Selecting the best pool heater for me

PoolBrews

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Oct 16, 2019
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The Villages, Florida
30,000 gallons in NC? I wouldn't even consider a heat pump. It will take a loooong time to heat that, and will never keep up when you really need it (unless you are are looking at using multiple heat pumps), and even then it will depend on the air temp as to whether it will actually work.

I had the largest heat pump you can buy on an 18,000 gallon pool in GA, and it really struggled during the cooler months of Sep-Nov, and March-May.

Go with gas, get the largest gas heater you can get (400K BTU), and if there is any way to connect to NG do it. Your wallet will thank you. I had a 400K heater in MI on a 42000 gallong pool, and was able to keep it heated through September, and in April.
 
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mwemaxxowner

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SC, but yes.

I would be trying to warm the pool once our outside temps reach 80, but might be starting it when they're 70-75. I'm not sure, I'd have to. I'm guessing that would work out to using I in May and in September, or perhaps a few weeks into October. I don't necessarily have any particular time frame in mind, but rather dependent on weather.

Homebrewale said he was heating 20,000 gallons in a few days with a heat pump, which had me wondering if I could do it in a week.


I guess "loooooong time" is subjective and I'm trying to figure out how to put a rough number on that. Once the swimming season really gets going we don't need it.

I was all set for a gas unit until I ran the numbers through the calculators that are listed in this thread.
 

Newdude

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It’s a tough call for most people. If you want to swim in North Dakota in April it’s a no brainer for NG. If you want you south FL pool to be 95 in July, it’s a no brainer HP. The rest of us fall into grey area.

To extend your season pretty much regardless of the weather pattern year over year, you want NG. And the biggest one they make. But if you have a heater you might use it mid season during a cooler week when you didn’t necessarily need the extra BTUs and will burn just as much gas for little gain as you did when you got a lot of gain in the early late season. So you have a plus and minus at the same time.

If you go heat pump it will be much more efficient during the season if you have a cool week and will work so-so in the extended season. It will either work at greater cost or not at all. If it is working because the weather allows it in the extended season, it can use energy on par with the NG heater because it has 1/3 the BTUs to overcome the heat loss.

Sooooooooo. The million dollar question which still has no clear winner ??? Do you want it to be better overall on your wallet and accept its limitations if that year is particularly cool ? Or pretty much garauntee it will work while it costs more in the regular season ?

If you want the kids to swim on Xmas as a treat you will not care if it costs $75 to heat the pool. It’s a treat, money well spent. The same goes for any early/late swims. It will cost the same $75(?) a weekend in July to bump the pool just a few degrees and it might not be worth it in those times.
 
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mwemaxxowner

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We definitely don't want to swim at Christmas! 😆

The draw for me, and why I keep wondering if I *could* get the HP to work, IS the fact that it is so energy efficient to maintain temps. That's not my primary goal, but if it could work for my warm-up and I have that as a bonus if we get a cold spell mid summer, I'd love to have the ability to kill those two birds with one stone!

I'm okay with a longer warm-up period if it would actually happen around a week or even two, it seems like that would come out to about the same amount of energy costs as a shorter warm-up with gas. That's less convenient but it's something I would accept.

Now, if I'd be looking at something more like having to run it 3+ weeks during the warm up period, I don't think I'd consider that acceptable! If I could get a week warm up at 75 daytime temps, I'd accept my limitations and go that route, I think.

On the other hand, I'm guessing once we get it up to temps with gas, if I'm keeping it covered, if we have plenty of daytime sun I won't have much issue with needing to use much gas to maintain.

Pentair estimates that their hybrid unit will warm it 10° in 14 hours. Paying more for that unit may wind up being my best option, but I do wish they offered that but with more BTUs. I do like the simplicity of it being all in one. I've got a lot to mull over for sure!
 

mwemaxxowner

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The Raypack calculator shows me roughly $200 gas use for May. I must have fat fingered something the last time I tried it because I thought I saw almost double that. I think that's plenty reasonable to get a jump start on our swimming season.

I could also plumb my hot tub over to that and get some use out of it in the winter months.
 

