BACKDRAFT DAMPER WITH ANGLED FRAME FOR TERMINAL UNIT

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a non-provisional of and claims the benefit of U.S. Provisional Patent Application No. 63/645,693, filed on May 10, 2024, the entire contents of which are incorporated herein by reference.

BACKGROUND

This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present techniques, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.

A heating, ventilation, and/or air conditioning (HVAC) system is often utilized to regulate environmental conditions, such as temperature and/or humidity, within a building or other conditioned space. For example, an HVAC system may include equipment, such as one or more heat exchangers deployed in an HVAC unit, which operates to produce a flow of supply air. To direct the supply air to a conditioned space, the HVAC system may include ductwork configured to direct the supply air from the HVAC unit to the conditioned space. In some applications, the HVAC system may include a terminal unit connected to an end of the ductwork. The terminal unit may discharge the supply air toward the conditioned space. Additionally, the terminal unit may be configured to receive a flow of plenum air, such as air within a plenum or space above a ceiling of the conditioned space. The terminal unit may also be desired to direct the plenum air flow to the conditioned space in order to recirculate air within the conditioned space. Unfortunately, existing terminal units are susceptible to various inefficiencies and operational inconveniences. For example, existing terminal units are susceptible to inefficient recirculation of air flow within the terminal unit.

SUMMARY

A summary of certain examples disclosed herein is set forth below. It should be noted that these aspects are presented merely to provide the reader with a brief summary of these certain examples and that these aspects are not intended to limit the scope of this disclosure. Indeed, this disclosure may encompass a variety of aspects that may not be set forth below.

In an example, a terminal unit for a heating, ventilation, and/or air conditioning (HVAC) system, comprises a collar where the collar includes a first collar frame wall defining a first opening and a second collar frame wall defining a second opening, wherein the second opening is positioned at an angle relative to the first opening. The terminal unit also includes a damper door, rotatably attached to the collar at a pivot, configured to abut the collar at the angle relative to the first opening to substantially cover the second opening in a closed position.

In some aspects, the techniques described herein relate to a terminal unit for a heating, ventilation, and/or air conditioning (HVAC) system, including: a housing including a base wall, a first chamber configured to receive a first air flow, and a second chamber configured to receive a second air flow; an internal wall disposed within the housing and extending between the first chamber and the second chamber, wherein the internal wall includes an opening formed therein, and wherein the second air flow selectively flows through the opening from the second chamber to the first chamber along an air flow path; and a damper door rotatable relative to the internal wall and configured to substantially prevent the first air flow from flowing through the opening from the first chamber to the second chamber in a closed position, the damper door positioned at an angle relative a vertical plane that is perpendicular to the base wall.

In some aspects, the techniques described herein relate to a terminal unit for a heating, ventilation, and/or air conditioning (HVAC) system, including: a housing including a first chamber configured to receive a first air flow and a second chamber configured to receive a second air flow; an internal wall disposed within the housing and extending between the first chamber and the second chamber, wherein the internal wall includes a first opening formed therein; a damper collar including a mounting surface configured to be coupled to the internal wall, a collar wall positioned at an angle relative to the internal wall, and a second opening extending through the damper collar, the second opening in fluid communication with the first opening; and a damper door rotatably attached to the damper collar and configured to abut the collar wall to substantially cover the second opening in a closed position.

In some aspects, the techniques described herein relate to a terminal unit for a heating, ventilation, and/or air conditioning (HVAC) system, including: a housing including a base wall, a first chamber configured to receive a first air flow, and a second chamber configured to receive a second air flow; an internal wall disposed within the housing and extending between the first chamber and the second chamber, wherein the internal wall is supported by the base wall at an oblique angle, and wherein the internal wall includes an opening formed therein; and a damper door rotatable relative to the internal wall and configured to substantially cover the opening in a closed position.

BRIEF DESCRIPTION OF THE DRAWINGS

Various aspects of this disclosure may be better understood upon reading the following detailed description and upon reference to the drawings in which:

FIG. 1 is a partial cross-sectional view of an example of a building that includes a heating, ventilating, and air conditioning (HVAC) system, in accordance with aspects of the present disclosure;

FIG. 2 is a schematic of an example of a portion of a building, illustrating air flow to a conditioned space via a terminal unit of an HVAC system, in accordance with aspects of the present disclosure;

FIG. 3 is a perspective view of an example of a terminal unit, in accordance with an aspect of the present disclosure;

FIG. 4 is an exploded perspective view of an example of a portion of a terminal unit, illustrating a backdraft damper assembly of the terminal unit, in accordance with an aspect of the present disclosure;

FIG. 5 is a side view of an example of a backdraft damper assembly of a terminal unit, in accordance with an aspect of the present disclosure;

FIG. 6 is a perspective view of another example of a terminal unit, in accordance with an aspect of the present disclosure; and

FIG. 7 is a side view of an example of a backdraft damper assembly of a terminal unit, in accordance with an aspect of the present disclosure.

DETAILED DESCRIPTION

One or more specific examples of the present disclosure will be described below. These described examples are only examples of the presently disclosed techniques. Additionally, in an effort to provide a concise description of these examples, all features of an actual implementation may not be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but may nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.

