Residential Boiler to heat pool

Jul 6, 2008
7
Has anyone used their residential boiler to heat their pool? Plumb out a zone and use a water to water exchanger?

I'm thinking of going this route. I currently have 4 2'x20' sungrabber solar panels. They work very well when its sunny.
Problem is. It hasn't been that sunny around here in the North East.
 
To be brief, it won't work. (been there, tried that :oops: )

The energy required to heat your pool is so much more than is required to heat your house it is stunning. Your entire boiler capacity could not effectively heat the pool.
 
Sorry for not posting the pool.

It is a 27' round ag 48" deep.

I'm on the border of PA and NY.

I'm not trying to heat it to 100 degrees like this guy

Just trying to help my solar out when its cloudy. And to extend the season some.
 
There are quite a few challenges to using a home furnace for heating a pool, but it can be done. They really aren't designed to take pool water directly, so you normally need an additional heat exchanger. Finding a heat exchanger that is suitable for use with pool water is a little tricky and will lower the overall efficiency.

The distance between the pool and the furnace can also become an issue if they are far apart. You will want a substantial pipe size on all the plumbing runs. Furnaces that size are designed to heat several zones, and trying to feed all of the heat to one zone takes a few plumbing tricks, nothing too complex but it can't just be the same as all the other zones and remain efficient.

If you deal with all of that, yes it will heat your pool. But it will heat the pool fairly slowly (pools like really large heaters), it won't be as efficient as installing a standard pool heater, and will probably end up costing as much or more than a standard pool heater.
 
With that size pool and that size heater (that's huge for a house) you may be able to have some affect on your pool but, as Jason says, the cost of fuel and the cost of the equipment will be troublesome.

YOu will need a 250,000 water-to-water heat exchanger......I think they're about $1500 but I can't remember for sure. It will require 1.5" plumbing to perform properly. Unless your pool is quite close to the boiler, you will surely need insulated supply and return pipes on the boiler side.

What do you use for fuel for the boiler? Is it cheap?
 
duraleigh said:
What do you use for fuel for the boiler? Is it cheap?

Anthracite Coal.
Its the cheapest avaible to me. I have a 4600 sq foot Victorian Home that was built in 1895. It has poor insulation so it takes the btu's to keep it warm here. The boiler pretty much idles during the summer just to heat my domestic hot water. Propane would be almost 4 times the cost of coal and fuel oil is almost 3 times as expensive. Wood is to much work and Natural Gas isn't avalible although there are a ton of NG wells going up all around me.

The reason I'm even thinking about this is related to the thread in my last post. That guy is heating his pool with a boiler almost half the size of mine. His pool is about half the size of mine also. He claims to have it up to 100 degree's. Wow I only want to get it up to about 85. I was thinking about a water to water nickel brazed plate exchanger.
Similar to http://www.flatplate.com/pdf/hydronic/MPbrochure3-00.pdf
1 1/4" copper from my boiler to the exchanger. Then from the exchanger to the pool? I'm not sure. How much heat could pvc take? insulated Pex? That was some questions I had.

I have been pretty good about keeping the solar cover on when the pool isn't in use. Missed a few nights. I try and shut the solar off when its not sunny out. But the pool isn't that warm. Its not cold 78-80 but the wife won't go in. The kids and I have no problem with it.
 
Well, you have some parameters that might make it worthwhile to look into further. The best info is on wood heating forums. I tried it several years ago and the btu's required to heat my 42k pool were massive. The wood heater I was using simply didn't have the capacity.

If you progress further, I have a stainless steel water-to-water exchanger (about 450,000btu) that I will give you a good price on. :-D
 

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I may take you up on the exchanger. Send me a PM on what you want for it.

I went the outdoor wood boiler route already. This house is such a beast to heat. Wood was just to much work. I was burning between 20-24 full cord of wood a year. That was 4 triaxle loads of hard wood. Mostly maple, ash and oak. Wood prices went from $300 triaxle to $600. That combined with back surgery put me out of the wood buisness. Coal cost me about $1300/year for heat and hot water. I fill the bin 3 times a year and take ash's out. Can't beat that in this area.
 
duraleigh said:
To be brief, it won't work. (been there, tried that :oops: )

The energy required to heat your pool is so much more than is required to heat your house it is stunning. Your entire boiler capacity could not effectively heat the pool.
I didn't believe this... until I looked into putting in a pool heater. I can say that the Hayward H400 in our last pool was larger then the furnace in our 1800sqft house, and 400,000 btu only lifted the temp at 1deg/hr (25k in-ground). It's amazing what it takes to heat that much water!
 
I only asked because my boiler is very large compared to most homes. I know it will but out 200k all day. If I ran it continous it would cost about $200/month. Of course I wouldn't run it all the time.
 
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