Electric Heat Pump vs. Gas for Saltwater Pool

nlblit

0
Jul 15, 2018
15
Detroit, MI
We're trying to figure out what to do as far as a pool heater goes. We have a 25,0000 gallon AG pool. Here are the 3 main factors we're weighing out:

1) Our pool is about as far away from our gas meter as you can get - the quotes to run a gas line are CRAZY expensive
2) We live in Michigan, and we've been told that that heat pumps are a better option for warmer states like Florida
3) We have a Saltwater pool

I have talked to 4 pool professionals. One strongly recommended an electric heat pump, the other three recommended gas... but one changed his mind when he found out we had a Saltwater pool. So I guess I'm really in need of personal experiences. Our goal is to be able to comfortably swim from May -> September. Michigan weather is crazy and can be cooler (this year is a perfect example).... will a heat pump still give us the results that we're looking for? I know that gas is more of an instant heat, but can we maintain a good temp with an electric pump?

If anyone could let me know your experience running on an electric pump in a cooler state I would appreciate it. Also, if you have an electric pump that you love or hate, please let me know. I need to make a decision quick. Thanks for any input!
 
I have a heat pump, not by choice, but clearance issues. Even though heat pumps are clearly more efficient regarding cost of electricity vs. cost of natural gas or propane, the issue is that the pool pump must run longer. So for me, with an in ground pool, I have to use a solar cover (covers 80% of the pool) and the heater works very well. I had to cut my solar cover to allow the pool to breathe, and this eliminates any potential algae, etc.

For you, a heat pump is a wise choice as above ground pools have the sun beating down on the sides of the pool and the water will heat up was faster than an
in ground pool. My pool is buried in concrete, soil and the sides are cooler. In addition, 8' of water vs. 54" is a big difference in the deep end. A heat pump will be plenty for your pool. It is suggested you go to www.poolheatpumps.com, and Asa Strong is will assist you in choosing the right heat pump for your pool.

The other thing is that an electric line (installed to code) is not that big of a deal and you can even dig the trench for the electrician. Adding a solar cover will keep your pool warm enough that the heater should only run a few hours per day at most, and you may not even need it in the summer. If you purchase a solar cover, cut it in half so it is easier to put on and remove.
 
My experience has been excellent with a heat pump in Ohio. I keep it on 85, and it honestly isn't expensive to run one it is past the initial 3 day long 60 to 85 degree heating cycle. I spent about $75 extra in electrical costs to run AND heat my pool in May. I was prepared for a much higher bill and was pleasantly surprised. With a gas heater you are going to only heat it only when you want to swim, and let it cool down when your not using the pool, so a bit of planning will be ahead of you choose to go that route. I kept my pool open through the first week in October last year and opened April 27th this year and the kiddos were in almost immediately. I wouldn't go to a gas heater since having the heat pump. As long as you have the available amperage in your sub panel they are an easy and fast install.

And as stated above, a solar cover is a necessity. You will be shocked how much heat it will retain at night and in cold days.
 
I have a heat pump, not by choice, but clearance issues. Even though heat pumps are clearly more efficient regarding cost of electricity vs. cost of natural gas or propane, the issue is that the pool pump must run longer. So for me, with an in ground pool, I have to use a solar cover (covers 80% of the pool) and the heater works very well. I had to cut my solar cover to allow the pool to breathe, and this eliminates any potential algae, etc.

For you, a heat pump is a wise choice as above ground pools have the sun beating down on the sides of the pool and the water will heat up was faster than an
in ground pool. My pool is buried in concrete, soil and the sides are cooler. In addition, 8' of water vs. 54" is a big difference in the deep end. A heat pump will be plenty for your pool. It is suggested you go to www.poolheatpumps.com, and Asa Strong is will assist you in choosing the right heat pump for your pool.

The other thing is that an electric line (installed to code) is not that big of a deal and you can even dig the trench for the electrician. Adding a solar cover will keep your pool warm enough that the heater should only run a few hours per day at most, and you may not even need it in the summer. If you purchase a solar cover, cut it in half so it is easier to put on and remove.
Thanks so much.... your information was a huge help. I did call and talk to Asa yesterday.... also a huge help! I see from your signature that you have a Gulfstream - are you happy with it? Have you had any problems? Thanks again!
 
