I need a pool heater!

[ds_girl]

Is there anyway to use the boiler in my house as a pool heater? Has anyone done this?

If I install a natural gas pool heater, does it need to be some distance away from the house or could it go in a covered area under a high deck?

Thanks for any advice. I live in NY and I'm tired of only being able to use the pool 6 months a year. I have an inground pool.

[Poconos]

Whether you can use your home boiler depends on some factors. Size of pool, boiler heat output rating, and your expectations. Probably not a good idea as typical home boilers have nowhere near the heat output of a pool heater which is sized for reasonable rates of temperature change. Where you place a NG pool heater depends on local ordinances, how the heater is designed, how it is vented, and common sense. Venting under a deck roof or near the house could lead to carbon monoxide drifting into living quarters.
Al

[CarlD]

If you want to use your pool all winter you will probably need a 400,000 BTU gas heater, just for the pool. That's probably a lot bigger than your home boiler, and maybe even your furnace.

[chem geek]

Just so you are aware, heating the pool with a gas heater is very, very expensive. We have a solar system to keep our pool at 88F (it's used for swim therapy for my wife, and I happen to like warmer water too) as much as possible and we use gas to assist in this, especially at the start and end of the season. Even so, we only are able to swim from around mid-April to mid-November and we live in a temperate climate (near San Francisco) that only sometimes gets to freezing (typical winter overnight temperatures are in the 40's). Part of the problem isn't the pool water temperature, but how cold the air temperature is outside, especially when wet. It's not like a spa where it is so warm that your body is able to bear the cold air briefly.

If you do plan to heat your pool with gas, then you should invest in a highly efficient insulated pool cover. We have an electric opaque cover that is not insulated (though it is convenient) and though it cuts down heat loss by about half, that still means we lose 3-4F overnight (instead of 6-8F) and a little less through a cold day. With an insulated cover, you could cut the loss in half again.

When comparing heaters, look at the output rating in BTUs. Every 100,000 BTUs will heat 10,000 gallons of water by 1.2F degrees every hour. However, remember that your pool will be losing heat rapidly if it is a lot warmer than the surrounding air and ground. The cost of a gas heater can be determined by it's input BTU/hr. rate which you divide by 100,000 to get Therms/hour. Natural gas costs about $1.39/Therm where I live. The bottom line is that you could easily spend $400 or more heating your pool for a month.

Richard

[CarlD]

You may also want to consider a cover over your pool-like a dome to act as a greenhouse and slow down heat loss. There are other types of enclosures as well that may help. The hundreds per month in heating costs will easily pay for it.

(Geek, I deleted you dupl post. FYI.--CarlD)

[Poolsean]

Consider how long you want to heat your pool also. Year around pool use may not be practical if the outside air temps are into the 20's and 30's. Who realistically goes out in a bathing suit when it's that cold?
We've successfully installed heat pumps in the northeast US for many years. Again, there are limitations as all heaters will reduce efficiency when it gets cold. However, you should know that the most efficient gas heaters (forced air induction types) are about 90% efficient, with most of the rest of the gas heaters being about 70% efficient. That reduces the amount of BTU's being produce.
The 100,000 BTU's of gas that you're paying for is only giving you 70,000 BTUs (or 90,000 BTUs with the efficient gas heaters) in return.
Heat Pumps give you 500 to 600 times the investment cost to heat the water and are the most cost effective for consistent heat.
Solar is even more efficient, but is inconsistent on overcast or cloudy days, or operated at night time.

To look at it another way, you can actually afford to KEEP your pool heated using a heat pump for less than the cost of a gas heater being used to heat
it on demand (when you want to use it). The pool is always ready for swimming with a heat pump.
Benefit to gas? Because you can get gas heaters with copious amounts of BTUs, 400,000 BTUs for the largest residential gas heater, you can heat the water faster when you want to use it.

As ChemGeek mentioned, a solar cover is a worthwhile investment, if you use it. Most pool owners, depending on the size of their pool, will used a solar cover the first month, but then decide to just leave it off to avoid the hassle.

Venting with a gas heater is very important and I support the cautions that ChemGeek mentioned. By the way, that's where the other 30% of inefficient heating BTUs go, out the vent in wasted heat.

Hope this helps.