When introducing elements of various examples of the present disclosure, the articles “a,” “an,” and “the” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. Additionally, it should be understood that references to “one example” or “an example” of the present disclosure are not intended to be interpreted as excluding the existence of additional examples that also incorporate the recited features.

As used herein, the terms “approximately,” “generally,” and “substantially,” and so forth, are intended to convey that the property value being described may be within a relatively small range of the property value, as those of ordinary skill would understand. For example, when a property value is described as being “approximately” equal to (or, for example, “substantially similar” to) a given value, this is intended to mean that the property value may be within +/−5%, within +/−4%, within +/−3%, within +/−2%, within +/−1%, or even closer, of the given value. Similarly, when a given feature is described as being “substantially parallel” to another feature, “generally perpendicular” to another feature, and so forth, this is intended to mean that the given feature is within +/−5%, within +/−4%, within +/−3%, within +/−2%, within +/−1%, or even closer, to having the described nature, such as being parallel to another feature, being perpendicular to another feature, and so forth. Further, it should be understood that mathematical terms, such as “planar,” “slope,” “perpendicular,” “parallel,” and so forth are intended to encompass features of surfaces or elements as understood to one of ordinary skill in the relevant art, and should not be rigidly interpreted as might be understood in the mathematical arts. For example, a “planar” surface is intended to encompass a surface that is machined, molded, or otherwise formed to be substantially flat or smooth (within related tolerances) using techniques and tools available to one of ordinary skill in the art. Similarly, a surface having a “slope” is intended to encompass a surface that is machined, molded, or otherwise formed to be oriented at an angle (e.g., incline) with respect to a point of reference using techniques and tools available to one of ordinary skill in the art.

As will be discussed in further detail below, a heating, ventilation, and/or air conditioning (HVAC) system may include a terminal unit for delivering air to a conditioned space of a structure. In general, the terminal unit may be located near or within the conditioned space, and the terminal unit may be configured to receive one or more air flows for supply to the conditioned space. For example, the terminal unit may receive a first air flow (e.g., a primary air flow, a conditioned air flow) from an HVAC unit (e.g., air handler) via ductwork extending from the HVAC unit to the terminal unit. To this end, the terminal unit may include a first air inlet configured to receive the first air flow from the ductwork. The terminal unit may also be configured to receive a second air flow (e.g., a plenum air flow, a return air flow) via a plenum air inlet of the terminal unit. For example, the second air flow may be received from a plenum space, such as a space above a ceiling of the conditioned space, in which the terminal unit is disposed.

In some examples, the terminal unit may include a first chamber configured to receive the first air flow and to discharge the first air flow from the terminal unit. The terminal unit may also include a second chamber configured to receive the second air flow. In some examples, the terminal unit may be configured to direct the second air flow from the second chamber and into the first chamber to enable discharge of the second air flow toward the conditioned space from the first chamber. In some examples, the terminal unit may be configured to receive the first air flow, receive the second air flow, and direct the second air flow from the second chamber and into the first air flow within the first chamber to generate a mixed air flow that is discharged to the conditioned space.

The first chamber and the second chamber of the terminal unit may be generally divided by an internal wall disposed within a housing of the terminal unit. To enable flow of the second air flow from the second chamber into the first chamber, the terminal unit may include a damper (e.g., backdraft damper) coupled to the internal wall. That is, the internal wall may include an opening to fluidly couple the first chamber and the second chamber, and the damper may overlap with the opening to enable control of the second air flow from the second chamber into the first chamber. In some examples, the damper may also enable control of the first air flow from the first chamber into the second chamber. In particular, the damper may be configured to block flow of the first air flow from the first chamber into the second chamber.

In some examples, the terminal unit may include a blower configured to drive flow of air through the terminal unit. For example, the blower may be disposed within the second chamber and may be configured to force the second air flow from the second chamber and into the first chamber via the opening of the internal wall. As the blower forces the second air flow toward and through the opening, the second air flow may impinge against the damper and force the damper to transition toward an open position. In some circumstances, the blower may not be operated to force the second air flow through the terminal unit. In such instances, the damper may transition toward a closed position to at least partially block the opening in the internal wall. In this way, the damper may at least partially block flow of the first air flow from the first chamber and into the second chamber via the opening.

