Patent Publication Number: US-10760816-B2

Title: HVAC damper system

Description:
This is a continuation of U.S. patent application Ser. No. 15/583,647, filed May 1, 2017, and entitled “HVAC DAMPER SYSTEM”, which is a continuation of U.S. patent application Ser. No. 13/523,724, filed Jun. 14, 2012, and entitled “HVAC DAMPER SYSTEM”, now U.S. Pat. No. 9,664,409, both of which are incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     This disclosure generally relates to dampers, and more particularly, to dampers that are used for controlling air flow through a duct of an HVAC system. 
     BACKGROUND 
     Heating, ventilation and/or air conditioning (HVAC) systems are often used to control the comfort level within a building or other structure. Such HVAC systems typically include an HVAC controller that controls various HVAC components of the HVAC system in order to affect and/or control one or more environmental conditions within the building. The HVAC components can include, for example, a furnace and an air conditioner. 
     In forced air systems, the conditioned air is typically provided by a furnace and/or air conditioner through a plenum to a network of supply air ducts that distribute the conditioned air throughout the building. A network of return air ducts is often used to return air from the building back to the furnace and/or air conditioner. A blower is used to draw the return air through the return air ducts, and drive the return air through the furnace and/or air conditioner and into the supply air ducts via the plenum. In some cases, some of the air is replaced over time with fresh outside air, often through an energy recovery ventilator. 
     In a zoned system, conditioned air is delivered to each zone based on the heat load in that zone. Damper actuators are typically placed in the supply air ducts that feed each zone. By activating the damper actuators, the conditioned air may be delivered to only those zones that are calling for conditioned air. When multiple zones are serviced by a common blower, the pressure in the supply air duct can change dramatically depending on how many zones are calling for conditioned air. For example, if all of the zones are calling for conditioned air, the pressure in the supply ducts that are open may be lower than if only a single zone is calling for conditioned air. In some cases, a bypass damper may be placed between in a bypass duct that extends between the supply duct (or the plenum) and the return air duct. This may allow some of the supply air to pass directly to the return air duct when the pressure in the plenum rises above a threshold value, such as when only a small number of zones are calling for conditioned air. Because the bypass damper may reduce the overall energy efficiency of the HVAC system, it is desirable for the bypass damper to only be opened when necessary (e.g. to help protect the HVAC equipment). 
     SUMMARY 
     This disclosure generally relates to dampers, and more particularly, to dampers that are used for controlling air flow through a duct of an HVAC system. In one example, a damper system is provided that has a damper blade that is configured to be positioned within a bypass duct of a duct system. A shaft is in communication with the damper blade, and an actuator or force adjustment mechanism is in communication with the shaft. The shaft, the damper blade, and the actuator or force adjustment mechanism may be configured such that the shaft may affect movement of the damper blade about a rotation axis in response to a pressure within the duct or a force acting on the damper blade, where the actuator or force adjustment mechanism may bias the damper blade toward a desired position (e.g. a first or closed position). 
     In some instances, the actuator or force adjustment mechanism may be in removable communication with the shaft and may include a spring within a housing, where the spring is configured to communicate with the shaft to apply a force on the damper blade. In some cases, the actuator or force adjustment mechanism may include a clip configured to facilitate fixing the housing with respect to the shaft by connecting with a standoff extending from the duct. To facilitate releasing the housing from a fixed position with respect to the shaft, the actuator or force adjustment mechanism may include a quick release mechanism configure to engage the clip, where the quick release mechanism may be actuated from exterior the housing. 
     In some instances, the spring may be a soft spring and the damper blade may have a center of gravity at a position offset from a diametrical axis of the damper blade. In some cases, the offset center of gravity may be at position at which the shaft communicates with the damper blade. To facilitate positioning the center of gravity at a position offset from a diametrical axis of the damper blade, the damper blade may support a weight at a position that moves the center of gravity of the damper blade away from a diametrical axis thereof. 
     In some instances, the actuator or force adjustment mechanism may be configured to establish a pressure set point for the damper system. The established pressure set point may be an amount of pressure within the duct that is required to open that damper blade from a closed position. In some cases, the established pressure set point may be indicated with an indicator viewable from exterior the housing. 
     The preceding summary is provided to facilitate an understanding of some of the innovative features unique to the present disclosure and is not intended to be a full description. A full appreciation of the disclosure can be gained by taking the entire specification, claims, drawings, and abstract as a whole. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure may be more completely understood in consideration of the following description of various embodiments in connection with the accompanying drawings, in which: 
         FIG. 1  is a schematic perspective view of an illustrative damper system and a duct section; 
         FIG. 2  is a schematic front view of the illustrative damper system and duct section of  FIG. 1 , with insulation material represented by a dotted line; 
         FIG. 3  is a schematic top view of the illustrative damper system and duct section of  FIG. 1 ; 
         FIG. 4  is a schematic cross-sectional view of the illustrative damper system and duct section taken along line  4 - 4  of  FIG. 2 ; 
         FIG. 5  is a schematic exploded perspective bottom view of the illustrative damper system and duct section of  FIG. 1 ; 
         FIG. 6  is a schematic side view of an illustrative standoff of the illustrative damper system of  FIG. 1 ; 
         FIG. 7  is a schematic perspective cross-sectional view of the illustrative standoff of  FIG. 6 . 
         FIG. 8  is a schematic perspective top view of an illustrative damper actuator of the illustrative damper system of  FIG. 1 ; 
         FIG. 9  is a schematic perspective bottom view of the illustrative damper actuator of  FIG. 8 ; 
         FIG. 10  is a schematic first side view of the illustrative damper actuator of  FIG. 8 ; 
         FIG. 11  is a schematic second side view of the illustrative damper actuator of  FIG. 8 ; 
         FIG. 12  is a schematic exploded perspective top view of the illustrative damper actuator of  FIG. 8 ; 
         FIG. 13  is a schematic cross-sectional view of the illustrative damper actuator of  FIG. 10  taken along line  13 - 13 ; 
         FIG. 14  is a schematic cross-sectional view of the illustrative damper actuator of  FIG. 11  taken along line  14 - 14 , with the handle in a first handle position; 
         FIG. 15  is the schematic cross-sectional view of the illustrative damper actuator of  FIG. 14  with the handle in an opened position; 
         FIG. 16  is the schematic cross-sectional view of the illustrative damper actuator of  FIG. 14  with the handle in a second handle position; 
         FIG. 17  is a schematic bottom perspective view of an illustrative drive gear mechanism; and 
         FIG. 18  is a graphical representation of a change in pressure versus a change in volume flow for a CPRD damper compared to a SPRD damper. 
