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In this post we are looking at how BigT installed a passive solar hot water system on the roof of his Transit Connect.

In this post we are looking at how BigT installed a passive solar hot water system on the roof of his Transit Connect.

I have two more posts coming up on the environment in order to complete my thoughts on the subject. But, my passion for the environment annoys some people so I’m going to break it up a little before we come back to that subject. Hopefully no one will object to this pro-environment post.
(Editors note, all these pictures and text originated in a thread on the 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: )

Solar Power and solar hot water. That’s green living!

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.
He put the snadpaper on the big pipe with the grit side up, and then rubbed the other pipe back and forth on it until it perfectly conformed to the curve of the big pipe.

He put the sandpaper on the big pipe with the grit side up, and then rubbed the other pipe back and forth on it until it perfectly conformed to the curve of the big pipe.

Perfect match!

Perfect match!

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
The finished product in action: hot water on demand anytime, anyplace!

The finished product in action: hot water on demand anytime, anyplace!


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:

  1. Because they are heavy (40 pounds) many of the ones I tried eventually stretch and break at their hang point.
  2. Many have poor water inlets that are hard to open and close and eventually leak.
  3. 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.

Thanks for supporting this site by using these links to Amazon. I’ll make a small percentage on your purchase and it won’t cost you anything, even if you buy something different. 

RV Parts and Accessories at


  1. Calvin R

    This is a good bit to complex for me, although I get the general idea. Would it work to set up a piece of PVC or similar pipe painted black along one or both sides, vent via a T and threaded cap on one end, and set up a hose outlet on the other end?

    • Calvin R

      Removing the threaded cap (or plug) would give a filler opening. This would also give a nice blue-collar look for those who need stealth.

    • Bob

      Me too Calvin. I’d not bother with pressurizing it and just let it be gravity fed. That would be pretty simple.

    • BigT

      People have made these shower-tubes dozens of different ways.. I see not reason why your idea wouldn’t also work. Give it a try and let us know how it turns out!

  2. Al Christensen

    There’s a guy marketing a very similar mobile shower. After many prototypes, he saw that plastic wasn’t a very good conductor of heat, so he’s making them out of aluminum. Since that’s way out of the skill set of most of us vandwellers, this ABS version is a viable alternative.

    • Bob

      Al, he copied this from the commercial design. I don’t think the problem is the plastic, it’s too big a pipe–not enough surface for that amount of water. If he had used 2 inch pipe and wound it back and forth across the roof I think it would get very hot.
      Yeah, anyone can work with ABS or PVC.

      • Calvin R

        Online calculators give me a volume of over 15 gallons by using 4 x 5′ of 2″ pipe and 4 x 1′ to join them. That’s a lot of hot water! PVC is also my favorite material. Even with my very limited money, tools, workspace, skills, and physical abilities, PVC projects are still “doable.”
        However, doing that hot-water system with a roof rack takes away the choice of solar PV up there. There are other ways of doing PV, and I’d probably change the PV.

        • Bob

          Calvin, you’re right he has a Connect and they are tiny, no room for a big water system up there. That was probably the only option he had for a mounted system

      • BigT

        Actually, I copied it from the way countless DIY’ers do it, and the reason it doesn’t heat up as much as you might think is because ABS works more as an insulator than it does a heater.
        The wall of the plastic is very porous and acts like insulation.
        The water does heat up, just not as much as it would if the pipe were made of aluminum.

        • Camper Dave

          I made a very similar heater using aluminum lamp posts from home depot. I haven’t used it yet but I was able to couple abs fittings and use the same design. I’m hoping it gives me good hot water without breaking the bank by buying the commercial model

    • Ming

      I thought so, and perusing my bookmarks confirmed that it is the road sower (.com), for those not DIY oriented.

  3. Linda Sand

    As a short person I wonder how you get up there to refill it?

    • Calvin R

      I’d use a step stool, which is multi-purpose for me because I’m 5′ 2″ tall, or I’d use the step well of a door if the pipe reached close enough.

    • Bob

      Linda the easiest way would be a D-battery operated pump. Just use a step stool to open the top spout and stick the hose in and turn on the pump.

      • Gabriel

        but if water pump brokes down you can just dream about a shower

  4. Cae

    Nice set up. Petty stealthy looking. At 20 psi, for how long will it run before going dry? What is the water capacity ?
    I saw a guy using a 5 gallon, pump up bug sprayer with a shower head at the end of the hose that he’d painted black and had a removable mount on his roof. Simple, effective and clever. I think he said the sprayer with shower head was about $40 and another
    $10 for the mounting set up.
    Made a mental note to copy it.

    • Rob

      This water system takes zero room inside the van & that’s a very positive thing.

    • Bob

      I’m sorry Cae, I don’t know any of the details about the system. I’ve done the sprayer painted black and it works okay, I don’t think I’d mount it to the roof though. Might be worth a try.

      • Cae

        Oh. He told me he only mounted it to get warm and then use it. He had a quick release for easy mounting and then removing it.