Unfortunately, existing dampers (e.g., backdraft dampers) in terminal units may rely upon a force of the first air flow directed through the first chamber to maintain the damper in a closed position to block flow of the first air flow into the second chamber. For example, existing backdraft dampers may include one or more protrusions (e.g., flanges) that extend outwardly from of a panel (e.g., body, door) of the damper and into a flow path of the first air flow. In some existing designs, a terminal unit may include a baffle configured to direct a portion of the first air flow toward the damper to bias the damper toward a closed position against the internal wall. In this way, the protrusions and/or baffle may harness the force of the first air flow to bias the backdraft damper toward the internal wall and in a closed position. However, traditional backdraft dampers including such features may generate acoustic energy (e.g., noise) as the first air flow contacts the protrusions, and the acoustic energy may manifest as undesirable noise and/or vibrations that are emitted from the terminal unit. Further, the protrusions of traditional backdraft dampers may create undesirable air flow resistance (e.g., a pressure drop) in the first air flow, thereby adversely affecting the discharge of air from the terminal unit and into the conditioned space. In some traditional backdraft dampers for terminal units, the backdraft damper may simply rely on the force of gravity to rest in a vertical position, whereby the backdraft damper may generally occlude the opening in the internal wall. However, as a speed of the first air flow through the first chamber increases, a pressure within the first chamber may decrease (e.g., relative to a pressure within the second chamber), thereby creating a pressure differential between the first chamber and the second chamber. In such instances, the pressure differential may urge traditional backdraft dampers toward an open position that enables undesirable flow (e.g., leakage) of the first air flow into the second chamber.

It is now recognized that improved backdraft dampers and related features may enable improved flow of air flows through a terminal unit. Accordingly, present examples are directed to backdraft damper assemblies that are configured to reduce undesired and/or unintended flow of air within and/or through the terminal unit. For example, the disclosed techniques enable a reduction in flow of air from the first chamber (e.g., primary air chamber) into the second chamber (e.g., plenum air chamber). As described in further detail below, the backdraft damper assembly may include a damper collar (e.g., damper frame) and a damper door. The damper collar may be coupled to an internal wall of the terminal unit and may generally extend about (e.g., surround) an opening formed in the internal wall. The damper door may be mechanically attached to an upper portion (e.g., side, edge, frame) of the damper collar, such as via a hinge, and the damper door may be configured to rotate or pivot (e.g., via the hinge) relative to the damper collar to enable and/or block air flow through the opening of the internal wall. The damper collar may be configured to harness (e.g., utilize) a force of gravity to bias or urge the damper door toward a closed position, such as during instances in which a blower of the terminal unit is not operating to force the second air flow (e.g., plenum air flow) into the first chamber. For example, the damper collar may have an angled or slanted geometry against which the damper door may rest via the force of gravity acting on the damper door, such as during non-operation of the blower. In this way, the damper door may rest against the damper collar in a closed position under the force of gravity, which may reduce flow of the first air flow from the first chamber and into the second chamber of the primary airflow into the plenum space, and the plenum airflow into the mixing chamber. Indeed, present examples enable improper operation of backdraft dampers to control flow of air through a terminal unit without use of protrusions, baffles, and/or other features that may otherwise impede flow of the first air flow through the terminal unit and/or generate undesirable air flow recirculation, acoustic energy, noise, vibrations, and so forth.

Turning now to the drawings, FIG. 1 illustrates an example of a heating, ventilation, and/or air conditioning (HVAC) system for environmental management that may employ one or more HVAC units. As used herein, an HVAC system includes any number of components configured to enable regulation of parameters related to climate characteristics, such as temperature, humidity, air flow, pressure, air quality, and so forth. For example, an “HVAC system” as used herein is defined as conventionally understood and as further described herein. Components or parts of an “HVAC system” may include, but are not limited to, all, some of, or individual parts such as a heat exchanger, a heater, an air flow control device, such as a fan, a sensor configured to detect a climate characteristic or operating parameter, a filter, a control device configured to regulate operation of an HVAC system component, a component configured to enable regulation of climate characteristics, or a combination thereof. An “HVAC system” is a system configured to provide such functions as heating, cooling, ventilation, dehumidification, pressurization, refrigeration, filtration, or any combination thereof. The examples described herein may be utilized in a variety of applications to control climate characteristics, such as residential, commercial, industrial, transportation, or other applications where climate control is desired.

In the illustrated example, a building 10 is air conditioned by a system that includes an HVAC unit 12. The building 10 may be a commercial structure or a residential structure. As shown, the HVAC unit 12 is disposed on the roof of the building 10. However, the HVAC unit 12 may be located in other equipment rooms or areas adjacent the building 10. The HVAC unit 12 may be a single packaged unit containing other equipment, such as a blower, heat exchangers, integrated air handler, and/or auxiliary heating unit. In other examples, the HVAC unit 12 may be part of a split HVAC system, which includes an outdoor HVAC unit and an indoor HVAC unit.

The HVAC unit 12 may be an air-cooled device that implements a refrigeration cycle to provide conditioned air to the building 10. Specifically, the HVAC unit 12 may include one or more heat exchangers across which an air flow is passed to condition the air flow before the air flow (e.g., primary air flow) is supplied to the building. In the illustrated example, the HVAC unit 12 is a rooftop unit (RTU) that conditions a supply air stream, such as environmental air and/or a return air flow drawn from the building 10. After the HVAC unit 12 conditions the air flow, the air flow, also referred to herein as a primary air flow, is supplied to the building 10 via ductwork 14 extending throughout the building 10 from the HVAC unit 12. For example, the ductwork 14 may extend to various individual floors or other sections of the building 10. In certain examples, the HVAC unit 12 may be a heat pump that provides both heating and cooling to the building with one refrigeration circuit configured to operate in different modes. In other examples, the HVAC unit 12 may include one or more refrigeration circuits for cooling an air flow and a furnace for heating the air flow. The primary air flow supplied to the building 10 by the HVAC unit 12 may include environmental air, such as air from outside the building 10, and/or recirculated air from within the building 10, which may or may not be actively and/or passively heated or cooled by the HVAC unit 12. For example, the HVAC unit 12 may operate in a recirculating or economizer mode, such that the supply air flow, and thus the primary air flow, is not actively heated or cooled in some operating modes.

