Many people who are interested in alternative energy are also interested in solar water heating. I can’t really blame them because this is something that intrigues me as well. Several years ago we did some experimenting with a rudimentary homemade solar water heater. We didn’t know much about this technology at the time. What started my interest in this use of solar energy was when something interesting happen to me that caused me to have and “aw-haw” moment.
I had been hiking for several hours and when I finally made it back to the house I couldn’t wait to take a big long drink out of our garden hose but shortly after I turned the water on, I held the hose up to my mouth and the water that came out of the hose almost scalded my tongue! I couldn’t believe that the water that was coming straight from the hose was actually hot enough that I could have taken a shower with it.
The reason the water was so hot was because the black hose was about 100 feet long and it was stretched out in the yard collecting sun all day. The fact that I had a long length of black hose with water in it that was exposed to the sun’s rays was enough to not only warm the water but make it very hot. This is when we decided to start experimenting with heating water with the power of the sun.
A Look At Our First DIY Solar Water Heater
We figured that if something as simple as a length of hose could heat water, we could surely come up with a better design and save on our water heating costs. We contemplated several designs but we eventually went with a very simple passive solar water heater design. All we did was build a simple greenhouse like structure on a tower that was about 10 feet in the air. The walls were insulated to hold in the heat and we then lined the inside with sheets of galvanized metal roofing tin that were painted flat black.
Then we simply placed two black 50 gallon barrels in this greenhouse in the sky that were equipped with plumbing fittings so that we could draw hot water from them as we needed it and pump water to them when they needed to be refilled.
They were actually plumbed so that we would drain one out completely and then refill it. We would then switch a valve and draw water from the other tank. Rotating them this way meant that we were never adding cold water to the water that the sun had already heated as this would have been counter productive.
Our DIY solar hot water system was plumbed directly into a little outbuilding that had a shower stall in it. We had to pump water up into the barrels to fill them but after that the entire system was passive meaning that no electricity was used to pump water out of the tanks and no electricity or propane was used to heat the water in the tanks.
Problems With Our Homemade Solar Water Heaters
At night we would lose some of the heat from the tanks so showers were best if we took them just after the sun went down. This would give the tanks an entire day to warm up. Another problem was that the water pressure wasn’t that great but it did the job fine for our little shower room. One other problem is worth mentioning. Have you noticed how this entire article was written in the past tense? That’s because our DIY solar water heating system doesn’t exist anymore.
We learned a hard lesson about that fact that untreated pine posts will rot at ground level. After a couple of winters, the posts we used rotted all the way through and the entire contraption can crashing to the ground.
While it wasn’t exactly perfect, we got a lot of use out of this makeshift water heating system. We plan on eventually building another one with a better design but all in all, this was a fun experiment that we learned a lot from.
Warning: While our simple homemade water heating system worked fine for us, I recently read an article that said that water heaters that are set at too low of a temperature could make you sick. My husband always added some non-scented liquid household chlorine bleach to our water and we never got sick but I thought that I should mention that apparently it is possible to get sick if the water in your hot water tank isn’t kept at a high enough temperature. I believe it’s called Legionnaires’ disease that you can get. Consequently, I don’t recommend that anyone build or use a system like the one described in this article. I’m sure that our water didn’t get to the recommend temperatures for safe hot water storage. Here’s a link that describes the disease in more detail. www.osha.gov/dts/osta/otm/legionnaires/faq.html.