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
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
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.