Lennox ROOFTOP FLEXY FXK 55, Installation, Operating And Maintenance Manual

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ECONOMISER AND EXTRACTION
FLEXYII_WSHP-IOM-1307-E - 38 -
ECONOMISER
Free cooling is provided through the use of fresh air which is more appropriate than
excessive cooling amounts of return air.
The economiser is factory fitted and tested prior to shipment.
It includes two dampers operating from a 24V actuator
RAIN HOOD
It also includes a factory fitted rain hood. Hoods is folded during transportation to limit
risks of damage and must be unfolded on site as shown on fig. 9
EXTRACTION
Installed with economiser assembly, the gravity exhaust dampers relieve the pressure when outside air is introduced into the
system.
When large amount of fresh air is introduced into the system power exhaust fans can be used to equalise the pressures.
The extraction fan runs when return air dampers are being closed and supply air blower is in operation. The extraction fan runs
when outdoor air dampers are at least 50% open (adjustable value). It is overload protected.
NOTE: When horizontal flow configuration is required, the multidirectional roof curb will be installed.
F
RESH
A
IR
R
ETURN
A
IR
E
XHAUST
A
IR
S
UPPLY
A
IR
Fig. 9
F LEXY II PRINCIPLE SKETCH
M ULTIDIRECTIONAL ROOFCURB
PRINCIPLE SKETCH
E NERGY RECOVERY MODULE PRINCIPLE SKETCH R ETURN ROOFCURB PRINCIPLE SKETCH