Commercial and school pool heating case study 250-300sqm pool approx


We are pool heating experts and are impartial. We offer a wide range of products from heat pumps, blankets, rollers and a range of solar heating. We don’t just sell one style of product and try to push customers into our singular product. We focus on the outcome and work on the best solution.

Often we get feed back from other pool heating suppliers i.e. Solar heating doesnt work but we can sell you a heat pump.

A heat pump and solar have the same outcome. They heat pools and get there in totally different ways. 

Solar is quick to heat with good weather and with sun can get to the set temp very fast. A heat pump has to work and build over time often 3-5 days to lift the base temp up to target temp. Gas is instant heat on demand. 

This is how you heat a pool.

Solar is the primary heat source(even without a blanket), gas is the back up, because it is the fast and effective, heat on demand. A heat pump takes its time and works hard, but will get up to temp over time. A Heat pump must have a blanket on the pool, in order to heat effectively. 

We focus on the outcome and work on the solution.  This will determine what tools you will need to achieve this.

Important to note. We install solar systems on pools without blankets, because solar alone will do the job. Maybe not when its cold, ( but you are not swimming when cold) a heat pump will absolutely not work to heat a pool on a cold day, without blanket.

Below we have modelled a large volume of water with a heat pump appliance and a blanket. Over a 16 hour + filtration period. 

Running costs per season (8 months) season. Equal to pool solar heating.

Location New Plymouth - Gisbourne, per swim season Sept to April 30th (Which is in line with a Pool solar heating swim season)

  1.         $25,888 @ 26 deg C
  2.        $33,898 @ 28 deg C


Heat pump running costs for extended season. Calculations are based on:

    • (i)26 deg C for swimming training OR (ii)28 deg C if run higher to show the difference.


  • 25m x 10m wide x 1.4m average
  • Next to ocean - full wind
  • Must be covered for a period of time when not in use, un covered during the day
  • No additional water features
  • 30c kW/h electricity costs adjust for local charges
  • Open pool Sept 1st and close pool April 30th. Pool heater off: May 1st to Aug 31st.
  • Heater run time 16 hours a day
  • Season Sept to end April - Like for like pool solar heating season
  • 28 degree target max, but we recommend 26 degrees for community pool
  • Calculations based on 16 hour day or 8-10 hours if off set by PV
  • If using PV panels you can off set costs by 23% reduction approx
  • Covers are OFF the pool, during the day while pool is in use and heat pump running
  • Important to note, heater run times won’t change the ‘electricity cost’ of heating (ignoring the PV) but cover times will
  • Based on 8 hour a day max run times to utilise the PV (i.e. sun shining times) the heater sizes will range from:
  • We suggest that you will require the largest heating option as follows - RTHP440-3 or RTHP540-3 for Minimum size to achieve  28 deg C for 8 months. 440kw - 540kw units
  • Heat pump will give you better control( during some periods) over pool temps during the season when cold i.e. in case of competitions etc
  • Please check all assumptions from other heating companies and ensure correct cover on pool times and correct utilisation of PV if using to offset as no point calculating the energy to be covered by PV and then have the heaters run 16+ hours a day
  • Ratio to heat air vs water is 1:3500 times. Therefore the appliance must be able to manage target temps taking into account all variables
  • Cost to run a swimming pool heat pump is a simple formula, once we factor all variables, as per above.
  • A large volume of water will require a large draw of electricity
  • By saying solar doesn’t work during a cloudy day, is simply not a true statement. Implying solar doesn’t work and only offering a heat pump is not offering a heating solution. It is offering a heat pump.
  • Heating a pool with a heat pump is not equal to a cup of coffee a day, to run a heat pump ie $4.50 per day, $31.50 per week, $126 per month, $1008 per 8 month swim season. It can’t be $3000, $5000 or even $10,000 per season. It is a formula of the KW out put, per hour per day and averaged against the ambient air temp vs cost to heat a degree of water, per volume of pool water per day
  • Please ask us for a free pool heating audit and real costings to do so

Solar heating performance including payback vs running heat pump, domestic: HERE 


Solar heating charts vs heat pump 30sqm domestic pool 12hr filtration. Target temp 30 degrees.