Despatch LAC2-12-6 - Manual (Page 17)

LAC Series Oven Owner’s Manual T HEORY OF O PERATION
Version 106 17
Copyright © 2011 by Despatch Industries.
All rights reserved. No part of the contents of this manual may be reproduced, copied or transmitted in any form or by any
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3.2. Damper Control
The LAC-6 oven is equipped with a manually-adjustable damper mechanism. The
damper control arm is located on the front panel of the oven (Figure 1). The damper
adjustment controls the fresh air opening which, due to pressurization of the oven
chamber, controls the flow of exhaust. If the damper is in the full open position, the
maximum exhaust rate is achieved. If the damper is in the fully closed position, the
minimum exhaust rate is achieved.
3.2.1. Determining Damper Settings
The optimum setting for the damper depends on a variety of
factors. These factors include ambient environment
temperature, load conditions, load distribution, heat-up and
cool-down rates, desired temperature uniformity and most
importantly the desired operating temperature. Additionally,
engineering tradeoffs for each factor must be carefully
weighed. While considering each factor independently may
be too daunting, guidelines provide a simpler way to
determine damper settings.
In general, set the damper so the amount of fresh air flowing
into and exhausting from the chamber agrees with the
desired operating temperature conditions. The following
outline provides practical considerations for various damper
position settings (Figure 3).
3.2.1.1. Damper Full-Closed Position
The damper in full-closed position allows maximum attainable heat-up rates for the
chamber. In addition, the chamber uses minimum power to operate at the desired
temperature. In most cases, maintain the damper in the full-closed position to efficiently
operate at the maximum operating temperature for the chamber.
3.2.1.2. Damper Full-Open Position
The damper in full-open position allows minimum operating temperature for the
chamber. Friction heat from the air recirculation system builds up in the chamber. This
causes chamber temperature to rise slightly though the heating system is not ON. After
Warning!
Do not remove the hat bracket (located in rear of oven) as it
distributes exhaust air and protects the exhaust opening from
being completely covered.
Figure 3. Damper Positions.