CO
2
sensor
The CO
2
sensor must be positioned on the return air duct, so that it can measure the CO
2
level emitted from the part(s) treated.
This sensor is supplied as a spare part and the manual for this is included in its packaging.
Operating principle:
To configure the CO
2
level activation threshold, refer to the information on air quality for the town/city in which the AHU is installed.
CO
2
concentration scale and the effects on humans:
CO
2
concentration
Effect on humans
380 - 480 ppm
Normal atmospheric level
600 - 800 ppm
Correct level for enclosed spaces
1000 - 1100 ppm
Tolerable level for enclosed spaces
5000 ppm
Upper limit for 8 hours of exposure
The CO
2
sensor provides an operating range of 0 to 2000 ppm and must be installed in a duct (refer to the attached supplier instructions).
Constant pressure sensor
Constant pressure is only controlled on the
flow of fresh air being supplied (if the optional constant pressure kit has
been purchased).
The fresh air fan is controlled by the signal from this pressure sensor in
the duct.
The exhaust air flow is controlled by the flow rate signal read off the flow
of fresh air, and may vary according to a factor M (0.5 – 1.5).
Two pressure values can be configured: Nominal pressure and Reduced
pressure.
The duct pressure sensor must be positioned on the supply air inlet duct
at a distance:
D = 2 Dh
(hydraulic Ø)
■ If the duct is circular, Dh = Ø of the duct
■ If the duct is rectangular
Dh =
2 x L x L
L + l
Changeover thermostat for mixed coil:
The customer is responsible for installation on the hydraulic system. The changeover thermostat installed
on the pipe must be integrated into the insulation of the hydraulic pipe.
CO
2
sensor
6 - DESCRIPTION OF THE UNIT & TECHNICAL CHARACTERISTICS
12
