Water Flow Rates - andrews FASTflo WH42 Installation Design Manual

2

Water flow rates

2 Water Flow Rates
2.1 WH and WHX water flow rates
Fig. 9
Andrews Model
Reference
Water flow
at different
WH42, LWH42
temperature
rises
WH56, LWH56
WHX56, LWHX56
WH42, LWH42 = 42 kW output
WH56, LWH56 = 55.8 kW output
WHX, LWHX56 = 55.8 kW output
8
Temperature Temperature
Rise 25°C Rise 35°C
L sec L min L sec L min
0.40 24.0 0.29 17.4
0.53 31.8 0.38 22.8
0.53 31.8 0.38 22.8
Flow rate L/S =
Performance Chart
Temperature Temperature
Rise 45°C Rise 55°C
L sec L min L sec L min
0.22 13.2 0.18
0.30 18.0 0.24
0.30 18.0 0.24
The flow rate will vary dependant upon the temperature
selected at outlet and the incoming water temperature.
The flow rate can be calculated using the following formula or
by referance to the charts above.
(Heater output) kW
∆t (temperature rise) x 4.2 specific heat
In addition to the above the maximum flow through each heater
is pre-set independent of temperature, maximum flow rate for
the WH42 is 24 L/min and maximum flow rate for the WH56
and WHX56 is 31.8 L/min.
Temperature Temperature
Rise 65°C Rise 75°C
L sec L min L sec L min
10.8 0.15 9.2 0.13
14.4 0.20 12.3 0.18
14.4 0.20 12.3 0.18
Draft A 18/07/16
8.0
10.6
10.6