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Cost To Heat a Pool

Posted by Dr Gregory Grochola (physicist) on 7th Mar 2019

Sometimes we get asked about swimming pool heating costs, so we thought we might write this article and have it as a reference.

cost-savings

The answer depends on your pools heat loading scenario, the type of heater you use, how long you run your heater for in the off-season, your set pool temperature and of course your energy costs. It can get difficult to work out as each state has different pool heating season months, energy costs and different climates, ect... Let's look at the science to get some accurate numbers and see exactly how much a gas or heat pump pool heater costs to run.

In this article we use our online pool heating running cost simulator to work out running costs for a range of scenarios, for all the major Australian capitals, to produce a few standard quick reference tables.

Our simulator was extensively checked against the pool heat loading standards AS 3634-1989 and ISO TR 12596 1995 here).

Using the reference tables below, with your pool's total water surface area and energy costs you should be able to work out your running costs to within 5-10% accuracy of the pool heat loading Australian Standards AS 3634-1989.

But before we get into the costings lets define how we performed these calculations.

Calculation Definitions and Data Used

Heating Season Length

We calculated two extreme swimming season lengths - some people use their heaters year-round while others are more conservative and may only heat during a standard swimming season (or even less). Knowing this range allows you to get a good idea of what you're up for if you choose to run your heating somewhere in between these two limits.

Year-round heating means we ran the heater year-round of course, while a standard solar heating season was defined as what you'd get from a well sized solar pool heating system:

Standard Solar Season Heating Month Definitions

Month
Hobart
Melbourne
Canberra
Sydney
Perth
Adelaide
Brisbane
Darwin
Jan
Heat*
Heat*
Heat*
Heat*
Heat*
Heat*
Heat*
Heat*
Feb
Heat
Heat*
Heat*
Heat*
Heat*
Heat*
Heat*
Heat*
Mar
Heat
Heat
Heat
Heat
Heat
Heat
Heat*
Heat*
Apr
...
...
Heat
Heat
Heat
Heat
Heat
Heat*
May
...
...
...
...
...
...
Heat
Heat
Jun
...
...
...
...
...
...
...
Heat
Jul
...
...
...
...
...
...
...
Heat
Aug
...
...
...
...
...
...
...
Heat
Sep
...
...
...
...
...
...
...
Heat*
Oct
...
...
...
...
...
...
Heat
Heat*
Nov
...
...
Heat
Heat
Heat
Heat
Heat*
Heat*
Dec
Heat
Heat
Heat
Heat
Heat
Heat*
Heat*
Heat*

* if required

Pool Heat Loading Scenarios

We show results for: an average pool, a cold pool and a warm pool to highlight the different heat loading scenario ranges; these are defined as follows:

Average Pool

  • Average suburban setting - pool has average wind sheltering
  • Pool has light blue walls and floor
  • No shading on pool

Cold Pool

  • Open area - pool is exposed to the wind
  • Pool has light blue walls and floor
  • 50% shading on the pool

Warm Pool

  • Pool is well sheltered from the wind with surrounding shrubbery and buildings
  • Pool has dark blue walls and floor
  • No shading on the pool

Pool Size, Energy Cost and Pool Temperatures Used

All calculations were performed on a 32m² pool, if you need to find the costings for your size pool, just multiple the cost in the table by the area ratio: Your pool area (m²) / 32 (m²). For example, for a 48m² pool your ratio is 48 / 32 = 1.5 - you'll need to multiply the costings in the table by this ratio. The table below shows the gas and electricity tariff rates used, these represent averages for each state. The pool temperatures used for each Australian state are also shown in the table below, as each state will have a different preferred pool temperature.

State Capital
Tariff ($/KWH)
Gas Cost (c/MJ)
Pool temperatures
Hobart
0.33
3.9
29°C
Melbourne
0.34
2.3
29°C
Canberra
0.28
3.0
29°C
Sydney
0.38
3.4
29°C
Perth
0.33
4.1
29°C
Adelaide
0.48
4.5
29°C
Brisbane
0.35
6.4
31°C
Darwin
0.29
4.5
33°C

Gas heater efficiency used: 87.5%, which corresponds to a typical gas heater efficiency. Gas prices sourced from: "Gas Price Trends Review 2017", Version 2.1 March 2018, source: https://www.energy.gov.au/publications/gas-price-trends-review-report

AHRI Standard heat pump COP efficiencies used: HAHH, HAMH, LAMH: 5.79,  5.54  and 3.99, which corresponds to a typical heat pump. Electricity tariffs shown are sourced from: https://reneweconomy.com.au/market-insight-residential-electricity-price-series-96026/

All gas and electricity costs are also shown in the tables, if you need to scale the heating costs based on your specific tariffs then use a scaling ratio - Your Tariff ($) / From Table ($).

