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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.
6.5 Air heater water (code ETAB-VV) and Thermoguard (ETAB-TV)
Air heater water
The heating coil consists of a number of copper tubes with aluminium fins
pressed on them. The coil will have impaired capacity if dust forms a coating on
the coil surfaces.
Not only does this impair the heat transfer capacity of the coil, it also increases
the pressure drop on the air side. Even if the ventilation system is fitted with
high quality filters, as time passes dust deposits will form on the front edges
of the coil fins (at the inlet side). To utilise its full capacity, the coil must be well
vented. The pipework should be vented by opening the bleeder screws in pipe
connections and/or an air vessel.
Inspection
Check:
1. The coil fins to detect possible mechanical deformity
2. That the water coil is not leaking.
Cleaning
If the fins on the batteries are dirty, clean them by vacuuming from the inlet side,
or carefully blow them clean with compressed air from the outlet side. In the
event of stubborn dirt, use a mild, alkaline detergent.
Bleeding
Bleed the heating coil and the pipework if needed. Bleeder screws are on top of
the coil or on the tube connections.
Function
Check that the coil is radiating heat. This can be done by temporarily increasing
the temperature setting (setpoint).
