Help me decide how to heat my pool

4rings6stars

Active member
Oct 4, 2016
37
Littleton, MA
#1
I bought my house last fall just in time to close it, so this will be my first season with a pool.<br>

We are in MA so the swimming season is already pretty short, so I want to use a heater to extend the swimming season. The pool doesn't get a ton of sun (will chop a few trees in the spring to solve as much of that as I can). I'm trying to decide whether I want to use solar, natural gas or electric heater.

Can you fine folks help me decide what will be the best option, considering effectiveness, cost, efficiency, ease of installation and maintenance, longevity, etc.

Factors to consider:
My town has relatively low electricity rates. Ends up about $0.11 per kWh.
I use natural gas to heat my house and could get a gas line run out to the pool area for a few hundred $. Costs about $1.38 per "therm".
I don't think there would be a great place to put panels near my pool. My house roof is oriented well, but is about 40-50 feet from the pool pad.
My equipment works fine, but is aging. I will probably get a new multi-speed pump in a year or two.
I will use liquid chlorine to sanitize for this first year, may eventually get a SWG.

Any and all thoughts or recommendations are welcome. Thanks!

I have attached a picture from google to show the layout. Pool is on the right hiding in the trees. Photo is oriented so north is straight up. <br>

<img src="https://www.troublefreepool.com/attachment.php?attachmentid=58152&stc=1" attachmentid="58152" alt="" id="vbattach_58152" class="previewthumb">
 

pooldv

Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
Aug 10, 2012
24,993
DFW, TX
#2
A 50' plumbing run over to the house for solar isn't a big deal. I wouldn't let that be a determining factor. Solar is the best first choice and your roof is just right for it. We use solar to keep the pool as warm as it can and then we use a heat pump to supplement as needed. Like last weekend solar and the solar cover got us up to 77-78 and then the heat pump bumped us to 81-83.

Our solar install is smaller than recommended so we don't get as much heat as we need. It is normally recommended to install 50-100% of the pool surface. We have 240 sf of panels and 700+ sf pool. But, we ran out of room.

Generally, the heat pump vs gas heat goes like this. Heat pump is slow and steady and really good for maintaining the pool at a certain temp. Gas is good for faster heating of the pool. Heat pumps are usually a little cheaper to operate in the long run for continuously maintaining your pool at a certain temp.

A solar cover is needed to hold in heat overnight. If you aren't using one now I would try that first. It will raise the temp of you water 5-7 degrees or so just by slowing heat loss overnight.

A variable speed pump can save you quite a bit of money. We run our pump at 1100 rpm for solar standby and it only uses 150 watts. We can run the pump 24x7 at 10.25c/kWh for less than 12 bucks per month. And it runs at 1950 rpm when solar is on and uses about 550 watts. Quite a bit less than a 1hp single speed pump.
 

4rings6stars

Active member
Oct 4, 2016
37
Littleton, MA
#3
Thanks for the info pooldv. Solar or a heat pump sound better and better. I just need to do some more research to determine if the heat pump would work well in my climate and if I could get solar done for a reasonable amount of money. I did a "custom pool heating analysis" on the Hayward website and these are the results:


