As the winter season starts to settle in, we were in a bit of a quandary. You see, in our happy place, we would already be gone from here and tucked nice and warm in our new home in the frozen North. However, your happy place and a buck two fifty will get you a coffee at Micky D’s. So it pays to check in with reality now and then to keep a grip on things.
Things like we had to take out our wood stove, so we could sheet rock the wood portion of the house. And the sheet rock guys just called and said they are coming Nov 30th to do the job. That means no heat in the house for a good long time. We usually get a mean streak of winter starting around December 1st. The way things are going, I will have the wood stove installed and fired up about the second week of December. While I like winter, I hate being cold and it was time to take some preventive action to keep from being hunched over and grumpy for the holidays.
I had me an idea that I would whip up a solar appliance that would keep us warm and happy until I could install a real heating system. We also ordered a gas furnace from one of the big box stores and have since learned that it ain’t gonna get here any quicker than the sheet rock guys. So, I headed out to the shop.
Solar is one of those things that sounds so good, but has a tough time scaling up to make anything big of itself. What I mean is, your house would do well with solar heat. Done right, it does not cost much and can do a good job in a single family dwelling. Where it fails is wild eyed dreamers, without too much learnin’ in the practical science end of things, tend to think they can take a good chunk of Arizona and make it provide electricity for a bunch of people. They are trying a version of that at Ivanpah, California. 3 huge solar plants, lots and lots of money, some of it yours and mine, and they can provide power for maybe 140,000 homes, oh and reduce carbon dioxide or some such nonsense. They always get into the hand wavy parts when they talk alternative energy. That is usually when they want you to pay for their dreams.
So, like I said, solar, great stuff, has trouble scaling without spending lots of money. My idea was to make a sealed insulated box, glaze it with something transparent and through the natural convection effect, pipe it into the house. We had done a similar thing a couple of years ago. I whipped up a quick green house on the south side of our house and it gave us a very nice heat throughout the winter.
It was not meant to be permanent and was taken down in the spring. I had done quite a bit of research on my solar box idea. They are called many things online, but beer can heater is a popular name for them. Since I had most of the stuff lying around, I got to work.
Formed up a box of 3/4 inch plywood. Made it out of what I had so it was a weird size, 36 inches by 55 inches. I had a sheet of one inch styrofoam insulation and installed that in the box. Next, drink 130 beers so you can use the cans, or save your liver and make tubes out of the aluminum flashing I had. The cans or tubes are painted black and absorb heat and let it flow to the top of the box.
I had to think a bit on how to make the tubes. It turned out to be an evolution of creation in making them. I needed the tube to be around beer can sized, so you find the circumference, 2 x pi x radius which came out close enough to 10 inches, I could get 2 pieces from my 20 inch aluminum flashing. Next, to get them in a tube shape, you had to form them, in stages. I had a 4 inch pvc pipe that I used to start the forming, then pushed them into a cardboard tube that I had that was a little smaller. To get it down to the size I needed, I had to use my jigsaw and make a 3 1/8 inch hole in some 3/4 inch plywood and another one at exactly 3 inches. Now that I had the tube down to size, I needed to drill a hole for a rivet and, well, the first one was not real pretty and had way too many rivets, the second one looked much better and by the time I finished the 11th one, I was pumping them out like a pro.
I used a generous gob of caulking to stick them to the styrofoam backing. While I was tube making, I was sort of wondering about exposed styrofoam. I know the box is going to get hot; I was concerned that it would get too hot and melt, so I thought I would cover it with more of my left over aluminum flashing. This presented a new problem, how to bend the aluminum at a 90 degree angle. A metal brake is needed and something I have been wanting to build for quite a while, so I went back to the internet for a decent design.
