Reverse Cycle Pool Heat Pump
Most heat pumps are not reverse cycle heat pumps. They are either set up as heaters or as coolers. This means they can perform a duty.
Swimming pool heat pumps are designed to do just that, heating the swimming pool. The only responsibility is to ensure that the pool temperature does not drop below the set point. However, on very hot days, they do not prevent the pool or any body of water from overheating.
The same goes for the chiller. Their job is to keep bodies of water, such as aquaculture ponds or cold-water diving pools, cold. On frosty cold days, they won't stop the water from getting too cold.
However, reverse cycle heat pumps are designed to do just that. Prevent the water from getting too hot or too cold. They are set to maintain the set point or deadband temperature range.
Another benefit of a reverse cycle system is that you can reduce the number of systems. You don't need separate heaters and coolers. So not only are they more efficient than natural gas heating, but you also don't need to buy a separate cooler. 2 systems for 1.
How does a reverse cycle heat pump work?
Standard heat pumps use fans to draw air through their coils to collect heat from the environment (how heat pumps work). The coil acts like a radiator, transferring energy to the refrigerant, which is then compressed, increasing the heat collected and dissipating it into the pool water.
Set the heat pump for the chiller to run in reverse. This is done by acting as a radiator for the body of water rather than air. This draws heat from the circulating water circuit and discharges it to the surrounding environment through the coil.
70% or more of the heat pumps are set up as heaters only or as coolers only. The balance is heater-cooler.
Considerations for choosing a reverse cycle heat pump?
Heat pumps contain refrigerant gas. Different gases have different properties. They are considered low, medium, high and combined range gases. Different gases belong to these flags.
R404A is a low to medium refrigerant
R410A is a medium to low refrigerant
R407C is a medium to high refrigerant
R134A is a medium to high refrigerant
R32 is a medium refrigerant (flammable)
It's important to know this when you're choosing the temperature range you want. Leomon chose R407C as the refrigerant. Not only is it ozone safe, but it has a wide hot and cold range. Covers comfortably from 10°C to 45°C. It also has the highest total efficiency kW power to kW output in this temperature range. Reduce the size of the required equipment.
Other considerations are that the cooling process is not as efficient as the heating process. Heat pumps are typically rated at 30% higher in heating mode compared to cooling mode.
Therefore, it is very important to calculate the heating and cooling loads for the requirements of the water body. Then select the largest load, either cold or hot, and select the appropriate unit size.
Many people buy their heater-cooler (reverse cycle heat pump) based on the kW rating of the heat pump, not realizing that this is usually the heating rating not the cooling rating. Therefore, it is difficult for the device to cool water.
Another important fact when choosing the right reverse cycle heat pump is that there are two main types of reverse cycle heat pumps, although they both have the ability to perform both heating processes.
On-Off Cycle - Reverse Cycle Heat Pump
Switch Cycle - Similar to an air conditioner, with a heating mode and a cooling mode. But you have to choose the mode you want to operate in. They do not execute in both modes at the same time.
This means you can use them to cool water in summer and heat it in winter. However, if you need to change the mode, you may need to manually change the settings throughout the year.
Most of the coolers and heaters on the market are designed this way.
True reverse cycle - reverse cycle heat pump
A true reverse cycle heat pump such as the Leomon heat pump range of heat pumps will perform heating and cooling as needed.
This means you can set the desired temperature and the heat pump will automatically switch between heating and cooling to maintain the set temperature.
In swimming pools, for example, the temperature is usually set for the whole year. The heat pump will alternate between heating and cooling modes to maintain this set temperature, usually with a buffer of half or a few degrees.
Only a few brands of heat pumps handle this process well.
Reverse Cycle Heat Pump Summary
Most heat pumps are only used as heaters or coolers. Some come as heater-cooler or reverse cycle, but care must be taken to select the correct type of system to meet the needs of the project's temperature range.
Leomon has been making heat pumps for over 30 years, not just a dealer of other brands. This means we have extensive experience designing, building and recommending systems for a variety of commercial swimming pool projects.