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    Are heat exchangers a viable way to heat swimming pools? (6 Posts)

  • Hank_CT Hank_CT @ 8:37 AM
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    Are heat exchangers a viable way to heat swimming pools?

    Looking for advice on whether we should use our home oil burner to heat our new pool or to just go with a traditional gas burner. We'd like to use an exchanger and are willing to sacrifice some heat-up time. The pool will have a cover, which should help. We have researched around the web but are amazed at how little discussion there is. Does that mean that it a heat exchanger really isn't viable? And then I saw multiple complaints about Triangle Tube, which seems to be the main supplier. Any advice???
  • Zman Zman @ 9:51 AM
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    Maxi Flo

    Hank,
    You have quite a few questions rolled into one.
    The Triangle tube maxi flow is an excellent product. Triangle tube in general is one of the better supported companies we work with.
    To answer your question about using your current boiler, it really depends. I would have a qualified heating (not pool) contractor determine the BTU's needed to heat your pool. You will have to let them know if you intend to leave your pool at a constant temp or if you require the heating system to be able to raise the temp significantly on demand.Once you have this info, you can determine if your boiler is large enough. If the pool is only used in the summer, this may be a great match, as you will not need to heat the pool and the house at the same time.
    I would give a lot of thought to converting your whole system to gas if possible. Oil is far more expensive.
    In my opinion, stand alone pool heaters are very low quality.
    I would look at a condensing gas boiler that will handle all you needs, in the end it will be more affordable and reliable.
    Carl
  • Gordy Gordy @ 11:28 AM
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    Pool size?

    In gallons.

    In ground , or above ground?

    Typically a stand alone 150000 btu input ng pool heater will raise 15000 gallon pool 1/2* per hour. So you have to plan ahead for usage, or maintain a constant temp.

    Evaporation is your biggest heat loss so use a solar cover .

    Longevity: I have a Hayward 150k that's 11 years old trouble free.

    Bottom line you will have a fuel bill higher than your coldest home heating bill month on pool opening depending on water/air temps when opening.

    I notice you have gas fuel option vs oil assuming lp that may be cheaper than running your oil fired boiler.

    Good luck with the new puppy;-)
    This post was edited by an admin on July 7, 2013 11:59 AM.
  • Gordy Gordy @ 12:19 PM
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    Answer to Original question

    Is yes when properly sized equipment is used. From the boiler to the HX to the piping used.

    So the big question for you is your boiler big enough? Some btus are lost in the transfer of heat to the HX.

    Something else is how far away is the pool from the boiler in your home?
  • SpeyFitter SpeyFitter @ 10:44 PM
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    Also, if possible

    If you COULD convert to a gas condensing boiler, spend a little more money and get as large of a heat exchanger as you can afford (within reason of course). The bigger the heat exchanger heat transfer surface area, the lower water temperatures you can run with a condensing boiler, and subsequently the more efficiently things run (as long as it doesn't end up meaning you have to use a larger pump of course due to potential increased head loss of a larger heat exchanger).

    Heating a pool with a boiler seperated from the pool water with a heat exchanger is done more commonly than thought and is an excellent way to heat a pool.

    A couple things - if you have a chlorine pool you'll want a stainless shell & tube heat exchanger. If you go salt water you'll want a Titanium heat exchanger, which is SIGNIFICANTLY more expensive than a stainless (you can also use Titanium with chlorine which will last longer). If you go ALL Titanium fully welded shell & tube, which is the best case, but most costly, it will be about 10 times or more the cost of a stainless, BUT, it'll give you less installation headaches (many titanium heat exchangers that are shell & tube have a composite portion with threads that can be a PITA to install as sometimes the composite splits on you if you're not careful). I've heard of some guys use plate & frame titanium heat exchangers to bring down costs as well as eliminate having to deal with the breakable composite threaded connections on some titanium heat exchangers. But plate and frames often have smaller passages which could potentially plug up earlier.

    IF, you are heating a Hot tub with a heat exchanger, make DAMN sure you have a manual reset high limit on the HOT TUB WATER SIDE, set just slightly above (maybe 2 degrees max) the hottest water you would expect to soak in (it would be located on the return before the heat exchanger so it is sampling the actual temperature of the hot tub water). I heard a story that happened around 10 years ago in a high end home - the maid was told to go turn the hot tub temperature up - she went into the mechanical room and pressed the wrong buttons (or something along those lines). One of the kids came home from school, jumped in the hot tub, and just barely made it out, with serious burns to her body. It's not a bad idea to put a high limit on the pool side too although most boiler set ups often do not have the BTUH's to juice a pool high enough to cause burns as there is usually way more water in a pool to heat. Again though, not a bad idea either.

    Make sure your disinfection medium (chlorine, saltwater, etc.) is downstream of your heat exchanger. This will ensure the heat exchanger does not get lambasted with chemicals which can shorten it's life span.
    Class 'A' Gas Fitter - Certified Hydronic Systems Designer - Journeyman Plumber
  • ColoradoDave ColoradoDave @ 12:14 AM
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    Solar Thermal

    I would seriously consider a set of solar thermal panels (2, 3, 5? )

    The energy is relatively free (just the electricity to run a few pumps) and with a solar storage tank installed, it could provide a nice pre-heat for domestic hot water.

    You'd want to consult a local professional for your specific situation, but you could heat your pool as the primary function (with adjustable high limit to lower the setting in winter), storagetanks to store the surplus production for domestic hot water and finally, a heat exhanger to heat the house via the furnace air handler, boiler tie in or seperate solar heat emitters (fan convectors or some radiant heat in the main living area)
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