hot weather from sprite

start with some 2×4s and plywood to build a simple box.

built the box to certain dimensions. That sure was a lot of Sprite. Fifty cans in five columns of 10.

Sealed the box using adhesive caulk, just to keep any heated air from escaping the box.

So you may have already thought, “How can air climb the columns of cans when there’s no hole at the bottom of the can?” Answer: drill press and 3/4-inch bit. Times 45.

The last five cans, the bases of each column, will sit on the bottom of the box and thus will

be unable to draw air from underneath, so I poked holes in the sides of each of the five.

Stack the cans with liberal doses of adhesive caulk. Give them enough time to dry.

Once they’re dry, I painted each column with black BBQ paint. Black to best absorb the sun’s heat, BBQ paint to keep from flaking off the cans. At the top, I drilled an outlet hole. I left an inch or two of space between the tops of the columns and the top of the box to permit air to flow out of the columns.

I drilled the outlet hole based on the diameter of some wet-dry vacuum hose I picked up, about 1-1/2 inches in diameter.

At the bottom, I used another wet-dry vacuum attachement that would more evenly disperse the incoming air. Screwed it in at each end, then caulked the seal.

Then started to caulk the columns in place. At the bottom, you can see the inlet hole I drilled. At about this point, I realized that a better place for the inlet would have been through the plywood at the bases of each column. In this location, the air can simply pass over the cans (there’s about 1/2 to 3/4 of an inch between the cans and the upper edge of the 2×4 frame) and not really pick up that much heat. If I were to relocate the inlet, it would force all the air to pass through the cans and pick up the absorbed heat. Next time.

Had some red paint left over from one of Heather’s previous projects, so slapped on a couple coats to at least keep the weather off the bare wood.

The caulk is pretty strong. Kept the cans from falling out while I had the box inverted.

Also had some 3/4-inch PVC pipe from another previous project. Bought a couple elbows and T-fittings and whipped up a simple frame to keep the box off the ground and to angle it upward toward the sun. Didn’t give the exact angle too much thought.

Caulked a clear plexiglas cover on the front and sat the furnace out in the sun for a full day over the weekend to see how it would work.

Using some advanced technological

equipment, such as this precisely calibrated pyrometer, I determined the intake air temperature, which should have been the same as the ambient air temperature, to be about 80 degrees.

Using the same equipment and methods, I determined the outlet temperature to be about 95 degrees - thus a 15 degree temperature differential. Not 110 degrees, but not bad , considering I didn’t even break $50 in materials - most of that being the plexiglas window.

Tags: heather, vacuum hose, weather