A control device 16, one type of which may be a thermostat, may be used to designate a desired temperature of a conditioned space 18 within the building 10. The control device 16 also may be used to control the flow of air, such as volume, through the ductwork 14 to different areas within the conditioned space 18. For example, the control device 16 may be used to regulate operation of one or more components of the HVAC unit 12 or other components, such as dampers, fans, and/or terminal units 20 within the building 10 that may control the flow of air through and/or from the ductwork 14. In some examples, other devices may be included in the system, such as pressure and/or temperature transducers or switches that sense the temperatures and pressures of the conditioned air, return air, and so forth. Moreover, the control device 16 may include computer systems that are integrated with or separate from other building control or monitoring systems, including systems that are remote from the building 10.

As mentioned above, an HVAC system may include one or more terminal units 20 fluidly coupled to the ductwork 14 of the HVAC system. The terminal units 20 may each be configured to receive a first air flow, such as the primary air flow discharged by the HVAC unit 12, and may direct the first air flow into the conditioned space 18. In some examples, the terminal units 20 may also be configured to receive a second air flow, such as a plenum air flow or return air flow. To this end, the terminal units 20 may be disposed within and/or adjacent a plenum space 22 within the building 10. In some examples, the plenum space 22 may facilitate transfer of return air back to the HVAC unit 12. For example, the plenum space 22 may be above a dropped ceiling 24 that separates the plenum space 22 from the conditioned space 18. Moreover, in some examples, the terminal unit 20 may be implemented in the building 10 without the dropped ceiling 24, and the terminal units 20 may be configured to receive a plenum air flow or other air flow from a portion of air near a ceiling or another area of the conditioned space 18.

FIG. 2 is a schematic diagram of an example of a portion 26 of the building 10, illustrating an example of the terminal unit 20 implemented within the building 10. As discussed above, the terminal unit 20 may receive a first air flow 28 (e.g., a primary air flow), such as via the ductwork 14 extending from the HVAC unit 12. Accordingly, the first air flow 28 may be a conditioned air flow (e.g., a heated air flow, a cooled air flow, a dehumidified air flow) that is produced by the HVAC unit 12 or other HVAC system. The terminal unit 20 may also be configured to receive a second air flow 30, such as a plenum air flow from the plenum space 22 within the building 10. In the illustrated example, the terminal unit 20 includes a housing 50 defining a first air inlet 52 configured to receive the first air flow 28 and a second air inlet 54 configured to receive the second air flow 30. The terminal unit 20 may be configured to mix the first air flow 28 and the second air flow 30 within the housing 50 to generate a mixed air flow 56 (e.g., discharge air flow, supply air flow) that is then supplied to the conditioned space 18 via an air outlet 58 of the terminal unit 20 (e.g., the housing 50). In some implementations, the plenum space 22 may receive a return air flow 60, for example, drawn into the plenum space 22 via a vent 62, which may be formed in the dropped ceiling 24. In some examples, a portion of the return air flow 34 may be directed back to the HVAC unit 12 (e.g., via the ductwork 14) for conditioning. Additionally or alternatively, a portion of the return air flow 34 may be drawn into the housing 50 of the terminal unit 20, via the second air inlet 54, as the second air flow 30. The mixed air flow 56 may include a portion of the first air flow 28 and/or a portion of the second air flow 30 received by the terminal unit 20. That is, during some operations of the terminal unit 20, the mixed air flow 56 may include both the first air flow 28 and the second air flow 30, and in other operations the mixed air flow 56 may include one of the first air flow 28 or the second air flow 30 without the other of the first air flow 28 or the second air flow 30. To this end, the terminal unit 20 may include one or more valves, dampers, and/or other flow control device configured to regulate flow of air (e.g., first air flow 28, the second air flow 30) into and/or through the housing 50. For example, if the first air inlet 52 of the terminal unit 20 or the second air inlet 54 of the terminal unit 20 is closed (e.g., via a damper or valve), the mixed air flow 56 may include air from a single source. In other words, if the first air inlet 52 is closed, the terminal unit 20 may receive and supply the second air flow 30 alone to the conditioned space 18, and if the second air inlet 54 is closed, the terminal unit 20 may receive and supply the first air flow 28 alone to the conditioned space 18

As mentioned above, present examples are directed to systems and methods configured to enable improved control of air flow through the terminal unit 20. In particular, examples of the terminal unit 20 incorporating the present techniques may include a damper assembly 66 (e.g., backdraft damper assembly) configured to block undesired flow of air through the terminal unit 20. For example, the damper assembly 66 may be configured to block a flow (e.g., a backdraft) of the first air flow 28 through the terminal unit 20, such as toward the second air inlet 54. In this way, the present techniques may enable more efficient operation of the terminal unit 20 and/or the HVAC unit 12. For example, one or more fans or blowers of the terminal unit 20 and/or the HVAC unit 12 may be operated with reduced energy consumption due to more efficient flow of air through the terminal unit 20. Details of the damper assembly 66 are described further below.

