7 Commissioning [specialist]
18
99640141x-mub-en - V02
2017/07
7.3
Maximum withdrawal flow rate
The following diagram illustrates the maximum withdrawal flow rate depending on the tank
temperature with a preset hot water temperature of 45 °C at the tap. The integrated control
avoids temperature drops as long as the maximum flow rate is not exceeded.
W
ithdr
aw
al
fl
ow
ra
te
[l/
m
in]
Pow
er
[k
W
]
Domestic hot water temperature: 45 °C
Boundary conditions: Cold water temperature: 10 °C
Maximum pressure drop on the domestic hot water side of the DHW module: 1000 mbars
The following examples illustrate the correlation between the domestic hot water temperature,
the withdrawal flow rate and the temperature of the buffer tank and show their impact on the
heat transfer capacity of the DHW module.
Example 1
Domestic hot water temperature at the withdrawal point: 45 °C
Temperature in the buffer tank: 50 °C
DHW module: max. withdrawal flow rate: 18 l/min, heat transfer capacity: 41 kW
Example 2
Domestic hot water temperature at the withdrawal point: 45 °C
Maximum withdrawal flow rate: 27 l/min
DHW module: temperature in the buffer tank: 60 °C, heat transfer capacity: 67 kW
FriwaMi
Temperature of the buffer tank
Example 2
Example 1
