screwed up my plumbing

PVC at 104 degrees is fine. I assume that it's also not under pressure.

What happens with PVC is that you have to derate the pressure that it can withstand as the temperature increases. In your setup, there shouldn't be any real pressure to speak of.

My hot tub heat exchanger is made of PVC. Don't know if it will work or not - only had it running for six years so far.

I used a piece of 6" PVC with 16' of 1/2" copper running back and forth inside.

Ya, like NoFo said! PVC is rated at 73 F. It looks like you are using 3/4 schedule 40 pipe which is rated around 480 PSI at that temperature. Larger sizes are less, but I routinely see 6" pipe carrying 100F water all the time. Just make sure any fittings are also schedule 40 and not DWV (drain pipe).

Chris

My Hot tub setup is 3/4" sch 40 pvc and it will be fine at 104 f, my problem I am a well driller not a plumber so I am use to making a mess and used purple cleaner(should of used clear but code for filters etc you need to see it) and it is all over my pipes. Did not bother me at first but now every time i go into the mud room it glows at me. Going to break it down and use brass and upnoor (wirsbo) so instead of $ 40 worth of pvc it will be $200

In regards to your question about how well it works:

Here's a graph showing the heating system after filling the hot tub with fresh water. Starting temp is 64 degrees, ending temp is 104 degrees. Hot tub is 550 gallons.

The heavy black line near the bottom of the graph is the hot tub zone valve. You can see that it was open for almost exactly 3 hours. That works out to a bit over 12 degrees per hour temperature rise, and an average of 61,000 BTU/hr delivered into the hot tub. Roughly 18 kw equivalent, or about three times the heat capacity of the electric element that came with the hot tub.

603doug said:

...my problem I am a well driller not a plumber so I am use to making a mess and used purple cleaner(should of used clear but code for filters etc you need to see it) and it is all over my pipes. Did not bother me at first but now every time i go into the mud room it glows at me. Going to break it down and use brass and upnoor (wirsbo) so instead of $ 40 worth of pvc it will be $200

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Acetone will take the purple off.

Or you can spray-paint the pipes.

Either is cheaper than re-piping it. Not that re-piping it would be bad, but there are certainly ways to solve the aesthetic issue, without spending that money.

Joe

I have my setup using schedule 80 pvc off the stainless heat exchangers. However, I went with a 12" stainless pipe on each side of the exchanger just to help keep possible high temps away from the pvc. I also have a flow switch in the pool flow loop that is a permissive for the heating loop to start. I also have an aquastat that cuts out the heat at around 100 deg F. I can't tell the exact size of the exchangers you have but it seems like with 180 deg water flowing through them you will never see 104 deg pool water. My pool flow rate is around 40 gpm and it can really remove heat from the boiler water.

603doug said:

My Hot tub setup is 3/4" sch 40 pvc and it will be fine at 104 f, my problem I am a well driller not a plumber so I am use to making a mess and used purple cleaner(should of used clear but code for filters etc you need to see it) and it is all over my pipes. Did not bother me at first but now every time i go into the mud room it glows at me. Going to break it down and use brass and upnoor (wirsbo) so instead of $ 40 worth of pvc it will be $200

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Insulation hides a myrad of ugliness!

Now; about that chair...

Chris

Whatever failure that may occur will be on the male/female adapters...ask me how I know!

Man, that looks like the plumbing for a nuclear reactor! Nice to hear that it's working for you. Nothing like soaking in a hot tub heated with free heat.

hi Nofo I like your hot tub heat exchanger, can you explain more how you built it? Im guessing inside the pressurized heat zone loop is in the copper and the hot tub is pumped through the PVC pipe but not under pressure? How did you make the connections going in and out for the pressurized system and not have leaks on the non pressurized side?

mpilihp said:

hi Nofo I like your hot tub heat exchanger, can you explain more how you built it? Im guessing inside the pressurized heat zone loop is in the copper and the hot tub is pumped through the PVC pipe but not under pressure? How did you make the connections going in and out for the pressurized system and not have leaks on the non pressurized side?

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You're exactly right - the PVC has unpressurized hot tub water. The only fancy thing that I did was to drill out two 1/2" NPT-copper sweat adapters so that 1/2" copper would slide through them. I soldered each in the middle of a section of 1/2" copper, then threaded them into holes that I drilled and threaded in the PVC cap. I then assembled the rest of the HX to those pipes and screwed the PVC end cap in. Boiler water never touches PVC.

I think I can picture what your saying, very clever. So the hot tub water is held in by the NPT adapters threaded into PVC, havent had any leaks with that?? Are the end caps glued on to the 6" pvc pipe??

mpilihp said:

I think I can picture what your saying, very clever. So the hot tub water is held in by the NPT adapters threaded into PVC, havent had any leaks with that?? Are the end caps glued on to the 6" pvc pipe??

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No real leak problems, except threaded PVC end cap had to be glued in. It's a sealed and non-serviceable unit.