Heat Pump versus Natural Gas Heater in North Alabama

[JamesW]

CoPilot:

Now, diving into your pool heater considerations, you've clearly done your homework, and you’ve presented very detailed data and calculations.

Let's break down the main factors to help clarify your path forward.

Gas Pool Heater vs. Heat Pump: Cost and Efficiency

1. Heating Speed: Gas heaters are indeed faster in heating your pool compared to heat pumps.
2. This responsiveness makes them ideal for irregular use, like those spontaneous afternoons when your grandkids want to swim.
3. Energy Cost Comparison:
   • Your calculations for daily heating costs are spot on. A natural gas heater at $14.34 per day for a 5°F increase is about twice the cost of the heat pump ($5.98 for the same increase). Over time, using a gas heater frequently for quick heating will likely result in higher monthly utility bills.
   • On the other hand, heat pumps are more efficient at maintaining a set temperature due to their lower operational costs. If you plan to keep your pool at 85°F consistently and cover it well at night, a heat pump could become the more economical long-term choice.
4. Initial Installation Costs:
   • Gas heaters are cheaper to install in this case since you're already set up with gas infrastructure that can support the 250K BTU Hayward heater without major upgrades to the meter or pipes.
   • Heat pumps, however, require a significant electrical overhaul due to the lack of sufficient amperage in your existing setup. The installation costs for running new circuits and wiring would be substantial and add to the already higher upfront cost of the unit itself.

Regional Considerations: Huntsville, Alabama

Given Huntsville’s relatively mild climate, heat pumps tend to perform well because the outside air temperature in spring and summer provides favorable conditions for their efficiency. Even with nighttime cooling, heat pumps can maintain your desired pool temperature with less intensive use than a gas heater would require.

Usage Patterns and Solar Cover Impact

You mentioned adding a solar cover reel, which will greatly improve your pool’s heat retention. By keeping your pool covered when not in use, you reduce overnight heat loss significantly, especially with a consistent temperature-maintenance approach using a heat pump.

Decision Time: What Matters Most

• If cost is the top priority: For infrequent use and quick heating, the gas heater is more straightforward and avoids expensive upgrades to your home's electrical system. However, the higher operational cost can add up with frequent use.
• If long-term efficiency matters more: If you expect consistent use and want to maintain the pool at 85°F all summer, the heat pump will be the better option overall, despite the upfront installation effort.

Additional Tips

1. Consider consulting with HVAC professionals to weigh the specific installation costs for upgrading gas or electrical systems.
2. Explore hybrid approaches: Use a gas heater for quick boosts when needed and leverage the heat pump for maintenance and efficiency.
3. Look into rebate programs from utility companies—some offer incentives for energy-efficient installations like heat pumps, which could offset initial costs.

 

[SJPoe]

Just wondering if you put the roll behind the rail at the step end, if there is enough space there. My solar roll stands about 2 feet off the ground, and the straps are probably 4ft long, so it would be fairly easy to roll it over the top of the railing, and then kind of 'tuck it under' once it was unrolled. Same at the deep end, rolling the cover up or on over the diving board is doable, but I don't see where you would keep the 18FT long roll when not in use so that it didn't interfere with the diving board or access.

 

[jfmorris]

@SJPoe and others - anyone seen one of these low profile solar reels in actual use?

Doheny's Low Profile Reel System - Doheny's Pool Supplies

Shopping for Doheny's Low Profile Reel System? Doheny's has Doheny's Low Profile Reel System in stock now at the guaranteed lowest price.

www.doheny.com

That looks like it could be an option, even though twice as much as a conventional reel. The drawback is it has no wheels on one end, so it would always be there when rolled up, and hard to cover to keep sun off. However, that is the most shaded part of the pool, only getting late afternoon sun from the west.

One thing I don't see with most of the reels is how you EXTEND the cover. It's effectively a giant sheet of bubble wrap - does it really just float back across the pool as you crank the handle, or do you have to get someone at each corner and drag it the length of the pool?

Last year it was a struggle getting the cover on and off by myself. I would basically drag it up onto the concrete on the wider section of the deck, next to the house, hose off any debris, then "accordion fold" the next section on top of that, until I had it off the pool. Then roll it up. Then manhandle it around the corner to the end of the house, and out of sight. Invariably if it had rained, there was water and leaves and debris on top that dropped into the pool as the last section came off. I still see that as a factor with the reel, but something you just have to deal with.

Putting it on was the reverse, with me just dragging it across the width of the pool, after unrolling down the length on the side towards the house.

