Pool Heat Pump vs. Gas Heater vs. Both vs. Hybrid Heater

[Sharkygirl]

Alright, I will try to make this short. We are building a new pool. Freeform with the hot tub part on one end, 527sq. feet overall. I originally wanted to do a Pentair Mastertemp 400 gas and Pentair Ultratemp 140 Heat Pump. The problem is my pad doesn't have room for both. So am I better off with just the heat pump or just the gas pump?

This is how we plan to use our pool. We live in Florida. In the winter, the temps can get into the 50's, every once in a while the 40's. But during the day in the winter, 70's-80's. I'm not worried about summer. We will use the hot tub every day, in the evening for sure. The pool we like to keep at 85-88 degrees. We would like to swim when we feel like it. Maybe some days we do, some days not, but we want to keep my pool ready for swimming. Then if we decide to throw a pool party, I don't want to have to plan 2 days ahead to heat the pool. We have never had a pool with the hot tub part of the pool. In the past we had separate everything.

1. Can I just heat the spa when I want to use it- without having to heat the pool body of water. So in the winter, if it's in the 60's and I am not planning on swimming at all, the pool might be in the 60's (and the spa too), but I only want to heat the spa in the evening when I want to use it. Will the heat pump work for this? (Spa is 1500 gal). Do I need to tell my PB to plum things a certain way to accomplish this? or is this standard?

2. How long to bring a pool from 60 degrees to 88 degrees with the heat pump? What about the gas heater? We plan on keeping the pool heated, but we do not want a pool cover as we don't really have room to keep it and they are heavy.

3. How common is it to have both the heater and heat pump?? Should I try to find a way to make the room?

Curious about others thoughts.

 

[ajw22]

Have you considered the Pentair ETI Hybrid Heater?

UltraTemp ETi® Hybrid Heater

The Pentair UltraTemp ETi® Hybrid Pool Heater is the first swimming pool heater to combine a heat pump and a gas fired heater for an energy saving alternative.

www.pentair.com

 

[treyrich]

I can only speak from my experience (I have both the mastertemp and the ultratemp)
1. Yes, you can do this, however a heat pump will make this difficult. My heatpump would take 1/2 day at least to get my spa up to temperature, but my mastertemp gets my spa up to temperature in like 15 minutes.
2. This ultimately is going to come down to the number of gallons of water you're trying to heat. There are very easy calculations that can be done to tell you exact numbers. In my pool in the real world what I can say is that my gas heater heats my pool about 2° per hour, so it would take 14 hours to heat my pool from 60 to 88. My heatpump does about 0.5° per hour for my pool size (depending on ambient temperature), so it would take about 56 hours to heat from 60 to 88.
3. I don't know how common it is, but I like it.

My overall opinion is, if you can only have 1 do the mastertemp. UNLESS you have a large PV Solar system that is generating excess energy that you can utilize for the ultratemp. Even then the ultratemp is a tough sell on its own if you want to use the spa frequently. If I didn't have a large PV system I would not have done the ultratemp and would have just stuck with the mastertemp.

 

[Sharkygirl]

Have you considered the Pentair ETI Hybrid Heater?

UltraTemp ETi® Hybrid Heater

The Pentair UltraTemp ETi® Hybrid Pool Heater is the first swimming pool heater to combine a heat pump and a gas fired heater for an energy saving alternative.

www.pentair.com

We have, but our concern is if it can handle our pool needs without being very inefficient. (bigger is better!) So we have a total of 21,000 gal for the pool and 1500 gal for the spa.

 

[Sharkygirl]

We still can change our pool size as it is only on paper. So here are my questions:
1. If we went with the Pentair Hybrid Heater, what is the maximum pool galllons that it could comfortably handle?
2. If money is not an issue and space is not an issue, is having both the ideal situation?

 

[ajw22]

We have, but our concern is if it can handle our pool needs without being very inefficient. (bigger is better!)

Why do you think it will be inefficient?

Bigger is better for heating speed, not efficiency.

The gas heater in it will beat any Heat Pump.

So we have a total of 21,000 gal for the pool and 1500 gal for the spa.

That is not a very big pool.

 

[Sharkygirl]

Oh, well I was thinking the BTU's of the Hybrid heater didn't compare to the MasterTemp 400,000 BTU. In the very fine print it says on their website the heating efficiency is based on a 17,000 sq ft. pool until ideal controlled conditions.

 

[JoyfulNoise]

I would stay away from the eTI hybrid heater. It’s is too new and there are probably 5 people on planet earth that understand how it works and how to service it. Sure, it’s cool and neat and does both but, as my Dad always reminded -

A Jack of all trades is master of none.

