There has been discussion about some kind of reflective window film called "zilla" or some other stupid word. I tried that on a sun-facing side window, and although it worked, I was not able to get a smooth application. And it is now deteriorating AND glued on. Conclusion: stay away from "zilla" or what ever it is called.

My current thought, which is inspired by bennelson's excellent example, is to use some of the reflective mylar that I got for my Multi Layer Insulation experiments, and apply it to the kitchen skylight windows with soapy water and a squeegee.

As I said above, I really like it that the skylights open, it's an important part of my summer cooling.

-AC

Not crazy at all. Skylights are terrible from an efficiency point of view. They simply do NOT have the R Value of a properly insulated wall.

But I would very much miss my skylights if I didn't have them. The one upstairs is on the side that otherwise has no windows. (It's a very low second story. The skylight actually gives you extra headroom right there.)

The kitchen skylight is on the side of the room that otherwise only has one window. The kitchen and living room are one large room with a vaulted ceiling. The skylight is a central part of that character. In terms of lighting and aesthetic value, I wouldn't trade that skylight for anything, but yes, it does become a pretty hot shaft of sunlight on summer afternoons.

Some removable shade cloth seems like a good simple answer to summer heat gain.

I have also considered designing some sort of internal insulated shutters to be closed at night in the winter, but have never really gotten around to it.

I was up on the roof again today, and took what I had left of the solar screen with me.

I didn't have a big enough piece to entirely cover either of the two panes that make up the kitchen/great room skylight. So, I just put up what I had, using some black gaffer's tape to pin it in place.

Here's a photo from in my kitchen looking up. From left to right, it's direct sunlight, sunlight through the shade cloth, and then the wall shaded from the sun.

http://ecoprojecteer.net/wp-content/...n-IMG_4029.jpg

The area with the shade cloth is SIGNIFICANTLY darker than the direct daylight.

I really like the idea of a simple, removable exterior shade using this "solar screen" material. I'm not sure of the best way to mount it, especially on the kitchen skylight. The roof is 10/12 pitch, which means I can walk on it, but just barely. It would be relatively easy to lose traction and fall right off the roof.

So, a very simple way of attaching the screen, that DOESN'T involve too much time with me on the roof would be good.

At this point, I'm thinking about a light-weight wood frame that would sit on TOP of each of the two panes of the skylight.

The flashing on the uphill end of the skylight sticks up more than anything else, and might make a good point to clamp the screens to.

Sounds like a good idea to me. Thats gotta help a fair amount for keeping things cooler in the house (or at least lessening the A/C load).

Ben, since the solar screen is tucked around the edges and goes through any seals, may that cause water to seep in when it rains?
I noticed this problem in my car - the external windshield cover tucks in between the A-pillar and door, and after rain the front seats and carpet are damp.

I like the ingenuity of the solution you're testing. It seems to be a great, budget friendly approach to lowering energy consumption from excess solar heat gain.

It will be interesting to here what you decide the long term solution will be, even if it is to keep using this clamped screen method.