FIG. 3 is a perspective view of a portion of an example of the terminal unit 20 including the damper assembly 66 and the control system 68. As mentioned above, the terminal unit 20 includes the housing 50 having a first end wall 50a, a second end wall 50b opposite the first end wall 50a, a first side wall 50c, a second side wall 50d opposite the first side wall 50c, a base wall 50e coupled to each of the walls 50a-50d, and a top wall (not shown) coupled to each of the walls 50a-50d and opposite the base wall 50e. In the illustrated example, the first air inlet 52 is positioned in the first end wall 50a and configured to receive the first air flow 28. In the illustrated example, the second air inlet 54 is positioned in the first end wall 50a and configured to receive the second air flow 30. In the illustrated example, the air outlet 58 is positioned in the second end wall 50b and configured to discharge the first air flow 28 and/or the second air flow 30 received by the terminal unit 20. In other examples, the first inlet 52, the second inlet 54, and the air outlet 58 may be positioned in other walls of the housing 50. Another example of the relative positions of the inlets 52, 54 and the outlet 58 is discussed below with respect to FIGS. 6-7. The housing 50 generally defines a first chamber 100 (e.g., first section, first volume) configured to receive the first air flow 28 via the first air inlet 52 and a second chamber 102 (e.g., second section, second volume) configured to receive the second air flow 30 via the second air inlet 54. In the illustrated example, the first chamber 100 generally extends from the first air inlet 52 to the air outlet 58 defined by the housing 50. In some examples, the terminal unit 20 may include an inlet valve 104 configured to enable flow of the first air flow 28 from the HVAC unit 12 to the terminal unit 20. The second air inlet 54 may be an opening formed in the housing 50 and may be exposed to the plenum space 22 within the building 10 to enable flow of the second air flow 30 from the plenum space 22 into the terminal unit 20 (e.g., the second chamber 102).

The first chamber 100 and the second chamber 102 within the housing 50 are generally divided (e.g., separated) by an internal wall 106 disposed within the housing 50. As shown, the internal wall 106 is supported by and coupled to the base wall 50e. The internal wall 106 extends between the first and second end walls 50a, 50b. In the illustrated example, the internal wall 106 is positioned at a substantially perpendicular angle relative to the base wall 50e. As described in further detail below with reference to FIG. 4, the internal wall 106 includes an opening 140 configured to enable fluid coupling of the first chamber 100 and the second chamber 102. In accordance with present techniques, the terminal unit 20 includes the damper assembly 66 (e.g., backdraft damper assembly) configured to enable improved control of air flow through the opening 140 and between the first chamber 100 and the second chamber 102. The damper assembly 66 is configured to couple to the internal wall 106, such that the damper assembly 66 generally overlaps with the opening 140 formed in the internal wall 106. In the illustrated example, the damper assembly 66 is coupled to the internal wall 106 and is disposed within the first chamber 100.

As described in further detail below, the damper assembly 66 of FIGS. 3-5 may include a damper collar 108 (e.g., damper frame, damper mount) that is attached (e.g., fixed) to the internal wall 106 and generally surrounds the opening 140 formed in the internal wall 106. As shown, the damper collar 108 thus defines an opening 109 extending therethrough that is configured to be in fluid communication with the opening 140 in the internal wall 106. The damper collar 108 may include a mounting flange 110 configured to mount the damper collar 108 to the internal wall 106 of the terminal unit 20. The mounting flange 110 may include mounting holes configured to receive fasteners, screws, or any other suitable attachment device to secure the damper collar 108 to the internal wall 106. Further, in other examples, the damper collar 108 may be affixed to the internal wall 106 of the terminal unit 20 via welding, adhesives, or any other suitable attachment mechanism. The damper assembly 66 may also include a damper door 112 (e.g., panel, cover) adjustably coupled to the damper collar 108. For example, the damper door 112 may be coupled to damper collar 108 via a hinge, a pivot joint, or other suitable connection configured to enable relative movement between the damper collar 108 and the damper door 112. In the illustrated example, the damper door 112 is shown in a closed position, whereby the damper door 112 overlaps with the openings 109, 140 formed in the damper collar 108 and the internal wall 106 to block air flow between the first chamber 100 and the second chamber 102.

As will be appreciated, it may be desirable to enable flow of the second air flow 30 (e.g., received via the second air inlet 54) from the second chamber 102 to the first chamber 100 to enable discharge of the second air flow 30 from the terminal unit 20 via the air outlet 58. To this end, the terminal unit 20 may include a blower 114 disposed within the second chamber 102. The blower 114 may operate to draw the second air flow 30 into the second chamber 102 via the second air inlet 54 and may force the second air flow 30 to flow toward the opening formed in the internal wall 106. In this way, the second air flow 30 may be directed into the first chamber 100 and may be discharged via the air outlet 58. The second air flow 30 driven by the blower 114 may impinge against the damper door 112 and force the damper door 112 to rotate or pivot at least partially into the first chamber 100. The second air flow 30 may then be directed into the first chamber 100 via the openings 109, 140 formed in the damper collar 108 and the internal wall 106.