Newdude

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We definitely don't want to swim at Christmas
Tell me that *after* you have the option. :)
The draw for me, and why I keep wondering if I *could* get the HP to work, IS the fact that it is so energy efficient to maintain temps
Yes. Maintaining temps wasn’t bad and was nice to have the pool just a few degrees warmer on a cool summer week to take the edge off. Now, *creating* temps was a whole different animal. I spent $600-$800 in the cool/ cold months and quickly ran out and bought a solar cover. It cut the bill in half, but $300/$400 was still a big nut when it had to run 24/7 and didn’t overcome its limitations at times. There were weeks that we paid for nothing. Not every week, but still.
I'm okay with a longer warm-up period if it would actually happen around a week or even two, it seems like that would come out to about the same amount of energy costs as a shorter warm-up with gas. That's less convenient but it's something I would accept
Totally ok if the weather allows and basically a half a dozen or six example.
Now, if I'd be looking at something more like having to run it 3+ weeks during the warm up period, I don't think I'd consider that acceptable! If I could get a week warm up at 75 daytime temps, I'd accept my limitations and go that route, I think
All depends on the weather year over year. It’s a calculated risk. Have 4 warmer years in a row and the HP will be the best thing ever. If 4 in a row are too cool, you’ll be sad. Realistically you will win some and loose some with probably more wins than losses. As long as you know the limitations going in, they are easier to swallow when it’s not ‘your year’.
On the other hand, I'm guessing once we get it up to temps with gas, if I'm keeping it covered, if we have plenty of daytime sun I won't have much issue with needing to use much gas to maintain
Covering is a must to protect your heating investment either way. Or you are rich and can just watch that heat evaporate because the cover is it’s own PITA.
Pentair estimates that their hybrid unit will warm it 10° in 14 hours. Paying more for that unit may wind up being my best option, but I do wish they offered that but with more BTUs. I do like the simplicity of it being all in one. I've got a lot to mull over for sure
I won’t say it’s the best, but closer to the better of both worlds IMHO. Either way, the coulda woulda shouldas will keep you guessing until the end of time. Aint human nature great ? :ROFLMAO:
 
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mwemaxxowner

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Everyone keeps reminding me to cover it. IT WILL BE COVERED 😆.

I'm going to have a cover on it this year even without a heater. I'd like to have that as a baseline to see how well temps do *just* covered with a solar cover vs whenever I eventually add a heater.

There's no way I'll try to heat it uncovered with any sort of cover.
 
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Newdude

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I'm going to have a cover on it this year even without a heater. I'd like to have that as a baseline to see how well temps do *just* covered with a solar cover vs whenever I eventually add a heater
*my backstory for reference

i started with the heater and got the first electric bill for 2 months and raced out to by a cover. Once the newness wore off, (1.5 years) we didn’t swim enough times to justify the heater so I only used the cover. For 3 years the cover worked awesome to its abilities which, more often than not, we only needed a little help to take the edge off. If it was much cooler and the cover didn’t matter, nobody felt like swimming anyway. When the cover finally ripped I was so sick of the process to use it I threw it out and didn’t replace it. We spent the last 2 or 3 years just enjoying running down to the pool and going airborne immediately. Some days were more ‘brisk’ than others.
 

mwemaxxowner

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If it was much cooler and the cover didn’t matter, nobody felt like swimming anyway.

That's where I am. It doesn't matter how warm I can get the water in December, we won't enjoy being in and around the pool when it's cold. We do, however, now have a hot tub, and as far as my daughter is concerned it's a small pool. 😆 She goes hog wild playing in it just like she does a pool, lol. So when we get an itch to be in the water outside the swimming season that's where we'll be. Momma 'n me for a relaxing soak, my daughter to be a water crazed 5 year old.

That said, I think I still need to probably just decide on a gas heater to warm us up in the spring, and depend on a solar cover to stabilize temps through the season if we have some unusually chilly nights or something. I would still obviously have the ability to give it a boost with gas.

This seems to be the best course of action if I decide I don't want to spend as much up front for the hybrid unit. And, at the end of the day, that is still only 200,000 btus.

I can get some value out of the gas heater in the off season at the hot tub if I choose to do so, I couldn't get didley out of the HP in winter.
 

Newdude

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I can get some value out of the gas heater in the off season at the hot tub if I choose to do so, I couldn't get didley out of the HP in winter
For that one off Xmas swim, it will be fun to run out there in the cold. Every day ?? No way. Lol.

A friend hosted a really late season swim party for one of the sports teams before the surges surged again. All us adults were bundled up and huddled around a fire pit while the kids had a blast without a care in the world. If they got chilly they hung out in the hot jets for a few minutes, then went right back to cannonballs.

It was really really nice to have that option that it just worked and they could do it. My party would have been cancelled a few days before when the weather tanked.
 
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HeyEng

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Cover your pool!!! (Just kidding...I see it has been suggested a couple of times). :)

We have a pretty small pool and a 400K NG heater and I wouldn't want it any other way. We are in energy country so NG is relatively cheap (but I think this might be ending soon!) currently it's $3.37 per dekatherm ( 0.337 per therm). On a GOOD day, it will heat at about 3 degrees an hour but tends to average out at 2.5 degrees an hour. We do not have a cover and do not keep it heated unless we are going to "hot tub" the pool in the winter or take the chill off at the beginning/end of the pool season.

As a reference, I ran it for 24 hours during this crazy cold snap to get the pool temp up. I started at 36 degrees pool temp and in 24 hours it made it to 80 degrees which is about 1.8 degrees an hour. The highest ambient temperature in that period was 18 degrees and the coldest was 2. The total cost for that 24 hours was $32.35. NOTE: It is recommended that you NOT use your heater in such terribly cold conditions. I did a risk/benefit analysis and determined I would rather replace an almost 15 year old heater than have to potentially tear up decking for frozen pipes. While the odds of the below ground pipes freezing is pretty low, I didn't want to take the chance. Also worth noting that the lowest soil temperature at 4" we got was 34 degrees. 10" depth got to 37 degrees and that is with 11 days of below freezing and the lowest temperature of -11.

