This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure, which are described 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.
HVAC systems are utilized in residential, commercial, and industrial environments to control environmental properties, such as temperature and humidity, for occupants of the respective environments. The HVAC system may control the environmental properties through the control of an airflow delivered to the conditioned environment. For example, a rooftop unit (RTU) of an HVAC system may include a heater, such as an electric heater, configured to heat an airflow delivered to the conditioned environment. In traditional embodiments, certain traditional heaters may be incompatible with the RTU based on a discharge configuration of the RTU. Facilitating compatibility between traditional heaters and RTUs having various discharge configurations may increase a part cost, and may cause expensive and complicated installation processes.
A summary of certain embodiments disclosed herein is set forth below. It should be understood that these aspects are presented merely to provide the reader with a brief summary of these certain embodiments 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.
The present disclosure relates to a heating, ventilation, and/or air conditioning (HVAC) unit. The HVAC unit includes a heater housing having a first side wall, a second side wall opposing the first side wall, and a ceiling extending between the first side wall and second side wall. The HVAC unit also includes a first mounting rail disposed across the first side wall at a first distance from the ceiling, and a second mounting rail disposed across the second side wall at a second distance from the ceiling. The first distance is greater than the second distance. The HVAC unit also includes a heating element assembly coupled to the first and second mounting rails and having a planar heating interface extending from the first mounting rail to the second mounting rail.
The present disclosure also relates to a heating, ventilation, and/or air conditioning (HVAC) unit. The HVAC unit includes an electric heater housing having a side wall, an opposing side wall, and a ceiling extending between the side wall and the opposing side wall. The HVAC unit also includes an electric heater disposed in the electric heater housing and having a planar heating interface formed by a heating element of the electric heater, wherein the planar heating interface extends between the side wall and the opposing side wall and forms an oblique angle relative to the side wall.
The present disclosure also relates to an electric heater for a heating, ventilation, and/or air conditioning (HVAC) unit. The electric heater includes a first mounting rail configured to be mounted on a first side wall of an electric heater housing of the HVAC unit, and a second mounting rail configured to be mounted on a second side wall of the electric heater housing. The electric heater also includes a heating element assembly coupled to the first mounting rail and the second mounting rail and having a planar heating interface formed by a heating element of the heating element assembly, wherein the planar heating interface is configured to form an oblique angle with the first side wall and the second side wall of the HVAC unit.
One or more specific embodiments of the present disclosure will be described below. In an effort to provide a concise description of these embodiments, 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 would 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 embodiments of the present disclosure, the articles “a,” “an,” “the,” and “said” 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. Any examples of operating parameters and/or environmental conditions are not exclusive of other parameters/conditions of the disclosed embodiments.
The present disclosure is directed toward a heater of a unit, such as a rooftop unit (RTU), of a heating, ventilation, and/or air conditioning (HVAC) system. As mentioned above, HVAC systems are utilized in residential, commercial, and industrial environments to control environmental properties, such as temperature and humidity, for occupants of the respective environments. The HVAC system may control the environmental properties through the control of an airflow delivered to the conditioned environment. For example, an RTU of the HVAC system may include a heater configured to heat an airflow delivered to the conditioned environment. Facilitating compatibility between traditional heaters and HVAC units having various discharge configurations may increase a part cost, and may cause expensive and complicated installation processes.
For example, HVAC units, such as RTUs, may be configured for bottom discharge, whereby a duct receives a conditioned airflow, such as a heated airflow, from the HVAC unit through a bottom air output opening of the HVAC unit, or for side discharge, whereby the duct receives the conditioned airflow, such as the heated airflow, through a side air output opening of the HVAC unit. The bottom air output opening may refer to, for example, an opening formed in a bottom of the HVAC unit extending substantially perpendicular to gravity, whereas the side air output opening may refer to, for example, an opening formed in a side wall of the HVAC unit extending substantially parallel to gravity. In traditional embodiments, separate traditional heaters may be employed for bottom discharge unit configurations and for side discharge unit configurations. That is, for a bottom discharge HVAC unit, a first traditional heater may be installed in a heater housing of the HVAC unit, and for a side discharge HVAC unit, a second traditional heater different than the first traditional heater may be installed in the heater housing of the HVAC unit. The first traditional heater, configured for bottom discharge, may be incompatible with HVAC units configured for side discharge, and the second traditional heater, configured for side discharge, may be incompatible with HVAC units configured for bottom discharge. Alternatively, the first traditional heater, configured for bottom discharge, may operate at substantially reduced efficiency if installed in an HVAC unit configured for side discharge, and the second traditional heater, configured for side discharge, may operate at significantly reduced efficiency when installed in an HVAC unit configured for bottom discharge.
