Pool Heater Mysteries

czipper

LifeTime Supporter
May 12, 2014
77
Long Island, NY
#1
I am trying to choose a pool heater for next year (live on Long Island NY). My pool is quite shaded, I want it to be 80 degrees from mid april to end September. It ranged only from 55-70 degrees all season .
There is obvious choice of propane gas (i wish natural gas was an option for me:() or heat pump, this boils down to cost/benefit. This one is easy to see I don't need more advice on that.
What is out there about choosing pool heaters boils down to these two primary considerations:
The primary complaints about Heat pumps: 1 Heat pumps don't cool well as temps go below 70 degrees outside, 2 they take time to heat up and 3 require a solar cover to really keep temp properly.
The primary complaint about Propane gas heaters: They cost a whole heck of lot more. I did the Aquacal calculator and no question that would be VERY true for me ($3.30 per gal vs $0.09 per kwH).

There is more info I want but haven't been able to find through my searches. It has been really difficult to find info on the more practical aspects running of pool heaters. I'm hoping the wonderful people at TFP can fill in my blanks (you guys really are wonderful!):

The money has me seriously thinking heat pump but it sounds like it would be of limited use exactly when i want it most. However it seems that the first complaint was about "standard" heat pumps and there are newer generation low temp heat pumps that have a defrost cycle to decrease the outside temp at which they work. How much better do these low temp heat pumps work? Will they solve the first problem with heat pumps or are they marginally better so as to not really be worth the added expense (it seems they are a lot more expensive)?

I invested in a programmable energy efficient pump last summer to save electricity (and $$) and run the pump less. When i add the heater will i need to run the pump all day or can heaters circulate the water on their own? How do i integrate heating time and pump running? This feeds into the second problem with heat pumps.

There are different btu outputs of pool heater, how do i figure out what size of heater i shold be looking at? Should i be aiming for a heater that puts out as much heat in as short a timeframe possible to reduce pump run time, or look for lower heat output over longer time frame since i'll need to run the pump anyway? This gets back to the pump run time issue. I haven't found anyone addressing these issues in their heater choices, it would be nice to know if it is something should think about.
I would value any viewpoints or help in finding the info i haven't been able to find.
 
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zethacat

LifeTime Supporter
#2
I lived on Long Island (Nassau County) for most of my life so I know what the weather is like there. I would definitely not recommend a heat pump. It will probably need to run 24/7 during those off months and you will pay through the nose for that with LILCO. I have a friend in Nesconset who just built a pool and says she keeps it at 90 and barely notices much difference in her gas bill.. so I would go that route.
 

czipper

LifeTime Supporter
May 12, 2014
77
Long Island, NY
#3
I'd Love love love Natural Gas but it is not available to me, the gas company may never get around to my street (we have oil heat, apparently not an option for pool heating around us). Propane is quite a bit more than NG. the conversion is a bit mysterious, but i figure propane about 4-5 time more than NG.

Extended run time of a heat pump could still cost less than bursts of heat from propane since electricity isn't very expensive relative to propane. Do you have experience with low temp heat pumps zethacat?
 

EVChargeGuy

LifeTime Supporter
Jun 16, 2014
340
Long Island, NY
#4
No Natural gas here also.
I have a Oil fired heater and it works great, Bought it 12 years ago for about $3K, today there are only a few new ones in the market and they're $5-6K!! so I just spent $1400 rebuilding it and hope I get 3-5 more years from it.

My oil company is out of Greenlawn and he may have a used rebuilt system?
 

czipper

LifeTime Supporter
May 12, 2014
77
Long Island, NY
#5
No Natural gas here also.
I have a Oil fired heater and it works great, Bought it 12 years ago for about $3K, today there are only a few new ones in the market and they're $5-6K!! so I just spent $1400 rebuilding it and hope I get 3-5 more years from it.

My oil company is out of Greenlawn and he may have a used rebuilt system?
The pool service that opened us up last year told me that new oil heaters were not allowed anymore. it wouldn't surprise me if he was completely wrong but he did seem to be a very knowledgeable person.....
 

bk406

Well-known member
Dec 3, 2009
2,690
Central Massachusetts
#6
Im in central Massachusetts, in southern worcester county. I have a heat pump and a gas heater on LP. Heat pump wont do much here in April, a lot of May, and September. I got an LP heater i'm really happy with. I dont run it all the time, just when I want to use the pool. In early May when the air temp gets up into the low 60's (if I'm lucky), I can heat the pool into the mid 80's pretty fast. I use a solar cover (a must). Once I shut off the heat and put the cover on, I might lose 6 degrees over night. The next day i'll pop the heat on again and bring it back to 85. If I dont use it again for a week, the pool might get back to 73-75, but it doesnt take much to bring it back to 80+ again. I burn maybe $800 worth of LP per season. I heat starting in early may depending on the weather. I use it off and on thru the season. I havent used the HP in a couple years. Actually thinking of just getting rid of it. My LP price is around $3.00 a gallon.

as far a s size, get a big one, 400,000 BTU. They burn more gas, but you wont have it on as long. The gas used vs. run time is pretty linear. A 250,000 BUT heater will burn half as much gas, on average, but you'll run it twice as long.
 

JasonLion

TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
37,879
Silver Spring, MD
#7
Any way you heat the pool is going to be expensive. On the east coast heat pumps are generally noticeably less expensive than gas, but still quite expensive if used regularly.

Low temperature heat pumps continue working even when the outside temperatures are low, but their efficiency still drops off as the air temperature goes down, just as a regular heat pump does. So you will get some heat at low air temperatures, but the cost will go up and total capacity will go down as the air temperature goes down, just as it does for a regular heat pump.

Heat pumps are best for keeping the pool warm 24/7 in areas where electricity is not too expensive. Gas heaters are much better for "event" heater, i.e. that one nice weekend in September (rather than using every day).
 

zethacat

LifeTime Supporter
#8
Do you have experience with low temp heat pumps zethacat?
I've only had mine operational for a month and have only used it twice, so I can't really give you much of a review. My unit is advertised to run at very low temps, but the lowest temp I've run at is around 60 and I can do about 1 degree per hour. I am still trying to narrow down exactly how much electricity it uses but I think it may be somewhere in the range of $10/day at 6.4c kWh, assuming 24/7 operation which should not be necessary if being used to constantly maintain a specific temp.