Frequently Asked Questions About Dampers

Q: Do manual balancing dampers come standard with a hand quadrant?
A: Yes, manual hand quadrants are standard on manual balancing dampers.

Q: What is the pressure drop for my specific control damper?
A: Each damper has a pressure drop chart listed on its respective submittal. CAPS also has a performance calculator for 3V models (FSD, SMD, and VCD).

Q: Define all stainless steel construction on commercial control dampers.
A: When selecting a commercial control damper (model VCD) with all stainless steel construction, the customer receives 304 stainless steel blades, frame, axles, bearings, blade linkage, jamb seals (when applicable), and jackshafting (when applicable). Actuator linkages are not provided in stainless steel construction. For dampers made entirely of 316 stainless steel, see the severe environment product line (model SE).

Q: Why does my sleeve length change on combination fire smoke dampers in CAPS on certain line items on my selected pricing worksheet or submittal? I want the sleeve size I entered. (This occurs when an OCI, TOR, RRL or combinations of these are selected).
A: The sleeve length only extends when you have a height of less than 11 inches with a TOR, RRL, or OCI option. Because the actuator has to be mounted horizontally due to the height constraint, the sleeve length must be extended. When this occurs, the TOR, RRL, OCI option must be mounted in the sleeve in front of the actuator. The sleeve must be extended to provide enough room.

Q: How does Greenheck interpret their drive arrangement definition? (Example: 22-2FEL-2)

Q: Do you offer thermally broken insulated blade and/or frame dampers?
A: Yes, Greenheck offers an insulated control damper (ICD series) that is a thermally broken frame and blade, which eliminates the transfer of cold or heat penetration and reduces condensation.

Q: What is the "damper location" under the configuration tab in CAPS?
A: The damper location for all multi-blade models (FSD, SMD, VCD and DFD-210 series) is referred to as the A dimension (distance from end of sleeve to face of damper). The minimum space allowed is 7.188 inches and is the default in CAPS. The damper location for curtain style fire dampers (FD and DFD) is referred to as the K dimension (distance from end of sleeve to centerline of damper frame).

Q: What are typical actuator "running times"?
A: Electric: Belimo – 135 seconds
Siemens GGD – 15 seconds
Honeywell FATPA – 15 seconds
Belimo FSLF & FSNF – 15 seconds
Pneumatic: Siemens 331-4551 – 5 seconds
Siemens 331-2976 – 7 seconds
Siemens 331-2856 – 10 seconds

Q: Can I have an explosion proof (NEMA 7) or weather proof (NEMA 4) actuator?
A: Yes, Greenheck can provide the enclosures on volume control dampers. Where available, these enclosures can be found in CAPS.

Q: What is a pilot positioner on a pneumatic actuator?
A: A pilot positioner is a valve that allows pneumatic actuators on control dampers to modulate.  It requires a separate control air line. 

Q: Can you field change actuators from internal to external, or external to internal on a commercial control damper?
A: Commercial control damper actuators can be changed in the field from external to internal, and internal to external on most control damper models. Consult factory for details. On smoke and combination fire and smoke dampers the actuator location cannot be changed in the field.

Q: What are the running and holding AMPS of certain actuators?
A: This information varies by actuator manufacturer. Exact detail is available on each actuator’s submittal.

Q: What is the difference between an open close indicator (OCI) and an end switch?
A: An OCI kit provides feedback to a control panel, which indicates if the blades are in an open or closed position. An end switch is in the actuator, normally built in as an auxiliary switch for end position indication. Both provide feedback to the control panel. OCI's indication at damper, end switch is at the actuator.

Q: Can we field mount an open close indicator (OCI) kit?
A: Yes, OCI’s can be field mounted on VCD and smoke dampers by using the OCI kit (Part # 851848). Units less than 11 inches high with an A dimension of less than 10.5 inches there will be no room to mount the OCI. Consult the factory on combination fire smoke dampers.

Q: What hour-rated fire damper do I use in a two hour fire-rated wall?
A: Fire-rated barriers of less than three hours will typically use a 1-½ hour-rated fire damper. Fire-rated barriers of three hours or more will typically use a three hour fire-rated damper.

Q: Does Greenheck manufacture support mullions for fire dampers for field installation?
A: Greenheck does not provide support mullions for fire dampers for field installation, however, we do have supplemental instructions on how to manufacture mullions for Static rated curtain dampers. Mullions are not UL approved for dynamic fire dampers.

Q: How small can I make a combination fire smoke damper and still use an internally mounted electric actuator?
A: Greenheck can produce a damper as small as 12 inches wide by 12 inches high and still provide an internal electric actuator on a combination fire smoke damper.

Q: Can a combination fire smoke damper be used with a flush mount grille?
A: Greenheck offers an out-of-wall combination fire smoke damper (OFSD) that may work for this application

Q: What is a momentary test switch and how is it used on a combination fire smoke or smoke damper?
A: Momentary test switches are available as an option on FSD, SSFSD, OFSD, SMD, and SSSMD. This switch allows for a cycle test to be completed at the damper. One test switch is required per closure device.

Q: What do I do when my wall opening exceeds the maximum allowed dynamic fire damper (DFD) curtain style?
A: First look at selecting a multi-blade DFDTF-210, then a DFD-210 model, and lastly selecting a combination fire smoke damper (FSD).

Q: Can a single sided retaining angle be used on a three hour rated damper?
A: No, it is to only be used on a 1-½ hour rated damper. There is no UL certification for a three hour rated damper. Single side angle on a three hour rates is not UL qualified.

Q: Does Greenheck have a spring kit to convert a fire damper  vertical mount unit to a horizontal mount?
A: No, because any field modification to the original product will void the UL rating.

Q: Can dynamic closure dampers be multi-sectioned in the field to fill an over-sized opening?
A: Mmultiple-section dampers must be ordered from the factory as a single unit per UL. The local authority having jurisdiction could approve the multi-section application.

Q: Does Greenheck provide smoke detectors on smoke dampers and combination fire smoke dampers?
A: Greenheck does offer smoke detectors on our smoke dampers and combination fire smoke dampers. The smoke detectors can be shipped mounted or loose.

Q: Does Greenheck offer a zero flow smoke detector?
A: Yes, Greenheck offers a zero flow or no flow smoke detector which samples air currents passing through a duct without airflow.

Q: Can Greenheck manufacture a stainless steel backdraft damper?
A: Yes, the HB Series backdraft dampers are available in 304 stainless steel.

Q: Are counterbalance weights adjustable?
A: Counterbalance weights on Greenheck’s backdraft dampers (BR, EM, ES, HB) are all adjustable for each specific application. Each blade has the option to add, remove, or position the weights to fine tune your system. Installation, operation and maintenance instructions are available on the web site for your reference.

Q: How many sections will I receive with my given backdraft damper.
A: Each backdraft damper submittal provides a chart explaining how many panels and sections your size will have.

Q: Do you offer factory mounted access doors on UL dampers?
A: Yes, on any factory sleeved damper.

Q: Do you offer a 24 Vdc actuator for FSD/SMD models?
A: Yes, the Belimo FSAF-24 actuator is designed to operate on either 24 Vdc and 24 Vac power. Most other 24 Vac actuators are not designed to operate with 24 Vdc power.