Control Dampers:
For controlling air distribution, such as
Fire damper:
A thermally actuated damper arranged to
automatically restrict the passage of fire and/or heat at a
point where an opening violates the integrity of a fire
partition or floor.
Smoke damper:
A damper arranged to control passage
of smoke through an opening or a duct.
Volume control damper (VCD):
A device used to regulate
the flow of air in an HVAC system.
Common types:
Š
- Opposed blade dampers (e.g. in AHU).
- Parallel blade dampers.
- Butterfly dampers (e.g. in VAV box).
- Linear air valves (e.g. in fume hood).
- Specialty dampers.
Damper Sizing
- Typically chosen based on duct size and convenience of location.
- Proper selection and sizing provides the following benefits: Š
- Lower installation cost (damper sizes are smaller).
- Smaller actuators or a fewer number of them are required.
- Reduced energy costs (smaller damper, less overall leakage).
- Improved control characteristics (rangeability) because the ratio of total damper flow to minimum controllable flow is increased.
- Improved operating characteristics (linearity).
Selecting and Sizing Dampers:
The three basic damper applications are:
„
- Two-position duty.
- Capacity control duty.
- Mixing duty.
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