I would suggest just going with the largest gas heater you can install. They are fast, reliable and easily (somewhat) serviceable. Even pool heat pumps can be a pain to service because most pool companies know nothing about HVAC equipment and HVAC service companies will rarely ever want to work on pool equipment.

 

[Sharkygirl]

I would stay away from the eTI hybrid heater. It’s is too new and there are probably 5 people on planet earth that understand how it works and how to service it. Sure, it’s cool and neat and does both but, as my Dad always reminded -

A Jack of all trades is master of none.

I would suggest just going with the largest gas heater you can install. They are fast, reliable and easily (somewhat) serviceable. Even pool heat pumps can be a pain to service because most pool companies know nothing about HVAC equipment and HVAC service companies will rarely ever want to work on pool equipment

I would stay away from the eTI hybrid heater. It’s is too new and there are probably 5 people on planet earth that understand how it works and how to service it. Sure, it’s cool and neat and does both but, as my Dad always reminded -

A Jack of all trades is master of none.

I would suggest just going with the largest gas heater you can install. They are fast, reliable and easily (somewhat) serviceable. Even pool heat pumps can be a pain to service because most pool companies know nothing about HVAC equipment and HVAC service companies will rarely ever want to work on pool equipment.

Okay, do you agree the ideal situation would be to have both? My pool pad is next to my garage and we could maybe put the gas heater in the garage suspended from the ceiling?? Just a thought.

 

[JoyfulNoise]

Okay, do you agree the ideal situation would be to have both? My pool pad is next to my garage and we could maybe put the gas heater in the garage suspended from the ceiling?? Just a thought.

I would install the gas heater and only make space and utilities available for heat pump without actually purchasing one. Live your pool life with the gas heater for a year and try to make it work. You may be surprised by how your preconceived notions change once you actually have a pool to deal with.

The best laid plans of mice and men oft go awry …

PS - A gas heater cannot be easily installed indoors in a residential structure as it presents a safety and fire hazard. To do so would either violate building codes or, at the very least, require some very expensive exhaust duct work with active ventilation to be installed along with any associated permitting and inspections. Pool heaters are intended to be installed outdoors. Any other installation requires a lot more work.

 

[Sharkygirl]

Ok, you make a very good point. I want my cake and I want to eat it too! Ideally I want both so that I have the ability to heat up the hot tub quickly and so that I don't have to spend bundles with gas to keep my pool at a constant temp. Our issue is, right now they put the gas line right where the pool equipment is supposed to go, and an air conditioner. We can move the air conditioner to the other side of the house, but we still won't have room because of that gas service. You loose 3 feet on either side of it, as per code we can't have any equipment within three feet and a wall needs to be on the one side. It's a ****** situation as I told the contractor and architect in the very beginning that I wanted to make sure I had enough room for pool equipment. I was assured I had plenty. Then they start putting electrical panels and gas feeds in my pool equipment area and now I don't have the room. So I am at a point where I can still move the gas line to the other side of the garage (it will cost me more to move it further, but this is a permanent situation) and move the A/C to the other side of the house (this makes my A/C less efficient too) and then move a dividing wall that is on the equipment pad now over a bit and I just might have enough room. I know the gas heater is quick, but it's the huge amount of gas that it's going to take just to keep my pool at temp 9 out of 12 months of the year. I don't like the idea of having to "plan" when I want to swim. That's now how we live. My husband doesn't want a cover on the pool because he feels it takes away from all the ambiance we have created for around the pool. The house is there now, just not the pool or the landscaping. I have a very narrow window to make some decisions. Thank you so much for the input you have provided. It definitely has given me information that I need. Have any more thoughts!?

 

[JoyfulNoise]

You have to look at it this way - a BTU is a BTU is a BTU. Every unit of energy you put into the pool water does the same thing - one BTU of energy raises the temperature of one pound of water one degree Fahrenheit. Now there can, in some areas, be significant utility cost differences between electrical energy versus gas energy. In my area, the differences are not terribly substantial. When the differences aren’t going to result in some kind of huge cost savings, then the choice of heating becomes simple - get the biggest heater you can afford so that it will heat the water up the fastest. So, in reality, it might not matter much if you heat the pool with a gas heat source or an electric heat pump. Once the water is up to temperature, using a gas heater to thermostatically control it isn’t all that different than running a giant heat pump to control it.

You also have to be careful with complexity. Sure, in theory running two different heat sources makes sense. But the reality is you now have two different pieces of equipment, both fairly costly (your looking at $10k just in equipment cost), that you have to service and maintain. That can be a fairly substantial amount of time and money.

Will this pool be in a screen room or screened off porch?

