Monday, May 30, 2016
Monday I finally got around to disassembling one of my projects that no longer made any sense. Some years ago I built a solar batch hot water heater. It was maded from a salvaged propane water heater, salvaged windows and scrap plywood.
Our tankless water heater failed and at the time money was especially tight. The local building supply company had a small 3.5 gallon water heater for sale at a ridiculously low price. It was just barely big enough to make hot water to wash dishes or take a quick shower. The solar hot water tank, on good days, provided enough hot water to fill the bathtub for a hot soak.
Over the year the 3.5 gallon heater failed and was replaced with a 40 gallon tank. The big tank was also hooked up to heater coils off the woodstove. The solar water heater, over time, became heavily shaded by trees. Some of those trees were actually on the neighbor's land. My quickly growing nut trees provided even more shade.
Monday my lovely wife asked if I was ever going to do anything with the solar water heater or if it was time to scrap it. As much as I hate to let things go it was time to take it apart. Some of the glass could be salvaged, as the tank itself plus the insulation. The wood had both rot and an ant infestation. The remains are now burning in the fireplace.
Solar hot water only makes sense here for about 3 or 4 months out of the year. At least, the low cost 1970s, style low tech heaters only make sense for that long. Current high end systems with sophisticated controls, large storage tanks and a freeze proof working fluid can work year round. My daughter has such a system and it makes sense for her.
Right now I might just suck up a couple months of higher cost hot water. It's only until the short summer is over and we start burning wood again.
That doesn't mean we aren't thinking of solar options. I do have a large coil of ¾ inch plastic pipe that I could toss on a sunny roof then feed into the hot water heater. Perhaps if I can get away without spending to much money or time on it, that might just happen.