Heat pump & heat exchanger calculator

Calculate heat output and COP for a system with a counterflow plate heat exchanger between the heat pump and the radiator system. Calculation based on effectiveness NTU method [1].

Heat exchanger heat transfer rate

W/m2.K

Heat exchanger Area

	Heat pump side (Primary)	Radiator side (Secondary)
Flow rate	L/min	L/min
Heat capacity	J/kg.K	J/kg.K
Flow temperature	°C	°C
Return temperature	°C	°C
Mean water temperature	°C	°C

Room temperature

°C

Outside temperature

°C

Rated radiator output [2]

@ Rated deltaT (MWT - Room)

°K

Radiator output

Heat pump COP

Comparison with open-circuit system without a heat exchanger:

Radiator output if driving radiators directly at primary flow temperature: {{ app.Thi | toFixed(1) }}°C (COP: {{heatpump_COP | toFixed(2)}})

or heat pump COP if driving radiators directly at the secondary flow temperature: {{ app.Tco | toFixed(1) }}°C

[1] Effectiveness NTU method, implementation here ported from python CalebBell/ht library.

[2] 15000 W @ 50K = 7x 1200x600mm K2 double panel radiators, each with an output of 2145W @ 50K.