copper tubing?

[PoolDoc]

As I said, building a heater is potentially life threatening. You seem familiar with the safety devices typically used on water heating systems, so I presume you can experiment safely. But I didn't know that when I posted. There have been 3 or 4 prior posters this year with some other DIY pool heating system ideas and not one of them had a clue about safety.

When I post as I did above, I'm not only writing for you -- since you hadn't mentioned T&P valves, etc -- but also for all the lurkers who will Google "DIY pool heater", and end up here.

[Charlie_R]

I agree with your reasoning behind the reply, and I appreciate the reminder. I like the fact you care enough to post that kind of safety warning.

[PoolDoc]

Thanks for understanding!

[Charlie_R]

Well, I did it.

Took an old bbq grill for the housing/firebox, and bought 50' of 3/4" copper pipe along with a bunch of tees and els etc. Even with the fairly small firebox, I'm able to keep 80* water with overnight temps in the high 50s to low 60s, burning junk pallet wood.

I do need to make a few improvements to it, mostly to the flue gas path to bring more of the hot gasses in contact with the copper for longer time. I'm also going to have to enlarge the firebox a bit so I'm not having to add wood so often.

Took a swim this afternoon, 65* air temp, 82* water. felt good, as long as I was in the water, but getting out was problematic.....I got cold real quick!

[Charlie_R]

I goofed. Cost me 2/3 of the water in the pool.

Heater exterior was cool enough to hold my hand on. so I shut off the pump last night. Got up this morning to a muddy mess. One PVC joint failed, and broke free. I assume from residual heat in the firebox.

However, the up side to this is I was able to make the improvements to the heater.

Incoming fill water is measured 63*, yet the pool is holding at 72*, while filling. Current air temp 64*, high today was 68*.

I guess that means the changes to the heater are successful. Looks like I'll be able to get the water back to swimming temperature by tomorrow afternoon. Shooting for 80*+. Anything over that is just gravy......

[Charlie_R]

According to the typical internet meme, pics or it didn't happen, right?

With that said, here is what is happening:

Overall view of the system --



Yes, it looks hillbilly. That is what happens when you use what you have on hand. No filter in the canister, to keep the flow rate fairly decent.

Nice bed of coals --



This is what a pile of used, broken pallets are good for.

Detail of the suction/return lines --





And of course, I can't forget the thermometer --



According to http://www.wunderground.com/cgi-bin/...:65265.1.99999 current air temp is 68*.

I must have done something right, this time!

[PoolDoc]

Uhm. Interesting?

Not sure what to say. It shouldn't be too dangerous, since if the copper overheats, the PVC will collapse before there's any sort of pressure build up. Plus, it doesn't look like you have any valves that would allow a pressure increase to occur.

Not sure how durable it all is, though. Any joints you have that are exposed to the fire are unlikely to last long, unless you used high temp silver solder. If you have calcium in your pool, and get build up in the coil, it can insulate the pipe from the water enough to allow the pipe to over heat. And . . . copper is not especially resistant to combustion gas effects.

But, time will tell.