     
    
    
     While the disclosure is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit aspects of the disclosure to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the disclosure. 
     DESCRIPTION 
     The following description should be read with reference to the drawings wherein like reference numerals indicate like elements throughout the several views. The description and drawings show several embodiments which are meant to be illustrative of the claimed disclosure. 
     For convenience, the present disclosure may be described using relative terms including, for example, left, right, top, bottom, front, back, upper, lower, up, and down, as well as others. It is to be understood that these terms are merely used for illustrative purposes and are not meant to be limiting in any manner. 
     Forced air zoning systems may be used to enable better temperature control in homes and/or buildings by breaking the control and conditioning into small zones. By doing this, the home or building owner cannot only achieve better temperature control, but also realize energy savings by setting unoccupied areas of their home to more energy efficient set points. When the zoning system is calling to condition only one or a small number of zones, static pressure can rise in the discharge air plenum of the HVAC system. This static pressure rise can often be mitigated or avoided with multi-stage or variable speed forced air equipment. In many cases, however, forced air equipment in homes or buildings is single stage, which does not usually, by itself, allow for static pressure rise control or the equipment is multi-stage but cannot fully compensate for the static pressure rise. In at least these cases, undesirable increased static pressure can occur that may or may not exceed the rated static pressure of the equipment, where the increased static pressure may cause noise in the ducts and/or noise at the discharge registers of the zoned forced air system. One solution may be to include a bypass damper in the forced air equipment. A bypass damper may assist in reducing the rise in static pressure by opening in response to a rise in static pressure reaching a threshold level and “bypassing” air from the discharge plenum to the supply plenum and/or to any other desired plenum or duct. 
       FIGS. 1-3  show views of a damper system  10  integrated with or including a duct  2  that may be used with, for example, single stage forced air equipment and/or other equipment. In some cases, the damper system  10  may be used to limit the rise in the static pressure when a low percentage of zones in a zone system are calling for air through: facilitating re-circulation of excess air from a supply plenum to a return plenum or other plenum or duct of the forced air HVAC system; providing access to a pressure relief dump zone and dumping excess air into a closet, hallway, or other high load and large zone area; dumping excess air into closed zones (e.g., zones not calling for conditioned air) downstream of the zone control dampers; or through any other technique as desired. 
     In some cases, the damper system  10  may be integrated in a duct  2  of a forced air equipment system and may include a damper actuator  20 , an optional standoff  70 , a damper or damper blade  15 , a damper shaft  18  and a damper stop  16 . In an illustrative set up, the damper actuator  20  may be connected to the standoff  70  and the standoff  70  may be connected to duct  2  with one or more fasteners  80  (e.g., screws, rivets, adhesive, solder, weld, etc.), as seen in  FIG. 1 , and/or through any other connection technique (e.g., any mechanical, electrical, or other connection technique). Illustratively, the damper shaft  18  may extend from the damper actuator  20  through standoff  70 , duct  2 , one or more damper clamps  11  attached to damper blade  15  and to a shaft receiving area adjacent the other side of duct  2 . Alternatively, or in addition, one or more damper shafts  18  may extend any portion of the distance or space from damper actuator  20  to the shaft receiving area adjacent the other side of duct  2 , as desired. 
     In some instances, damper shaft  18  may engage the damper or damper blade  15  and damper clamps  11  at a position offset from a center axis of the damper blade  15 , as shown in  FIG. 2 . In some cases, damper blade  15  may include one or more weights  17  placed on or adjacent to or affixed to a surface of the damper blade  15 . In situations where damper shaft  18  interacts with the damper blade  15  at a position offset from a central diameter axis of the damper blade  15 , the one or more weights  17  may be placed on a first or large area portion A of blade  15  or a second or small area portion B of blade  15  (shown in  FIG. 2 ), or both, where a surface area of the first or large portion A of the damper blade  15  may be greater than a surface area of the second or small portion B of the damper blade  15 , for example. The offset positioning of the shaft  18  with respect to a center axis of the damper blade  15  along with the positioning of the one or more weights  17  may result in a center of gravity of the damper blade  15  being offset from a center axis of the damper blade  15  and optionally, substantially located at the rotation axis of the damper blade  15 . 
       FIG. 2  is a schematic end view of the damper system  10  connected to an insulated duct  2 , where an insulating layer  13  (the outer circumference of which is shown by the dotted line around duct  2 ) is positioned about or at least partially around the duct  2 . In some cases, the insulated duct  2  may include an outer surface  12  of the duct  2 , the insulating layer  13  on or abutting the outer surface  12  of the duct  2 , and an outer surface  14  of the insulating layer  13 , where the outer surface  12  of the duct  2  may be an outer layer of a duct or other object at least partially within the insulating layer  13  and the outer surface  14  of the insulating layer  13  may optionally include the outer surface of any layer added to typical insulating layers  13  or an outer surface of any other material positioned about the duct  2 . For example, the outer surface  12  of the duct  2  may include the surface on which the insulating layer  13  is placed and the outer surface  14  of the insulating layer  13  may be a surface adjacent a second flange  76  of the standoff  70 . 
     As discussed in further detail below, the standoff  70  may be configured to allow the duct  2  to be insulated, while providing substantially unobstructed access to a damper control or damper actuator  20 . The unobstructed access to a damper actuator  20  connected to a duct  2  having an insulation layer  13  thereon may be facilitated by the standoff  70  providing space for the insulation material  13  between the damper actuator  20  and the duct  2 . The standoff  70  may provide for any distance, as desired, between the duct  2  and a bottom surface of the damper actuator  20 . For example, the standoff  70  may provide a distance between 0.5 inches and 3 inches between the duct  2  and the bottom surface of the damper actuator  20  in order to facilitate the prevention of sweating (e.g., condensation) on the duct  2  and/or on the damper system  10 . In another example, the standoff  70  may provide a distance between one inch and two inches between the duct  2  and the bottom surface of the damper actuator  20  in order to facilitate the prevention of sweating on the duct  2  and/or on the damper system  10 . 