[TABLE]
[TR]
[TH="align: left"]POOL DATA[/TH]
[TH="align: left"]FUEL PRICES[/TH]
[TH="align: left"]POOL HEATER[/TH]
[/TR]
[TR="bgcolor: #dff4f9"]
[TD][/TD]
[TD]Size: 512 sq. ft.[/TD]
[TD]Electric: $ 0.110 $/KWH[/TD]
[TD]HP21104T[/TD]
[/TR]
[TR="bgcolor: #ffffff"]
[TD][/TD]
[TD]Volume: 17233.92 gallons[/TD]
[TD]LP Gas: 2.360 $/Gallon[/TD]
[TD][/TD]
[/TR]
[TR="bgcolor: #dff4f9"]
[TD][/TD]
[TD]Desired Temperature (F): 83[/TD]
[TD]Oil: 2.440 $/Gallon[/TD]
[TD][/TD]
[/TR]
[TR="bgcolor: #ffffff"]
[TD][/TD]
[TD]Covered: Yes[/TD]
[TD]Natural Gas: 1.380 $/Therm[/TD]
[TD][/TD]
[/TR]
[/TABLE]
[TABLE]
[TR]
[TD]
[/TD]
[/TR]
[/TABLE]
[TABLE]
[TR]
[TH][/TH]
[TH]MONTH[/TH]
[TH]HEAT REQ'D
MILL BTU[/TH]
[TH]LP GAS[/TH]
[TH]OIL[/TH]
[TH]NAT. GAS[/TH]
[TH]ELECTRIC[/TH]
[TH]UNITS
REQ'D[/TH]
[TH]HP21104T
HEAT PUMP†[/TH]
[/TR]
[TR="bgcolor: #dff4f9"]
[TD][/TD]
[TD]JUN[/TD]
[TD]23.38[/TD]
[TD]$925.49[/TD]
[TD]$815.12[/TD]
[TD]$496.47[/TD]
[TD]$753.68[/TD]
[TD]1[/TD]
[TD]$145.07[/TD]
[/TR]
[TR="bgcolor: #ffffff"]
[TD][/TD]
[TD]JUL[/TD]
[TD]18.52[/TD]
[TD]$732.82[/TD]
[TD]$645.43[/TD]
[TD]$393.12[/TD]
[TD]$596.78[/TD]
[TD]1[/TD]
[TD]$107.56[/TD]
[/TR]
[TR="bgcolor: #dff4f9"]
[TD][/TD]
[TD]AUG[/TD]
[TD]20.79[/TD]
[TD]$822.66[/TD]
[TD]$724.55[/TD]
[TD]$441.31[/TD]
[TD]$669.94[/TD]
[TD]1[/TD]
[TD]$122.67[/TD]
[/TR]
[TR="bgcolor: #ffffff"]
[TD][/TD]
[TD]SEP[/TD]
[TD]28.62[/TD]
[TD]$1,132.68[/TD]
[TD]$997.60[/TD]
[TD]$607.62[/TD]
[TD]$922.41[/TD]
[TD]1[/TD]
[TD]$185.88[/TD]
[/TR]
[/TABLE]
[TABLE]
[TR]
[TD]
[/TD]
[/TR]
[TR]
[TD]POOL HEATED 4 MONTHS/YEAR[/TD]
[/TR]
[/TABLE]
[TABLE]
[TR]
[TH][/TH]
[TH][/TH]
[TH]HEAT REQ'D
MILL. BTU[/TH]
[TH]EFF'CY (%)[/TH]
[TH]LP GAS[/TH]
[TH]OIL[/TH]
[TH]NAT. GAS[/TH]
[TH]ELECTRIC[/TH]
[TH]HP21104T
HEAT PUMP†[/TH]
[/TR]
[TR="bgcolor: #dff4f9"]
[TD][/TD]
[TD]Covered[/TD]
[TD]91.31[/TD]
[TD]176.39%[/TD]
[TD]$3,613.64[/TD]
[TD]$3,182.71[/TD]
[TD]$1,938.52[/TD]
[TD]$2,942.80[/TD]
[TD]$561.18[/TD]
[/TR]
[TR="bgcolor: #ffffff"]
[TD][/TD]
[TD]Uncovered[/TD]
[TD]176.54[/TD]
[TD]176.39%[/TD]
[TD]$6,986.76[/TD]
[TD]$6,153.58[/TD]
[TD]$3,748.02[/TD]
[TD]$5,689.74[/TD]
[TD]$1,082.53[/TD]
[/TR]
[/TABLE]
 

jtrovato21

Well-known member
May 26, 2016
139
Northeast MA
#4
How do you want to use the heater? Do you want to turn it on to bump up the temp for weekend swims or parties? Or do you want to get the pool to your desired temp and leave it there for the whole season? If you don't intend or want to keep your pool at your desired temp for the whole season, then a heat pump is probably not the best choice. You would want natural gas if that's the case, you can get a quick burst of heat and get your pool up to temp in a few hours as opposed to a few days with a heat pump, but if you want to maintain that temp over a long time using gas, it will cost you. If your desire is to open your pool in May, get it warmed up to temp and leave it there until September, get a heat pump. This is what we are doing and what my mother has done on her pool. We are located in MA also. Whatever route you choose, you will want to get a solar cover and at a minimum use it at the beginning and end of the season, but preferably all season long if you can.
 

