Pressurized Shower Heater

[Sunking]

Here in Panama your next door neighbor to the east, outdoor showers are quite common. Most are nothing more than a barrel painted flat black and elevated above the shower area. Others like me use a coiled 50 meter black PEX pipe and at times can be too hot.

[sanramon]

Hi Sunking, yes I have seen reference to this type of solar water heater. I understand they work great at the end of a hot day. I am hoping to be able to store enough warm water for a comfortable shower in the morning. And yes my project is more expensive, but then I tend to over engineer everything. Whether it needs it or not.

When I lived in Papua New Guinea in the 1960's, our home had a steel tank on the roof peak, painted black as you mentioned. As we lived on rain water collected off the roof and stored in tanks in the yard, a daily chore was to pump water up into that roof top "heater tank". If you forgot - no warm shower tonight! And the first person into the shower got the warmest water. Ah, memories. But now we have mains delivered water (yes, here in Costa Rica) and a 20 tube evacuated-glass tube heating system that can boil water. Now we are spoiled.

[Mike90250]

Here in Panama your next door neighbor to the east, outdoor showers are quite common. Most are nothing more than a barrel painted flat black and elevated above the shower area. Others like me use a coiled 50 meter black PEX pipe and at times can be too hot.

Thats what we had before the house was built. 10-11Am was the time to take a comfortable shower, after 11am, the water was too hot.

[sanramon]

The project is built, tested and ready for installation tomorrow morning. Set up in my yard with sun available only from 6:45am-1:30pm, It reached 34, 36 and finally 39.5*C at noon on the third day. This may be a bit of an unfair test as I did not draw off any hot water, as would be done in real life. But also, the rooftop install will get more sun. Unfortunately the orientation is at 60 degrees from north due to roof angle. Collector tilt angle will be at 15 degrees, just a bit more than the 10 degree roof angle.

Temperature loss overnight (17 hours without sun) was 3.8 and 4.5 or just around 1/4 to 1/3 of a degree per hour. Not bad for broken styrofoam chips as insulation.

Total cost was about $350 US - a little more than I had hoped for, but I did use best quality parts like CPVC tube, brass valves and such.
Here is the test setup, it will look tidier on the roof!

[sanramon]

The now NON-pressurized shower water heater is installed. During a 3 day test before installation it reached 39.5*C with about 5 hours of direct sun - then tree shade took over. Temperature loss over 17 hours of non-heating evening and night was only 4.5*C. I am happy, the new owners are happy!

However.....I bin thinkin'... This system faces 60 degrees from north, and is at 10 degrees latitude. Southerly facing mounts are not possible. I feel it could use an extra collector. I see two options:
1. place a second collector beside the first on the east facing roof slope, plumbed in parallel or
2. place a second collector on the west facing roof slope, and again plumbed into the first and the tank with Tees.

The outlet to the collector is well above the roof ridge line, so there should be no blockage to thermosyphon flow. It does mean longer piping for the cool and heated water, though and 2 extras Tees.

Any helpful thoughts on this setup will be greatly appreciated - diagrams below.

[LucMan]

Because of the 10 degree roof pitch it will not make much difference either way. I would go for the easiest piping arrangement.

[sanramon]

LucMan - thanks for the vote - I will go with your suggestion. Keep It Simple... And after drawing more diagrams of solar angles, etc, I agree it wouldn't make enough difference to mount the second collector on the west side.

The family is ecstatic with the hot water shower! First in the house, in 30 years. I was surprised that the head available of only about 2.5 meters was sufficient to give a good shower spray.

If anyone wants drawings, photos, experiences with this type of project, just let me know.
Here's the finished project.

[sensij]

Thanks for the update, congrats on a job well done.

[Logan005]

Amazing, the panel looks great, the tank not so much, but is the only way. I am so happy you can provide your family hot water.

[sanramon]

Thanks for the comments guys. Logan005 - My last post wasn't too clear - its not my family but a neighbouring Costa Rican family. We're good friends and help each other out. They bought the parts and I did the labour.

The hot water tank had been a bulk soap container inside that yellow barrel for bulk shipping apple pulp from Chile to Costa Rica, so aesthetics weren't part of the plan. I thought it looked pretty neat, complete with a green logo .