Heat pump & low loss header calculator

Calculate heat output and COP for a system with a low loss header between the heat pump and the radiator system.

Room temperature

°C

Outside temperature

°C

Heat output

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

Rated radiator output [1]

@ Rated deltaT (MWT - Room)

°K

COP method

Heat pump COP

Comparison with open-circuit system without a low loss header:

Heat pump COP if driving radiators directly without the low loss header (Flow: {{ app.HE_flowT | toFixed(1) }}°C, Return: {{ app.HE_returnT | toFixed(1) }}°C):

or direct radiator output at the primary flow temperature: {{ app.HP_flowT | toFixed(1) }}°C, return: {{ app.HP_returnT_direct | toFixed(1) }}°C and COP: {{heatpump_COP | toFixed(2)}}

[1] 15000 W @ 50K = 7x 1200x600mm K2 double panel radiators, each with an output of 2145W @ 50K.

[2] Carnot COP equation based on +4K offset on flow temperature, -6K offset on outside temperature and a practical efficiency factor of 50%.