     In some cases of typical damper systems, sweat or condensation may form on the exterior of the duct  2  due, at least in part, to cool fluid (e.g., conditioned air, etc.) within the duct and a warm and/or humid environment exterior the duct. As a result, if an actuator is thermally coupled to the duct (e.g., the duct&#39;s interior), the actuator may be cooler (e.g., similar to the interior of the duct) than the dew point of the air in which the actuator resides and moisture may condense thereon. In some instances, the distance provided by the standoff  70  between the duct  2  and the bottom surface of the damper actuator  20  that is configured to facilitate the prevention of sweating (e.g., condensation) may provide space for receiving the insulating layer  13 , where the insulating layer may have a known R-value and may be used to isolate a cool interior of the duct  2  and the shaft  18  from the surrounding environment to prevent sweating. Example distances provided by the standoff  70  between the duct  2  and the bottom surface of the damper actuator  20  may include distances configured to facilitate receiving one or more insulating layers having R-values between 6 ft 2 ·° F.·h/Btu and 8 ft 2 ·° F.·h/Btu, 1 ft 2 ·° F.·h/Btu and 10 ft 2 ·° F.·h/Btu, 1 ft 2 ·° F.·h/Btu and 20 ft 2 ·° F.·h/Btu, or other R-values, as desired. 
     In some cases, standoff  70  may include a first flange  74  and a second flange  76  (e.g., a taping flange) separated, at least partially, by a body  72  to form an open space  92  having one or more ribs  82  extending between the first flange  74  and the body  72  and between the second flange  76  and the body  72  for support. The open space  92  may be used for any purpose. For example, the open space  92  may be used for receiving the insulating layer  13  or for other purposes. The position of the actuator  20  outside of any insulating layer  13  (as seen in  FIGS. 1 and 2 ) may allow for indicators  44 ,  50 ,  56  and any indicia depicted on or through housing  60  to be easily viewed and/or read by a user. 
       FIG. 3  depicts a schematic view of a top of the damper system  10  connected to duct  2 . As seen in  FIG. 3 , one or more indicators  44 ,  50 ,  56 , along with a handle  34  may be positioned on or adjacent the exterior surface  64  of the housing  60  and/or seen on and/or seen through the exterior surface  64 . For example, the exterior surface of the housing  60  may include a handle  34  extending therefrom, one or more of a damper blade position indicator  44 , a flow direction indicator  56 , a pressure level indicator  50  and/or other similar or dissimilar maneuvering and indicator mechanisms. 
       FIG. 4  is a schematic cross-sectional view taken along line  4 - 4  in  FIG. 2  of the damper blade  15  within the duct  2 , where the damper blade  15  is in an opened position or a second position. Illustratively, the damper blade  15  may be considered to be in the opened position when the damper blade  15  or object configured to rotate with the damper blade  15  is not touching the damper stop  16  or at least a portion of the damper blade  15  or object configured to rotate with the damper blade  15  is not touching the damper stop  16 . When the damper blade  15  or object configured to rotate with the damper blade  15  abuts at least a portion of the damper stop  16  and the damper blade  15  forms a seal or a closure within the duct  2  (e.g., substantially blocks a flow through duct  2 ), the damper blade  15  may be considered to be in a closed position or a first position. 
     The damper blade  15  may be configured in any dimension or shape and may be made of one or more pieces of material, as desired. For example, the damper blade  15  may be completely straight, may have a bent or angled portion or otherwise may be formed to have an angled portion  15   a  and a straight portion  15   b , or may take on any other shape. In some cases, the angled portion  15   a  may be bent or formed toward an inlet I of the duct  2  and may be on the first or large portion A of the damper blade  15 , or on any other portion of the damper blade  15 . The forming of a portion of the damper blade  15  toward the inlet I of the duct  2  may facilitate mitigating pressure rise in the duct  2  by allowing the flow through duct  2  to contact the damper blade  15  in a substantially perpendicular manner as the damper blade  15  opens and/or releases from damper stop  16 . In addition, or alternatively, the damper blade  15  may be made of a plurality of pieces of material that at least partially form the portion of the damper blade angled toward the inlet I. 
     In some cases, the damper stop  16  may be positioned interior the duct  2 , as shown in  FIG. 4 . As shown in  FIG. 4 , illustratively, the damper blade  15  may be configured to match the shape of the damper stop  16  to create a seal or closure with damper stop  16  within the duct  2 . Alternatively, or in addition, the damper stop  16  may be positioned exterior the duct  2  and may be configured to engage any feature or object that rotates with the damper blade  15 . For example, the damper blade stop  16  may engage the shaft  18  or a clip or object extending from the shaft  18 , as desired. 
     In some instances, the damper system  10  may include a second damper blade stop (not shown) configured to limit the how far the duct may open from its closed position. The second damper blade stop may be positioned interior the duct  2 . Alternatively, or in addition, the second damper stop may be positioned exterior the duct  2  and may be configured to engage any feature or object that rotates with the damper blade  15 . For example, the second damper blade stop  16  may engage the shaft  18  or a clip or object extending from the shaft, as desired. 
       FIG. 5  is a schematic exploded view from a bottom of the damper system  10 , with the damper actuator  20  and duct  2  separated from the standoff  70 . The bottom of damper actuator  20 , as seen in  FIG. 5 , may include a connector opening  68  through which a second end  72   b  of the standoff  70  may extend to connect with the damper actuator  20 . After standoff  70  has been connected with the damper actuator  20  and when the damper actuator  20  is to be released from the standoff  70 , connector release  58  may be actuated to release body connector  96  from connector  54 , as discussed in greater detail below. 
     As seen in one or more of  FIGS. 5-7 , the standoff  70  may be comprised of one or more pieces of material fitted together and may include a body  72 , a mounting mechanism  73 , and a flange  76  spaced from the mounting mechanism  73 . The mounting mechanism may include, but is not limited to, a first end  72   a  of the body  70  and a first flange  74 , where the mounting mechanism  73  and at least the first flange  74  may be configured to facilitate mounting the body  72  relative to a duct  2  adjacent an outer surface  12  of the duct  2 . Illustratively, the flange  76  may be a second flange  76  spaced from the first flange  74 , where a space  92  configured to receive the insulating layer  13  is formed between the first flange  74  and the second flange  76 . Thus, when so configured, the first flange  74  may be mounted relative to the outer surface  12  of the duct  2  and the body  72  extends through (or receives) the insulating layer  13  of the duct  2  such that the second flange  76  may be positioned adjacent an outer surface  14  of the insulating layer  13 . In some cases, the standoff  70  may be mounted to the duct  2  from inside the duct  2 , where the first flange  74  may be mounted to an inner surface  9  of the duct  2  and the body  72  may be inserted through the duct. The second flange  76  may facilitate taping the insulation layer to the standoff  70  and may be a taping flange. In some cases, the body  72  may have the first end  72   a  extending through the first flange  74  and an opposing second end  72   b  extending through the second flange  76 , as seen in  FIG. 6 , or body  72  may take on any other desired orientation with respect to the first flange  74  and the second flange  76  to create the open space  92 . 