 

[TimZ]

We have both a Pentair MasterTemp 400 and a Pentair UltraTemp 140 for our 30k gallon pool. We don't have natural gas, so the Mastertemp runs on propane, which was a big motivator to get both. In our area natural gas is much cheaper than propane, so I'm not sure we would have done both if gas were available. I'm in Pennsylvania, and in the summer season (which is probably kind of like your spring/fall) we keep the pool around 85. How long it takes to heat the pool with the heat pump is hugely dependent on air temperature/sun/shade/wind/clouds/etc. On a mostly sunny summer day we can turn on the heat pump in the morning and raise the pool a few degrees by the afternoon. On a fall day when the overnight temps get to below 50 the heat pump will need to run most of the night just to maintain temperature. In our summer months we could probably get by with just the heat pump even for the hot tub (although we'd have to plan ahead for the hot tub) but in the early spring / late fall when we no longer heat the pool and the water temp is in the 60s, the gas heater is a big benefit for the hot tub.

You asked about heating from 60 to 88, but that seems unlikely if your daytime temperatures in the winter are typically 70-80. Do unheated pools in your area actually get that cold?

 

[Sharkygirl]

You have to look at it this way - a BTU is a BTU is a BTU. Every unit of energy you put into the pool water does the same thing - one BTU of energy raises the temperature of one pound of water one degree Fahrenheit. Now there can, in some areas, be significant utility cost differences between electrical energy versus gas energy. In my area, the differences are not terribly substantial. When the differences aren’t going to result in some kind of huge cost savings, then the choice of heating becomes simple - get the biggest heater you can afford so that it will heat the water up the fastest. So, in reality, it might not matter much if you heat the pool with a gas heat source or an electric heat pump. Once the water is up to temperature, using a gas heater to thermostatically control it isn’t all that different than running a giant heat pump to control it.

You also have to be careful with complexity. Sure, in theory running two different heat sources makes sense. But the reality is you now have two different pieces of equipment, both fairly costly (your looking at $10k just in equipment cost), that you have to service and maintain. That can be a fairly substantial amount of time and money.

Will this pool be in a screen room or screened off porch?

No the pool is on the West side of the house. You have given me a lot to think about. I will let you know what we decide. Thank You!

 

[Sharkygirl]

We have both a Pentair MasterTemp 400 and a Pentair UltraTemp 140 for our 30k gallon pool. We don't have natural gas, so the Mastertemp runs on propane, which was a big motivator to get both. In our area natural gas is much cheaper than propane, so I'm not sure we would have done both if gas were available. I'm in Pennsylvania, and in the summer season (which is probably kind of like your spring/fall) we keep the pool around 85. How long it takes to heat the pool with the heat pump is hugely dependent on air temperature/sun/shade/wind/clouds/etc. On a mostly sunny summer day we can turn on the heat pump in the morning and raise the pool a few degrees by the afternoon. On a fall day when the overnight temps get to below 50 the heat pump will need to run most of the night just to maintain temperature. In our summer months we could probably get by with just the heat pump even for the hot tub (although we'd have to plan ahead for the hot tub) but in the early spring / late fall when we no longer heat the pool and the water temp is in the 60s, the gas heater is a big benefit for the hot tub.

You asked about heating from 60 to 88, but that seems unlikely if your daytime temperatures in the winter are typically 70-80. Do unheated pools in your area actually get that cold?

Well I was trying to describe the most extreme situation. We typically will use our hot tub in the evenings. Also, I would venture that in the summer months, not very much at all. We will be using the hot tub 9 months out of the year. The other 3 months we go back to our home in Wisconsin. This isn't set in stone, sometimes we only go back a few weeks here and there. When we lived in Key West I had a 10,000 gal pool and it was separate from our hot tub. Our Hot Tub was about 600 gallons. We had a separate heat pump for each. The heat pumps were the same size. So even though the hot tub was not a large body of water, it still took an hour to get it from 80 to 103 degrees. Key West the temps are pretty consistent. We maybe only experienced the 60's 4 or 5 times in 7 years! I set the heat pump to 89 degrees for the pool. It just turned on whenever it needed to for a consistent temperature setting. During those times when the temps fell below the 70's, I just turned off the heat pump for the pool because it would run all the time to keep up. The hot tub I never kept at temp. I just turned it on when we were going to use it. So that is all I have to go on. Now we are in Sarasota. We are building the pool with the hot tub connected on the one end. I'm not familiar at all with this situation. So that is how I came up with the heat pump and a gas heater. I figured the gas heater could be used to get the hot tub up to temp when we use it and the rest of the time the heat pump could keep the pool at temp. But Joyful Noise gave me a lot to chew on, so now I'm thinking perhaps just the gas heater and call it a day.