Solar Hot Water System
(Editors note, all these pictures and text originated in a thread on the cheaprvliving.com forum, in a thread by BigT about how he converted his Ford Transit Connect into a tiny RV. I was so impressed with his hot water system I asked if I could post them here for all of you. He graciously agreed so here are the pictures and text from the thread. Bear in mind some of it is in answer to questions and is an explanation of the pictures, so often there is no context. While some of the things he did would be beyond the skill level of many of us (including myself) if you printed this post out with the pictures and took it to a handyman proficient in plumbing, he could easily reproduce it for you. See the whole thread here: http://www.cheaprvliving.com/forums/Thread-My-2010-Ford-Transit-Connect-conversion?highlight=water )
The rack is a Yakima with towers designed to mount to the factory hard points on the roof. I think I paid (way too much) about $400 for it. The panel is a 190W Grape Solar I picked up at my local solar shop for a little less than $1 per Watt.
Before anyone asks….. I hung it from the crossbars instead of mounting it on top because I have clearance issues under my carport. When I move I plan to flip it.
I thought about PVC, but it weights 3 times more than ABS. Cheaper, though. Sometimes, if I’m worried about it, which isn’t often, I’ll put hot water straight from the water heater into the tube when I fill it instead of cold water. The insulating properties of the ABS keeps it warm for a long time.
I made the aluminum frame for the tube almost the length of the tube itself to eliminate the chances it would warp.
I decided to go with gluing a threaded fitting w/cap over a 2″ hole I drilled in the side of the ABS instead of using a t-fitting, because the t-fittings are $25 each. They’re also pretty darn big. Placing a piece of sand paper on the side of the pipe is a good way to insure that the fitting perfectly seats against the pipe-wall.
Fitting the Schrader valve to the end-cap takes a little more finesse, as the ABS is too thick for the sealing area of the stem. A spade-bit works well as a countersink bit.
Clamping the end-cap to a piece of wood is a good way to ensure that the drill bit stays centered in the hole.
I used a radiator drain valve to release air pressure from the tank to make it easier to remove the cap.
This angle gives you a better view of the curve I sanded into the fitting/filler-tube.
As stated, there’s a 2″ hole under the threaded fitting for filling the tube with water (or beer, as a friend suggested). Once the glue sets, the finish is much cleaner than as seen in this photo.
I went with a 4.5′ length of aluminum channel I picked up for $10 at the local metal scrap yard to mount the tube to, but in hindsight I probably could have just used a length of Super-Strut from Home Depot. The Super-Strut would likely have been much lighter weight, but it would also have been a lot more expensive.
My system, however, is considerably more sturdy than what the S-Strut would provide, so I’m not really sorry I chose it.
As with everything but the kayak rack, I used u-bolts to secure it to the crossbars.
Originally I was just going to use a simple valve and shower head, but I quickly realized that if I was going to have pressurized water at my disposal, I was going to want to have the option to use it for more than just showers.
Having a hose gives me a lot more options, like washing the salt water off the the kayak and solar panels, and washing the dirt off my feet before putting them inside the van after getting out of the water. I’ve also used it to rinse off my neoprene gear before removing it and placing it in its plastic tub. Pretty much anything I need water for, this system provides, though I don’t drink it or cook with it.
Some people feel that the toxic chemicals that go into the production of ABS plastic can leach out into the water. Personally I’m more concerned with the toxic glue I used to fasten the pieces together, getting into the water, so I don’t ingest it.
So the hose system won out over the shower head. I used a low-flow shower head at the end of the hose, and have a valve at both ends of the hose.
I was going to use a 12V mini compressor to keep the tank pressurized, but most 12V systems I found were far too loud for my taste, so I went with a simple foot-pump. It’s silent and works just fine. I rarely pressurize the tank more than about 20 psi.
I went with simple brass fittings and valve to deliver the water from the tank. I was going to use plastic, but it was 3X larger and 2X more expensive than brass. I painted the valve with flat black paint so the brass wouldn’t stick out on the side of my van, tempting scrappers to help themselves to some free cash at the local recycling center.
Durability is another reason I went with brass. The tube shades the valve most of the time, but it will still be outdoors its entire life, so I wanted something that would stand up to abuse and extended exposure to sunlight.
I’m still shopping for an affordable, quiet, 12V mini-compressor with a pressure regulator. Being able to set it to 20-30psi and forgetting about it would be nice. Though there is something nice about the entire system being silent
Thanks BigT for letting me use your posts and photos!!!!
Of course there is a much simpler way to get hot water and that’s with a simple solar shower, hot water bag. I’m sure you know they are a black bag you set in the sun and the sun warms the water inside. It’s ancient technology and it works remarkably well!
However, I’ve found several problems with them that are weak points in their design:
- Because they are heavy (40 pounds) many of the ones I tried eventually stretch and break at their hang point.
- Many have poor water inlets that are hard to open and close and eventually leak.
- The shower head may not have an on-off ability and the water flow is often too weak.
I’ve tried several brands from cheap to expensive and never been happy with them and so I gave up on them. But my friends Kyndal and James have tried them all (and hated most) but eventually found the one that they highly recommend. Get it from Amazon here: Seattle Sports Solar Shower-5 Gallon
This one is highly rated on Amazon Viking Nature Solar Shower Bag
Whichever one you get, I recommend you not hang them, for two reasons, first, they are so heavy it’s a pain to do it and then a pain to refill them, second, eventually the hang point will fail. I suggest you just lay them down at the most convenient place you can find. One good choice is on the roof of the van or your car.