    • BigT

      How long you can shower with it depends on how much water you use.
      I installed a low-flow shower head with an on/off valve so I can take very efficient “Navy Showers” with very little water.
      The capacity is 4.5 gallons. I thought about going with something similar to the bug sprayer system, but the van has precious little room inside, so I wanted something permanently mounted outside. I suppose I could have mounted the bug sprayer on the roof, but that would create a lot of drag, and I have very limited room under my carport. I’m working with about 2 inches of space above the crossbars.

  5. hotrod

    I have been fascinated with the potentail of “fresnel lens” since I first heard about them. A google search for “fresnel lens water heater” will reveal many possibilities for a mobil hot water heater. Overall this is why I would prefer cooler temperatures to camp in. I am hoping a simple sponge bath will do the trick of keeping myself fresh until I can make it to a shower at a truck stop. Once, when living in a Portland, Oregon in an apartment, as an experiment,I went 2 weeks without a bath. No sponge baths or anything. Yep 2 weeks that is as long as I could stand my smell. Now my significant other might say otherwise.

    • Lucy

      Hotrod, 1 ) Thanks for the information on ‘ fresnel lens water heater’.
      2 ) Perhaps after 2 weeks without @ shower you could have been called ‘ stinkyRod ‘ instead of hotrod !! LOL.
      My regards, Lucy

    • Bob

      Hotrod,everybody has a different body chemistry, some people get out of the shower and smell within minutes, others can go forever without any odor. It’s the luck of the draw! Sounds like you were dealt an average hand.

      • Lucy

        So true what U’re saying, Bob, our physical make up is due to genetics & there is not much we can do about it ! I worked as a nurses aid ( long time ago ) at the hospital there used to be this man that scrubbed himself well every single day & regardless he smell so, SO bad that he requested something for his condition, the doctor prescribed chlorophyll capsules & that help some, but not 100 %.

        • Bob

          That poor guy! I am 100% the opposite, I can go years without a shower and not have slightest odor. He got all my smell!!

  6. Andy

    That’s and interesting setup. Have you seen this item from Coleman. Really handy for having on demand hot water anywhere. The temperature can be set as desired and gets hot enough to make coffee or tea with it as well as wash dishes and take a shower, and it has a built in pump so no gravity feed. Battery can be charged off 12v in the vehicle and lasts a long time.

    • Bob

      I’ve seen those before Andy, they are pretty interesting.

  7. Canine

    Whatever plastic pipe you choose, be sure it is UV stabilized or paint it. It doesn’t take much to stop ultraviolet light from breaking down the plastic. ABS is particularly vulnerable to UV without being stabilized or being protected. ABS handles impacts in cold weather better than PVC. There’s lots of plastics out there, so one should check into whatever type you are going to use.
    Just a little info that may help someone decide what plastic is best for them.

    • Bob

      Thanks Canine, I know little about it so that’s helpful.

  8. Jeremy

    Hey Bob, If you put a solar shower bag against your paint on the hood or roof it eats the paint job off. I found out the hard way ?

    • Bob

      Jeremy,thanks for letting me know, I had no idea! Have you ever tried putting Reflectix under it, or even cardboard to protect the paint? That might protect it.

  9. lisa

    The ABS will warp in time due to the sun
    ( the pvc will not)

    • Bob

      Lisa, I’ve never worked with either so I didn’t know that, thanks for letting me know.

    • BigT

      As described above, I used a 4.5′ length of aluminum channel to mount the 6.5′ piece of ABS pipe to the crossbars. This means that only 1.0′ of pipe sticks past the mounting channel at each end, eliminating the possibility of warpage to the pipe.
      It’s good of you to let others know about the potential of warpage if they don’t provide sufficient support, though.

  10. hotrod

    Hey Bob,
    Just saw your video on you tube with a guy named Sameer. He was a 60 yr old man vandwelling for about three years. He was showing his very nice and organized setup in his van. I am given thoughts on going with a van but not sure if I could comfortable maneuver in and around like Sameer could. I am 6’ and around 250 lbs something..ish.*clears throat*. He appeared slim and I guess short and slim works best for any tight space.
    I did really like his idea for shower. Use tea kettle and fill a battery powered sprayer with hot water. I would like to use the same setup but would try it outdoors so i could stand up and use somthing other than a clear shower curtain ofcourse. Thanks Bob.

    • Bob

      I’m glad you liked it hotrod. Sameer has a very nice setup and he’s a heckofa a nice guy!
      Being a bigger guy does make a van more difficult, but I have several friends who have done it. Ie key is to be able to spend most of your time outside and sleep in the van. Then the tiny space isn’t such a problem. Of course in bad weather you are forced inside but usually just for a few days at a time.
      The next step up would be a box or step van and above that a small Class C. They are what work for a lot of people but you lose half your MPG.

  11. jeff

    Vandwelling is catching on. Check out for neat story.

  12. jeff under popular articles.

    • Bob

      Thanks Jeff.

