Fig. 4.3
A
= Head available to boiler
B
= Power absorbed by the pump (dotted area)
Alpha E-Tec Hybrid - General Information
10
20
30
40
50
60
70
80
0
1
2
3
4
5
6
7
8
0
200
400
600
800
1000
1200
1400
0
Head (m water)
Flow rate (l/h)
Pump electrical consumption (W)
A
B
Speed 9
Speed 5
Available head to boiler
4.4 AVAILABLE PUMP HEAD AND POWER CONSUMPTION
Total head available to the system.
To obtain the available head for the system, subtract the head losses of the outdoor heat pump from the available head of the
boiler.
Fig. 4.4
4.5 OUTDOOR HEAT PUMP HEAD LOSS
The resistance of the hydraulic circuit of the outdoor heat pump must be taken into account when calculating the flow rate and
head values available to the system.
The graph, Fig. 4.4, shows the resistance (pressure drops) of the outdoor heat pump circuit as the system flow rate varies.
For the correct connection of the outdoor unit, refer to the E-Tec EHP instructions.
Head losses (m water)
Flow rate (l/h)
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
0
200
400
600
800
1000
1200
1400
1600
9