duraleigh

Admin
Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
In The Industry
Apr 1, 2007
31,333
Sebring, Florida
#5
After attempting to calculate ALL the variables, j21 is guiding you down the best path.....
How do you want to use the heater?
Reread j21's post above......it'll help you make your decision without ANY calculations whatsoever.
 

jtrovato21

Well-known member
May 26, 2016
139
Northeast MA
#6
Also, forgot to mention, with your low electric rate in Littleton, the heat pump is a great choice.

As for your question on how well it will work in our climate, they work well, as long as you don't expect to be heating your pool when it's 50 degrees outside (which why would you want to, nobody's going to swim at those temps!). You only want to run the heat pump in the daytime, when outside temps are at their warmest, because the heat pump is more efficient the warmer the outside temp is. Don't run it overnight, my mother made that mistake the first year she got hers trying to heat the pool up as quick as she could and found that she was just wasting money. The next year she only used it in the daytime and started heating around the end of May. By Memorial Day, the pool temp was at 84 degrees and stayed there until two weeks after Labor Day when she closed the pool.
 

4rings6stars

Active member
Oct 4, 2016
37
Littleton, MA
#7
Thanks for all of the responses.

Regarding how we want to use it...I'm still figuring that out! It's going to be our first season with a pool. We have a 2.5 year old (and his 3 and 5 year old cousins that live down the street) and my wife works two days a week so will be home a lot in the summer. I'm thinking we will want a more or less constant swimmable temperature, so a heat pump is probably the way to go.
 

Joshii

Well-known member
Jul 15, 2013
178
#8
Hey, 4rings6stars, I'm also in MA. I'm having a hard time believing those electric prices. My "electric" rate is also around $0.11/kwh. But my "transmission" rate is about that, too. That brings my total electric charge to $0.22/kwh! Is your electric bill really under $80 per month?
 

CJadamec

TFP Expert
Apr 29, 2016
2,194
Quaker Hill, CT
#9
I'm going to second the heat pump route. With a solar cover on the pool it was easy to keep the pool at 86 all season long for very little extra monthly on the utility bill. I'm adding solar this year to work with my heat pump because who doesn't love heat with no utility costs. It would be a lot of money to do it all in one season but there's nothing stopping you from adding a second source of heat in the future. JT is spot on in how he described things.
 

4rings6stars

Active member
Oct 4, 2016
37
Littleton, MA
#10
Hey, 4rings6stars, I'm also in MA. I'm having a hard time believing those electric prices. My "electric" rate is also around $0.11/kwh. But my "transmission" rate is about that, too. That brings my total electric charge to $0.22/kwh! Is your electric bill really under $80 per month?
Littleton has their own utility company, so they are able to keep prices low. Copied this from my most recent bill! (sorry formatting is bad)

BASE CHARGE =5.00
ECS =1.00
SURGE PROTECTOR =2.86
DISTRIBUTION CHARGE 0.02650 300 =7.95
PPC 0.08290 300 =24.87
PASNY CREDIT -0.0021 300 =-0.63
TOTAL TAX =0.18
TOTAL AMOUNT DUE =41.23

- - - Updated - - -

I'm going to second the heat pump route. With a solar cover on the pool it was easy to keep the pool at 86 all season long for very little extra monthly on the utility bill. I'm adding solar this year to work with my heat pump because who doesn't love heat with no utility costs. It would be a lot of money to do it all in one season but there's nothing stopping you from adding a second source of heat in the future. JT is spot on in how he described things.
More good info, thanks. Going to do some research now on what heat pump to buy... We plan on getting a solar cover too.

Any recommendations on brand/size? I'll probably end up getting a new pump too.
 