     As shown in  FIGS. 5 and 7 , the first flange  74  may include one or more mounting holes  78  configured to receive a fastener  80  that may be configured to fasten the first flange  74  to the outer surface  12  or the inner surface  9  of the duct  2 . Alternatively, or in addition, the mounting mechanism  73  and/or the first flange  74  may take on a configuration that facilitates a connection to the duct  2  by twisting onto and/or engaging the duct  2  in a bayonet-style and may be held in place with a snap, latch, screw, etc.; the mounting mechanism  73  and/or the first flange  74  may connect to the duct  2  with a nut positioned on or about the duct  2  that may engage threads on the bottom of or that extend from the mounting mechanism  73  and/or the first flange  74 ; the mounting mechanism  73  and/or the first flange  74  may connect to the duct  2  by engaging a retaining part on the inner surface  9  of the duct  2  that snaps onto, slides onto, twists onto, otherwise engages features of the mounting mechanism; the mounting mechanism  73  and/or the first flange  74  may connect to the duct  2  by using an adhesive; the mounting mechanism  73  and/or the first flange  74  may connect to the duct  2  in any other releasable or non-releasable manner; and/or the mounting mechanism  73  and/or the first flange  74  may connect to the duct  2  in any combination thereof. 
     As discussed above, to add support to the body  72  and the flanges  74 ,  76 , the standoff  70  may have one or more ribs  82  extending to or from one or more of the flanges  74 ,  76  and from or to body  72 . For example, one or more ribs  82  may extend between the first flange  74  and the body  72  of standoff  70 . In some instances, the rib(s)  82  may extend entirely from the first flange  74  to the second flange  76  along body  72  or the rib(s)  82  may extend partially the distance between the flanges  74 ,  76  along body  72 . 
     The second end  72   b  of the standoff  70  may connect to a connector  54  (e.g., a clip connector or another connector type) at or near the body connector  96 , such that the housing  60  of the actuator  20  may be fixed with respect to the shaft  18 . The body connector  96  may be any type of connector configured to engage or facilitate engagement of the standoff  70  with the connector  54 . For example, the body connector  96  may include a ridge capable of making a snapping or other connection with the connector  54 , as shown in  FIG. 6 ; the body connector  96  may include an indentation configured to receive and connect with the connector  54 ; or, the body connector  96  may take on any other form that may be configured to connect with the connector  54 , as desired. 
     The body  72  of the standoff  70  may have a pass-through cavity  94  that extends from the first end  72   a  of the body  72  through to the second end  72   b  of the body  72 . The pass-through cavity  94  may be configured to receive the damper shaft  18  and have shaft  18  pass therethrough. Further, the pass-through cavity  94  may be configured to have a bearing surface  95  configured to engage and/or abut a bearing in communication with the shaft  18 . 
     In some instances, where the body  72  includes the connector  96  (e.g., a releasable connector) and is connected to the damper actuator  20 , the standoff  70 , the damper actuator  20 , and the damper shaft  18  may be configured to drive the damper blade  15 . In addition, or alternatively, the pass through cavity  94  may receive other features and have one or more of those other features pass therethrough. For example, where a temperature sensor, pressure sensor, flow sensor, or other electronic, chemical, or mechanical sensor or probe or object is positioned within duct  2 , about or adjacent duct  2 , or is exposed to an interior volume of an insulated duct  2 , one or more wires supporting the sensor or electronic object may pass from the duct and at least partially through the pass-through cavity or opening  94  of the standoff  70 . 
     As shown in  FIG. 7 , the pass through cavity  94  and/or the body  72  may be elongated and extend along a main body axis B-B, where the flanges  74 ,  76  extend radially outward relative to the main body axis B-B. For example, the first flange  74  may have a first flange perimeter  84  defined by one more first flange sides  88 , where the first flange  74  extends outward (e.g., extends radially) relative to the main body axis B-B to the first flange perimeter  84 . Further, in the example, the second flange  76  may have a second flange perimeter  86  defined by one or more second flange sides  90 , where the second flange  76  extends outward (e.g., extends radially) relative to the main body axis B-B to the second flange perimeter  86 . The first flange perimeter  84  may be defined by any number of sides  88  and the second flange perimeter  86  may be defined by any number of sides  90 . For example, each perimeter  84 ,  86  may have one side  88 ,  90  (e.g., where the flanges  74 ,  76  have a circular and/or rounded shape), respectively; at least two sides  88 ,  90 , respectively; at least three sides  88 ,  90 , respectively; at least four sides  88 ,  90 , respectively; or any other number of sides  88 ,  90 , respectively, having sharp or rounded corners, as desired. As discussed, the open space  92  configured to receive an insulating layer  13  may extend between the first flange perimeter  84 , the second flange perimeter  86 , and the main body  72 . 
     As seen in  FIGS. 8-12 , damper actuator  20  may include a housing  60  having a bottom  60   a  and a top  60   b , with a handle  34  and a connector release or quick release  58  accessible through or from the exterior surface  64  of housing  60  and configured to engage the clip and release the housing  60  from a fixed position with respect to the shaft  18  and/or the standoff  70 . In some cases, a drive gear arm  32  of a drive gear mechanism  28  may extend from or extend through or be formed integral with the housing  60 , such that the drive gear arm  32  may be configured to engage the handle  34 . In addition, or alternatively, the handle  34  and the drive gear arm  32 , along with the drive gear  30 , may be integrally formed of one or more pieces of material. To facilitate operation of the drive gear mechanism  28 , as further discussed below, the drive gear arm  32  may extend from the housing  60  at a position adjacent a contact surface or area  66  of the housing  60  and connect with handle  34  such that the handle  34  may be configured to hinge about the drive gear arm  32  and about a fulcrum when in an opened or second position. Illustratively, the fulcrum may be accomplished by a raised ridge or shoulder extending any distance around the connection of the handle  34  with the drive gear arm  32 , a raised feature (e.g., a bump) on the top surface  38  of the handle  34  that makes contact with a flat, raised or indented surface that at least partially surrounds the connection of the handle  34  with the drive gear arm  32 , or any other feature configured to act like a fulcrum, as desired. 
     Illustratively, the handle  34  may include a bottom surface  36  and a top surface  38 , where the top surface  38  may include brand indicia  55  and/or other markings, as desired. In some instances, the housing  60  may form a handle gap  61  below the handle  34 , which may be defined at least partially by the exterior surface  64  of the housing  60  and the bottom surface  36  of the handle  34 . The handle gap  61  may be configured to facilitate opening the handle  34  by applying a force on the bottom surface  36 , where opening the handle  34  may include moving it from a first position to a second position. 