My point here is that I would get the largest heater you can and if NG prices aren't too bad where you are, give consideration to having the line run.
 
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mwemaxxowner

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If what I can look up on the Google about Dominion Energy's rates for SC, I'm looking at 1.18 per therm. I won't need any lines run. I already have a tap from the gas company, right beside the pool house, it's just shut off now with no meter. If the tap isn't corroded or anything the gas company would just come slap a meter on it. The tap is located exactly where I would put my heater. It may have been for a heater once upon a time.

Here is my analysis from Hayward:

Screenshot_20210219-105900.png
 
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ajw22

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Your NG price looks way too high. I pay 0.75/therm of NG here in NJ. And nothing is cheap in NJ.

NG bill.png
 

setsailsoon

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I've had a gas heater for years and most of my friends do as well. I'd go with the biggest gas heater you can. Should be 400k Btu. Make sure the gas company knows the gas consumption. A 250 meter works well for most folks I know in my development. The meter is rated at standard conditions for 250 but easily handles more. Heat pumps are expensive up front and don't have the capacity to heat quickly other than spas. When we build our new house we will be on bulk propane so I'll likely do a hybrid or duel units.

With reasonable care and attention to TFP water balance parameters your gas heater should last at least 10 years. Most brands are similar. Raypak has a great reputation here with experts but my experience and observations locally is they have a bad problem with rust inside the housing around the burners. If it were me I'd look at a Pentair Stay Rite but that's mostly personal preference. Hayward, Jandy and Pentair have very similar design internally. Also, if you maintain good water balance I don't think it's worth it to pay for higher cu alloy header.

I hope this helps.

Chris
 
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mwemaxxowner

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Screenshot_20210219-120229.png

I think I misinterpreted this. That rate is for a second dwelling, looks like the regular rate is 0.629 and change. That sounds more accurate?
 

Homebrewale

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Apr 21, 2020
428
Apex, NC
I've read the whole thread. Let me address some of the things I read. First is a solar cover. Yes, it is absolutely necessary to keep the pool covered with a solar cover when not in use during the cooler months. I don't take off my solar cover until around mid-June and keep it off until around early to mid September. I'm trying to maintain my water temperature, not let it go up and down like a yoyo that it seems people with natural gas heaters do. Some people think solar covers are a hassle. Some people leave their robots in the pool all the time because putting them in and out is a hassle. I must have a higher tolerance for physical work since I don't find either to be a hassle. A good solar cover reel make taking off and putting back on the solar cover easy.

My wife is the main user of the pool. I take care of it but may only be in it about 2 hours a week during the summer. She swims laps at 5:00am every morning before going to work. On weekends, she sits in her foam floating chair for about 4 hours each day. She alternates between reading a book, sipping her favorite beverage, and sleeping. It is her favorite activity and the main reason why we own a pool. When the morning temperatures fall below 60F, she stops her lap swimming. Once the temperatures start falling below 80F during the day, she stops her weekend floating. Floating in 87F water with air temperatures in the low 70s is just not fun. There is absolutely no desire to swim at Christmas.

Based on the above, I don't open my pool and start heating until late April. I would probably wait longer but my wife wants to use the pool on her birthday in early May. I close my pool in mid-October because my wife stops her lap swimming around mid-September and is ready to quit floating mid-October. A second reason why I shut down my pool in mid-October is because during one warm fall I kept the pool open until November 11 which is Veteran's Day. Keeping the leaves out of the pool in November was a hassle. The pool cleaner at the time, a Polaris 380, had to be pulled out of the pool every few minutes to empty it's net. If I did it by hand vacuuming, the skimmer basket needed emptying every few minutes. Using a leaf net was also a labor and time consuming process. There were several threads this fall from NC pool owners trying to decide to shut their pool down or run through the winter. I shut my pool down because I don't want to worry about cold temperatures and loss of power during the winter. This past week in Texas reinforces my decision to shut down.

As for the heat pump not being able to keep up in cooler temperatures, I don't have that problem. My pool is 20k gallons and the heat pump is rated for 118,000 BTUs/hr. It has an efficiency (COP) of 6.4. It keeps up during April and May in the spring and September and October in the fall. The only time it has to run for long periods of time (other than startup in spring) is if we get a heavy cold rain. Again, the solar cover is important during these months. Using several of the online calculators to determine seasonal cost to run the heat pump, the results show I would spend almost $1200 more per swimming season if I used natural gas.

Edit: I forgot to say earlier that my wife wants the pool temperature to be 87F.
 
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ajw22

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View attachment 176312

I think I misinterpreted this. That rate is for a second dwelling, looks like the regular rate is 0.629 and change. That sounds more accurate?

Looks to me like you will pay $1.1823/therm which INCLUDES the 0.629 gas charge. That is still better then the $1.77 you have in the Hayward model you posted.

My 0.75/therm includes 0.45 in delivery charges and 0.32 in gas.
 

setsailsoon

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Allen,

That's a great gas price compared to mine. I pay $1.29 per therm all in. I believe it was a lot less back when we lived in Texas. Congrats, there is something that's priced great in NJ!

Chris
 

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