The present disclosure relates generally to heating, ventilating, and air conditioning systems. A wide range of applications exist for heating, ventilating, and air conditioning (HVAC) systems. For example, residential, light commercial, commercial, and industrial systems are used to control temperatures and air quality in residences and buildings. Such systems often are dedicated to either heating or cooling, although systems are common that perform both of these functions. Very generally, these systems operate by implementing a thermal cycle in which fluids are heated and cooled to provide the desired temperature in a controlled space, typically the inside of a residence or building. Similar systems are used for vehicle heating and cooling, and as well as for general refrigeration. In many HVAC systems, an HVAC unit may be positioned on a rooftop. In such circumstances, technicians or other personnel may utilize a catwalk to move about the HVAC unit to perform various operations such as installation and maintenance.
The present disclosure relates to a heating, ventilating, and air conditioning (HVAC) apparatus including a catwalk pivotally attached to the HVAC apparatus such that the catwalk is configured to be folded toward the HVAC apparatus.
The present disclosure also relates to a heating, ventilating, and air conditioning (HVAC) system including an HVAC apparatus and a catwalk configured to couple to a base of the HVAC unit. The catwalk includes a plurality of platforms and a plurality of support members pivotally coupled to the HVAC apparatus and configured to couple the plurality of platforms to the HVAC unit.
The present disclosure further relates to a heating, ventilating, and air conditioning (HVAC) system including an HVAC apparatus having a base and a catwalk coupled to the base of the HVAC unit. The catwalk is configured to be pivoted between a first position and a second position about a hinge coupled to the base.
The present disclosure is directed to heating, ventilating, and air conditioning (HVAC) systems and units, such as rooftop HVAC units, that include a catwalk. The catwalk may be coupled to a base of the HVAC units via a base rail and/or lifting lugs of the base. Particularly, the base of the HVAC unit may fully support the weight of the catwalk. In this manner, the catwalk may be standardized to fit rooftop units disposed on a variety of different building roofs. Moreover, due to the standardization of the catwalk and integration of the catwalk with the HVAC unit, the catwalk may be attached to the rooftop HVAC unit prior to installation of the rooftop HVAC unit on a building, thereby increasing efficiency of installation.
Turning now to the drawings,
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 air flow is passed to condition the air flow before the air flow 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 air flow 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 air flows through the heat exchanger 28 before being released back to the environment surrounding the rooftop 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 the 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 the 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 outdoor the 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 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 38 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 discussed below, an HVAC unit, such as the HVAC unit 12, may include a catwalk, or elevated platform, coupled to a base of the HVAC unit, which may fully support the weight of the catwalk. In certain embodiments, the catwalk may be disposed in a folded-up, retracted, or travel, position and transitioned to a folded-down, deployed, or operational position, or vice versa. For example,
In certain embodiments, the catwalk 100 may be equipped with handrails 114. The handrails 114 may provide for containment and/or stability for persons while on the platform 110 of the catwalk 100. For example, the handrails 114 may be coupled to the catwalk 100 at an edge of the catwalk 100 and may be disposed substantially perpendicular to the platform 110 of the catwalk 100.
Further, in certain embodiments, the catwalk 100 may be configured to transition between a folded-down or deployed state 120 as shown in
Furthermore, in some embodiments, portions of the catwalk 100 may be integrally coupled to the HVAC unit 12, while other portions may be detachable. For example, referring to
Moreover, the catwalk 100 may provide access to an exterior surface of the HVAC unit 12. Indeed, the HVAC unit 12 may include a panel 132, or door, which may provide access to internal components of the HVAC unit 12. Particularly, as shown, the catwalk 100 may provide easy access to the panel 132 such that service personnel may easily service the HVAC unit 12. As discussed below, in certain embodiments, the catwalk 100 may also provide access to a panel 132, or door, that is disposed on the roof of the HVAC unit 12.
Moreover, the catwalk 100 may be at an elevated position above the attachment element 104, and generally adjacent to, or at, the top of the HVAC unit 12. For example, as shown, in
In certain embodiments, as shown in
In some embodiments, the catwalk 100 may be formed from detachable components that are configured to easily attach to the attachment element 104. Therefore, in certain embodiments, the catwalk 100 may be transported as separate pieces from the HVAC unit 12. The catwalk 100 may then be attached to the attachment element 104 through any suitable fastening means, such as bolting. Indeed, the catwalk 100 may easily couple to the HVAC unit 12 regardless of the surrounding environment provided by the roof of the building. For example, the platforms 110, the base frame 160, the support members 162, the overhead platform 174, and other features may easily be attached and detached from the HVAC unit 12, and more specifically, from the attachment element 104.
Accordingly, the present disclosure is directed to providing systems and methods for an elevated catwalk for a rooftop HVAC unit. The catwalk may be coupled to and fully supported by a base of the HVAC unit via a base rail and/or lifting lugs. Particularly, the catwalk may be fully supported by the HVAC unit without interacting with, or directly relying on, a roof on which the rooftop HVAC unit is disposed. In this manner, the catwalk may be easily assembled and utilized without first having to customize the catwalk for the roof of the building. Moreover, the catwalk may transition between a retracted state, which may result in a decreased footprint for transportation purposes, and a deployed state, for operation purposes. Overall, the catwalk may provide for easy access to components of the HVAC unit for installation and maintenance of the HVAC unit.
While only certain features and embodiments of the present 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, such as temperatures or pressures, mounting arrangements, use of materials, colors, orientations, and so forth, 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 present 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 present disclosure, or those unrelated to enabling the claimed embodiments. 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 is a Non-Provisional application claiming priority to U.S. Provisional Application No. 62/634,056, entitled “HVAC UNIT CATWALK SYSTEMS AND METHODS,” filed Feb. 22, 2018, which is hereby incorporated by reference in its entirety for all purposes.
Number | Date | Country | |
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62634056 | Feb 2018 | US |