Solar Heat Collectors

We use six 4-foot by 10-foot Heliodyne Gobi flat plate collectors to heat water for space heating and domestic hot water. The heat from these panels is stored in a large storage tank and then used to heat water for showers and other fixtures, and to heat the water flowing through the radiant floors in the winter.

November 9, 2009
We mounted the six collector panels on the vertical wall above the south side of the garage. Liz, Bruce and Dan unloaded them from the trailer and lifted them up onto the roof above the front porch. Each panel weighs about 150 pounds so they’re manageable but not exactly lightweight. We set them on an aluminum rail bolted into the wall structure at the bottom, and then attached them to the wall with small clips on the sides. The panels come with union fittings at the top and bottom corners so we just screwed them together. The pipes running along the bottom connect to form a manifold into which the cold fluid flows from the left (west) end. The fluid then picks up heat as it flows upward through each panel, and the pipes running along the top form another manifold that sends all the hot fluid out the right (east) end. From there it goes directly to the storage tank and through a copper heat exchanger that transfers the heat to the water in the tank, then through a pump and back to the cold inlet. The fluid in this loop will be a mixture of water and non-toxic antifreeze so it won’t freeze on cold winter nights.

It only took us about 2 hours to mount all 6 panels. The hardest part was the heavy lifting, most of which was done by Dan and Bruce.

Even with the very weak sunshine today, the panels were already getting hot. After less than an hour in the weak sun, the copper fittings at the top were too hot to hold comfortably, perhaps 120 degrees F. The panels are designed to withstand “stagnation”, meaning sitting in full sun without any fluid flowing through them, but it will make them quite hot and rather than stress the panels we covered them with tarps for now. We will uncover them after the rest of the plumbing is connected and fluid is circulating through the panels.

December 29, 2009
Here’s a photo of the collectors finally in operation, on the first sunny day after we got the plumbing hooked up.