Pumping Height And Pipe Network Resistance - Panasonic WH-SDF03E3E5 Series Design Handbook

5.13.2 Pumping height
and pipe network
resistance
Pump speed 3
Pump speed 2
Pump speed 1
Aquarea air / water heat pump – design handbook 07 / 2014
The device-internal water circulation pump of Aquarea heat pumps differs
in delivery height and delivery volume according to the series and model
version. In addition, there are distinctions between standard pumps, high-
efficiency pumps without differential pressure control and high-efficiency
pumps with differential pressure control (see also unit overview at the
start of the document and the technical data).
While standard pumps have fixed configurable pump levels, high efficiency
pumps have automatic speed control with a finer pump level setting
option, which results in different pump curve characteristics (see the
following sections).
When designing the pump delivery head, all components of the piping
network and their individual resistances must be incorporated at their
rated volume flow. Components like mixers, valves and heat meters
must be selected so that the rated flow matches the rated volume flow
of the heat pump system.
Tipp 1: Note the rated volume flow
For efficient heat generation, heat pumps work with a spread between
the supply and return flows of approx. 5 K. That distinguishes them from
heat generators with burners, which can easily cope with a spread
between the supply and return flows of roughly 10 or 20 K. The low
temperature spread of heat pumps means that the volume flow of heat
pumps is generally higher than heat generators with burners for trans-
porting the same heat output. When planning, you must therefore pay
particular attention to the rated volume flow and the resulting resistance
of the pipe network .
Minimum circulation
90
80
70
60
50
40
30
20
10
0
0 10 20
Sample pipe network resistance characteristic curve with a correctly set rated volume
circulation at pump level 2 (standard pump) for the WH-MXF12D6E5

Pumping height and pipe network resistance

Rated volume circulation
30 40 50
Flow rate [l / min]
Project Design
Hydraulics
60
97