Joshii

Well-known member
Jul 15, 2013
178
#11
That is really incredible. Good for you! With those prices it would be heat pump all the way.

Do you have central AC? Then you already have a heat pump. I would be remiss if I didn't mention the Hotspot FPH as an option. It transforms your home AC into a water-cooled unit, dumping your house heat into your pool. Open the shades, turn your house into a heat collector, run the AC, and heat your pool.
 

CJadamec

TFP Expert
Apr 29, 2016
2,194
Quaker Hill, CT
#12
That's cheap electric. Mine is about double your cost per kwh. For sizing your heat pump I would be looking in the 110kbtu range for your pool. The cover is a must and its worth investing in a cover reel to make taking off and putting it on easy and convenient so that you use it as often as possible.

As for the pump if you are looking to add solar down the road a VS pump might be worth looking at. Other wise your current pump is probably plenty
 

4rings6stars

Active member
Oct 4, 2016
37
Littleton, MA
#13
That is really incredible. Good for you! With those prices it would be heat pump all the way.

Do you have central AC? Then you already have a heat pump. I would be remiss if I didn't mention the Hotspot FPH as an option. It transforms your home AC into a water-cooled unit, dumping your house heat into your pool. Open the shades, turn your house into a heat collector, run the AC, and heat your pool.
I do have central AC... I was just thinking that the Hayward heat pump looked a lot like our AC unit. The AC unit is on the opposite side of the house as the pool, which doesn't seem ideal. But I'm going to look more into this. Thanks for the heads up.
 

CJadamec

TFP Expert
Apr 29, 2016
2,194
Quaker Hill, CT
#14
A word of caution about the heat recovery units is that they only provide heat when your central air unit is running. For us in New England this is not very useful for early and late season heating of a pool when you will likely not be running the air conditioning in the house.
 

bmoreswim

Gold Supporter
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Jul 16, 2012
4,311
Central MD
#15
Do you have central AC? Then you already have a heat pump. I would be remiss if I didn't mention the Hotspot FPH as an option. It transforms your home AC into a water-cooled unit, dumping your house heat into your pool. Open the shades, turn your house into a heat collector, run the AC, and heat your pool.
Why haven't I heard about his before? Brilliant concept. Only real downside is that I don't run my A/C all of the time I would want to heat the pool (most of May). But I could if it ran more cheaply being water cooled and also heated the pool. Hmmm.
 

ps0303

TFP Expert
In The Industry
Jul 6, 2011
3,956
FL
#16
A word of caution about the heat recovery units is that they only provide heat when your central air unit is running. For us in New England this is not very useful for early and late season heating of a pool when you will likely not be running the air conditioning in the house.
Exactly. When you might want to heat your pool, you're not using the AC especially in certain areas such as the Midwest or Northeast.
 

Joshii

Well-known member
Jul 15, 2013
178
#17
A word of caution about the heat recovery units is that they only provide heat when your central air unit is running. For us in New England this is not very useful for early and late season heating of a pool when you will likely not be running the air conditioning in the house.
I have the unit in MA and love it. Your word of caution actually applies to all heaters. A dedicated pool heat pump will not be very efficient at heating your pool when it is cool outside. So it will not work very well at either end of the season. Also, it will cost a LOT to heat your pool when it is cool out no matter what heater you choose. And if it is cool out, I personally do not really like swimming in the cool air. But this is a personal preference. I suppose it works well for my use.
 

pooldv

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Aug 10, 2012
24,993
DFW, TX
#20
I have the unit in MA and love it. Your word of caution actually applies to all heaters. A dedicated pool heat pump will not be very efficient at heating your pool when it is cool outside. So it will not work very well at either end of the season. Also, it will cost a LOT to heat your pool when it is cool out no matter what heater you choose. And if it is cool out, I personally do not really like swimming in the cool air. But this is a personal preference. I suppose it works well for my use.
A dedicated pool heat pump will operate very efficiently when it is 70 to 80 degrees outside during the day and 60 at night. It is these temps in spring and fall when heat is most needed in the pool and the AC isn't on in the house yet.