Patent Application
20180347835
The present disclosure relates generally to air conditioner units, and more particularly to packaged terminal air conditioner units and related methods of operation.
Air conditioner or conditioning units are conventionally utilized to adjust the temperature indoors—i.e. within structures such as dwellings and office buildings. Such units commonly include a closed refrigeration loop to heat or cool the indoor air. Typically, the indoor air is recirculated while being heated or cooled. A variety of sizes and configurations are available for such air conditioner units. For example, some units may have one portion installed within the indoors that is connected, by e.g., tubing carrying the refrigerant, to another portion located outdoors. These types of units are typically used for conditioning the air in larger spaces.
Another type of unit, sometimes referred to as a packaged terminal air conditioner unit (PTAC), may be used for somewhat smaller indoor spaces that are to be air conditioned. These units may include both an indoor portion and an outdoor portion separated by a bulkhead and may be installed in windows or positioned within an opening of an exterior wall of a building. PTACs often need to draw air from the outdoor portion into the indoor portion. Accordingly, certain PTACs allow for the introduction of make-up air into the indoor space, e.g., through a vent aperture defined in the bulkhead that separates the indoor and outdoor side of the unit. The vent aperture is usually equipped with an auxiliary fan and/or make-up air module to urge a flow of make-up air from the outdoor side of the PTAC into the conditioned room.
The amount of outdoor air, i.e., “make-up air,” needed varies depending on a variety of factors, such as the number of room occupants, the size of the room, etc. For example, a facility manager could program the PTAC to provide sufficient make-up air to meet government regulations or building codes based on the number of room occupants or the room size. In certain situations, the auxiliary fan may not be capable of providing a sufficient flow rate of make-up air to meet the room requirements. Alternatively, the auxiliary fan may generate too much noise or consume too much energy when trying to supply higher flow rates of make-up air.
Accordingly, improved air conditioner units and methods for providing make-up air would be useful. More specifically, a packaged terminal air conditioner unit that can supply the requested make-up air while reducing auxiliary fan noise and energy usage would be particularly beneficial.
The present subject matter provides a packaged terminal air conditioner unit (PTAC) and methods for operating the same. The PTAC includes a vent aperture defined in a bulkhead of the PTAC through which make-up air may flow. An indoor fan urges a flow of primary make-up air at a primary flow rate and an auxiliary fan urges a flow of auxiliary make-up air at an auxiliary flow rate. A controller determines a target make-up air flow rate, e.g., based on a user setting which is determined from building code calculations factoring in expected room occupancy, room size, and other factors. The controller then operates the auxiliary fan to urge the flow of auxiliary make-up air at the auxiliary flow rate which is substantially equivalent to the target make-up air flow rate minus the primary flow rate. Additional aspects and advantages of the invention will be set forth in part in the following description, may be obvious from the description, or may be learned through practice of the invention.
In accordance with one embodiment, a packaged terminal air conditioner unit is provided including a bulkhead defining an indoor portion and an outdoor portion and a vent aperture defined in the bulkhead. An indoor fan is positioned within the indoor portion and being configured for urging a flow of primary make-up air from the outdoor portion through the vent aperture to the indoor portion. An auxiliary fan is positioned proximate the vent aperture and is configured for urging a flow of auxiliary make-up air from the outdoor portion through the vent aperture to the indoor portion. A controller is operably coupled to the indoor fan and the auxiliary fan. The controller is configured for determining a target make-up air flow rate and determining a primary flow rate of the flow of primary make-up air urged by the indoor fan. The controller is further configured for operating the auxiliary fan to urge the flow of auxiliary make-up air at an auxiliary flow rate, the auxiliary flow rate being substantially equivalent to the target make-up air flow rate minus the primary flow rate.
In accordance with another embodiment, a method of operating a packaged terminal air conditioner unit is provided. The packaged terminal conditioner unit includes an indoor fan positioned within an indoor portion and an auxiliary fan positioned adjacent a vent aperture defined in a bulkhead of the packaged terminal air conditioner unit. The method includes determining a target make-up air flow rate and operating the indoor fan to urge a flow of primary make-up air through the vent aperture to the indoor portion at a primary flow rate. The method further includes operating the auxiliary fan to urge a flow of auxiliary make-up air through the vent aperture to the indoor portion at an auxiliary flow rate, a sum of the primary flow rate and the auxiliary flow rate being substantially equivalent to the target make-up air flow rate.
