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Operation and Maintenance
Envistar Top 04-21
DSET.190501.01.EN
Continuous product development may give rise to specification changes without notice.
6.3 Rotary heat exchanger (code TXRR)
The purpose of the recovery unit is to recover heat from the
extract air and transfer this heat to the supply air in order to
minimise energy use.
Faults in recovery unit functionality result in reduced heat re-
covery efficiency and increased energy use and means that the
design supply air temperature cannot be obtained when the
outdoor temperature is low
A conceivable reason for reduced recovery efficiency may
be that the rotor rotates too slowly because the drive belt
is slipping. The rotor speed should not be lower than 8 rpm
during full energy recovery.
It is not usual for the rotor passages to become fouled with
dust, since the rotor is normally self-cleaning. However, this
might occur if the dust is of a sticky nature.
A reduction of the extract air flow, e.g. due to fouling of the
extract air filter, entails reduced heat recovery efficiency.
Units in the Home Concept design are equipped with a function to control the
pressure balance of the rotor to ensure the correct leakage function and purging
function. For units supplied with control equipment, the function is connected
and activated at the factory. For units without control equipment, this function
must be connected to the unit.
Inspection
1. Shut down the unit via the service switch in the control equipment, safety
switch in the 0 position.
NB:
The safety switch is not designed for starting/stopping the unit. Always
use the control equipment to start and shut down the unit.
2. Wait until the fans have stopped, then open the inspection door.
WARNING!
Positive pressure inside the unit, risk of personal injury.
Allow the pressure to drop before you open the inspection
doors.
3. Check that the rotor rotates easily. If it is sluggish, you might have to adjust
the bristled sealing strip.
4. Check that the rotor’s bristled sealing strip seals against the side plates and
that it is not worn. The bristled sealing strip is subject to wear and can be
adjusted or replaced if the need arises.
5. Check that the drive belt is properly tensioned and does not slip. If it slips,
it will have to be shortened. The rotor speed should not be lower than 8 rpm
during full energy recovery.
6. Check that the drive belt is intact and clean.
7. Check that the rotor’s inlet surfaces are not covered with dust or other
impurities. NB: Avoid touching the rotor inlet and outlet surfaces with your
hands or tools.
Rotary heat
exchanger