As discussed in further detail below, the damper collar 108 may have a configuration to enable more reliable control of air flow through the terminal unit 20. In particular, the damper collar 108 may be configured to establish an improved sealing interface between the damper collar 108 and the damper door 112 in a closed position of the damper door 112. In some examples, the damper collar 108 may have an angled (e.g., inclined) configuration or geometry that enables the damper assembly 66 to harness a force of gravity and bias or urge the damper door 112 against the damper collar 108 in a closed position of the damper door 112. That is, via force of gravity, the damper door 112 may rest against the damper collar 108 to more completely seal (e.g., close, block) the openings 109, 140 formed in the damper collar 108 and the internal wall 106 and thereby more effectively block undesired flow of air between the first chamber 100 and the second chamber 102 during certain operations of the terminal unit 20. For example, during instances in which the blower 114 is not operating (e.g., when the terminal unit 20 receives and discharges the first air flow 28 and not the second air flow 30), the damper door 112 may rotate toward (e.g., via force of gravity) the damper collar 108. In accordance with present techniques, the damper collar 108 may include an angled (e.g., inclined, non-vertical) wall or surface configured to engage with the damper door 112 under the force of gravity. In this way, the damper door 112 may more reliably rest in a closed position against the damper collar 108 and create a sealing interface between the damper collar 108 and the damper door 112, thereby enabling improved blockage of air flow between the first chamber 100 and the second chamber 102. Moreover, with the damper door 112 abutting the damper collar 108 under the force of gravity, the damper door 112 may be more restricted from movement (e.g., relative to the damper collar 108) that may otherwise be induced, such as via a pressure differential between the first chamber 100 and the second chamber 102). As a result, undesired flow of the first air flow 28 from the first chamber 100 to the second chamber 102 (e.g., backflow of the first air flow 28) and/or undesired flow of the second air flow 30 into the first chamber 100 may be reduced, which may enable more efficient operation of the terminal unit 20. For example, a fan or blower of an HVAC unit (e.g., HVAC unit 12) associated with the terminal unit 20 may be operated with reduced energy usage due to more efficient flow of the first air flow 28 through the terminal unit 20.

FIG. 4 is an exploded perspective view of an example of the damper assembly 66 and the internal wall 106 of the terminal unit 20. As mentioned above, the internal wall 106 is configured to extend between the first chamber 100 and the second chamber 102 within the housing 50 of the terminal unit 20, and the internal wall 106 includes an opening 140 (e.g., aperture) configured to enable flow of air along an air flow path (e.g., a plenum air flow path) between the first chamber 100 and the second chamber 102. In accordance with present techniques, the terminal unit 20 includes the damper assembly 66 to enable improved control of air flow between the first chamber 100 and the second chamber 102 via the opening 140. More specifically, the damper assembly 66 is configured to enable improved regulation of flow of the second air flow 30 from the second chamber 102 into the first chamber 100 and to more effectively block flow of the first air flow 28 from the first chamber 100 into the second chamber 102 (e.g., backflow or backdraft of the first air flow 28).

As mentioned above, the damper assembly 66 includes the damper collar 108, which is configured to be mounted to the internal wall 106 (e.g., via the mounting flange 110), such that the damper collar 108 generally extends about (e.g., surrounds) the opening 140. In particular, the damper collar 108 may be coupled to a first side 142 of the internal wall 106 facing the first chamber 100 within the housing 50. The damper assembly 66 also includes the damper door 112, which is configured to adjustably couple to the damper collar 108. For example, the damper door 112 may couple to the damper collar 108 via a hinge joint 144 (e.g., a pin connection, pivot joint). The hinge joint 144 may be disposed at an upper or top end 146 of the damper assembly 66. Thus, the damper door 112 may be configured to pivot, rotate, or swing further into the first chamber 100, such as in response to a force applied to the damper door 112 by the second air flow 30 (e.g., via operation of the blower 114). In other examples, the damper door 112 may be pivotably coupled to the internal wall 106 (e.g., instead of the damper collar 108), as will be discussed in greater detail below with respect to FIGS. 6-7. The damper door 112 may have any suitable mass to enable a force of the second air flow 30 produced by the blower 114 to rotate or pivot at least partially away from the damper collar 108 and bias the damper door 112 toward an open position, thereby enabling flow of the second air flow 30 from the second chamber 102 into the first chamber 100 via the opening 140.