If the low profile reel doesn't seem like a good way to go, I am thinking the idea of just cutting the cover into several sections, across the width of the pool, that I can pull out and fold up over on the pool deck by the house, and store out of sight around the corner by the pump and HVAC system.

 

[Newdude]

does it really just float back across the pool as you crank the handle, or do you have to get someone at each corner and drag it the length of the pool?

With a rectangle and returns pointed that way, I'd crank the pump up and pretend I was a Jedi putting the cover back on as I unrolled it.

Without the returns assisting i needed a 2nd person to drag it perfectly, or had to run around side to side a couple times for readjustments along the way by myself.

 

[jfmorris]

@JamesW thanks for all of your AI generated research on the pool heater topic. I was hoping I was wrong on the math for how much it would cost to heat the pool 5 degrees with gas. It does make me want to think hard about the heat pump.

One thing I will say is last year with the solar cover on at night, even with cool evenings that we have in the summer (it often drops to the upper 60's at night here), my temperature loss most days averaged about 2F overnight. So if the pool was 85, 88, or whatever, the next day, assuming the cover was on, we would only need to restore 2F to the pool.

 

[JamesW]

 

[jfmorris]

With a rectangle and returns pointed that way, I'd crank the pump up and pretend I was a Jedi putting the cover back on as I unrolled it.

Without the returns assisting i needed a 2nd person to drag it perfectly, or had to run around side to side a couple times for readjustments along the way by myself.

My two returns are at diagonal opposite ends of the pool - one in the deep end, one in the shallow end. So I might get some assist from the one if I pointed it up towards the surface, but the one at the shallow end would be fighting against me, or need to be angled down towards the bottom of the pool maybe...

 

[jfmorris]

Just wondering if you put the roll behind the rail at the step end, if there is enough space there. My solar roll stands about 2 feet off the ground, and the straps are probably 4ft long, so it would be fairly easy to roll it over the top of the railing, and then kind of 'tuck it under' once it was unrolled. Same at the deep end, rolling the cover up or on over the diving board is doable, but I don't see where you would keep the 18FT long roll when not in use so that it didn't interfere with the diving board or access.

If I had one of the reels I've seen with 2 wheels at one end, and could make it work around the diving board somehow, I was thinking I could just lift the other end, and roll it away into the end yard up against the fence, out of sight around the end of the house.

There really is not room to do the same thing at the shallow end, due to that angle at one corner of the pool deck, and the fact it would block access from the house.

 

[SJPoe]

One thing I don't see with most of the reels is how you EXTEND the cover. It's effectively a giant sheet of bubble wrap - does it really just float back across the pool as you crank the handle, or do you have to get someone at each corner and drag it the length of the pool?

Getting the cover off is fairly easy for me - you stand by the reel, and turn the wheel. I occasionally stop to 'true it up' a couple times, but thats my OCD, not really a requirement.
Getting it 'on' - if we've been swimming, I usually just grab the middle of the cover from in the pool, and swim to the shallow end pulling it behind me. Its a bit of a faff to do it solo outside the pool, you have to cross back and forth a couple times to pull the corners back straight and so on. I've thought about adding a long piece of PVC pipe to the 'leading edge' to help, but never quite got around to it. With two people (even an 8 year old), you can easily pull it over the pool with minimal effort.

Last year it was a struggle getting the cover on and off by myself. I would basically drag it up onto the concrete on the wider section of the deck, next to the house, hose off any debris, then "accordion fold" the next section on top of that, until I had it off the pool. Then roll it up. Then manhandle it around the corner to the end of the house, and out of sight. Invariably if it had rained, there was water and leaves and debris on top that dropped into the pool as the last section came off. I still see that as a factor with the reel, but something you just have to deal with.

The reel really makes it much easier - on my pool, it just lives at the deep end, gets covered when it's rolled up etc. We don't use the diving board (my son dove into a pool when he was 16/17, banged his head, broke his neck, spent months in a Halo...fun times...no diving allowed) so it doesn't really get in the way.

Putting it on was the reverse, with me just dragging it across the width of the pool, after unrolling down the length on the side towards the house.

You just pull it, and it unrolls...once it starts moving, it's very minimal effort to keep it rolling along.

 

[jfmorris]

Ok, I came to a decision here on the heater. While the heat pump is certainly cost savings, the more I looked at the electrical work needed - 4 AWG wire for a 60A circuit is NOT cheap - and the fact that the only salt water rated heat pump I could find was $2600 more than the salt water rated 250K BTU Hayward natural gas heater, it kinda made my decision for me. Even if I pay $150 versus $50 per month to heat the pool for 3-4 months of the year, it will take quite a few years to make up the difference in cost. And right now, with my wife's terminal cancer diagnosis, I am more focused on short term than long term things. If she is miraculously healed, I'll worry about more efficient pool heating down the road.