     In some instances, one or more visual indicators may be visible from the exterior of the housing  60 . For example, as shown in  FIG. 8 , one or more of a damper blade position indicator  44 , a pressure level indicator  50 , an air flow direction indicator  56 , duct size indicator  57 , and any other indicator or indicia may be viewed on or through or positioned on the exterior of housing  60 . The structure and position of these indicators  44 ,  50 ,  56  are discussed in greater detail below. 
     As shown in  FIGS. 9 and 12 , the housing  60  may include a connector opening  68  through which an object may engage a connector  54  or any other type of connector. The connector  54  may be any type of connector configured to receive body connector  96  of the standoff  70 . For example, the connector may be a u-clip connector, as seen in  FIG. 12 , or any other desired clip or other connector or fastener. In some cases, a connector release  58  may be in communication with the connector  54  and may extend from interior the housing  60  to exterior the bottom side  60   a  of housing  60  or to any other position in relation to housing  60 . Although the connector release  58  may take on any configuration based at least partially on the type of connector (e.g., clip connector  54 ) used in damper actuator  20 , the connector release  58  depicted in  FIG. 9  may operate by facilitating a release of an object connected to clip connector  54  through applying a force in the direction of the connector opening  68  to an end of the connector release  58  extending exterior the housing  60 . Once the force is applied to connector release  58 , the connector release may act on an open end of the connector  54  to spread or open the connector and release a body connector  96  inserted through connector  54 . 
     In relation to the housing  60 , the connector  54  may be positioned substantially interior the housing  60 . Illustratively, the connector  54  may be positioned around a connector opening  68  in the housing  60  and may be snapped into place. In order to engage the body connector  96  of the standoff  70 , the connector  54  may extend through one or more openings in the housing  60  adjacent the connector opening  68  to engage a body connector  96  extending into and/or through the connector opening  68 . In some instances, the connector release  58  may be positioned around and/or over the connector  54  and may be configured to slide radially with respect to the connector opening  68 . The connector release  58  may be connected to housing  60  in any manner, for example, the connector release  58  may be snapped into clasps  67  extending from the interior surface  62  of the housing  60  and may be configured to slide along or within guides  69 . 
     In addition to, or alternatively to, the actuator  20  being connectable to and releasable from the standoff  70  with the connector  54  and the connector release  58 , the actuator  20  may be connected to the standoff  70  in any similar or dissimilar manner, as desired. For example, the actuator  20  may connect to the standoff  70  by twisting onto and engaging the standoff  70  in a bayonet-style and may be held in place with a snap, latch, screw, etc.; the actuator  20  may be screwed onto the standoff  70  at the second flange  76  and/or with a flange of the housing  60 , where the flanges may be substantially normal or parallel to the shaft  18 ; the actuator  20  may connect to the standoff  70  with a nut positioned on or about the standoff  70  that may engage threads on the bottom of or that extend from the actuator  20 ; the actuator  20  may connect to the standoff  70  with a nut and lever connection; the actuator  20  may connect to the standoff  70  in any other releasable or non-releasable manner; and/or the actuator  20  may connect to the standoff  70  in any combination thereof. 
     In some instances, the housing  60  may include a female key  71  (or a male key or other key, as desired) within the connector opening  68 . The female key  71  may be configured to engage one or more ribs or male keys  75  (see  FIG. 7 ) (or female key or other key, as desired). Any connections between keys  71 ,  75  may facilitate fixing the actuator  20  in a position with respect to standoff  70 , the shaft  18 , the duct  2 , and/or other features. For example, the connector  54  and the keys  71 ,  75  may be configured to fix the actuator  20  translationally in three degrees of freedom and rotationally in three degrees of freedom with respect to the standoff  70 , shaft  18 , the duct  2 , and/or other features. Alternatively, or in addition, the locks  71  and  75  may be configured to connect the actuator  20  to the standoff  70  such that the actuator may only connect in a single orientation or in a limited number of orientations with respect to the standoff  70 , the shaft  18 , the duct  2 , and/or other features. 
     The damper system  10  may be used in conjunction with one or more ducts  2  and may include the damper blade  15  positioned within the duct  2  and in communication with the shaft  18 , such that the shaft  18  may be configured to affect movement of the damper blade  15  within the duct  2  and about a damper blade rotation axis between a first position and a second position different than the first position. Illustratively, the damper actuator  20  may communicate with the shaft  18  to move the damper blade  15  from the first position to the second position. To facilitate such movement, the damper actuator  20  may include a soft spring and/or a torsion spring  22  (e.g. coil spring) that may be in communication with the shaft  18 , where the soft spring and/or torsion spring  22  may be configured to provide a bias force to the shaft  18  and apply a counter balance or bias to the damper blade  15  toward one of the first or second positions, or any other position. Further, the damper actuator  20  may include a housing  60  that at least partially encloses the torsion spring  22  and other features of the damper actuator  20  including, but not limited to, a winding or bias force adjustment mechanism  24 , where the mechanism  24  may be in communication with the torsion spring  22  and may be configured to load the torsion spring  22  or otherwise adjust the bias force provided from the torsion spring  22  to the shaft  18 . 
     Illustratively, a soft spring may be a spring having a low stiffness. For example, a soft spring may have a low stiffness if it has a stiffness in the range of 0.1 Newton-millimeters/degree to 0.6 Newton-millimeters/degree, 0.02 Newton-millimeters/degree to 1.0 Newton-millimeters/degree, 0.02 Newton-millimeters/degree to 2.0 Newton-millimeters/degree, or other range of stiffness, as desired. Whether a stiffness of a spring is considered a low stiffness may depend at least partially on the size of duct to which the soft spring is to be applied. For example, a low stiffness spring used in conjunction with an eight inch duct may have a stiffness of or about 0.11 Newton-millimeters/degree; a low stiffness spring used in conjunction with a ten inch duct may have a stiffness of or about 0.16 Newton-millimeters/degree; a low stiffness spring used in conjunction with a twelve inch duct may have a stiffness of or about 0.29 Newton-millimeters/degree; and a low stiffness spring used in conjunction with a fourteen inch duct may have a stiffness of or about 0.50 Newton-millimeters/degree. 
