Gas heater vs heat pump--which one do I pick????

domshort

Member
Jun 14, 2019
10
la vista, ne
Hello everyone. Sorry if this subject has been talked about, I searched and could not seem to find any discussions. We in the process of putting in an 18x38 sport pool. We live in Omaha, NE and our pool will be on the south exposure. Our general swim season is May through Sept, from what I've been told. I'm currently trying to decide between a heat pump and gas heat at a relatively similar initial cost as they have to extend the gas line to the opposite side of the home. Would love to hear from those that have heat pumps and if there has been any disappointment since they heat a pool slower, especially from those in a similar climate. Would also like to hear about electric vs gas costs based on your specific usage. I'm leaning toward gas for the convenience of the quick heat but am drawn to the heat pump cost savings and tendency to require less repairs vs gas heaters (per my pool contractor). Thoughts? Thanks in advance for your time/replies.
 

Pool_Medic

In The Industry
Apr 1, 2018
1,197
Bangor Maine
Heat pump will be more efficient than gas but gas will heat up the water quicker. If I had the choice, I would go gas and be selective of when I allowed it to run.
 

Joshii

Well-known member
Jul 15, 2013
240
Same. Gas will be more effective, smaller, and quieter than a heat pump. It will also be using your fuel on the opposite season - a heat pump would use a lot of electricity in a season that already uses a lot of electricity. Probably not a problem with if your house has 200 amp service, but still. You don't have limitless electric capacity.
 

Chickinvic

Well-known member
Jul 12, 2017
266
Ottawa, Ontario, Canada
Natural gas for sure.

PS - I'm in Ottawa, Canada and we swim from May through most of October, and it is more or less the leaves dropping into the pool that gets to a point that I can't keep up when we close it - otherwise I'd swim even longer some years:)
 

Chickinvic

Well-known member
Jul 12, 2017
266
Ottawa, Ontario, Canada
Chick, what is your gas bill to heat your pool?
I don't know exactly. I went back and looked at our gas usage for last year (May through October). During this 6 month period we averaged just over 700 cubic meters of gas per month. Gas was about $0.119 per curic meter. Some of this would be our air conditioning and hot water heater in the house, but much more would be the pool I imagine. So, our gas usage was over $80 per month. We pay much more than that though since there is delivery fees, etc. We are on equal monthly billing which they recalculate each year based on the previous year's usage. This year it is just under $200 per month, but I suspect it will go up next year due to our horribly cold and long winter this year (lots of furnace usage).

PS - the heater is on all the time since hubby won't swim in under 86 degree water , but we had a pretty hot summer so I don't think it actually kicked in much for times during the heat waves. It was close to 90 degrees just from the sun. So, I think once we finally get it up and running this year (we are having g work done such as liner replacement right now) it will be a much more expensive year to run it with the lousy weather we've been having.
 

Newdude

Well-known member
Jun 16, 2019
2,566
NY
I went with the big pentair heat pump. We have one of the highest electric rates in the country and spent $1200 the first season. Haven't used it since. I promptly got a thick clear/white solar cover for years 2-5. It really helped the heat loss at night and gained several degrees during the day. But even with a HD reel, it was just so heavy that my wife and 2 small daughters couldnt take it off as a team. It was more pain than it was worth and we look directly at the pool from my kitchen table so it was a constant eyesore. The last 2 years we just let the weather decide how warm the pool will be. In May and September, nodoby feels like swimming often anyway.
 

domshort

Member
Jun 14, 2019
10
la vista, ne
Thanks for everyones replies. Seems like the consensus is natural gas. Hoping to get heat from the south exposure and saw a good diy on the site for a solar cover roller so hoping this will work out well to keep our water nice and warm. I can surely be selective of when to run the heater, I'll just need to make sure the hubby and kids don't know how to turn on! Now if it would just stop raining so they can dig...sigh.
 
Apr 16, 2019
12
Chicago, IL, USA
I would get the highest rated gas heater you can afford. I have a 250k heater for my pool and its about 1 degree rise an hour. A solar cover is a must for us cooler climate areas. Drastically keeps the heat loss from overnight to a minium, and helps warm the water faster during the day. When this heater goes, I will get a 400k system or larger if my gas line can support it. faster heat rise means less pump time and faster enjoyment. My pool is a weekend use only so I heat the pool friday night to 86F and keep it their until sunday afternoon. Then the solar cover goes on and helps hold the temp until next friday.
 

Newdude

Well-known member
Jun 16, 2019
2,566
NY
I spent $500 on my reel. It was a commercial grade heavy duty reel with upgraded bushings for easier use and the 5 inch tubing was reinforced to prevent bending. Neither mattered. The 20X40 16mil cover was so heavy that only i could open it and it still sagged in the middle from the weight. Putting the cover back on the pool i would turn the pump on high and let the returns do most of the pushing for me. There is no question it made a big difference in heat retention and gaining heat during direct sunlight. But for us it was just too much work. Somebody else posted somewhere to buy the thinnest cover possible to make it easier to remove. Also, it kept all the pollen and leaves that fell in a thin puddle of water on top of the cover. They brown and yellow stains were even more of an eysore than the cover itself. Good luck on whatever you decide to go with.
 
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domshort

Member
Jun 14, 2019
10
la vista, ne
Sorry it took me awhile @Old Yankee, but here you go if you haven't already found

 

usedtobeayooper

Active member
Aug 20, 2019
32
Hamilton, MI
Finally a topic I can contribute to in a helpful manner.

The way I would look at it is: Do you plan to swim spontaneously throughout the week, or plan ahead and swim primarily on the weekends?

