How Does A Pool Heat Pump Work? A Comprehensive Guide

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By Debarghya Roy

A pool heat pump? Wondering how it works? Get the scoop on this energy-efficient device. Find out how it can help you keep swimming all year round! Learn the key concepts now.

What is a Pool Heat Pump?

A Pool Heat Pump is a device that uses electricity to heat pool water. It doesn’t generate heat, but transfers it from the surrounding air. 

How Does A Pool Heat Pump Work

How Does a Pool Heat Pump Work?

A pool heat pump works by taking the air temperature outside and compressing it. This makes the temperature higher, which is transferred to a refrigerant. This process can heat the refrigerant from 45°F to a temperature to warm up the pool water.

The heated refrigerant passes through copper coils. As the warm air and water move through these coils, the heat is released. The water is then sent back into the pool, where it circulates and warms up.

The device has an electric compressor motor too. It helps circulate cool water and uses the heat from the evaporators’ surfaces to heat the water even more.

Ideal Conditions for a Pool Heat Pump

A pool heat pump works best when the temp is over 45°F and the air is clear with a proper flow rate. The follow are ideal ranges:

ConditionIdeal Range
Temperature of Pool Water78-82°F
Air TemperatureAbove 45°F
Air Obstructions and Flow RateUnobstructed, proper flow rate maintained
Humidity LevelBelow 70%

Air movement in a swimming pool heat pump

  • A pool heat pump is a great way to warm up the water in your pool. 
  • It works by taking in outside air, compressing and heating it with a fan and a refrigerant. 
  • This hot gas is then transferred to the water in the heat exchanger, where a fan removes heat from the air. 
  • As this continues, the water gets warmer until it’s comfortable for swimming.
  • Choosing the right location to install your heat pump is important. 
  • Good air circulation will help it work more efficiently. 
  • Different models may have different components, but they all use the same principle of transferring energy from air to water.

Heating pool water with a pool heat pump

A pool heat pump is a great way to heat up the pool water. Heat is taken from the air around the pool and moved to the water by compressing and expanding the refrigerant. 

  • The evaporator takes heat from the air. The compressor increases the pressure and makes it hotter. 
  • The condenser then passes this thermal energy to the water going through its pipes. When it has given all the heat, the refrigerant returns to liquid form and goes through the expansion valve, cooling it.
  • Bigger pools need bigger pumps for better performance. Remember to turn the pump on before you swim and keep the caps on when not in use to increase its lifespan.

The table below explains the components and what they do.

EvaporatorRefrigerant absorbs heat
CompressorRefrigerant pressurization
CondenserHeat transfers to water
Expansion ValveReduces pressure

Sizing a Pool Heat Pump

Choosing the right size heat pump for your pool is key for efficiency. 

Factors such as pool size, desired temperature, humidity levels and location must be taken into account. Look below for a table with pool sizes and their required heat pump BTUs.

Pool SizeRequired Heat Pump BTUs
Up to 7,500 gallons50,000 – 60,000
10,000 – 15,000 gallons75,000 – 85,000
20,000 – 25,000 gallons100,000 – 110,000
Above ground poolsVariable

Manufacturer recommendations To Select The Pool Heat Pumps

Manufacturers of pool heat pumps recommend certain guidelines, methods and precautions. 

These are crucial for avoiding damage, prolonging equipment lifespan and reducing maintenance costs. T

Here is a table with recommendations like location, plumbing works, electrical works, water chemistry and winterization.

Reading and following the user manual is advised. Regular inspections by a professional service technician should be done. T

temperature differential and pressure readings should be monitored.

Unusual sounds or smells from the equipment should be noted

Issues or repairs should be addressed promptly. Neglecting these recommendations can lead to decreased efficiency of heating output, higher power consumption and even safety hazards.

Therefore, adhering strictly to manufacturer recommendations is key to optimal performance and cost reduction! Why not get a workout from lifting frustration too?

Troubleshooting Common Pool Heat Pump Issues

Keep it running at its best by troubleshooting any issues as soon as they arise. Here are some tips to help you out:

Check the filters 

Dirty filters reduce airflow, making the pump work harder and less efficient. Regularly clean or replace them.

Look at the thermostat 

Check the proper installation and working of thermostats.

Check for leaks

Water leaks can impact the pump’s function and efficiency. Quickly inspect and seal any identified leaks.

Tripped Breaker

Electricity overload protection has kicked in! The safety system shuts off the power if too much current flows. That way, burnout won’t happen.

Why bother with a pool with low water flow? It’s like a slow baptism from a leaky faucet!

Low Water Flow

Inadequate water flow can hamper your pool heat pump’s performance

It can affect efficiency and create issues like low-temperature output and increased energy consumption. Not enough water passing through the system can result in slow or poor heating.

Check the pool’s filtration system and pump are working properly. Ensure skimmers and drains are clean of debris to allow efficient water circulation. Maintenance is vital for optimal performance.

Clogged Evaporator Coil

Pool heat pumps can suffer from ‘Restricted Flow in Coils’ when the evaporator coil gets blocked. 

Dirt, dust or debris buildup can cause air to be unable to flow properly over the heat exchange surface. 

To fix this, the evaporator coil must be cleaned with special equipment and chemicals. In extreme cases, the coil might need to be replaced.

Many home-owners don’t realize that a clogged evaporator coil leads to higher energy consumption, which can lead to high utility bills. Regular inspections and maintenance are key to avoiding these issues.

Frequently Asked Questions

How does a pool heat pump work?

A pool heat pump uses heat from the outside air to heat the pool water. It draws in heat from the ambient air and transfers the heat to the water in your pool.

How is a pool heat pump different from a pool heater?

A pool heat pump and a pool heater both heat the pool water, but a pool heat pump uses heat from the outside air, while a pool heater may use gas, propane, or solar power to generate heat.

How does a pool heater work?

A pool heater works by using energy in the form of gas, propane, or solar power to generate heat, which is then transferred to the pool water. 

Gas pool heaters use natural gas or propane, while solar pool heaters use the sun’s energy to heat the water.

How does a pool heat pump use heat from the outside air?

The pool heat pump draws in heat from the ambient air using a fan, which is then absorbed by a liquid refrigerant. 

The refrigerant is then compressed by a compressor, which increases the temperature of the gas. The compressed, high pressure gas flows back into the evaporator, where the heat is transferred to the pool water.

How does the heat from a pool heat pump get transferred to the pool water?

After the refrigerant gas is compressed and heated, it flows through a heat exchanger, which absorbs the heat and transfers it to the pool water. The heated water then flows back into your pool.

What are pool heat pump uses?

Pool heat pumps are used to heat swimming pools and spas.

What is titanium used for in pool heat pumps?

Titanium is often used in the heat exchangers of pool heat pumps because it is resistant to corrosion from pool chemicals and salt water.

How do refrigerant gasses work in pool heat pumps?

Refrigerant gasses are used to transfer heat in pool heat pumps. The gasses absorb heat from the ambient air and are then compressed by a compressor, which increases the temperature of the gas. 

The gas then flows through a heat exchanger, where the heat is transferred to the pool water.

How does an inverter heat pump differ from a traditional heat pump?

An inverter heat pump has a variable-speed compressor that adjusts the amount of energy used to heat the pool water based on the temperature of the air outside. 

Traditional heat pumps have a fixed-speed compressor that runs at the same speed regardless of the outside temperature.


Pool heat pumps are an efficient and cost-effective way to heat your pool. They use the air around us to transfer heat via a compression-expansion cycle. This keeps your pool temperature consistent. Also, remember that states pool covers can reduce pool heating costs by up to 70%!

Heat Pump