Pentair Hybrid vs Heat Pump & NG Heater vs Just NG Heater

[ajohansson]

Im in Murrieta a So Cal interior valley city about 19 miles from coast. Days warm mid to upper 90s and nights down to mid 60s in summer.

9k gallon pool, 600 gallon spa.
Would like to keep pool at around 80.
I do have solar and can add some more panels with micro inverters if necessary.

The questions/options I have.

1. Go Pentair Hybrid combo unit 220k gas 110k Heatpump
2. Go Heat Pump and a 400k NG heater
3. Just a NG heater 400k NG heater

I like the idea of the heat pump as I have a mitsubishi minisplit AC/Heater in my garage and its works great. I see there are some threads on this but no real long term use cases right now.

My pool builder like the pentair line.

I dont have any more room on my roof for a water/solar system.

Any info appreciated.

AJ

 

[ajw22]

Welcome to TFP.

The hybrid combo is expensive and costs as much as separate gas heater and HP. If you want both then get separate units.

With a spa you need a NG heater for the on demand heating. I suggest you get a 400K NG heater, use it for a season or two and then decide if you need a HP in addition.

Size your equipment pad for a MasterTemp heater and an UltraTemp HP.

Are you installing a Pentair IntelliCenter? With the possibility of dual heaters you really need automation to manage them.

Equipment Pad Best Practices - Further Reading

www.troublefreepool.com

How to select pool equipment - Further Reading

www.troublefreepool.com

Construction Best Practices - Further Reading

www.troublefreepool.com

 

[ajohansson]

@ajw22 thanks for the advice. I think I will do the 400k heater and leave room for a stand alone heat pump if needed down the road. I want to heat up the spa quick so 400k is a must.

Here is my logic for heat pump. I need the pool pump to run for the filter 8 hours a day during summer. During the hot days of summer with sun hitting the pool I don't imagine a whole lot of heat loss except that as evaporation happens new water that gets added to the pool by the auto filler is goin to be cool water. Not sure if thats enough to cause heater to fire.

But let's say as sun sets and temps drop that is gonna cool the water enough and then the heater is going to fire. So I am imaging that during the summer the Heat Pump would be running mostly at night? So if the pool pump needs to run anyway for the filter is this serving dual purpose? This maintains temps over night and then the next day it shuts off eventually as its not needed and starts all over again.

Am I off? First time pool owner here.

Figure I might want to swim April to October. The bookends here would have more heat pump time during the day to maintain.

 

[ajw22]

Your 400K NG heater will heat your 9,000 gallon pool by over 5 degrees an hour. It will restore any heat lost overnight in an hour or two.

I think the difference in energy you would save with a HP will not pay for the cost of the HP. The NG heater will heat your pool and spa rapidly as needed.

 

[ajohansson]

@ajw22 thank you so much for the info.

 

[scdaren]

If you are set on having a gas heater, there is absolutely no need for the heatpump -- it's not worth the cost of doing both. In our California climate you could do a heat pump alone -- the disadvantage being that it won't heat as fast and it won't work in the winter when temps are under 55 degrees. But they are quite cost efficient (especially if you have solar with excess production) and work great for maintaining a pool at a constant temperature.

Edit -- just noticed you are heating a spa as well. Just get the natural gas heater. Your pool is not big enough to warrant both. Even if you just want to add the empty space for one, you'll still need to pay for the additional electric capacity, and that should be done at initial construction to be practical.

 

[ajohansson]

@scdaren thanks for your reply. I have the power at the sub panel. I do plan on adding some more solar panels.

so during pool dig had to move AC units and i told my AC guy a week ago one unit has oil around it but still blowing cold air. When he came to move the ac so the bob cat could get buy he saw the unit had blown a leak. These acs were badly abused by the previous owners dog. They are 19 years old and well it needed to be replaced. I told him to replace them both. So moving to seer 19 units i may have some excess power now.

so im gonna have the 400k heater no matter what because i want to say hey babe want to go in spa and heat it up fast. So is the add of the heat pump really worth it for a 9k gallon pool? And what is return on investment like? I am sold on doing two units instead of a hybrid now if i do it.

anymore comments i would love to hear them.