In accordance with the present disclosure, a heater may be configured for compatibility with both a bottom discharge HVAC unit and a side discharge HVAC unit. For example, the HVAC unit may include an air input opening, or multiple air input openings, to the heater housing of the HVAC unit. The air input openings may be formed, for example, in a side wall of the heater housing, whether the HVAC unit is configured for bottom discharge or side discharge. Blowers of the HVAC unit, which may correspond in number to the air input openings, may be disposed outside of the heater housing and may be configured to blow or induce airflows through the air input openings in the side wall of the heater housing. The heater, which is disposed within the heater housing of the HVAC unit, may include heating elements configured to receive the airflows passing through the air input openings from the blowers. The heating elements may correspond in number to the air input openings and the blowers. In accordance with present embodiments, the heating elements may form a planar heating interface extending at an oblique angle relative to the side wall having the air input openings, and relative to a direction of the airflows received from the air input openings. For example, in one embodiment, the planar heating interface may extend at a 45 degree angle relative to the side wall in which the air input openings are formed. The angle of the planar heating interface may be within a range of 20-70 degrees relative to the side wall. As used herein, the term “planar” refers to a geometry that is generally flat without pronounced bends, curves, or other undulations, but also not necessarily constrained by a mathematical or Euclidean plane.
The airflows may pass over the planar heating interface, through the heating elements, and into a hot air cavity of the heater housing of the HVAC unit. The hot air received in the hot air cavity of the heater housing may be guided through a bottom discharge air output opening or a side discharge air output opening, depending on whether the HVAC unit is configured for bottom discharge or for side discharge. Further, the heater may include a mounting rail assembly configured to install the heater in the heater housing of the HVAC unit at the above-described angle. For example, the heater housing includes the side wall having the air input openings formed therein and an opposing side wall. The heater is configured to be installed between the side wall and the opposing side wall. A ceiling of the heater housing may extend between the side wall and the opposing side wall, and over the heater. A first mounting rail of the heater may be disposed along the side wall at a first distance from the ceiling, and a second mounting rail of the heater may be disposed along the opposing side wall at a second distance from the ceiling, where the first distance is greater than the second distance. The heater may be mounted on the first and second mounting rails, such that the planar heating interface forms the above-described oblique angle relative to the side wall having the air input openings.
Further, since the first mounting rail is disposed a greater distance from the ceiling than the second mounting rail, the first mounting rail can be disposed along the side wall underneath the air input openings formed in the side wall, with the planar heating interface extending at an upwards, oblique angle toward the second mounting rail disposed on the opposing side wall. The airflows may be blown or induced through the air input openings in the side wall, over the angled, planar heating interface, through the heating elements, and into the hot air cavity of the heater housing, which is fluidly coupled to either a bottom discharge air output opening or a side discharge air output opening of the HVAC unit, depending on the embodiment. By configuring the heater for compatibility and efficient operation with both bottom and side discharge HVAC units, installation techniques may be simplified, and a part cost for producing compatible and efficient heaters for HVAC units may be reduced. These and other features are described in detail below with reference to the drawings.
Further, the discussion below describes embodiments in accordance with the present techniques in the context of rooftop units (RTUs) having bottom and/or side discharge configurations, electric heaters, and electric heater housings. However, it should be appreciated that the disclosed techniques may be utilized with other types of HVAC units, such as air handling units, and other types of heaters.
Turning now to the drawings,
In the illustrated embodiment, 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 package unit containing other equipment, such as a blower, integrated air handler, and/or auxiliary heating unit. In other embodiments, the HVAC unit 12 may be part of a split HVAC system, such as the system shown in
The HVAC unit 12 is 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 airflow is passed to condition the airflow before the airflow is supplied to the building. In the illustrated embodiment, the HVAC unit 12 is a rooftop unit (RTU) that conditions a supply air stream, such as environmental air and/or a return airflow from the building 10. After the HVAC unit 12 conditions the air, the air 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 embodiments, 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 embodiments, the HVAC unit 12 may include one or more refrigeration circuits for cooling an air stream and a furnace for heating the air stream.
