Pool Heat exchanger

Dave_15

Hi I need some help with a pool heater.
I have a 200,000 Btu boiler and my pool has 22000 gallons.
what size heat exchanger do I need and what size pipe do I supply the heat exchanger with as well as pump size ?
Thanks for any and all help i can get..
Dave

Dave Heath

Pool exchanger selection

You will need to ask a few more questions.1) Indoor or outdoor application? 2) What temperature are you trying to target? 3) How many hours from cold startup to operating target temperature? 24Hours, 36Hours, 48Hours 72 Hours.

The more Hours you have to heat pool the smaller the BTU load becomes, therefore a smaller heat exchanger can be selected.

FlatPlate have a great sizing selection software available that will be a benefit to you.

Contact your local Agent or the Factory.
Dave

Dave_15

Its an outdoor pool, Im not to worried about how long to get up to temp on the first start up. and around 85 max pool temp

Tony Conner

The Limiting Factor...

...will be your boiler. You've got 200,000 BTU/hr to work with.

You need to determine the GPM on your pool pump, as this will likely be the GPM through the cold side of the HX. The other bits of info are temperatures. The inlet and outlet temps across the HX for the pool water, and whatever the temps are for the boiler. You'll very likely be able to pull the return water temp to the boiler way down. Maybe further than you really should. You need to watch that, unless you've got a condensing boiler.

Another thing to watch is where the pool chemicals get added. Make sure that happens on the outlet side of the HX, on the way back to the pool. If you hit the HX with a chemical concentration, then heat it up, it's usually bad news, and the HX will fail long before it's time.

Tony Conner

The Limiting Factor...

...will be your boiler. You've got 200,000 BTU/hr to work with.

You need to determine the GPM on your pool pump, as this will likely be the GPM through the cold side of the HX. The other bits of info are temperatures. The inlet and outlet temps across the HX for the pool water, and whatever the temps are for the boiler. You'll very likely be able to pull the return water temp to the boiler way down. Maybe further than you really should. You need to watch that, unless you've got a condensing boiler. Another way you can arrange it, is for only some of the water from the pool pump to go through the HX. This water will be heated to more than you'd see with all of the pumped flow, but mixes with the rest of the pumped water downstream from the HX, giving you a blended temp. It doesn't always help, but sometimes it lets you use a smaller HX than you'd need with a full flow.

Another thing to watch is where the pool chemicals get added. Make sure that happens on the outlet side of the HX, on the way back to the pool. If you hit the HX with a chemical concentration, then heat it up, it's usually bad news, and the HX will fail long before it's time.

Make sure to install a relief valve on the cold side of the HX if it can be isolated by valves. Bottling up the cold side by accident can result in some spectacular pressures if the hot side is still coming. Thermal expansion of water can be pretty impressive.

kevin

If it were me...

I would use the Weil-Mclain/ Triangle tube-Ph3 pool heat x-changer. Really a good set up. There web site has the info. kpc

B.BART

POOL HEATER

ACCORDING TO THE PHASE THREE SIZING CHART YOU NEED HEAT EXCHANGER MODEL MF-260,THEY CALL IT A MAXI-FLO HEAT EXCHANGER.I'VE ALSO USED THE EZEE-FLO MADE BY DIVERSIFIED HEAT TRANSFER INC.THEIR MODEL FOR YOUR POOL WOULD BE AN EZ-250.

Russ_2

Pool heating, I am doing it..... but with a problem, 89% success

I use a 250K Wood boiler, operating at 189* with a Taco 007 pump and a 1" PEX feed and return line. I have a valve installed on either side of the pool water side of the HX and a bypass loop. I cant run full pool water flow through the exchanger as it will kill the temp in the boiler. I dont see much progress with it that way. If I run the pool pump on low, run the HX pool side at full open, throttle back about 50% on the outlet and close the bypass about 50% I get the best results. I fooled around with it last year and thats what works best. My problem is that the pool loop is shorter than the hot water domestic heater line and the pool will dominate the consumption of boiler flow. I have installed A check valve after the pool circuit circlator because when it was off, the main circuit for heat and hot water was pulling the water from the pool loop instead of from the boiler loop. Any Ideas ?

Tony Conner

The Valve In the By-Pass...

...around the HX must be throttled, or the flow takes the path of least resistance, and nothing goes through the HX. You've got a finite amount of heat to feed the hot side of the HX, so you can put a LOT of water through the pool (cold) side with a small delta-T, or a smaller flow and get a larger delta-T. The total BTU transferred will be the same, however.

Most heating boilers will be pretty small to heat a pool. You have to heat the pool up slowly, and then maintain the temp of the pool water by covering the pool when it's not in use, especially when it's cooler. The pool surface (where most of the heat loss occurs) IS a heat exchanger. And surface area is one of the BIGGEST factors in heat exchangers. The more square feet, the greater the loss - or gain if it's a hot sunny day. Get a cool night with a bit of a breeze, and watch that water temp just plummet if the pool's not covered.

Alan(CaliforniaRadiant)Forbes

What else

does the boiler do? Indirect hot water? fan coils? radiant? If so, you might want to read John Siegenthaler's article on "Load Diversity" and prioritizing the zones so they don't conflict with each other, i.e. heating the pool at night when boiler demand is low.

Here's the link:

http://www.pmmag.com/CDA/ArticleInformation/features/BNP__Features__Item/0,2379,25216,00.html

To Learn More About This Contractor, Click Here to Visit Their Ad in "Find A Contractor"

[Deleted User]

Save Yourself a Headache

Go buy a pool heater, about a 400,000btu. That way the pool heats up fast, and it doesn't cost any more for a big one than a small one to operate. The heater will eliminate all of the problems discussed here. Pool heaters have a by-pass built in so they don't condense the boiler, and still maintain optimum heat delivery. The best one out is Sta Rite. They have fan that supplies combustion air, and coversion from propane to natural is a simple "washer" in the gas pipe feed. Uses a negative pressure gas valve. Pretty state of the art as far as pool heaters go. Digital readout on water temperature and flue temperature, lots of diagnostics on board, vents through the wall on stainless. Only thing it doesn't have is outside combustion air.

munchkin-man

See the Superstor SSU20PH

Heat Transfer Products offers a 20 gallon stainless steel pool heater that works thesame way an indirect water heater works. It stands up well to the punishment has 1.50" supply and return. We have a pool heater control that installs easly to the return from the pool for efficient operation. The heat exchanger is made of high quality cuppernickle and is a full 1.25" ID for maximum flow from boiler and back. Our literature shows a calculation that gives you a factor that you can then find on our chart to determine your recovery based on rize and gallons of water in the pool. Check it out at www.htproducts.com under poolheater info. <(: