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Operation and maintenance instructions
Envistar / CRAMO
DSCR111125.01
Air handling with the focus on LCC
Continuous product development may give rise to specification changes without prior notice.
3.2 Rotary heat exchanger
The function of the heat exchanger is to recover heat from the extract air and
transfer this heat to the supply air. This reduces the power requirement and the
unit will then consume less power. If the heat exchanger does not operate as it
should, its efficiency on heat recovery will be lower and the air handling unit will
consume more energy. The unit will then not be able to reach the design supply
air temperature when the temperature of the outdoor air is low.
A conceivable cause of reduced efficiency on heat recovery could be that the
rotor is rotating too slowly because the drive belt is slipping. The rotor speed
should not be lower than 8 r/min for full heat recovery.
The air passages in the rotor rarely become clogged with dust, since the rotor
under normal conditions is self-cleaning. However this could occur if the dust is
of a sticky nature.
A reduction in extract airflow, e. g. when the extract air filter becomes fouled,
reduces the efficiency on heat recovery.
Rotary heat exchanger