A control device 16, one type of which may be a thermostat, may be used to designate the temperature of the conditioned air. The control device 16 also may be used to control the flow of air through the ductwork 14. 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 and fans, within the building 10 that may control flow of air through and/or from the ductwork 14. In some embodiments, 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 supply 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, and even systems that are remote from the building 10.
As shown in the illustrated embodiment of
The HVAC unit 12 includes heat exchangers 28 and 30 in fluid communication with one or more refrigeration circuits. Tubes within the heat exchangers 28 and 30 may circulate refrigerant, such as R-410A, through the heat exchangers 28 and 30. The tubes may be of various types, such as multichannel tubes, conventional copper or aluminum tubing, and so forth. Together, the heat exchangers 28 and 30 may implement a thermal cycle in which the refrigerant undergoes phase changes and/or temperature changes as it flows through the heat exchangers 28 and 30 to produce heated and/or cooled air. For example, the heat exchanger 28 may function as a condenser where heat is released from the refrigerant to ambient air, and the heat exchanger 30 may function as an evaporator where the refrigerant absorbs heat to cool an air stream. In other embodiments, the HVAC unit 12 may operate in a heat pump mode where the roles of the heat exchangers 28 and 30 may be reversed. That is, the heat exchanger 28 may function as an evaporator and the heat exchanger 30 may function as a condenser. In further embodiments, the HVAC unit 12 may include a furnace for heating the air stream that is supplied to the building 10. While the illustrated embodiment of
The heat exchanger 30 is located within a compartment 31 that separates the heat exchanger 30 from the heat exchanger 28. Fans 32 draw air from the environment through the heat exchanger 28. Air may be heated and/or cooled as the airflows through the heat exchanger 28 before being released back to the environment surrounding the HVAC unit 12. A blower assembly 34, powered by a motor 36, draws air through the heat exchanger 30 to heat or cool the air. The heated or cooled air may be directed to the building 10 by the ductwork 14, which may be connected to the HVAC unit 12. Before flowing through the heat exchanger 30, the conditioned air flows through one or more filters 38 that may remove particulates and contaminants from the air. In certain embodiments, the filters 38 may be disposed on the air intake side of the heat exchanger 30 to prevent contaminants from contacting the heat exchanger 30.
The HVAC unit 12 also may include other equipment for implementing the thermal cycle. Compressors 42 increase the pressure and temperature of the refrigerant before the refrigerant enters the heat exchanger 28. The compressors 42 may be any suitable type of compressors, such as scroll compressors, rotary compressors, screw compressors, or reciprocating compressors. In some embodiments, the compressors 42 may include a pair of hermetic direct drive compressors arranged in a dual stage configuration 44. However, in other embodiments, any number of the compressors 42 may be provided to achieve various stages of heating and/or cooling. As may be appreciated, additional equipment and devices may be included in the HVAC unit 12, such as a solid-core filter drier, a drain pan, a disconnect switch, an economizer, pressure switches, phase monitors, and humidity sensors, among other things.
The HVAC unit 12 may receive power through a terminal block 46. For example, a high voltage power source may be connected to the terminal block 46 to power the equipment. The operation of the HVAC unit 12 may be governed or regulated by a control board 48. The control board 48 may include control circuitry connected to a thermostat, sensors, and alarms. One or more of these components may be referred to herein separately or collectively as the control device 16. The control circuitry may be configured to control operation of the equipment, provide alarms, and monitor safety switches. Wiring 49 may connect the control board 48 and the terminal block 46 to the equipment of the HVAC unit 12.
When the system shown in
The outdoor unit 58 draws environmental air through the heat exchanger 60 using a fan 64 and expels the air above the outdoor unit 58. When operating as an air conditioner, the air is heated by the heat exchanger 60 within the outdoor unit 58 and exits the unit at a temperature higher than it entered. The indoor unit 56 includes a blower or fan 66 that directs air through or across the indoor heat exchanger 62, where the air is cooled when the system is operating in air conditioning mode. Thereafter, the air is passed through ductwork 68 that directs the air to the residence 52. The overall system operates to maintain a desired temperature as set by a system controller. When the temperature sensed inside the residence 52 is higher than the set point on the thermostat, or a set point plus a small amount, the residential heating and cooling system 50 may become operative to refrigerate additional air for circulation through the residence 52. When the temperature reaches the set point, or a set point minus a small amount, the residential heating and cooling system 50 may stop the refrigeration cycle temporarily.
