Economiser And Extraction - Lennox BAC020SNM Installation, Operating And Maintenance

ECONOMISER AND EXTRACTION

Economiser
Free cooling can be provided through the use of fresh air where appropriate rather than
cooling excessive 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. 26
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.
0-25% fresh air manual (Fig. 27)
It is enough to loosen the mobile grid's screws and to make it slip.
0%: screw into limit stop on the right
25%: screw into limit stop on the left
BALTIC R410A-IOM-0708-E
Fig. 26
Fig. 27
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