My experience has been excellent with a heat pump in Ohio. I keep it on 85, and it honestly isn't expensive to run one it is past the initial 3 day long 60 to 85 degree heating cycle. I spent about $75 extra in electrical costs to run AND heat my pool in May. I was prepared for a much higher bill and was pleasantly surprised. With a gas heater you are going to only heat it only when you want to swim, and let it cool down when your not using the pool, so a bit of planning will be ahead of you choose to go that route. I kept my pool open through the first week in October last year and opened April 27th this year and the kiddos were in almost immediately. I wouldn't go to a gas heater since having the heat pump. As long as you have the available amperage in your sub panel they are an easy and fast install.

And as stated above, a solar cover is a necessity. You will be shocked how much heat it will retain at night and in cold days.
Thank you for the reply! Have you been happy with your Pentair heat pump?
 
I have had no issues with my heat pump. What I like about the "Gulfstream", or even better dealing with www.poolheatpumps.com is that Asa Strong is always there to answer questions, whether by phone or e-mail. He is very patient and with me it took over 3 months to figure this out.

No matter which brand you get, you will be fine.

My issue is the IG with limited sun. Some pools have sun from dawn to dusk without any obstructions and this is huge. A solar cover will make your life real easy, but I would suggest working without one first to see how it goes. Thanks!
 
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I have an electric heater which does the trick but needs to run 24/7 in order to work well. Many places in the counrty have cheap electric but here on LI, NY we pay many times the national average. I used it for Sept and Oct when the pool was built and my electric bill was a $1200 increase over normal. I have pretty much only turned it on occasionally to prove it works in the 6 years since. 2 times when having a party i turned it on a few days prior and it barely raised the 70 degree water. Supposedly gas heaters can raise a degree or 2 an hour regardless of input temp. My pentair ultratemp only shines when the water is already around 80 degrees.
 
I have an electric heater which does the trick but needs to run 24/7 in order to work well. Many places in the counrty have cheap electric but here on LI, NY we pay many times the national average. I used it for Sept and Oct when the pool was built and my electric bill was a $1200 increase over normal. I have pretty much only turned it on occasionally to prove it works in the 6 years since. 2 times when having a party i turned it on a few days prior and it barely raised the 70 degree water. Supposedly gas heaters can raise a degree or 2 an hour regardless of input temp. My pentair ultratemp only shines when the water is already around 80 degrees.

Something must be wrong on your end. I can only imagine that your heat pump may not be working properly, and/or not sized properly. While the heat pump is on, you should be able to feel warmer water coming out of the return jets. In addition, one of the biggest issues with heating any pool is return eyeball location and how many one has. My heater works great and I have done extensive studies. (See below the link). From speaking to other people who own gas heaters in NJ, the monthly cost to maintain the pool to about 85* is anywhere from $400-$700 per month extra, which is a lot.

A gas heater will produce heat at twice the rate of a heat pump. Although if you use a solar cover (like my experiment), I produced the same heat rise as a gas heater. Remember that wind and evaporation will decrease efficiency no matter what the situation is. Without a solar cover, a heat pump will run longer, therefore amounting to more electricity on the pump, in where the savings are about 30-400% of natural gas (at least in NJ) based off my calculations. My next pump will be a VSP in where I can run on lower to compensate for cost. Instead of 6 hours, I would have to run my pump 9 hours, and that will only cost me $1 more in electricity per day for the pump only. If gas is 3X-4X the cost of the heat pump, then this can make a lot of sense. Even if I ran my pump 12 hours ($2 extra per day), the savings still amount to better than gas. Of course, a gas heater is far superior as it will heat up the pool faster, and if someone is in a bind.

 
My heater is oversized for my pool. It definitely works but doesnt work well at colder temps. My 2nd season i got a 16mil solar cover and the 2 in conjunction worked perfect together but my electric was still far more than i wanted to spend. So the few years after that we used just the solar cover and that really made a difference by itself with only sacrificing 5-7 degrees. The heavy and akward solar cover eventually became too much trouble even with a commercial grade reel. My wife and 2 elementary school daughters couldnt open it using teamwork so nobody could swim unless i was home or i left it open the day before. Eventually i came to resent it and would sigh at anybody asking if we could swim that evening. So we threw out the cover/reel and have a heater sitting there not being used. In the end nobody feels like swimming often in May and Sept/Oct anyway. The pool is open for aesthetics and is far nicer looking without the eyesore cover . The occasional time somebody wants to, we just swim chilly.