In a closed position, the damper door 112 may abut against the damper collar 108 and may generally block or occlude the openings 109, 140 to block air flow between the first chamber 100 and the second chamber 102. In some examples, the damper door 112 may be manufactured with certain dimensions that overlap and/or are greater than corresponding dimensions of damper collar 108. For example, the damper door 112 may include a main body 148 (e.g., main panel) and side flanges 150 extending from the main body 148. In a closed position of the damper door 112, the side flanges 150 may overlap with and/or extend along lateral sides 152 (e.g., side surfaces, lateral surfaces, side walls) of the damper collar 108 to more fully occlude the opening 140 and block air flow through the opening 140 (e.g., via a space or gap between the damper door 112 and the damper collar 108. Moreover, when the damper door 112 is in the closed position against the damper collar 108, movement of the damper door 112, such as in a lateral direction (e.g., along an axis 154) may be restricted via the overlap between the side flanges 150 and the lateral sides 152.

In some examples, the damper assembly 66 may include a gasket (e.g., a seal) 156 positioned on or against the damper collar 108, such as along an outlet face 158 or surface of an outlet collar wall of the damper collar 108 that generally faces the damper door 112. The gasket 156 may be configured to create a seal between the damper door 112 and the damper collar 108 in a closed position of the damper assembly 66. In this way, undesired flow of the first air flow 28 from the first chamber 100 to the second chamber 102, as well as undesired flow of the second air flow 30 from the second chamber 102 to the first chamber 100 may be blocked. The gasket 156 may have a similar geometry as the outlet face 158 to enable the gasket 156 to extend along a substantial portion and/or an entirety of the outlet face 158. The gasket 156 may be made of any suitable material, such as rubber, cork, silicone, a polymer, foam, and so forth.

In accordance with present techniques, the damper collar 108 may include a geometry or configuration configured to enable improved sealing between the damper collar 108 and the damper door 112 in a closed position of the damper door 112. In particular, the outlet face 158 of the damper collar 108 may be disposed at an angle (e.g., acute angle, oblique angle) relative to the internal wall 106. As will be appreciated, in an assembled and/or installed configuration of the terminal unit 20, the internal wall 106 may extend in a generally vertical direction (e.g., aligned along a vertical axis 160). The damper collar 108 may be attached to the internal wall 106, and the outlet face 158 of the outlet collar wall may extend at an angle 200 relative to the internal wall 106. More specifically, a first surface of the internal wall 106 to which the damper collar 108 is coupled defines a vertical plane P that is perpendicular to the base wall 50e. The outlet face 158 may extend at the angle 200 relative to the vertical plane P. In some examples, the outlet face 158 may extend at an angle 200 relative to an orientation (e.g., along the vertical axis 160) of one or more of the mounting flanges 110 of the damper collar 108. In a closed position, the damper door 112 may rest against the outlet face 158 of the damper collar 108, such that the damper door 112 is disposed at the angle 200 relative to the internal wall 106 and the vertical plane P thereof. Indeed, a force of gravity acting on the damper door 112 may at least partially bias the damper door 112 against the outlet face 158 of the damper collar 108. In this way, the force of gravity may be harnessed by the damper assembly 66 and may be utilized to provide an improved sealing engagement between the damper door 112 and the damper collar 108, such as during non-operation of the blower 114.

FIG. 5 is a side view of an example of the damper assembly 66 and the internal wall 106 of the terminal unit 20 in an assembled configuration. As mentioned above, the damper collar 108 may have a configuration that enables an improved sealing engagement between the damper collar 108 and the damper door 112 in a closed position of the damper door 112. In particular, the outlet face 158 of the outlet collar wall of the damper collar 108 may be disposed at an angle 200 relative to a base surface (e.g., mounting surface) of an outlet collar wall. For example, the base surface 202 may be at least partially defined by one or more mounting flanges 110 of the damper collar 108. In the assembled configuration, the base surface 202 may extend generally along the internal wall 106 of the terminal unit 20 and/or along the vertical axis 160. As shown, the opening 109 of the damper collar 108 extends therethrough. Due to the angle 200 between the outlet collar wall and the internal wall 106, when the blower 114 is operating, the second air flow 30 is guided from the second chamber 102 to the first chamber 100 through the openings 109, 140 along the air flow path 204, at least a portion of which is oriented at an angle relative to the base wall 50e. in the illustrated example, the angle of the air flow path 204 is non-parallel or oblique relative to the base wall 50e.

A magnitude of the angle 200 may be selected based on any suitable design parameters, such as a desired tangential gravitational force acting upon the damper door 112. The damper collar 108 may be manufactured to include the angle 200 defined by the outlet face 158 and the base surface 202 at a desired magnitude by, for example, adjusting a taper or geometry of the lateral sides 152 (e.g., side surfaces, lateral surfaces) of the damper collar 108 extending between the base surface 202 and the outlet face 158. In some examples, a material utilized to manufacture the damper door 112 may be selected to achieve a desired tangential gravitational force acting upon the damper door 112. During operation of the terminal unit 20, force of gravity may act on the damper door 112 and, in some instances, may cause the damper door 112 to rest against the outlet face 158 (e.g., angled surface). Indeed, during non-operation of the blower 114, the force of gravity may cause the damper door 112 to be at least partially biased against the outlet face 158 of the damper collar 108 to establish an improved sealing interface between the damper door 112 and the damper collar 108. A magnitude of the angle 200 may additionally or alternatively be selected based on a desired resistance provided by the damper door 112 against the second air flow 30. In some examples, the angle 200 may be between approximately 0.5 degrees and 10 degrees (e.g., 0.5 degree, 1 degree, 2 degrees, 3 degrees, 4 degrees, 5 degrees, 6 degrees, 7 degrees, 8 degrees, 9 degrees, 10 degrees). The magnitude of the angle 200 may be any suitable value that enables flow of the second air flow 30 to flow, such as via operation of the blower 114, from the second chamber 102 to the first chamber 100 while substantially blocking flow of air (e.g., first air flow 28, second air flow 30) through the opening 140 during non-operation of the blower 114.

