One of the most important tools in regards to HVAC applications are damper actuators. Here are answers to some of the most frequently asked questions.

Q: Are three-hour rated dampers compatible with single sided retaining angles?

A: No, they are not. Single sided retaining angles are only UL-approved to work in conjunction with dampers rated for one-and-a-half hours.

Q: Is it possible to replace actuators while working on dampers in the field?

A: As long as the actuator being replaced matches the UL listing for the damper that is being repaired, it is possible to do this. Just make sure to also match the actuator quantity and the arrangement of the drive with the specific UL listing when performing replacements.

Q: If a wall is fire-rated for two hours, what type of hour-rated fire damper should be used?

A: Generally speaking, when a wall is fire-rated for under three hours, a damper that is hour-rated at one-and-a-half hours should be used. If the wall is rated for three hours or more, a damper that is hour-rated for three hours is recommended.

Q: In regards to a pneumatic actuator, what is a pilot positioner?

A: The pilot positioner is actually a valve which works to modulate the control damper on the pneumatic actuator. For the positioner to work properly, a control air line needs to be installed which is separate from the control damper.

Q: If a hand quadrant is being used, is it possible to use manual balancing dampers?

A: Absolutely! Actually manual balancing dampers come standard when ordering hand quadrants from most any company.

Q: In regards to commercial control dampers, is it possible to change from internal to external actuators or from external to internal actuators while working in the field?

A: As long as the dampers are commercial it is possible. It is not possible to perform such reversals on smoke dampers or on fire and smoke combination dampers while in the field.

Hopefully, these answers to some of the most frequently asked questions about actuators and dampers have proven helpful. As always, make every job a safe and productive one!