 

[scdaren]

@scdaren thanks for your reply. I have the power at the sub panel. I do plan on adding some more solar panels.

so during pool dig had to move AC units and i told my AC guy a week ago one unit has oil around it but still blowing cold air. When he came to move the ac so the bob cat could get buy he saw the unit had blown a leak. These acs were badly abused by the previous owners dog. They are 19 years old and well it needed to be replaced. I told him to replace them both. So moving to seer 19 units i may have some excess power now.

so im gonna have the 400k heater no matter what because i want to say hey babe want to go in spa and heat it up fast. So is the add of the heat pump really worth it for a 9k gallon pool? And what is return on investment like? I am sold on doing two units instead of a hybrid now if i do it.

anymore comments i would love to hear them.

It really comes down to the cost of natural gas versus the cost of electricity in your area, and how often you’ll be heating. You would need to do an analysis of the annual cost of heating with gas versus electricity. That’s a bit complicated to figure out, tons of variables there. For what it’s worth, I know my Pentair 140 heat pump uses about 7500 watts, and heats my 15k gallon pool one degree per hour. I lose about 6 degrees of heat loss overnight in the seasons I am heating, versus 3 degrees if I put a solar cover on (which I no longer do bc I hate it). So when figuring out my cost, I have to look at the cost of power, which can be 3 different numbers depending what time it is, and the low price is in the middle of the night when it’s cooler out, and those numbers change on May 1. Plus I have solar. You can see how tricky it would be to really figure this out, doubly hard when you have two different energy sources to factor in. For example, if you used your heat pump to maintain a constant 80 degrees during the shoulder months, your gas heater would have to do less work to heat the hot tub.
Anyway, without knowing all these variables, my guess/theory is that with the smaller pool, which requires less energy to heat, and the fact you’ll be gas heating the spa anyway which will warm the whole pool, an extra $5000 or whatever it is to put in a heat pump is going to take awhile to get an ROI based just on the difference between the cost of gas vs electric.

Another factor, if you haven’t considered it, is that heat pumps are loud, and take up a lot of space. My Pentair is way louder than my 20 year old AC.

 

[ajohansson]

@scdaren Oh you sold me on the noise factor! I was sort of glad my one AC finally bit the dust cuz those suckers are so loud. I actually moved them from being under a bedroom window when we brought the gas line and power over for pool equipment. Now they are on bavkside of kitchen wall that has no window. Basically on the side yard but i could still hear those old beasts through the range hood! My AC guy says these new AC units he is putting in are super quite like you can hardly tell if they are on. My mitsubishi minisplit that heats/cools my garage is super quiet so im imagining these new AC units are like that. Curious why the pool heatpumps are that much louder than a new style air to air heat pump.. Another reason to not do it.

 

[scdaren]

@scdaren Oh you sold me on the noise factor! I was sort of glad my one AC finally bit the dust cuz those suckers are so loud. I actually moved them from being under a bedroom window when we brought the gas line and power over for pool equipment. Now they are on bavkside of kitchen wall that has no window. Basically on the side yard but i could still hear those old beasts through the range hood! My AC guy says these new AC units he is putting in are super quite like you can hardly tell if they are on. My mitsubishi minisplit is super quiet so im imagining these new AC units are like that. Curious why the pool heatpumps are that much louder. Another reason to not do it.

They are bigger for one. Also, I think they just don’t care. It’s not as competitive a field as AC units are. Maybe some other brands are quieter than Pentair, I don’t know.
We moved our AC as well when we built our pool, from under our bedroom window to behind a fence with the heat pump and pool equipment. It’s not too noticeable any more. I can’t hear the AC, but I can hear the heat pump if I listen for it.

 

[ajohansson]

@scdaren thanks again sooo much for the info!