DETERMINING PRESSURE LOSS IN THE AIR INLET AND OUTLET PIPELINE SYSTEM
The heat pump offers various installation options of connection of the air inlet and outlet pipelines. We recommend the connection
options, which enable the simplest installation of the appliance to the pipeline system. When designing the pipeline system for air
inlet and outlet to and from the heat pump it is essential to consider the aerodynamic characteristics of the heat pump fan, where
the static pressure loss occurs.
The aerodynamic characteristics are displayed in a graph as a pressure drop in relation to airflow. The operating point of the heat
pump fan is at 100 Pa of static pressure or at airflow of 330 m
is considered Δp= 100 Pa. If the calculations show higher pressure drops, the fan speed can be increased. The increase of the fan
speed is effective up to 80%. The airflow does not increase above this level, therefore we advise against further increase for it will
only cause higher levels of noise.
The diagram shows the following areas:
• High-efficiency area – area of high airflow rates (over 300 m
fan settings to 60% or 80%.
• Middle-efficiency area – area of middle airflow rates (between 200 and 300 m
60% or 80% of settings and pressure drops between 50 and 300 Pa.
• Expanded area for higher ambient temperatures – a wider range of settings and high pressure drops. These settings may be in
use only with air temperature over 20°C, otherwise an efficiency decline occurs.
700
650
80 %
500
550
400
450
60 %
400
350
300
250
200
40 %
150
100
50
0
0
20
40
60
80
Figure 4: Aerodynamic characteristics of heat pump fan
High-efficiency area
Middle-efficiency area
Expanded area for higher ambient temperatures
100
120
140
160
180
200
. Working drop of static pressure in an air pipeline of heat pumps
3
) requires lower pressure drops (pipeline free or short pipeline) and
3
/h), 40% fan settings, minimum pressure drop,
3
220
240
260
280
300
320
Airflow [m
/h]
3
operation point
340
360
380
400
420
440
460
480
500
25