[towney]

Consider how long you want to heat your pool also. Year around pool use may not be practical if the outside air temps are into the 20's and 30's. Who realistically goes out in a bathing suit when it's that cold?
We've successfully installed heat pumps in the northeast US for many years. Again, there are limitations as all heaters will reduce efficiency when it gets cold. However, you should know that the most efficient gas heaters (forced air induction types) are about 90% efficient, with most of the rest of the gas heaters being about 70% efficient. That reduces the amount of BTU's being produce.
The 100,000 BTU's of gas that you're paying for is only giving you 70,000 BTUs (or 90,000 BTUs with the efficient gas heaters) in return.
Heat Pumps give you 500 to 600 times the investment cost to heat the water and are the most cost effective for consistent heat.
Solar is even more efficient, but is inconsistent on overcast or cloudy days, or operated at night time.

To look at it another way, you can actually afford to KEEP your pool heated using a heat pump for less than the cost of a gas heater being used to heat
it on demand (when you want to use it). The pool is always ready for swimming with a heat pump.
Benefit to gas? Because you can get gas heaters with copious amounts of BTUs, 400,000 BTUs for the largest residential gas heater, you can heat the water faster when you want to use it.

As ChemGeek mentioned, a solar cover is a worthwhile investment, if you use it. Most pool owners, depending on the size of their pool, will used a solar cover the first month, but then decide to just leave it off to avoid the hassle.

Venting with a gas heater is very important and I support the cautions that ChemGeek mentioned. By the way, that's where the other 30% of inefficient heating BTUs go, out the vent in wasted heat.

Hope this helps.

What is venting?
Thanx

[Poolsean]

Venting is controlling and directing the discharge exhaust from the heater so that, as Chem Geek said, the carbon monoxide doesn't flow towards the home or where it can be inhaled; or in the case of a heat pump, so the cooler exhaust air doesn't recycle around to the evaporator coil.

[chem geek]

Actually, it was Poconos (Al) that made the comment about the venting, but I'll take credit for someone else's intelligent comment any day! :)

[CarlD]

I did not suggest a heat pump because I assumed you wanted to use a pool in far lower temps than I would consider (unless it was an indoor pool). I totally use solar, but were I to install an active heater it would be a heat pump, just a Sean suggests.

Heat pumps got a lot of bad press when they were used incorrectly as whole-house heating systems in too-harsh environments. While a heat pump works INCREDIBLY efficiently from the mid-40's and above, they fall off in efficiency rapidly below that (Sean can probably get the exact figures). But when freezing temps hit, heat pumps fail completely and fall back on electrical resistance heating, the most expensive and inefficient means. Houses and town houses that use them in those circumstances tend to be chilly.

So heat pumps were installed in lots of town house and houses in the Northern Virginia and Maryland area around DC, where they were the WRONG system for the region--it usually gets far too cold even there for heat pumps. When we bought in that area, back in the late 80's, we specifically looked for a community being built with furnace/AC units rather than heat pumps.

I don't know why heat pumps aren't the standard throughout Florida rather than A/C. When they get those cold snaps that always seem to catch them by surprise, the heat pump would be the PERFECT solution as it is essentially a reversable A/C unit.

Yet for most pool owners, a heat pump is a marvelous solution. There's less installation, just elec, not elec & gas. They pay for themselves quickly in reduced cost of operations, and they are in their IDEAL operating range at temps most people want to swim. From 60 to 80, a heat pump's going to be super-efficient at heating your water. Even from the mid 40's through the 50's it should work well. Below that, well, if it was me, I wouldn't be swimming anyway!

Still, if you are planning on using your pool when it's in the freezing and below range, a heat pump won't work and you'll need to go to gas heat. But still, I think for that an enclosure will be necessary. It's not like a 105 deg hot tub.

[MarkC]

I Have a heat pump and love it(I live in PA). With that said it's pretty useless at 50 degree air temps.

[CarlD]

I Have a heat pump and love it(I live in PA). With that said it's pretty useless at 50 degree air temps.

Took me 20 times the space to say the same thing!:mad: :rolleyes:

[ChuckD]

(Even tho my pool's frozen over right now, I still check in. Come on Springtime!)