I just ordered the Hayward W3H250FDN pool heater from Leslie's Pool Supply. The local store didn't have any in stock, so I just got it for delivery from their website.

I'll continue to accept advice here (for which I am SOOOO grateful!). on the solar reel (or cutting the cover into smaller sections) as I realize I need to ensure it is easy to take the solar cover off and on in order to reduce heat losses overnight after the pool has been heated. Last summer, even though we didn't swim a lot, I monitored the pool temp with an Inkbird floating wireless pool thermometer, and the overnight loss when the temp would dip into the upper 60's on summer nights was at most 2 degrees.

Thanks!

Jim

 

[jfmorris]

You just pull it, and it unrolls...once it starts moving, it's very minimal effort to keep it rolling along.

Ok - that sounds good. And to be honest, most times the pool is used, I will be around, since I work from a home office, even if I am not swimming long with the grandkids, I could jump in and drag the cover back to the shallow end.

I am starting to think that low profile reel I saw and pasted a link to at Doheny's may be the way to go. I just wish it had more than 2 reviews!

 

[SJPoe]

Ok - that sounds good. And to be honest, most times the pool is used, I will be around, since I work from a home office, even if I am not swimming long with the grandkids, I could jump in and drag the cover back to the shallow end.

I am starting to think that low profile reel I saw and pasted a link to at Doheny's may be the way to go. I just wish it had more than 2 reviews!

I can't talk to the low profile real - I guess I'm not sure what the gain is (EDIT : Oh, maybe it would slip under the diving board...I could see that...) - once you roll up 36 feet of cover, it bulks out a fair bit (someone could probably do the math...I'm not going to)

Mine is more like this one - if it lasts a season, you could replace it 4 times and still be ahead....I would guess it will out-last the cover

 

[Newdude]

I am starting to think that low profile reel I saw and pasted a link to at Doheny's may be the way to go. I just wish it had more than 2 reviews!

Double check the measurements of the reel and board. I'm concerned the low profile reel (plus cover) won't fit your low profile board.

 

[jfmorris]

@Newdude and @SJPoe the Doheny "low profile" reel says it works if there is at least 10" clearance under the diving board. I just measured and have 11.

From the description:

• Fits Under Dive Board
• No Mounting Required
• Includes all Hardware & Instructions
• 5 Year Warranty

For rectangular pools with less than a 6" corner radius. Unique system fits under diving boards that have 10" of clearance between deck and board. Sits securely on deck without mounting. Includes all hardware and instructions. Comes complete with reel/blanket attachment kit. 5-year warranty.

• Extended length crank handle features ball-bearing action for an easier turn.
• Sits securely on deck without mounting. 40-ft. blanket rises approximately 8-in. over deck level.

And from the photos of it:




Each end is the same, and the detachable handle can hook onto either end. It looks to me like it HAS to be placed such that it laps over the pool itself, so that the roll can expand into that area, versus hitting the concrete. For me that would mean possibly needing to trim some of the width, since I cut a 20x40 cover down such that I have about 6 inches more width and length than needed - with the excess kinda curling up against either side of the pool walls.

That said... the $99 reel that @SJPoe linked to is 16 inches to the center of the reel from the pool deck. I.e. the reel COULD be placed above the diving board to start rolling up, but I think I would not be able to complete rolling up the cover before it started hitting the top of the diving board.

 

[SJPoe]

but I think I would not be able to complete rolling up the cover before it started hitting the top of the diving board.

If only there was a cheap and easy way to elevate the reel...



Amazon has a reel with 18.5" to the center : https://www.amazon.com/dp/B01MDLU2GG/ref=sspa_dk_detail_4?pd_rd_i=B01MDLU2GG

 

[jfmorris]

If only there was a cheap and easy way to elevate the reel...

View attachment 637349

Amazon has a reel with 18.5" to the center : Amazon.com

Haha. I get you. Put a block under each end before cranking things in.

I like that the reel on Amazon has aluminum of for the roll portion of the reel, versus plastic like many I look at. For the price, I may need to try that one, and see if I can make it work, even if I need to buy a roll of strap material to make longer straps.

Done. I just ordered that reel of Amazon, and I think if I lengthen the straps, I can make it work over the diving board, then roll it out of sight. Or it may be as simple as shifting the two ends past the end of the diving board before rolling up - it would pull from under the diving board, then roll up the shallow end.

If it doesn't work well, I can move to the low profile reel the next summer.

 

[SJPoe]

Necessity (and a piece of 4x2) is the mother of invention