I have a concete walled inground pool with an 8ft deep end. Most nights get into the 50s here early and late in the season. It probably doesnt matter which pump i go with, im gonna pay through the nose to use it.
 

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Newdude:

Regarding your 16 mil solar cover, this is part of the problem. A 12 mil or even 10 mil would have been perfectly fine. Your goal is to retain heat, and heat only, so here are some thoughts.

If you still have a cover, a little secret. You can cut the cover first into 3 parts, in half, or even 1/4th (10*20), whichever you prefer. This will be less weight. I remember having one car and what a PIA. Then go out and purchase 1" PVC. You can glued end caps (rounded like I did). Then pull the cover off the pool and lay the 1" PVC on it, and roll towards the pool. Then back it up a few feet and roll again. Works like a charm. You will then have 4 pieces that are not too heavy. When you put the cover back on, then you can lay the 1" pvc on the cover (experiment) to determine what works best. Your goal is to retain the heat at night.

What type size heater do you have? Pentair brand I see from signature? What is the cost per Kwh in NY? Out of curiosity. I am at .15 cents per Kwh, and yes during the summer the rates go up, but you will use less electricity as air will be warmer as well.
 
Newdude:

Just to piggy back on the heat pump working during colder weather, you are correct. For me, not a big deal as everyone is in school. Personally, we do not like being in 85* water, when ambient temperatures are 70-75 degree's. If you are are the type of person that enjoys this type of swimming, then YES, a gas heater is really the only option and a costly one at that. Think about all the heat loss at night and from the wind.

Unfortunately, this is the North and East Coast. Home ownership of a swimming pool is really not the best investment, but at least for 3 months we get to enjoy it. Thanks!
 
Catanzaro:

I thought of making smaller pieces of cover but the whole idea was to make less work, not more. The cover was thicker for more heat retention. I could be dead wrong but R30 insulation slows down heat transfer better that R15, why would a pool be different ? But yeah, it was heavy. It was also clear. Altho i considered it ,ore of an opaque white than clear. According to the manufacturer it allowed sumlight to pass through and help gain a few degrees during the day while retaining at night. There is no question the thick pool cover worked very well. Usually maintained around 78 degrees. But everytime we ran out to go swimming, it was a process that took a few minutes. We all grew to resent it for slowing down the fun. Since throwing it out, we race outside seeing who can cannonball first.

My heater is the ultratemp 120. It cooks when the air is warm and the water is already above 75 degrees. In late September and October we can have our first overnight freezing temps or very close to it in the low 40s. The only way it worked for us was if it maintained the temperature 24/7. Which killed my electric bill. The cover helped cut down the electric bill, but only to $400 a month instead of $600. I have to log into the electric company website to figure out my current electric costs. I havent seen a paper bill in ages. But will let you know.

Found my current online statement. NY electric is tricky. The first teir of Kw costs 8 cents. Once you go over that it goes to 9 cents. BUT, taxes, fees and surcharges amount to more than the cost of the electric. When i didved my bill amount by the Kw used, my realistic charge is 21 cents per Kw. This has come down substantially from a few years ago due to the solar boom. With many houses locally going solar, we have to buy less electric from out of state during peak times. Kinda funny and i love pointing out and thanking my friends who converted for helping to lower my bill..
 
I could be dead wrong but R30 insulation slows down heat transfer better that R15, why would a pool be different ?
The cover is stopping evaporation. That is what cools the pool water. Any thickness of cover will stop evaporation.
 
Mknauss

Thanks for the explanation



Nlblit

Sorry for unintentionally highjacking your thread. But back to the original question, i have a heat pump and had a solar cover in a similar climate to yours. Im pretty much due east of you. The cover was a must and will pay for itself many times over. If you find it to be too heavy (30 ft is quite large) you can cut it in half. In my personal experience it was all for nothing. If we needed the pool to be warm, nobody felt like swimming anyway 9 times out of 10. It was hard to justify the cost for 5 extra swims. Ultimately the costs for electric and gad fluctuate. 5 years from now, one may cost 5 times the other. Good luck with whatever you choose.
 
