Installation Instructions
55Mounting and installation work
5.6.3 System 3 – Supply air humidity control with continuous output limit ation
Supply air humidity control (humidity sensor installed in supply air duct) should be used only
where room humidity control is impracticable for technical reasons. Such systems always require
a PI-controller.
The humidity sensor (A1) is located in the supply air duct after the steam distribution pipe. The humidity
sensor (A2) for the continuous output limitation is located in the supply air duct before the steam distri-
bution pipe. Such a system requires a PI-controller with the option to connect a second humidity sensor.
Fig. 26:
System 3 – Supply air humidity control with continuous output limit ation
5.6.4 Which humidity control system for which application
Application Location of the humidity sensor
room or exhaust air duct supply air duct
Air conditioning systems with:
– supply air portion up to 33% System 1 System 1
– supply air portion up to 66% System 1 or 2 System 2 or 3
– supply air portion up to 100% System 2 System 3
– supply air humidity control — System 3
Direct room humidication System 1 —
Please contact your Condair supplier, if your application meets the following conditions:
– Humidication of small rooms up to 200 m
3
– Air conditioning systems with a high number of air exchanges
– Systems with variable air volume ow
– Test facilities with extreme control accuracy requirements
– Rooms with a high variation in max. steam capacity
– Systems with temperature uctuations
– Cold rooms and systems with dehumidication
A1/2 humidity sensor
B1 ventilation interlock
B2 airow monitor
B3 safety humidistat
PI
I
Internal PI controller
PI
E
External PI controller
Y input signal from A1
Z input signal from A2