5
Buffer Tank
A buffer tank is recommended to ensure a trouble free heat pump operation. A suitable
buffer tank can avoid excessive heat pump cycling (switching on and off).
The buffer tank provides a hydraulic separation from the volume flow in the heat
pump and heating circuits. The volume flow in the heat pump circuit remains constant,
even if the heating circuit volume flow is reduced by thermostatic valves.
If the total of the systems water volume is less than 12L/KW then a buffer tank should
be added to reduce the compressor from ON/OFF cycling. This will prolong the
compressor life span.
When a buffer tank is installed, the heating system will absorb energy from the buffer
tank first. To save energy consumption ,install the indoor pump P1 that is switched on
only when compressor is on. This is by changing EV01 to “1”.
RT sensor should be taken out of the unit and put into buffer tank’s sensor pocket. The
RT sensor is located at lower submerged sensor pocket of the plate heat exchanger.
The RT sensor in the buffer tank will control the tank temperature by starting and
stopping the compressor and pump together as required.
If RT sensor has not been changed to buffer tank’s sensor pocket when EV01 has been
changed to “1”, when the unit reaches its set temperature ,the compressor will stop,
pump P1 will also stop accordingly due to EV01 being set to “1”. When this
occurs ,there is no water circulation between the heat pump and buffer tank. RT will
keep its stopped temperature ,not the buffer tank water temperature. RT then can not
switch on compressor and pump P1 even when buffer tank water is getting cold.
Changing the RT sensor into the buffer tank will avoid this problem.
Buffer Tank