How We Defined "Running Costs"

In the reference tables that follow, "Running Costs" are defined as - 1st year energy cost ONLY. Please note,10 year averaged, annual running costs will be about 150% higher as they include 5% interest, 3% fuel inflation and 10-20% loss in heater efficiency. Lastly, these are running costs ONLY - they do not include heater unit replacement or maintenance cost.



Auxiliary Pool Heater Running Cost Reference Tables


Year-round Pool Heating Running Costs (32m² Pool)

Gas Pool Heaters

State Capital
Gas Cost (c/MJ)
Average Pool
Cold Pool
Warm Pool
Hobart
3.9
$20,831
$29,466
$14,863
Melbourne
2.3
$10,209
$14,819
$7,285
Canberra
3.0
$12,284
$18,411
$8,773
Sydney
3.4
$13,674
$21,173
$9,000
Perth
4.1
$14,189
$23,117
$9,147
Adelaide
4.5
$19,232
$30,015
$12,425
Brisbane
6.4
$19,894
$32,071
$13,489
Darwin
4.5
$7,949
$16,851
$3,837


Year-round Pool Heating Running Costs (32m² Pool)

Heat Pumps Pool Heaters

State Capital
Tariff ($/KWH)
Average Pool
Cold Pool
Warm Pool
Hobart
0.33
$10,251
$14,421
$7,348
Melbourne
0.34
$8,540
$12,294
$6,129
Canberra
0.28
$7,006
$10,341
$5,056
Sydney
0.38
$8,079
$12,366
$5,378
Perth
0.33
$6,106
$9,817
$3,992
Adelaide
0.48
$11,279
$17,428
$7,356
Brisbane
0.35
$5,868
$9,326
$4,030
Darwin
0.29
$2,485
$5,205
$1,222


Standard Pool Heating Season Running Costs (32m² Pool)

Gas Pool Heaters

State Capital
Gas Cost (c/MJ)
Average Pool
Cold Pool
Warm Pool
Hobart
3.9
$5,211
$8,413
$3,289
Melbourne
2.3
$2,736
$4,840
$1,639
Canberra
3.0
$3,879
$7,068
$2,360
Sydney
3.4
$4,532
$8,382
$2,410
Perth
4.1
$4,998
$10,126
$2,375
Adelaide
4.5
$6,694
$12,434
$3,653
Brisbane
6.4
$10,112
$18,402
$6,048
Darwin
4.5
$7,949
$16,851
$3,837


Standard Pool Heating Season Running Costs (32m² Pool)

Heat Pump Pool Heaters

State Capital
Tariff ($/KWH)
Average Pool
Cold Pool
Warm Pool
Hobart
0.33
$2,367
$3,819
$1,494
Melbourne
0.34
$2,096
$3,702
$1,257
Canberra
0.28
$1,980
$3,579
$1,215
Sydney
0.38
$2,442
$4,501
$1,305
Perth
0.33
$1,982
$3,996
$951
Adelaide
0.48
$3,653
$6,753
$1,943
Brisbane
0.35
$2,798
$5,044
$1,693
Darwin
0.29
$2,485
$5,205
$1,222


So there we have it, a full set of pool heating running cost reference tables for all Australian states, shown over a wide range of heat loading scenarios and heating season lengths.

Using these tables, your pool's surface area and your energy costs you should be able to work out your running costs to an accuracy within 5-10% of the pool heat loading Australian Standards AS 3634-1989.

Why Are Running Costs Important to Understand

Well interestingly pooledenergy is in a unique position to gain insight into peoples pool usage, when they analysed minute by minute electricity usage, pool water temperatures, ect... what they found for average Sydney pools... "Across the three types of pool heaters available – gas, heat pump and solar..."  

"... Solar is the most energy efficient and cost effective to run, followed by heat pumps then gas... "

"What our current data set suggests however is that people with gas or heat pumps simply aren’t using them as much or at all as those with solar heating. You can heat your pool if you buy a gas heater but you probably won’t! Given the significant cost of operating pool heating this is understandable. I suspect solar heaters and covers both get used a lot more by their owners."

Interesting indeed... from our analysis pools in Sydney are about average to heat, try living in Adelaide...

A Word on Solar Pool Covers

Lastly, we haven't mentioned pool covers. A pool cover can result in significant saving, anywhere from 52% to 86% (Hobart to Darwin) savings for an average pool dependent on climate temperature, we'll cover this in a different article here.

If you have a specific set of heat loadings on your pool, perhaps you only run it at different temperatures in different months, or would like to know how much a solar pool heating system would help bring down costs you'll need to use our online pool heating running cost calculator. Auxiliary heaters can get expensive fast without solar covers, so it's well worth spending some time playing around with the calculator trying different settings.

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