As mentioned above, the damper door 112 may include side flanges 150, extending from sides of the main body 148 of the damper door 112. The side flanges 150 may be configured to overlap with the lateral sides 152 of the damper collar 108. For example, the damper door 112 may have a width greater than a width of the damper collar 108. The side flanges 150 may extend from the main body 148 in a direction toward the damper collar 108, such that the side flanges 150 may at least partially extend along and/or overlap with the lateral sides 152 of the damper collar 108 in a closed configuration of the damper door 112. In this way, the side flanges 150 may further facilitate blockage of air flow (e.g., first air flow 28, second air flow 30) through the opening 140 during certain operations of the terminal unit 20.

FIGS. 6-7 illustrate another example form the terminal unit 20′ that is similar to the terminal unit 20 of FIGS. 3-5. Therefore, like structure is identified with like reference numerals and only the differences discussed herein. As an initial matter, the example of FIGS. 6-7 illustrates that the second air inlet 54 can be positioned in the second side wall 50d. As shown in FIGS. 6-7, the internal wall 106 is positioned at an angle 206 relative to the base wall 50e. The internal wall 106 is angled toward the second chamber 102 and away from the first chamber 100. That is, as shown, a first surface of the internal wall 106 facing the first chamber 100 and a second surface of the internal wall 106 facing the second chamber 102 are parallel to one another and are both oriented at the angle 206. Moreover, the second surface is closer to the base wall 50e than the first surface. The angle 206 is an acute angle between the second surface and the base wall 50e. A magnitude of the angle 206 may be selected based on any suitable design parameters, such as a desired tangential gravitational force acting upon the damper door 112.

Moreover, in the illustrate example, the damper door 112 is directly coupled to the internal wall 106 (e.g., the first surface thereof) and overlaps the opening 140. In the illustrated example, a blower deck 208 is coupled to the blower and makes up a portion of the internal wall 106. The blower deck 208 defines the opening 140 of the internal wall 106. As shown, the damper door 112 is coupled to the blower deck 208 to overlap the opening 140 of the internal wall 106. In another example, a modified damper collar 108, similar to the damper collar 108 discussed above, may be coupled to the first surface of the internal wall 106. In such case, the outlet collar wall and the internal wall 106 of the modified damper collar 108 would be parallel to one another, rather than positioned the angle 200. Regardless of whether the modified damper collar is used or not, in the example of FIGS. 67, due to the angle 206 between internal wall 106 and the base wall 50e, the damper door 112 is positioned at the angle 200 relative to a vertical plane P that is perpendicular to the base wall 50e. Accordingly, the second air flow 30 is guided from the second chamber 102 to the first chamber 100 through the opening 140 (and opening 109 if the modified damper collar 108 is included) along the air flow path 204, at least a portion of which is oriented at the angle relative to the base wall 50e. A gasket 156 (not shown in FIGS. 6-7) may surround all or a portion of the perimeter of the opening 140 to create a seal when the door 112 is in the closed position, as discussed above.

During operation of the terminal unit 20, force of gravity may act on the damper door 112 and, in some instances, may cause the damper door 112 to rest against the first surface of the angled internal wall 106 (or the outlet face 158 of the modified damper collar 108). Indeed, during non-operation of the blower 114, the force of gravity may cause the damper door 112 to be at least partially biased against the first surface of the internal wall 106 (or the outlet face 158 of the modified damper collar 108) to establish an improved sealing interface between the damper door 112 and the internal wall 106 (or the modified damper collar 108). A magnitude of the angle 206 may additional or alternatively be selected based on a desired resistance provided by the damper door 112 against the second air flow 30. In some examples, the angle 206 may be between approximately 80 degrees and 89.5 degrees (e.g., 80 degrees, 81 degrees, 82 degrees, 83 degrees, 84 degrees, 85 degrees, 86 degrees, 87 degrees, 88 degrees, 89 degrees, 89.5 degrees). The magnitude of the angle 206 may be any suitable value that enables flow of the second air flow 30 to flow, such as via operation of the blower 114, from the second chamber 102 to the first chamber 100 while substantially blocking flow of air (e.g., first air flow 28, second air flow 30) through the opening 140 during non-operation of the blower 114.

The specific examples described above have been shown by way of example, and it should be understood that these examples may be susceptible to various modifications and alternative forms. It should be further understood that the claims are not intended to be limited to the particular forms disclosed, but rather to cover all modifications, equivalents, and alternatives falling within the spirit and scope of this disclosure.