In summary, I believe that if one lives in a climate that has real cool evenings and wants to use the pool real early on, and real late, either the electric bill or gas bill will be real high (because of evaporation loss) or a solar cover must be used. Marty is 100% correct, that a cover does nothing more than merely stop evaporation. If you have a solid tarp, this will stop evaporation through the evening as temperatures changes. The only problem with a tarp is that the wind will take it off the pool and it will sink. Solar covers will last. Best way is to cover a pool at night with a solar cover.

Everyone has to find what works for them. We had no heater for 2 years and the pool had limited use. With the heater, we have more use. At the end of this month, I will have a better idea on what my electric bill is as the heater has not shut off, no matter what the temperature has been. We have had a lot of rain, but the cover is on and I do lose about 3-4 degrees overnight, but no matter what I will maintain the temperature.

I will report back in this post and give everyone an idea on what the difference between the last 3 years were based on electricity costs. They have not changed that much. Reason is that the first year I really did not use the cover in June. Last year I used the cover for part of the time but heater was shut off. Now the cover is on and heater is on to maintain the temperature. Unfortunately, this is the cost of home ownership with a pool (Expensive).
 
@Catanzaro any update on your #s?

Please note that I went back and tried to figure out the difference between last year and this year, and quite honestly it is near impossible. Only thing I can tell you is that the heat pump ran for an average of 4 hours, maybe 6 hours if the night temperatures dropped. This year, unfortunately the air conditioning was a lot lower, so I have nothing to base my estimates on.

Although, a few things to consider:

Without a solar cover, a gas heater will heat up water twice as fast. You will get 1* per hour with gas, while 1* will take 2 hours with a heat pump. You have to consider whether or not you will be using a solar cover. With a solar cover, the heat pump is just as fast as the gas heater. Even in colder climates I found that the heat pump raised the temperature pretty quickly. Now, if the weather is 90*-95*, that is very quick.

One thing to consider is pump run time. If you run your pump 12 hours per day, then clearly a heat pump is the way to go if you only use the pool from June-September. If you run your pump only 4 hours per day, then a gas heater may be best as this is really what you need. There are many variables. I know people who have gas heaters that tell me their gas bills in the summer here in NJ are between $500-$700 per month. My gas bill is usually $100 on average. So this was convincing enough. My electrical bill did not increase by $400-$500 or anywhere near this. If I had to ball park everything, it would be like $125 a month on average over 4 months. Some months more, some months less.
 
Thanks for this feedback. I'm on the fence between gas vs. HP for my new pool build in Bergen county, NJ that would be used mid May to mid September. My main concern is the stretches of colder nights in late may and early September. For example, this September has been interesting with coldish weeks but warm/beautiful weekends. I don't know how a HP would have handled that since it wouldn't have been able to keep up during the week to have warm water by the weekend. Normally I would just go with gas and call it a day, but I have solar panels on roof so running my pump/HP would essentially be "free"...if it can actually do the job of warming the pool when I need it warm.
 
The heat pump will work to about 65 degrees, which you will get from 10 a.m. until 4 p.m. The key is to retain the heat in the pool overnight. I cut my cover to short and now am getting a new one from a friend because I open and close his pool for no charge. If you can put the cover on at night, then you will retain most of the heat and this is the key. Keep the cover on all the time, and every day just lift off the pool (just about 5 feet) so pool can breathe, and then put back at night. Do not take off and put back on, just pull off the pool. I cut my cover in half. This one will be in 3 pieces. I can use both covers base on needs and temperatures, etc.

With the cover on and the heat pump running in 65* day weather you will be fine. It is really worth it if you have solar panels. If not, I probably would have gone for gas vs. heat pump at this stage. My problem was clearances from windows with gas. Also, I let the pool company convince me not to install a heater when we built the pool (why ? I have no idea).

No matter what, we had real rough August weather and September weather, so if the pool as not covered, you would lose a tremendous amount of heat overnight through evaporation and the heat pump would take forever to heat up the pool, and the gas heater (of course) would cost you a fortune. If you plan on using a solar cover, then heat pump all the way. You could also get a gas heater and use a cover, which takes heating the pool to a whole different level.
 

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