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Operation and Maintenance
Envistar Flex
DSEF191101.05.EN
Continuous product development may give rise to specification changes without notice.
6.9 Fan unit (code ELFF)
The purpose of the fans is to transport air through the system, i.e. the fan must
overcome the flow resistance in air terminals, air ducts and the unit.
The fan speed is regulated to provide correct air flow. If the fans generate a
lower air flow, this will impair the function of the ventilation system.
•
If the supply air flow is too low, the system will be out of balance, causing
poor room climate.
•
If the extract air flow is too low, the ventilation capacity will be unsatisfactory.
Imbalance may also force moist air out into the building structure.
One reason why the fans are generating too little air flow may be that
impurities have collected on the fan impeller blades.
•
If a centrifugal fan is rotating in the wrong direction, the air flow will still go
the right way, but with a considerable reduction in capacity. Therefore check
the direction of rotation.
Example, fan size 480-1540
1. Motor
2. Control unit
3. Fan impeller
4. Anti-vibration mounting
Example, fan size 060-190, 360-600, 1080, 1280
1. EC motor with control unit
2. Fan impeller
3. Anti-vibration mounting
1
2
3
1
4
2
3
Example, fan size 1540
1. Motor
2. Fan impeller
3. Anti-vibration mounting
1
2
3
Example, fan size 240-980
1. EC motor with control unit
2. Fan impeller
3. Vibration damper
1
2
3
