Thinking outside of the box...would this work?

[trumpeterb]

I am going to make the connections to heat my pool this summer. I was thinking of a way to do it cheaply, and had a couple of ideas that may seem crazy, but may just work. I don't need fancy electronics to monitor the temp and turn the heater on or off or anything like that. I just want to be able to manually turn on a pump, heat the water, and shut it off once it is warm enough. I looked at pool heat exchangers, and the ones I saw were quite expensive. Here are two other thoughts that I had:

1. What if I used copper pipe and elbows to construct some sort of "radiator-like" structure that would zig-zag back and forth and connect to the pex from the loop, perhaps utilizing 8-10 lengths of copper each 3 feet tall, and connect it to the pex coming from and to the boiler. This structure could be submerged in the pool somehow, most likely near the return from the pool filter, when the pool was not in use, and heat the water. When swimming, the structure could be easily lifted out of the water and stored beside the pool until needed again. A designated pump would circulate the boiler water through the pipes via a secondary loop off of the main loop, and could be manually turned on and off.

or...

2. Use one continuous loop of 1 inch pex from the boiler secondary loop to the pool, into the pool, and run it around the bottom of the pool close to the edge or "corner", somehow suspending it slightly above the liner and slightly away from the wall liner to avoid melting the liner. It could be turned on when nobody was swimming and off when the pool was in use. You would just have to be careful while swimming to not "trip" on it or somehow kick it or move it.

I don't know if either idea would really work, and I may be better off buying an expensive heat exchanger, but I would love to hear your thoughts on these ideas, or hear other "crazy" ideas that just might work.

 

[Dune]

The copper would be better than the pex.

 

[Piker]

To add to what dune just said.., you would need to have more feet of pex to transfer an equivalent amount of heat with copper. I can't find the chart I had with this information on it, but perhaps someone else could chime in on the difference.

cheers

 

[Dune]

Roughly three to one IIRC.

 

[Hunderliggur]

I don't know what the heat transfer rate is, but this could be a solution http://www.jgbhose.com/Data_Returns/detail_company.asp?prod_id=40206 I am asking for quote since this could work for my pool (later) and chicken brooder (right now).

 

[tom in maine]

Pex would be better in the sense of not having to deal with copper corrosion.
Copper could throw copper ions into the water if the pH goes off and chlorine is present.
Blondes become green haired in such instances.
Could be fun!

The copper issue is remote but it does happen.

I would not trust EPDM hose for a long term application, but it would be easier to handle than Pex.

Since the temperature difference is rather large, I would not worry too much about having to use gigantic
amounts of tubing to get good performance.

 

[Chris Hoskin]

would just echo that copper and chlorine are not a good mix. Part of the reason those pool heat exchangers are expensive is because they are stainless steel. I like the idea of a loose series of loops of PEX just hanging in the pool. One pump, no corrosion issues.

 

[goosegunner]

Check the guy on ebay freeheat4u his pool exchangers are pretty reasonable. It would probably be worth it to just buy one of his.

How big is your pool?

BTU demand?

gg

 

[heaterman]

Ahhhh....Yah. There is a very good reason that pool heat exchangers are made of stainless and the really good ones are made of Ti or Ti/stainless alloys. Nuff said? Industry consensus is that a stainless HX will last about 5-8 years depending on factors in the pool water. Copper..........much less than that. Then there is that pesky green hair thing...............

One thing I've learned, sometimes the hard way, is that there are no short cuts with hydronic heating.

 

[DaveBP]

In a number of the flat plate manufacturer specs I've read the models noted as appropriate for pools were built with a better (316?) grade of stainless steel and were brazed together with nickel alloy rather than copper alloy. More expensive for real reasons.

 

[trumpeterb]

The Pex idea still seems viable....copper is out, though, it sounds like.

 

[Hunderliggur]

You might consider Novaflex 2151 hot water washdown hose (rated 212F). Much more expensive/foot (about $5.00/foot www.jgbhose.com ) but much more flexible. I am considering it as one option since it would be easy to remove from the pool and could run withou a heat exchanger (it is the HX).

 

[DaveBP]

OK, now I'm wondering. With such a huge deltaT how much tubing would you need for a swimming pool HX if it were thin walled and good conductor?

How about corrugated stainless steel tubing like is used for propane gas supply line. That stuff can be twisted up into a pretty small spiral that wouldn't take up much room and might hold up to the chlorinated water pretty well.

Never priced it, though.

 

[leaddog]

OK, now I'm wondering. With such a huge deltaT how much tubing would you need for a swimming pool HX if it were thin walled and good conductor?

How about corrugated stainless steel tubing like is used for propane gas supply line. That stuff can be twisted up into a pretty small spiral that wouldn't take up much room and might hold up to the chlorinated water pretty well.

Never priced it, though.

I have four of these. 1/2in finned stainless about 14ft long each that I used in my unpressurized storage that I'd like to sell. They should work well. Pm me if interested.

 

[juddspaintballs]

Could you build and install a PEX loop into the pool for less than the price of a proper heat exchanger though?

$255 or so, with lots of BTU output, and nothing actually IN your pool.
http://www.outdoorfurnacesupply.com/series-155000-pool-heat-exchanger-p-184.html


One concern I'd have with a PEX loop on the floor of your pool is the entanglement hazard. Or, if too many people were to step on the PEX or otherwise abuse it (you know kids can be hard on things), the PEX getting a leak in it and leaking some nastified water into your nice clean pool water. The chlorine would only quicken the weardown process (still years, no doubt).

 

[Hunderliggur]

Sometimes the designed product is the way to go. I thought the Novaflex was a good idea until I got the quote. I can buy the HX and a lot of pipe and valves, even a circulator, for the price of the hose alone.