     As shown in  FIG. 12 , the winding or bias force adjustment mechanism  24  may include two gears and the back driving clutch or reverse stop mechanism  40  having a stop member  42  and a spring  52 , or may take on a different configuration. In some instances, mechanism  24  may include a driven gear  26  in communication with the torsion spring  22  and a drive gear  30  in communication with the driven gear  26 , where the drive gear  30  and/or the driven gear  26  may engage the back driving clutch or reverse stop mechanism  40  to facilitate preventing unintended movement of the gears  26 ,  30  in a direction biased by the torsion spring  22 . Illustratively, the drive gear  30  may be formed as a portion of the drive gear mechanism  28 , which may also include the drive gear arm  32 . Where the drive gear  30  engages a stop member  42 , the drive gear  30  may have an end with a chamfered portion  33  leading to a stop member engaging portion  31 , where the stop member engaging portion  31  may be a cut-away in an end of drive gear  30 , as best shown in  FIG. 17 , and may be configured to receive or engage the stop member  42 . In some instances, the winding mechanism or bias force adjustment mechanism  24  may optionally include features in addition to the driven gear  26  and the drive gear  30  that include, but are not limited to, the handle  34  (not shown as part of the winding mechanism or bias force adjustment mechanism  24  in  FIG. 12 ), shaft connector  19 , the torsion spring  22 , torsion spring plate  23 , the drive gear arm  32 , a spring  52 , indicator arms  45 ,  51 , spiral groove  48 , and other desired features. 
     The handle  34  may communicate with the drive gear  30  of the drive gear mechanism  28  through the drive gear arm  32 . Through interaction with the drive gear  30  which may engage driven gear  26 , the handle  34  may drive the driven gear  26  as the handle  34  is actuated (e.g., rotated). The torsion spring  22  may be in communication with the shaft  18  and the driven gear  26  through a mechanical couple or other direct or indirect coupling to operate in response to actuation of the handle  34 . In some instances, the torsion spring  22  may be positioned substantially between an outer circumference of the shaft  18  and an inner circumference of the driven gear, as best shown in  FIG. 13 . The torsion spring  22  may be directly or indirectly connected to the shaft  18 . For example, where the torsion spring  22  is indirectly connected to the shaft  18 , the torsion spring  22  may connect to the shaft connector  19 , which, in turn, may be connected to shaft  18 . Further, as the torsion spring  22  may be in communication with the shaft  18  and the driven gear  26 , the torsion spring  22  may operate to bias the shaft  18  and driven gear  26  in a first direction. In such an instance, the handle  34  may be actuated to move the driven gear  26  in a first or second direction. Where torsion spring  22  is connected to the shaft connector  19 , the shaft connector  19  may allow for winding or unwinding of the torsion spring  22  through rotation of the driven gear  26  to establish a pressure set point or threshold by adjusting the amount of pressure required to crack open the damper blade  15  from the damper stop  16  (e.g., a crack pressure), while allowing shaft  18  to rotate against the bias of the torsion spring  22  in response to a pressure differential between the inlet and outlet of (e.g., a pressure differential across the damper blade) the duct  2  (or a force against the damper blade  15 ) above the crack pressure and facilitating the indication of a position of the damper blade  15  through the damper blade position indicator  44 . An established pressure set point or crack pressure may be a pressure level expressed by a numerical value with some pressure units. Alternatively, or in addition, the established pressure set point or crack pressure may be set by relative position. For example, where a pressure level indicator  50  may be utilized, the pressure set point or crack pressure may be set relative to tick marks or other markings of the pressure level indicator  50 , where the tick marks or other markings may or may not be related to a known numerical value and may be viewable from exterior the housing  60 . 
     As the driven gear  26  is biased in the first direction, a lock may be utilized to secure the driven gear  26  at a desired position to maintain an established or desired pressure set point or threshold (e.g., a crack pressure). Such a lock of the driven gear  26  may result in the torsion spring  22  and the shaft  18  resisting rotational moments to the shaft below the torque applied by the torsion spring  22 , while also preventing the total unwinding of the torsion spring  22 . For example, a back driving clutch mechanism or reverse stop mechanism  40  may be utilized to lock the driven gear  26  in a particular rotational position. In some cases, the back driving clutch mechanism or reverse stop mechanism  40  may be configured to unlock drive gear  30  from a reverse stop member  42 . Alternatively, or in addition, the back driving clutch mechanism or reverse stop mechanism  40  may engage the driven gear  26 , as desired. 
     As seen in  FIGS. 14-16 , the reverse stop mechanism  40  may include the reverse stop member  42  extending from an interior surface  62  of the bottom  60   a  of the housing  60 . Optionally, a spring  52  positioned about or adjacent the drive gear mechanism  28  may be included with the back driving clutch mechanism or reverse stop mechanism  40  or, alternatively, the spring  52  may be separate from the back driving clutch mechanism or reverse stop mechanism  40 . The stop member  42  of the reverse stop mechanism  40  may take on any shape or size and may be configured to engage the drive gear  30  or other rotational feature in any manner. In some cases, the reverse stop member  42  may be a single feature or a plurality of features extending from the interior surface  62  of the bottom  60   a  of the housing  60 . For example, the reverse stop member  42  may include two features extending from the interior surface  62  of the bottom  60   a  of the housing  60 , where at least one of the two features is configured to engage a stop member engaging portion  31  of the drive gear  30  such that a handle  34  is aligned with and/or positioned to fit within a handle opening  65  in the housing  60 . 
     In some cases, it may be possible to increase the strength of the reverse stop member  42  and reduce the stress thereon by increasing the number of reverse stop members  42  configured to engage the drive gear  30  or other features. At the same time, it is understood that having many reverse stop members  42  configured to engage the drive gear  30  or other features may result in shorter time periods for the drive gear  30  to engage the reverse stop member  42 . Thus, both increasing the strength of the reverse stop member  42  and lowering the amount of time of the time periods for the drive gear  30  to engage the reverse stop member  42  may be weighed when designing the reverse stop member  42 . 
     In addition to, or alternatively to, utilizing the back driving clutch mechanism  40  to lock the driven gear  26  in place and/or prevent the torsion spring  22  from unwinding, one or more other locking techniques or mechanisms may be utilized. For example, the driven gear  26  and/or torsion spring  22  may be locked in place through a button or lever mechanism that must be held to wind or unwind the spring  22 ; through a friction lock (e.g., with a gear system having a low gear ration); through any other locking mechanism; and/or any combination thereof. 
