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4 - MAIN COMPONENTS
4.1 - Fresh air controller
4.1.1 - Constant fresh air controller
The 42EM Atmosphera can be fitted with a constant fresh air
flow controller allowing the introduction of fresh air and the
air change rate to be controlled. It is essential that the
selection of the regulator takes into account the intended usage
of the room.
The following range of fresh air controllers is available:
Option a: 8.3 l/s (30 m
3
/h) (-10%; +20%) (size 1)
Option b: 16.6 l/s (60 m
3
/h) (-10%; +20%) (sizes 1, 2 and 3)
The fresh air supply is located upstream of the water coil.
Options a and b: the diameter of the spigot housing the fresh
air flow controller is 125 mm.
The 16.6 1/s (60 m
3
/h) or fresh air controller may be modified
on site by relocating or removing two plastic restrictors in order
to increase the maximum constant fresh air flow capacity to
44.4 1/s (160 m
3
/h).
A label on the 42EM shows how to adjust the two plastic
restrictors.
IMPORTANT: If the Atmosphera is fitted with a return air
temperature sensor, the constant fresh air flow rate must not
exceed 50% of the unit supply air flow rate at minimum
speed.
NOTE: To operate correctly, the 30 m
3
/h or 8.3 l/s constant
fresh-air flow controller requires a differential pressure in
the range of 50 Pa to 200 Pa. The 60 m
3
/h or 16.6 l/s
constant fresh-air flow controller requires a differential
pressure in the range of 70 to 200 Pa.
4.1.2 - Variable fresh air controller
The 42EM Atmosphera can be equipped with an optional
variable fresh air flow controller from 0 to 55 l/s (0 to 200 m
3
/h).
This is connected to the numeric Carrier controller and can
regulate the fresh air intake in two ways:
• either using a fixed rate set by the installer that can be
reconfigured as required
• or based on the CO
2
level; in this case it is connected to a
CO
2
sensor via the Carrier numeric controller.
NOTE: With the variable fresh air flow controller the
upstream pressure in the fresh air duct must be 180 Pa.
4.2 - Filter and filter access
The Carrier Atmosphera is fitted with a 85% gravimetric filter
(G3), according to standard EN 779.
Medium fire rating M1, metal wire frame.
Different filter access options are available to suit different
site requirements:
• Unit with non-ducted return air:
- Access is from the rear of the unit.
• Unit with ducted return air:
- Access is from below.
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