Vexve TERMOVAR Handbuch Seite 30

Calculation in practice:
1 m of water requires 1.17 kWh of energy to warm up by 1°C.
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Example:
The aim is to heat a hot-water tank with a volume of 2 m
2 X 1.17 X 40 = 93.6 kWh
The boiler produces a peak output of 25 kW, of which 90% is available on average
due to the heater and fuel:
93.6 kWh
= 4.16 hours of heating time
0.9 X 25
In practice, the effect of sedimentation must be observed when monitoring the temperature of the
boiler with the instruments. The temperature MUST be lower at the bottom of the hot-water tank when
compared to the top part; the temperature at the bottom may increase quickly only after the hot-water
tank has warmed up completely.
Without the sedimentation, the hot-water tank system cannot be utilised in the best possible manner for
generating hot domestic water, for example.
Termovar instruments and estimating boiler output:
max. 5 m distance between boiler and tank
Full burn dT = 20 C (B-A)
Pump speed 3 = 2500 l/h >>>
20 X 2500 X 1.17 = 58.5 kW
In this situation, the readings shall be
stable during a follow-up of several minutes.
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from 35°C to 75°C.
3
A
A = 60°C into boiler
B = 80°C from boiler
C = 35°C from the hot-water tank
B
C
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