How to choose a pool heat pump? Power, COP, criteria…

Almost inevitable in some regions of France, pool heat pump However, it is essential to be able to benefit from a long period of swimming in ideal waters.

Given the wide range of pool heat pumps available on the market, it is sometimes difficult to know how to choose the pool heat pump you need.

How does the swimming pool heat pump work?

The pool heat pump is a slow heating device that captures calories in the air to release them into the pool water. The heat is transmitted using a refrigerant.

Everything happens in a closed circuit according to the following steps:

1. The evaporator it captures the heat present in the air which then comes into contact with the refrigerant in its liquid form. Low-temperature coolant will turn to vapor upon contact with heat
2. It is sucked in in the form of steamthe compressorthen brought to high pressure. This compression allows it to reach high temperatures (90°C).
3. Then leave the compressorthe condenserwhich has the task of recovering heat from the gas to transmit it to the water. When heat is transmitted, the gas loses temperature and cools. Once colder, it returns to liquid but remains at high pressure.
4. The refrigerant reaches its final stage the regulator and experiences a drastic drop in pressure and temperature. The cycle can then begin again.

You should expect a temperature increase of about 1°C per day. The warmer the air, the easier the heat pump will heat the pool water.

What are the criteria for choosing a pool heat pump?

The first thing to do before starting to choose a heat pump is to define your needs. In fact, for example, the same heat pump will not have the same performance depending on where you live.

• The volume of water in the pool
• Pool installation (above ground, semi-inground or inground)
• The desired bathing period (all year round or in season)
• The place of residence and the meteorological environment of your region
• Pool water treatment

Choose the power of the heat pump based on the volume of the pool

First of all, the power of the heat pump is chosen based on the size of the pool, more precisely on the volume of water in the pool.

In the product sheet of each heat pump you will find the recommended power and volume of water. However, you should know that this information is provided generically by the manufacturers. It is rated for in-ground pools located in the south of France.

And as already mentioned, the same heat pump will not have the same performance depending on the region of residence.

Read our article: How to correctly calculate the volume of your swimming pool?

Installation of your swimming pool

Pool installation plays a role in water temperature. For example, a semi-in-ground or above-ground pool will be more vulnerable to the cold than a fully in-ground pool.

To correctly evaluate the power of the heat pump, in this case it is necessary to add 20% of water to the actual volume of your swimming pool. Let’s take the example of a wooden above ground swimming pool with a water volume of 60 m³.

– Calculation: 60 + (60 x 0.20) = 72 m³

The heat pump must be able to heat a 72 m³ swimming pool, i.e. a power of 15 kW.

Your area of ​​residence or the location of the swimming pool

Still using the same principle as swimming pool installation, your place of residence will influence the calculation of the heat pump power.

While the Southern regions will be able to respect the indications presented by the manufacturers, the more Central and Northern regions will have to make a new calculation, this time adding 25% to the actual volume of your pool.

– Calculation: 60 + (60 x 0.25) = 75 m³ or a power of 15 kW

What if you combine the two previous conditions?

Also in this case you will have to combine the two calculations:

– Calculation: 60 + (60 x 0.20) + (60 x 0.25) = 60 + 12 + 15 = 87 m³ or a power of 18 kW.

Oversizing a heat pump will allow you to quickly increase the heat at the beginning of the season, however its operation during the beach season will be expensive.

Conversely, an undersized heat pump will cause the temperature to rise too slowly.

Which heat pump to choose based on pool water treatment?

This question mainly concerns pools treated with an electrolyser. Salt water, in fact, has a strong impact on the various components of your appliances and the heat pump will not be spared.

To ensure maximum longevity for your heat pump, you need to make sure you choose a heat pump with a titanium exchanger. This material has a very high resistance to corrosion.

What is COP?

You will always find this term mentioned in the description sheets of heat pumps.

The policemanit is simply the coefficient of performance of the heat pump. Indicates the efficiency between the heat it produces and the electrical energy it consumes.

To define its performance, the COP is evaluated and defined based on 3 factors: Air temperature/Water temperature and hygrometry rate.

Concretely, the COP is always accompanied by 2 temperatures (Air and Water).

For example :

• For an air/water heat pump with COP 5 for Air: 15°C and Water 26°C. This means that for an outside temperature of 15°C, the heat pump will consume 1 kW to generate 5 kW of heating to heat the pool water to 26°C.

The higher the COP and the more the heat pump will have a good efficiency between electricity consumption and water heating.

The inverter heat pump, the economical and silent heat pump

THEInverter heat pumpfor swimming pools it works differently from the classic heat pump.

In fact, while the classic heat pump works in On/Off mode, that is, at 100% or not at all. The Inverter heat pump, on the other hand, has the ability to adapt to different needs throughout the bathing season. It generally offers 3 different levels of operation.

For example, the Inverter heat pump can operate at 100% at the beginning of the season when the pool water requires it and then adapt to the needs. It is therefore less energy intensive and above all less noisy.