Basically, is your intent to KEEP the pool warm, or warm it when you want to use it?

I ask, because I went back and forth on this same question 3 years ago, and admitted to myself that we’re usually busy all week, but then play hard Friday night through Sunday.

For a heat pump to work efficiently, the water needs to stay relatively warm, basically offsetting your overnight loss each night. If you had both units on all the time, and kept the pool warm all the time, the heat pump would generally run less expensive over time than gas, despite the higher up-front costs. But, if you let your pool sit idly by all week, and then plan to jump in Friday night, the heat pump will take FOREVER to heat the pool back up compared to NG.

My 100,000 BTU NG heater used to heat my 5200 gallon AG roughly 2 degrees an hour… it now seems to average about 1.5 deg/hour with my 7600 gallon set-up. Turned it on this past Saturday AM at 7:00 AM (water temp 74 deg) and it was up to a comfortable 82 by Noon. Gained another few degrees throughout the day from the sun, and only had to run the heater for an hour or so to bring it to 86 Sunday morning. Then shut it back off and won’t worry about it again until next weekend if the weather looks favorable.

The last time I ran my own numbers, I believe I was at approx. $1.35-$1.50/hour to run the heater at my current gas price. The inter-webs vary by site, but seem to average on about $0.60/hour to run a heat pump. (obviously mileage will vary… probably significantly… but it’s a ball park)
 

usedtobeayooper

Active member
Aug 20, 2019
32
Hamilton, MI
Also, if you're running any sizing calc's, remember that you will pay for the rated BTU's in operating costs (in my case 100,000 BTU's) because that's what the unit is burning, but with most gas units, your pool will only recognize about 75-80% of those BTU's in terms of heat gain (in my case, when I back in the numbers very roughly by timing heat rise and run time), I seem to be averaging about 80% efficiency, or about 80,000 BTU's of heat out of my 100,000 BTU unit.

...and as stated above, this is one instance where bigger is (almost) always better. (in my opinion)
 

SBall

Well-known member
Jun 27, 2017
249
Nashville, TN
I have a 330k BTU natural gas heater and Pentair automation. I set it at 90 degrees in early April. It is still set at 90 degrees. Yesterday morning was cool...low 60s, I went for a run, then got in the pool at 6:30am and it was wonderful. I intend to turn off the heater in early November. Not surprisingly, the heater doesnt run much during July and August. Cost $200 for April, about $100 for May, didnt look at June, $35 for July, August bill not available yet. Based on our typical weather, September will probably cost $50-$100, and October $100-$200ish...kinda depends. Probably less than $800 for April through October to keep it at 90 degrees. Totally worth it for me. Sunday we went to the neighborhood pool, started thundering, storm rolled in and they shut the pool down...outside temperature dropped about 10 degrees, we went home and got in our pool for several hours until dinner.
 

swamprat69

Well-known member
Mar 30, 2019
181
Las Vegas, NV
I don't know exactly. I went back and looked at our gas usage for last year (May through October). During this 6 month period we averaged just over 700 cubic meters of gas per month. Gas was about $0.119 per curic meter. Some of this would be our air conditioning and hot water heater in the house, but much more would be the pool I imagine. So, our gas usage was over $80 per month. We pay much more than that though since there is delivery fees, etc. We are on equal monthly billing which they recalculate each year based on the previous year's usage. This year it is just under $200 per month, but I suspect it will go up next year due to our horribly cold and long winter this year (lots of furnace usage).

PS - the heater is on all the time since hubby won't swim in under 86 degree water , but we had a pretty hot summer so I don't think it actually kicked in much for times during the heat waves. It was close to 90 degrees just from the sun. So, I think once we finally get it up and running this year (we are having g work done such as liner replacement right now) it will be a much more expensive year to run it with the lousy weather we've been having.
 

swamprat69

Well-known member
Mar 30, 2019
181
Las Vegas, NV
I don't know exactly. I went back and looked at our gas usage for last year (May through October). During this 6 month period we averaged just over 700 cubic meters of gas per month. Gas was about $0.119 per curic meter. Some of this would be our air conditioning and hot water heater in the house, but much more would be the pool I imagine. So, our gas usage was over $80 per month. We pay much more than that though since there is delivery fees, etc. We are on equal monthly billing which they recalculate each year based on the previous year's usage. This year it is just under $200 per month, but I suspect it will go up next year due to our horribly cold and long winter this year (lots of furnace usage).

PS - the heater is on all the time since hubby won't swim in under 86 degree water , but we had a pretty hot summer so I don't think it actually kicked in much for times during the heat waves. It was close to 90 degrees just from the sun. So, I think once we finally get it up and running this year (we are having g work done such as liner replacement right now) it will be a much more expensive year to run it with the lousy weather we've been having.
Just so you know, normal ACs and heat pumps use electricity to run. Only Absorption units use gas and a smaller amount of electricity for the controls and fan.
 

chazas

LifeTime Supporter
Jun 4, 2007
147
Manassas, VA
^ This unit is really expensive. I am in the design stage for a new small fiberglass pool and thought about it briefly, but it doesn't make a lot of financial sense to me.

I ran some numbers for both natural gas and a heat pump in my location. Theoretically I would save a little on operating costs with the heat pump, a 3-4 year payback period at my pool installer's prices (they charge about $2K less for a gas heater). But I realized that in the shoulder seasons I'm not going to be swimming on weekday evenings, so will likely only fire up the heater on a nice weekend day rather than running it continuously as the calculators assume - that's behavior that's more consistent with a gas heater, and means the savings from a heat pump would likely be even less. I decided to go with gas.
 
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