7 Commissioning [specialist]
20
99640766x-mub-en – V03
2014/11
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
prevents the temperature from falling, as long as the maximum flow rate is not exceeded
and as long as the water in the buffer tank maintains a sufficient temperature.
W
ithdr
aw
al
fl
ow
ra
te
[l/
m
in]
Pow
er
[k
W
]
Boundary conditions: Cold water temperature: 10 °C
Maximum pressure loss on the domestic hot water side of the Friwa:
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 Friwa.
Example 1
Domestic hot water temperature at the withdrawal point: 45 °C
Temperature in the buffer tank: 60 °C
FriwaMega: maximum withdrawal flow rate: 123 l/min, transfer capacity: 300 kW
Example 2
Domestic hot water temperature at the withdrawal point: 45 °C
Maximum withdrawal flow rate: 120 l/min
FriwaMega: temperature in the buffer tank: ~70 °C, transfer capacity: 290 kW
Domestic hot water temperature: 45 °C
Example 1
Temperature of the buffer tank
FriwaMega
Example 2
