How Does a Pool Heat Pump Work in Winter?

Nothing compares to swimming in a nice warm pool, especially when it's cold outside. When winter approaches, the temperature decreases, making it harder for you to enjoy a comfortable swimming session. But you don't have to power through the cool temperatures to have a swimming session when you can get a pool heat pump.

A pool heat pump is an electrical appliance that warms your pool's water to a desirable temperature. If you are reading this article, you are probably wondering how a pool heat pump works and whether it's a good investment. Read on to find the technical analysis on how pool heat pumps work.

Well, what about winter times when the temperature drops? How will the heat pump work with cold air? Heat pumps can still do their job in temperatures as low as 50 degrees, and some can go beyond to work in temperatures around 25 degrees. These types of pumps are called reversible heat pumps or icebreakers.

A pool heat pump works the same way as in warmer temperatures by transferring the available heat in the air through the evaporator coil. The heat pump will freeze in winter when there are cooler temperatures, and condensate will generally form on the evaporator coil. Regular pool heat pumps will shut down in cooler temperatures to avoid circuit damage to the system because of the icing condition.

However, reversible heat pumps have a Hot Gas defrost unit that will apply a reverse cycle procedure to back-peddle the flow of refrigerated gas through the system. This process will defrost ice condensate on the evaporator coils, thus enabling the pool heat pump to continue its task. But this only applies to ice breakers/reversible pool heat pumps.

How do the filter pumps work?

A pool heat pump requires a stable source of water to function; therefore, a filter is necessary during the heating process. The filter pump kicks off the whole heating process once it sends water to the heating unit. When cool water starts flowing through the heat pump, it moderately moves to the heat exchanger, where the actual heating is done. We will continue that point later on; for now, we should learn how the evaporator coil extracts heat from surrounding air.

How do heat pumps harvest warm air?

Pool heat pumps harvest natural warmth from the surrounding air or environment and use it to warm your pool's water. They do so by using electricity as an energy source to power some inbuilt fans, which suck in ambient air. When water begins flowing in, the fans start spinning and create an airflow that sucks the surrounding air.

The air pulled in passes through the evaporator coil to be used for heating water. The blend of low energy use and natural warmth generation is perfect for conserving energy and efficiency in use.

How does the evaporator coil work?

The hot air sucked in from the surrounding environment interacts with cool water in the evaporator coil. This process happens gradually, allowing the cool water to heat up and become warmer. After enough air has passed through the evaporator coil, the water moves on to the next step of heating.

Warm vapor in the compressor

Water in the evaporator coil is heated up to produce a warm vapor, which is crucial in achieving the next step. For the procedure to continue, the refrigerant should be in gas or vapor form.

The water vapor moves to the next part, which is the compressor. The compressor is a big player in the heating procedure, and it's the system that changes the water vapor into gas that is warm enough to be utilized as a heat source. It does so by pressurizing the hot water vapor; when the water vapor pressure is increased, the temperature also increases. This process turns water vapor into a hot gas directed out of the compressor towards the heat exchanger.

A heat exchanger and how it works?

Before we discuss how the heat exchanger works, we first need to understand what it is. A heat exchanger is divided into two parts: the outer tube and the inner tube.

The outer tube is created out of PVC; this tube is where the water from the pool travels through, and inside it is a smaller tube. The smaller tube (inner tube) is made of titanium, where the hot gas from the compressor travels through. Both tubes are separate and not connected; in simpler terms, it's a tube within a tube.

When the hot gas travels through the inner tube, it heats up and releases warmth. Water in the outer tube flows simultaneously as the gas in the inner tube and is heated. This process is what is termed as heat exchange, whereby the heat from the inner tube diffuses into the water in the outer tube.

The gas is cooled down during this process, and the heated water is redirected back into the pool. But the heating process is still not complete; there is still one more step to go before a successful water heating occurs.

What happens to the cooled gas?

The hot gas in the inner tube cools down more and more as it loses heat to the water in the outer tube; eventually, it changes form to become a liquid. This means the refrigerant will be recycled back to its traditional form and directed out of the heat exchanger as a cooled liquid.

Once it leaves the heat exchanger, the liquid is directed through the expansion valve. The function of an expulsion valve is to cool down the liquid further until it's cold enough to return to the evaporator coil.

The process begins again since there is a new supply of refrigerant. The pool pump heater will go through all the previous processes until the targeted warmth of the pool is reached.

Since you understand how a pool heat pump is designed and works, the choice of whether you need it is left to you. Many people consider a pool heat pump a perfect solution that offers effective, affordable, and energy-saving pool heating techniques across all weather and climate conditions.

Also of Interest: 

• Are Pool Heat Pumps Worth It? How Do They Work?

• The Right Way to Install Swimming Pool Air Source Heat Pumps

• Air to Water Swimming Pool Heat Pumps vs. Traditional Pool Water Heaters

• What Size Heat Pump Do I Need for My Pool?