The residential heating and cooling system 50 may also operate as a heat pump. When operating as a heat pump, the roles of heat exchangers 60 and 62 are reversed. That is, the heat exchanger 60 of the outdoor unit 58 will serve as an evaporator to evaporate refrigerant and thereby cool air entering the outdoor unit 58 as the air passes over the outdoor heat exchanger 60. The indoor heat exchanger 62 will receive a stream of air blown over it and will heat the air by condensing the refrigerant.
In some embodiments, the indoor unit 56 may include a furnace system 70. For example, the indoor unit 56 may include the furnace system 70 when the residential heating and cooling system 50 is not configured to operate as a heat pump. The furnace system 70 may include a burner assembly and heat exchanger, among other components, inside the indoor unit 56. Fuel is provided to the burner assembly of the furnace system 70 where it is mixed with air and combusted to form combustion products. The combustion products may pass through tubes or piping in a heat exchanger, separate from heat exchanger 62, such that air directed by the blower 66 passes over the tubes or pipes and extracts heat from the combustion products. The heated air may then be routed from the furnace system 70 to the ductwork 68 for heating the residence 52.
In some embodiments, the vapor compression system 72 may use one or more of a variable speed drive (VSDs) 92, a motor 94, the compressor 74, the condenser 76, the expansion valve or device 78, and/or the evaporator 80. The motor 94 may drive the compressor 74 and may be powered by the variable speed drive (VSD) 92. The VSD 92 receives alternating current (AC) power having a particular fixed line voltage and fixed line frequency from an AC power source, and provides power having a variable voltage and frequency to the motor 94. In other embodiments, the motor 94 may be powered directly from an AC or direct current (DC) power source. The motor 94 may include any type of electric motor that can be powered by a VSD or directly from an AC or DC power source, such as a switched reluctance motor, an induction motor, an electronically commutated permanent magnet motor, or another suitable motor.
The compressor 74 compresses a refrigerant vapor and delivers the vapor to the condenser 76 through a discharge passage. In some embodiments, the compressor 74 may be a centrifugal compressor. The refrigerant vapor delivered by the compressor 74 to the condenser 76 may transfer heat to a fluid passing across the condenser 76, such as ambient or environmental air 96. The refrigerant vapor may condense to a refrigerant liquid in the condenser 76 as a result of thermal heat transfer with the environmental air 96. The liquid refrigerant from the condenser 76 may flow through the expansion device 78 to the evaporator 80.
The liquid refrigerant delivered to the evaporator 80 may absorb heat from another air stream, such as a supply air stream 98 provided to the building 10 or the residence 52. For example, the supply air stream 98 may include ambient or environmental air, return air from a building, or a combination of the two. The liquid refrigerant in the evaporator 80 may undergo a phase change from the liquid refrigerant to a refrigerant vapor. In this manner, the evaporator 80 may reduce the temperature of the supply air stream 98 via thermal heat transfer with the refrigerant. Thereafter, the vapor refrigerant exits the evaporator 80 and returns to the compressor 74 by a suction line to complete the cycle.
In some embodiments, the vapor compression system 72 may further include a reheat coil in addition to the evaporator 80. For example, the reheat coil may be positioned downstream of the evaporator relative to the supply air stream 98 and may reheat the supply air stream 98 when the supply air stream 98 is overcooled to remove humidity from the supply air stream 98 before the supply air stream 98 is directed to the building 10 or the residence 52.
It should be appreciated that any of the features described herein may be incorporated with the HVAC unit 12, the residential heating and cooling system 50, or other HVAC systems. Additionally, while the features disclosed herein are described in the context of embodiments that directly heat and cool a supply air stream provided to a building or other load, embodiments of the present disclosure may be applicable to other HVAC systems as well. For example, the features described herein may be applied to mechanical cooling systems, free cooling systems, chiller systems, or other heat pump or refrigeration applications.