Finally, after wading though many, many complicated designs, found one that was dead simple. I had an 8 foot piece of 1 1/2 inch angle iron. I just need to cut that in half and weld a pair of 3 inch hinges to them as they are butted up to each other. I had everything but a decent hinge, so I sent the wife off to Wally World and that took care of that. I had some oversized (for this job) 6011 rods for my stick welder and did an amazingly ugly, but successful weld. I added a pipe handle to my lifting side and scrounged a 1 inch angle iron for the top clamp and I was bending metal. It turned out that if you score the metal with an awl, on the line you want to bend to, the totally butt ugly metal brake will give you a 90 degree angle you could shave with. It was awesome. I had so much fun bending metal, that I was a bit sad when the whole thing was covered in aluminum.
It was getting close now. Tubes were on, the skin was aluminum and now I had to glaze it. In my research, I was getting wild temperatures that people said they were getting with their beer can heater. I had some poly glazing I got from Lowes and when I read up on the specs, the dang stuff will melt over 180 degrees. I was not real sure I was going to get to that temp, but since this was a passive system, I could not cool it down and I would be a sad puppy if my solar appliance melted, so, I needed glass to cover my box.
We recently pulled a very large window out of the living room. It was a really oddball size, 54 inches by 56 inches. The glass panes were a full 24 by 50 inches and since we were replacing them, I would scarf them up for my project. Getting them out of the frames and not breaking them was more fun than I want to talk about. Finally got them out and put them on my layout table. I made a quick window frame, rabbited out a place for the glass and now it was time to cut me some vintage 1950 melted sand. I have long planned to make stained glass windows for my future job, so cutting glass is no big deal for me. Got me a slick glass scoring tool, made my mark and scored the glass, slid the glass over to the edge of my table, a quick bend downward and you’ve got cut glass. First one went like planned, the second one I thought I would video and for some reason, only used one hand and it broke just fine, but the piece I was holding broke, too. Trying to be a show off I guess. No harm, no foul.
Got the glass installed in my window frame and used some hated silicone caulk to weather proof the window. I hate silicone, because you can’t paint it and it gets everywhere. Had the Mrs come out and clean the glass. I can do pretty much everything else, not much good on cleaning glass.
Screwed the window onto the box, gave it a quick coat of paint and the next day, it was ready to get installed to the house. Piping it into the house was kind of a pain but I like the versatility of pvc pipe. It would have been easier with flex pipe, but I only had that in 4 or 6 inch diameters. It would not work for my 2 inch pipe. As soon as the sun hit my solar box, it started putting out heat. Got it all piped into the house and it starts warming up the kitchen. I got an oven digital thermometer and check the temperature. I stopped checking at 155 degrees coming into the house. I guess the YouTube people were not making up claims of big heat.
Trouble in Paradise… I noticed after about an hour of heating, we were getting some, ah, off gassing of, I don’t know, paint or something. I pulled the connection and thought I would check it again in hour or so. An hour later, It was worse, so I took my digital thermometer and stuck it into the hot air outlet and was incredulous as to what I saw. It stopped at 236 degrees. This is a 3 by 4 and a half foot box, painted black and we are getting over 200 degrees. I am a little concerned my styrofoam may be getting light headed. Keep in mind folks, this kind of solar appliance will work in any sunlight, including the middle of winter. And it works even better with water. That will be plan B if my first box goes up in smoke. I will give it another whole day to get its act together and then, either run with it or put my thinking beanie on and come up with another way. I am quite amazed at what I have seen so far. Sunshine on my solar box makes me happy, fumes from my melting styrofoam makes me cry. I think John Denver did it better, but not by much.
Update and Postmortem:
I had to pull the plug on my Box of Sunshine & Doom – Version 1. It seems I might have built my box a bit too well. I noticed the next morning that the interior of the glass was misted with something ominous. I decided that I really did not want to be breathing whatever was gumming up the glass, and cracked the seal on the box. Wow. You know how when you heat styrofoam up past its happy place, it starts to shrink and deform. I did a bit of poking around to find what temperature would do that and 300 degrees is what the guys in the know say. So, I am guessing the top on the box was in that neighborhood and the white caulking turned to crumbly white particles. All in all, it was a resounding success, as far as heating air up with just sunshine. Nothing you want to breathe in however, and that means back to the drawing board. No worries though, got a new plan.