I think an important distinction needs to made as to what the source of the heat energy is for the heat pump. Clearly we're talking about using the outside air here. We bought our house with an air-source heat pump (Carrier) and an attractive pellet stove. We thought, 'how quaint, it'll be nice to look at on winter days'. Now we know it's essential to heating the house. As said, when the source of the heat energy drops toward, and below, freezing, efficiency goes out the window.

That said, heat pumps can be a very efficient way to heat if one uses sub-frostline ground temps as the source.
There's lots of info on the internets about 'geothermal' energy (50 to 55 degrees) to feed a heatpump and it's something I'm very seriously looking at.

So, more to the point, I wonder if the same idea doesn't exist for heating a pool as well?

Chuck

[Poolsean]

MOST heat pumps quit below 60 degrees. Because of that there is an option of "heat and cool" in which it will reverse the flow of freon to defrost the ice that forms on the side of the heat pump to stop it from working. Some do this automatically and some require a manual switch. Aqua Cal has this built into the Heat N Cool models and will work down to 23 degrees (albeit at a lower efficiency).

[CarlD]

(Even tho my pool's frozen over right now, I still check in. Come on Springtime!)

I think an important distinction needs to made as to what the source of the heat energy is for the heat pump. Clearly we're talking about using the outside air here. We bought our house with an air-source heat pump (Carrier) and an attractive pellet stove. We thought, 'how quaint, it'll be nice to look at on winter days'. Now we know it's essential to heating the house. As said, when the source of the heat energy drops toward, and below, freezing, efficiency goes out the window.

That said, heat pumps can be a very efficient way to heat if one uses sub-frostline ground temps as the source.
There's lots of info on the internets about 'geothermal' energy (50 to 55 degrees) to feed a heatpump and it's something I'm very seriously looking at.

So, more to the point, I wonder if the same idea doesn't exist for heating a pool as well?

Chuck


I know that there is a constant temp of, I believe, 58 deg F underground, like 3 to 5 feet, depending on location.

But I've NEVER heard of a heat pump that used THAT as the source of heat! Wow--that's a great idea, if it can be made to work--a sufficiently large heatpump would work no matter HOW cold it got.

[ChuckD]

CarlD, you of all people! I woulda thought you'd be all over this.
Start your journey here:
http://www.geoexchange.org

[CarlD]

CarlD, you of all people! I woulda thought you'd be all over this.
Start your journey here:
http://www.geoexchange.org

I hang my head in shame for my ignorance!:(

[Poolsean]

hmmmm, geothermal heat pumps.

http://www.symbiontservice.com/geo-thermal/index.html

Aqua Cal manufactures these.

[ChuckD]

Bingo!
Got any contacts in upstate NY, ps?
I'm actually more interested in it for the house than the pool. But it seems to be such an 'exotic' technology, it's tough to find someone knowledgable.

Chuck

[hoogie]

I had a zone off my boiler specifically to heat my pool through a heat exchanger. It worked wonderfully on my small pool(11 k gallons) in MA to bring it from 60 to the low 90's in about 20 hours. Oil use was minimal, about 20 gals to heat it for the weekend. not sure how gas would work but we were hap with the setup we had. During the cooler months like may,june and sept to keep it on say 82 the boiler would run a few hours a day depending on ouside temps of course.

[fcfrey]

I know that there is a constant temp of, I believe, 58 deg F underground, like 3 to 5 feet, depending on location.

But I've NEVER heard of a heat pump that used THAT as the source of heat! Wow--that's a great idea, if it can be made to work--a sufficiently large heatpump would work no matter HOW cold it got.

I'm in Central PA and I installed a Geothermal Heat pump for my home back in 1992. BELIEVE THIS!! It paid for itself in 4 years compared to the baseboard electric I had been using. There are Geothermal heat pumps for pool applications. If you are even thinking of a heater in PA I would recommend you look at Geothermal. The size is still determined by surface area and the temperature differential at which you intend to use it.

One other thing I have to mention is whether you asked yourself this question. "Am I going to use the pool when the air temperature is low?"

My wife and I don't go near the pool unless the air temp is above 75 - 80degrees even if the water is the same or higher. Maybe I'm chicken but it's cold out there when your all wet!!:eek: Any heater is expensive if you don't swim when the air is cool.