Operating Principle Of The Unit - Gree GRS-Cm18PdRe/NhA-M Owner's Manual

Air-to-water Heat Pump

3 Operating Principle of the Unit

The DC inverter air source heat pump system comprises the ODU, water tank, and user terminals.
Operation functions:
(1) Hot water;
(2) Heating;
(3) Cooling;
(4) Hot water+ Heating;
(5) Heating+ water heating;
(6) Mute function;
Hot water：In hot water mode, through heat pump circulation, the unit absorbs heat from the
low-grade energy (low-temperature air) in the surrounding environment and exchanges the heat with
water through the water-side heat exchanger. By controlling the engineering water valve, the water in the
engineering water tank enters the water-side heat exchanger to absorb heat. It is heated circularly to
reach the set value of water tank temperature and meet the user's hot water demand. Hot water mode
includes: standard hot water, energy-saving hot water and fast hot water.
Heating：In heating mode, through heat pump circulation, the unit absorbs heat from the low-grade
energy (low-temperature air) in the surrounding environment and exchanges the heat with water through
the water-side heat exchanger. By controlling the engineering water valve, the water in user terminals
enters the water-side heat exchanger to absorb heat. It is heated circularly to reach the set value of
leaving water temperature and meet the user's heating demand.
Cooling：In cooling mode, through refrigeration circulation, the unit absorbs heat from the cool
water in the water-side heat exchanger and releases the heat to the low-grade energy (high-temperature
heat source) in the surrounding environment. By controlling the engineering water valve, the water in
user terminals enters the water-side heat exchanger to release heat. It is cooled circularly to reach the
set value of leaving water temperature and meet the user's cooling demand.
Hot water+ Heating：In the mode of hot water + heating, hot water mode is given priority. In other
words, the unit will not switch to heating mode until the water tank temperature reaches the set value.
When in heating mode, if the water tank temperature is not satisfied, the unit will immediately switch to
hot water mode.
Hot water+ Cooling：In the mode of hot water + cooling, hot water mode is given priority. In other
words, the unit will not switch to cooling mode until the water tank temperature reaches the set value.
When in cooling mode, if the water tank temperature is not satisfied, the unit will immediately switch to
hot water mode.
Mute function：When mute function is enabled, the unit will automatically control and lower its
operating noise. This function is available in all kinds of running modes.
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