     As discussed, the damper blade position indicator  44  may be positioned adjacent an exterior of the housing  60 , at least partially (e.g., half way, substantially, etc.) within the housing  60 , and/or so as to be at least partially viewable from the exterior of the housing  60 , where the damper blade position indicator  44  may be configured to display a measure related to the current position of the damper blade  15  within the duct  2 . For example, the measure may include an axial position of the damper blade  15 , a distance of the damper blade  15  from the damper stop  16 , or any other measure related to the current position of the damper blade  15  within the duct  2 . In some instances, a damper blade position indicator arm  45  of the damper blade position indicator  44  may be connected to the shaft  18 , such that indicator arm  45  may move in response to movement of the shaft  18 . As desired, the damper blade position indicator arm  45  may be directly connected to the shaft  18  or may be indirectly connected to the shaft  18  through the shaft connector  19 , (as shown in  FIG. 13 ). 
     As discussed, the pressure level indicator  50  may be positioned adjacent an exterior of the housing  60  that at least partially encloses the torsion spring  22 , at least partially (e.g., half way, substantially, etc.) within the housing  60 , and/or so as to be at least partially viewable from exterior the housing  60 . The pressure level indicator  50  may be configured to display a measure related to the bias force provided from the torsion spring  22  to the shaft  18 , where the measure related to the bias force may include a pressure set point, pressure level, or force amount applied to the shaft  18  from the torsion spring  22 . In some instances, the pressure level indicator  50  may engage a spiral indicator mechanism  46  having a spiral groove  48  configured to rotate about the shaft  18  in response to movement of the driven gear  26 , where each rotation of the spiral indicator mechanism may equal a predetermined change in a crack pressure setting of the damper system  10 . In some instances, the spiral groove  48  may be configured on or integrally formed with driven gear  26  (as shown in  FIGS. 12 and 13 ). Through interacting with the spiral indicator mechanism  46  and/or a radially extending opening  63  in the housing  60 , the pressure level indicator arm  51  of the pressure level indicator  50  may engage the spiral groove  48  while being substantially rotationally fixed to travel linearly by opening  63 , which may result in radial movement of the pressure level indicator arm  51  in response to rotational movement of the spiral indicator mechanism  46 . 
     In addition, or alternatively, the pressure level indicator arm  51  may have a pivot at one end, a needle or other mechanism configured to engage the spiral grooves  48  of the spiral indicator mechanism  46  at another end, and a body extending there between. Such a configuration may facilitate at least partial radial movement of the pressure level indicator arm, in a manner similar to a needle arm of typical record players, in response to rotational movement of the spiral indicator mechanism  46 . In some instances, the pressure level indicator arm  51  may take on other configurations that may facilitate indicating a set crack pressure of the damper system  10 . 
     A handle mechanism of or for use with damper actuator  20  may include certain features already discussed above, along with other features, as desired. For example, the handle mechanism may include the drive gear mechanism  28  in communication with the driven gear  26  of the damper actuator  20 ; the handle  34  having a first surface (e.g., bottom surface)  36  and a generally opposing second surface (e.g., top surface)  38 , as best shown in  FIGS. 14-16 , configured to rotate the drive gear mechanism  28  about a drive gear rotation axis (e.g., the rotation axis may be a longitudinally extending axis D-D of the drive gear  30 ); the housing  60  at least partially enclosing the drive gear mechanism  28 ; and the spring  52  position about the drive gear mechanism  28  and configured to bias the drive gear mechanism  28  toward a first axial or locked position relative to the housing  60  and the reverse stop member  42 . 
     Illustratively, the handle  34  may be a flip over handle. A flip over handle may be a handle that is configured to flip over or hinge about a point or axis. As discussed, the drive gear mechanism  28  may include the drive gear arm  32  extending from the drive gear  30  and configured to engage the handle  34 . In some cases, the handle  34  may be configured to flip or hinge about or over the drive gear arm  32  between a first handle position (e.g., a closed position) and a second handle position (e.g., an opened position). The handle  34  may be configured in the first handle position when the first surface  36  of the handle  34  is adjacent the exterior surface  64  of the housing  60 , as shown in  FIG. 14 , and the handle  34  may be configured in the second handle position when the second surface  38  of the handle  34  is adjacent the exterior surface  64  of the housing, as shown in  FIGS. 15 and 16 . Further, when the handle  34  is in the first or closed position, the handle  34  may be locked in place with a snap fit, pressure fit, or other connection. For example, a handle extension  35  or other portion of handle  34  may have a snap connection or pressure fit connection with one or more walls of the handle opening  65  and/or other portion(s) of the housing  60  to facilitate preventing inadvertent movement of the handle  34 . The first position of the handle  34  may allow for storing of the handle  34  in a position that mitigates the likelihood of snagging insulation as it is brought over the damper actuator  20  during installation. 
     In some instances, in response to movement of the handle  34 , the drive gear arm  32  may be configured to effect axial movement of the drive gear  30  along the drive gear rotation axis or longitudinal axis D-D. For example, if a force (arrow F,  FIG. 16 ) (e.g., a light force) is applied to the first surface  36  of the handle  34  in the direction of housing  60  and contact area  66  when the handle  34  is in the second handle position, the handle may use the contact area  66  as a fulcrum or pivot and act on the drive gear mechanism  28  to move the drive gear mechanism  28  up from the first axial or locked position relative to the housing  60 , as shown in  FIGS. 14 and 15 , to a second axial or unlocked elevated position relative to the housing  60 , as shown in  FIG. 16 . Removing the force F from the first side  36  of the handle  34  may cause the spring to move or bias the drive gear mechanism  28  back to the lowered first axial position. Illustratively, the first axial position of the drive gear mechanism  28  is depicted in  FIGS. 14 and 15 , where the drive gear  30  of the drive gear mechanism  28  is in or near contact with the interior surface  62  of the housing  60  and stop member  42 . Further, the second axial position of the drive gear mechanism  28  is depicted in  FIG. 16 , where a bottom of the drive gear  30  of the drive gear mechanism  28  is positioned above stop member  42 , such that drive gear  30  may be disengaged from the reverse stop mechanism  40  and may rotate freely about its axis D-D. 
     In addition, or alternatively, to the handle  34  being configured to effect axial movement of the drive gear mechanism  28 , the handle  34  may be configured to effect rotational movement of the drive gear  30 . For example, when the drive gear mechanism  28  is in the unlocked or second axial position, the handle  34  may be rotated about the drive gear longitudinal or rotation axis D-D and that rotation may cause rotational movement of the drive gear arm  32  and the drive gear  30 . Such rotational movement of the drive gear  30  by the handle  34  may rotate the driven gear  26  to set the crack pressure for the damper system  10 . 
