A pool’s heat pump: essential comfort and responsible equipment | Pentair Pool Europe

A pool’s heat pump: essential comfort and responsible equipment

fille accoudée à une piscine sur un paysage enneigé


The heat pump is one of the preferred water heating solutions of pool owners. Why is it so popular? Its operating mode and the technology used, such as the inverter, make it a particularly effective and virtuous product!

What is a heat pump? What are the differences compared to other heating systems?

The efficiency of a heat pump lies in the fact that it doesn’t generate heat but transfers it.

In effect, other heating systems such as heaters or boilers consume a resource (electricity, gas or diesel fuel) to generate the heat. In addition, in the case of energy losses, the performance can be less than 1 with this type of installation (one kW consumed produces less than one kW of heat).

In the case of a heat pump for a pool, there is no energy conversion but a transfer of pre-existing heat - the calories available in the air - to the water in the pool.

Therefore, the heat pump transfers more energy than it consumes: a heating capacity therefore of over 1. And depending on the technology used, a heat pump often has a heating capacity of 4 to 6: in other words, 1 kW consumed produces 4 to 6 kW of heat! Rather effective don’t you think?

How does a heat pump for a pool operate?

A heat pump operates on the same principle as a fridge or air conditioning system, but unlike these appliances it preserves the heat and rejects the cold (however certain models can also do the opposite! See below).

To go into more technical details, the heat pump operates by way of its refrigerant circuit which, through a loop, converts a liquid fluid into a gas fluid and vice versa. This fluid gives rise to heat when it changes to liquid (condensation): this heat is then sent to the pool water. The fluid then returns to gas (evaporation) and cools before returning to collecting the heat from the surrounding air.


Schéma fonctionnement de la pompe à chaleur


What are the different types of heat pump available?

On/Off Models

These models are the most basic and only heat the water based on a set temperature, without any possible power adjustment (“all or nothing”). These heat pumps are not equipped with an active defrosting system, which can be problematic at the start or end of the season if the air is too cold: during temperatures of less than 10°C, ice can form on the pump’s evaporator, which then loses all of its heating capacity.

Reversible On/Off models

These models operate as on/off variants, but with the possibility of an inversion cycle. A very useful system, as it offers the option of converting the condenser into an evaporator: the hot gas is then sent to the condenser to be reheated and melt any ice that may have formed, which allows you to make use of your pool earlier and later in the season! This heat pump model offers therefore a heat mode, a cold mode and an auto mode to switch automatically between cold and hot depending on the desired temperature.

Inverter heat pumps

While reversible, these models also allow you to vary the heating capacity depending on requirements. They are therefore very practical for controlling and adjusting the water temperature, while consuming little energy. This may in particular be useful in summer to prevent the water from becoming too hot, which can facilitate the growth of bacteria and may damage certain equipment. At the start and end of season, these heat pumps operate as standard On/Off variants as they require all of their capacity to maintain the water temperature.


Pentair InverTemp heat pump



Full inverter heat pumps

Compared to the inverter models, the full inverter models – such as the InverTemp heat pump – have the advantage of being able to modulate the rotation speed of the compressor and the ventilator, and therefore provide the possibility of reducing the noise emitted by the heat pump. It’s now possible for example to leave the heat pump running during the night at a slow heating rate, without disturbing your neighbours!


Pentair InverTemp noise


How can a heat pump make your pool more sustainable?

The heat pump is the smartest and most sustainable heating method. A reversible model automatically defrosts and heats the pool water early and late in the year, even at low outdoor temperatures. In the event of a heat wave, it also allows the water to be cooled, which increases the durability of the equipment (particularly the pool liner). Lastly, when equipped with the inverter technology, a heat pump is even more efficient as it delivers the right quantity of heat at the right time.

In summary, a reversible heat pump and more specifically a (full) inverter is the ideal system to extend your summer and enjoy your pool for as long as possible every year!

Answer comment

Submitted by Frédéric (not verified) on Sat, 10/09/2021 - 14:17




I have a question about the temperzture of the pool compared to external temperature. Is it  possible to have for example 28° celsius water  for external ai temperature of 5° celsius ? In other term what is the range of air temperature where the pump allows to have an adequate wqter temp ? Our pool is 14m3 (small pool).



Answer comment

Hello Frédéric,

Our heat pumps can operate until -15°C (of course there won't be much calories to transfer into the pool). 


For a pool of 14m3 such as yours, with a external air temperature of 5°C (as mentioned in your example) you can definitely reach a temperature of 28°C although you will need to cover the pool when you don't use it to avoid heat loss. 


You will also need to oversize the heat pump to have enough power to heat the pool water under such conditions. 


Ideally, we would recommend you to make a full study of your pool with your pool technician in order to know the right power to use. 



The Pentair Team

Answer comment

Submitted by Frigoul michel (not verified) on Sat, 09/17/2022 - 10:05


Piscine 60m3

Je voudrai un devis d une pompe à chaleur pour pouvoir se baigner en hiver et savoir le coût de sa consomation electrique

Answer comment


Merci de votre demande. 


Afin d'évaluer au mieux vos besoins, nous vous invitons à vous rapprocher de l'un de nos piscinistes partenaires via le lien suivant: https://www.pentair.com/en-us/find-a-dealer/pool-spa.html.

Nos professionels seront les plus à même d'évaluer vos besoins en fonction de votre bassin et de vous conseiller au mieux sur le choix de votre pompes à chaleur en fonction de votre installation existante et de la taille de votre bassin. 


Vous pouvez également consulter notre gamme afin d'anlalyser les caractéristiques techniques de nos differentes PAC: https://www.pentairpooleurope.com/fr/produits/pompes-a-chaleur.


En espérant avoir répondu au mieux à votre demande, nous vous remercions par avance de votre confiance dans les produits Pentair Pool. 


L'Équipe Pentair Pool Europe

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