Technical data

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V
Precision Air Conditioning
Precision Air Conditioning
24
Technical Manual : 6258867 F 07/2012
Design Features & Information
Controlled by the microprocessor, electronic expansion valves are unlike
their conventional thermostatic counterparts in that they can modulate independently of
the suction line temperature. This unique feature allows the controller to
raise the superheat set-point, in turn dropping the evaporating temperature to a point at
which considerable de-humidification takes place.
RAPID DE-
HUMIDIFICATION
(Only available with
Electronic Expansion Valves
(EEV))
This increase in the de-humidification rate means that time taken to reduce the room
humidity to the required level is drastically decreased, along with the energy required to
do so. The graph below shows the typical effect that the superheat set-point has on the
evaporating temperature and sensible heat ratio.
1.00
0.98
0.96
0.94
0.92
0.90
0.88
0.86
0.84
0.82
Effect of Superheat on
Evaporating Temperature
and SHR
Mean Evaporating
Tempera
ture (°C)
2
3
4
5
6
7
8
0
5
10
15
20
0.82
0.84
0.86
0.88
0.90
0.92
0.94
0.96
0.98
1.00
(1)
(2)
Sensible Heat Ratio
Superheat Set Point (°C)
(1) Normal Operating Conditions
(2) Rapid De-hum Condition
GENERAL