  13. raz

    canine is right pvc or abs are not friends with the sun. pvc electrical conduit is sunlight resistant. epoxy is your friend on diy fittings. instead of the rubber schrader valve they make metal ones. snifter valves. work easier with epoxy. the valve looks to be a gas valve. it will work better for this.
    for all practical purposes water does not compress. if it was mine, i would only pressurize it when i was going to use it. if at all. gravity is your friend here. if you fill it with cold water at night and then park it in the sun, well you might find out how much damage it can cause. to much. abs does not stretch like metal.
    all in all i like the idea. good work. it is easy to pick at a job after it is done. we do it all the time. bigT is adaptable. i would like to see what changes he makes on the next one.
    don’t drink the water. well you can if you want.
    ice cream. raz

    • Bob

      I know nothing about any of this raz, but thinks for all that great info. I think whatever you use it would be a good idea to paint it with black paint to give it some protection from the sun. My first thought would also be gravity, but more pressure is better.

    • BigT

      I tried using gravity, but because it required using a free-er flowing head, it was much less efficient.
      I don’t leave the pipe compressed all the time, I only add the 20 psi when I need to rinse something off. If I’m going into higher altitudes and have the pipe filled all the way to the top, I can always open the air release valve (radiator drain valve, mounted in the filler cap) to allow for pressure changes.

  14. Kennyboy

    I think the tubular solar heater is very neat! Myself, I am not a sufficient handyman/tinkerer to tackle it, but maybe it should be tweaked and manufactured so those of us in my situation could buy one.
    I’ve had success with three different approaches to camp showers. I have a camping buddy who introduced me to the Zodi shower which is like a metal bug sprayer that sits on a propane bottle powered burner. Works good. We have a pop up shower tent to go with it. Two people can take a decent shower one after the other on just one filling/heating.
    Another thing that works, except in the coldest months, is I bought one of those battery powered showers that you put one end in the water, and the other end is a shower nozzle. I took a squarish blue 5 gallon water bottle, like you can get at Walmart or camping stores, and painted it black. If you leave it in the sun all day, the water is gets quite warm, except maybe in December and January, especially at my latitude (So. AZ). So you use the water jug together with the battery powered shower.
    The third thing I’ve tried, I got one of those big plastic storage tubs you see for sale at Walmart or other stores. I heat some water on the travel trailer’s stove, put it in a hand pump sprayer, and using a couple of wash rags and soap, do kinda like a sponge bath and rinse off. I stand in the big plastic tub so drips don’t get on my little trailer’s floor. This is one way to do it if the outside temps are too cold to shower outside. My trailer is 7 X 11 and I don’t have a bathroom like larger trailers.

  15. LaMarr Harding

    I have used garden hose, with it’s standardized 3/4 inch pipe thread. A garden sprayer with a pistol grip works well to control flow. I used the black sewer pipe with top and bottom valves on both ends. (the cheap plastic hose shut off type)
    Gravity worked very well, I’ve also used some dunnage load bearing bags, gluing the cheap hose shut off on the lid.
    Laying the bag on the top of the vehicle, painting the bottom side of the bag black, gives warm water.
    On a friends boat, she had a bellowed pump on the floor near a sink. Short white garden hoses screwed on some 5 gallon plastic jugs that she modified to have threaded ball valves, to the bellows pump, and to the garden pistol spray nozzle. She showered, washed dishes, washed salt off the boat.
    She would step on the bellow, and open the valve, and had just the water flow she wanted.

    • Bob

      Lamarr, that sounds like a great system!

  16. Sam

    If you’re looking for something to keep a set pressure in the tank try a low pressure switch for an airbag system like this. Even though it’s preset to 10psi you can usually adjust them by removing a rubber cover on the terminal side and turn the allen head screw under it. I’m not sure how much adjustment range there is. The air fitting side is 1/8″ npt I believe. Be sure to mount it so the pressure sensing portion isn’t exposed to the water in the tank since it’s made for air use.

    • Bob

      Thanks Sam, that’s a very helpful tip.

  17. Paul

    Great staff, Bob!! Thanks for this informative article. It helped me a lot. Go ahead! I am waiting for your next post. Have a great day.

  18. Jony Deo

    Thanks for sharing such beautiful information with us. I hope u will share some more information about solar hot water system.
    Plumber mornington

  19. Happy Hiller

    Hey! How much does it cost to maintain a solar panel?

  20. Jackson Quinn

    Solar collector(s) are located on the roof structure, facing in a northerly direction. The sun heats the water in the collector, which then goes into a tank. The colder water at the bottom of the storage tank then travels into the collector and starts to heat up.

  21. Milo H.

    I have used the solar showers with some success. My only comments are…
    make sure they are in the sun until the last rays of the day. They tend to cool rather quickly. I like to shower later in the evening; not after dark but late evening.
    Putting them on a vehicle roof or hood helps get the water warmer than hanging on a tree limb or ladder. (in my opinion)
    Don’t put in more water than you will use because of the weight, but enough. It seems using more water keeps it warmer longer after the sun goes down. And that’s what we want – warm water!
    Sure would be nice if some company developed a bath water fizzie that could be dropped in at the time of your shower to create a little pressure and enhance water flow. (Sure does work on pressurizing water bottles with electrolyte tabs used for hydration during training runs. (different deal) )
    Thank you for your article. Good ideas.

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