As set forth above, embodiments of the present disclosure are directed toward a heater, such as an electric heater, configured for use in both a bottom discharge HVAC unit and a side discharge HVAC unit. That is, the heater can be installed in, and efficiently operated with, an HVAC unit configured for bottom discharge and an HVAC unit configured for side discharge. In doing so, manufacturing, installation, and part cost may be reduced, and installation techniques may be simplified. Aspects of the heater that enable the described compatibility effects and efficient operation include an angle of heating surfaces, such as electric heating elements, employed by the heater, mounting rail features of the heater, airflow partitions of the heater, a midsection or divider between heating surfaces of the heater, and other aspects described in detail below.
In
In
Focusing on
The lower mounting rail 112 and the upper mounting rail 114 of the electric heater 100 in
The lower mounting rail 112 may be mounted to the side wall 130 of the electric heater housing 101 at a first distance 160 from the ceiling 134 of the electric heater housing 101, and the upper mounting rail 114 may be mounted to the opposing side wall 132 of the electric heater housing 101 at a second distance 162 from the ceiling 134 of the electric heater housing 101. The first distance 160 is greater than the second distance 162, in the illustrated embodiment. Accordingly, the heating elements 102, which extend between the lower and upper mounting rails 112, 114, are disposed at an oblique angle relative to the side wall 130 and the opposing side wall 132. For example, the heating elements 102 individually and/or collectively form a planar heating interface disposed at the oblique angle. The heating elements 102 are also disposed at an oblique angle relative to the airflows directed through the airflow inlets 150 in the side wall 130 of the electric heater housing 101. By angling the heating elements 102, a surface area of the heating elements 102 may be increased relative to embodiments having heaters arranged in a perpendicular or parallel configuration relative to the side wall 130. Further, the angled configuration of the heating elements 102 may enable a reduction in back pressure on the airflows and corresponding airflow biasing devices, such as blowers.
To further illustrate the angled configuration of the heating element assembly 105,
It should be noted that the planar heating interface 182 may refer to an interface generally formed at least in part by, for example, glass-enveloped wires or wire coils electrically connected to the control box described with respect to previous drawings, where each heating element 102 may include several iterations of the glass-enveloped wires or wire coils forming the planar heating interface 182. That is, “planar heating interface” should be understood to refer to a plane extending across the two previously described heating elements 102 and the midsection 104, as opposed to necessarily referring to a single surface of a single heater component. For example, the heating element assembly 105 illustrated in
As the airflows 184 are passed over the heating elements 102, the airflows 184 may be directed downwardly into a hot air cavity 195 of the electric heater housing 101. In the illustrated embodiment, the hot air cavity 195 is fluidly coupled to the bottom discharge air output opening 138 formed in the bottom wall 140 of the electric heater housing 101. The bottom discharge air output opening 138 may be coupled to a duct 190, either directly or indirectly, such that the duct 190 can guide the heated air to a conditioned space.
As described above, and in accordance with the present disclosure, a heater, such as an electric heater, is configured for compatibility and efficient operation in both a bottom discharge RTU and a side discharge RTU. That is, the electric heater can be employed in both a bottom discharge and a side discharge RTU. For example, the electric heater may be configured to be installed at an angle within the RTU, and may include installation features, such as mounting rails, that enable the angled configuration. By configuring the electric heater for compatibility and efficient operation in both a side and bottom discharge RTU, a manufacturing and/or part cost may be reduced compared to traditional embodiments in which separate types of heaters are employed for separate types of RTUs. Further, an installation process may be simplified and a cost of installation may be reduced, compared to traditional embodiments.
While only certain features and embodiments of the disclosure have been illustrated and described, many modifications and changes may occur to those skilled in the art, such as variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters including temperatures and pressures, mounting rail arrangements, use of materials, colors, orientations, etc., without materially departing from the novel teachings and advantages of the subject matter recited in the claims. The order or sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the disclosure. Furthermore, in an effort to provide a concise description of the exemplary embodiments, all features of an actual implementation may not have been described, such as those unrelated to the presently contemplated best mode of carrying out the disclosure, or those unrelated to enabling the claimed disclosure. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation specific decisions may be made. Such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure, without undue experimentation.
This application claims priority from and the benefit of U.S. Provisional Application Ser. No. 62/823,201, entitled “ELECTRIC HEATER PACKAGE FOR HVAC UNIT,” filed Mar. 25, 2019, which is hereby incorporated by reference in its entirety for all purposes.
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62823201 | Mar 2019 | US |