3. The heat capacity of the furnace is controlled by
the burner orifices and the gas manifold pressure.
The manifold pressure is factory set but should be
checked at the time of start-up as described below.
It is important not to change the design conditions
or airflow, to measure the minimum and maximum
temperature rise sufficiently far enough downstream
(where the temperature is uniform) and make the
proper adjustments.
Figure K10: Vertical airflow configuration
WARNING
Operation of the furnace module at vent temperatures
below that specified for a Category III could result in
condensation during operating cycles causing premature
failure of the vent connections or heat exchanger and
hazardous operation. Operation of the furnace module
above the maximum air temperature rise could result in
excessive tube temperatures, premature failure and high
limit switch shut down.
VCES-VHC-IOM-1F – VHC-36, -42 & -50
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