     In operation, the damper system  10  (e.g., a mechanical, electromechanical, electrical damper system, or other damper system) may be utilized to set a crack pressure (e.g., note, crack pressure may be the minimum amount of pressure within a duct  2  that triggers or actuates movement of the blade  15  within the duct  2 ) of a bypass duct  2  of an HVAC duct system. The crack pressure may be set by disengaging the drive gear mechanism  28  from the reverse stop mechanism  40  by opening up the flip over handle to an opened or second position and applying a force to the handle in the direction of housing  60  and the contact area  66 . Once the drive gear  30  of the drive gear mechanism  28  has been disengaged from the stop member  42  of the reverse stop mechanism  40 , the drive gear  30  of the drive gear mechanism  28  may be rotated by rotating the flip over handle  34  while the handle  34  is in the opened position in order to set the crack pressure. Once the crack pressure of the duct  2  (e.g., the bypass duct) has been set, the force applied to the handle may be released and the drive gear mechanism  28  may automatically mechanically lock in place by engaging the drive gear  30  with the reverse stop member  42  due, at least partially, to a bias force of the spring  52 . In some cases, once the crack pressure of the duct  2  has been set, the handle  34  may be flipped from the second handle position or opened position to the first handle position or closed position to further lock the drive gear mechanism  28  in its desired position. 
     The damper system  10  having a mechanical actuator  20  or other actuator may facilitate better control of static pressure rise than in systems with typical static pressure regulating dampers (SPRDs) due, at least partially, to the relatively precise and secure crack pressure adjustment capabilities of the damper system  10 . SPRDs typically include a weighted arm to bias the damper in the bypass duct in a particular position and the ability or opportunity to calibrate or adjust the position of the damper is limited. Use of such a damping system may lead to a large increase in pressure (measured in inches of water, “in we”) as a bypass flow (measured in cubic feet per minute, “cfm”) increases in volume. When pressure increases in HVAC duct systems, the result may be increased harmonic motions and noise levels in the ducts and such noise may be generally undesirable. Also, the load on the blower of the HVAC system may be increased, possibly shortening the life of the equipment. By replacing the weighted arm in an SPRD system with a low stiffness torsion spring  22  to form a constant pressure regulating damper (CPRD) that results in an increased resolution of the desired crack pressure, the pressure rise in the bypass duct due to an increased flow volume can be reduced or lowered with respect to the pressure rise as the volume of flow increases in a bypass duct having a SPRD system, as shown in the graph of  FIG. 18 . Also, the torsion spring  22  may provide a more linear bias force to the damper blade over the range of movement of the damper blade. This may facilitate keeping the differential pressure across the damper blade  15  in the duct  2  relatively flat (e.g., relatively constant) over a wide range of flow volume (e.g., an operating volume flow rate), as also shown in the graph of  FIG. 18 . 
     Typical operating volume flow rates may differ depending on the size or configuration of the duct  2 , the damper blade  15 , and/or other factors. A relatively flat differential pressure across the damper blade  15  over a wide range of volume flow rate may be generally depicted by a flat curve over an operating volume flow rate for a specific damper system. For example, a curve of a pressure differential across the damper blade  15  over an operating volume flow rate for a specific damper size may be considered flat when a change in differential pressure over the operating volume flow rate range does not exceed one or more particular thresholds (e.g., 0.1 inches of water, 0.2 inches of water, 0.4 inches of water). Example operating volume flow rate ranges include, but are not limited to, ranges of 100 cfm (e.g., a minimum operating volume flow rate) to 2,000 cfm (e.g., a maximum operating volume flow rate), 0 cfm to 2000 cfm, 0 cfm to 5000 cfm and other similar and dissimilar typical operating volume flow rate ranges. In some cases, the minimum or lower operating volume flow rate for a duct  2  or damper system  10  may generally be 0 cfm, 100 cfm, any volume flow rate therebetween, and/or any other volume flow rate less than the maximum or upper operating volume flow rate. The maximum or upper operating volume flow rate for a duct  2  or damper system  10  may be the volume flow rate that results when the average velocity of a fluid flowing through the duct  2  or system  10  is, for example, fifteen feet per second, twenty feet per second, twenty-five feet per second, thirty-five feet per second, forty feet per second, any average velocity in the range of fifteen feet per second to forty-five feet per second, any other average velocity of a fluid flowing through the duct  2  or damper system  10  that results in a volume flow rate greater than the minimum or lower operating volume flow rate. 
     In some instances, a curve of a pressure differential across the damper blade  15  may be flat if the change in pressure differential across the damper blade  15  over a sub-range of the operating volume flow rate does not exceed a particular threshold. Generally, the particular threshold may be determined so as to provide a damper system  10  causing fewer harmonic motions and lower noise levels than typical SPRD systems. For example, where a duct has an operating volume flow rate range of 100 cfm to 2000 cfm, which may be typical of residential ducts, a curve of the pressure differential across the damper blade  15  may be flat if the change in pressure differential across the damper blade  15  is less than a particular threshold (e.g., 0.1 inches of water, 0.2 inches of water, 0.3 inches of water, 0.4 inches of water) over a sub-range of at least 600 cfm in width (e.g., 0-600 cfm, 500-1100 cfm, 700-1500 cfm, 200-1800 cfm) of the operating volume flow rate range. 
     In addition to utilizing the torsion spring  22  to set the crack pressure for a bypass duct and thus, lowering the pressure rise in the bypass duct, the design of the damper blade  15  further reduces the pressure rise due to increased responsiveness of the damper blade  15  to an incoming flow. As discussed above, a portion (e.g., an outermost radius of the damper blade  15  or other portion of the damper blade  15 ) of the damper blade  15  may be tipped, bent, formed, or otherwise configured toward an incoming flow. This configuration of the damper blade  15  results in a damper blade  15  that is more responsive to an incoming flow because the air continues to contact the damper blade  15  at a substantially perpendicular angle as the damper blade  15  is opened. 
     Further, in some instances where an electrical or electromechanical damper actuator may be utilized instead of a mechanical damper actuator  20 , the standoff  70 , the clip connector  54 , the quick release  58  and other features of the damper system  10  may be utilized to facilitate affecting movement of the damper blade  15  in response to the electrical or electromechanical damper actuator interacting with and/or in communication with the damper shaft  18 . When an electrical or electromechanical damper actuator is utilized, the spirit of the disclosure may be realized by substituting at least a portion of the electrical or electromechanical damper actuator for the mechanical actuator  20 . 
     Those skilled in the art will recognize that the present disclosure may be manifested in a variety of forms other than the specific embodiments described and contemplated herein. Accordingly, departure in form and detail may be made without departing from the scope and spirit of the present disclosure as described in the appended claims.