In accordance with still another embodiment, a packaged terminal air conditioner unit is provided including a bulkhead defining an indoor portion and an outdoor portion and a vent aperture defined in the bulkhead. A first fan is configured for urging a first flow of make-up air through the vent aperture and a second fan is configured for urging a second flow of make-up air through the vent aperture. A controller is operably coupled to the first fan and the second fan. The controller is configured for determining a target make-up air flow rate and operating the first fan at a first flow rate. The controller is further configured for operating the second fan at a second flow rate, the second flow rate being substantially equivalent to the target make-up air flow rate minus the first flow rate.
These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures.
Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.
Referring now to
A housing 20 of the unit 10 may contain various other components of the unit 10. Housing 20 may include, for example, a rear grill 22 and a room front 24 which may be spaced apart along the transverse direction T by a wall sleeve 26. The rear grill 22 may be part of the outdoor portion 14, and the room front 24 may be part of the indoor portion 12. Components of the outdoor portion 14, such as an outdoor heat exchanger 30, an outdoor fan 32 (
Referring now also to
Outdoor and indoor heat exchangers 30, 40 may be components of a refrigeration loop 48, which is shown schematically in
As is understood in the art, refrigeration loop 48 may be alternately be operated as a refrigeration assembly (and thus perform a refrigeration cycle) or a heat pump (and thus perform a heat pump cycle). As shown in
According to an example embodiment, compressor 34 may be a variable speed compressor. In this regard, compressor 34 may be operated at various speeds depending on the current air conditioning needs of the room and the demand from refrigeration loop 48. For example, according to an exemplary embodiment, compressor 34 may be configured to operate at any speed between a minimum speed, e.g., 1500 revolutions per minute (RPM), to a maximum rated speed, e.g., 3500 RPM. Notably, use of variable speed compressor 34 enables efficient operation of refrigeration loop 48 (and thus air conditioner unit 10), minimizes unnecessary noise when compressor 34 does not need to operate at full speed, and ensures a comfortable environment within the room.
In exemplary embodiments as illustrated, expansion device 50 may be disposed in the outdoor portion 14 between the indoor heat exchanger 40 and the outdoor heat exchanger 30. According to the exemplary embodiment, expansion device 50 may be an electronic expansion valve that enables controlled expansion of refrigerant, as is known in the art. More specifically, electronic expansion device 50 may be configured to precisely control the expansion of the refrigerant to maintain, for example, a desired temperature differential of the refrigerant across the indoor heat exchanger 40. In other words, electronic expansion device 50 throttles the flow of refrigerant based on the reaction of the temperature differential across indoor heat exchanger 40 or the amount of superheat temperature differential, thereby ensuring that the refrigerant is in the gaseous state entering compressor 34. According to alternative embodiments, expansion device 50 may be a capillary tube or another suitable expansion device configured for use in a thermodynamic cycle.
According to the illustrated exemplary embodiment, outdoor fan 32 is an axial fan and indoor fan 42 is a centrifugal fan. However, it should be appreciated that according to alternative embodiments, outdoor fan 32 and indoor fan 42 may be any suitable fan type. In addition, according to an exemplary embodiment, outdoor fan 32 and indoor fan 42 are variable speed fans. For example, outdoor fan 32 and indoor fan 42 may rotate at different rotational speeds, thereby generating different air flow rates. It may be desirable to operate fans 32, 42 at less than their maximum rated speed to ensure safe and proper operation of refrigeration loop 48 at less than its maximum rated speed, e.g., to reduce noise when full speed operation is not needed. In addition, according to alternative embodiments, fans 32, 42 may be operated to urge make-up air into the room.
According to the illustrated embodiment, indoor fan 42 may operate as an evaporator fan in refrigeration loop 48 to encourage the flow of air through indoor heat exchanger 40. Accordingly, indoor fan 42 may be positioned downstream of indoor heat exchanger 40 along the flow direction of indoor air and downstream of heating unit 44. Alternatively, indoor fan 42 may be positioned upstream of indoor heat exchanger 40 along the flow direction of indoor air, and may operate to push air through indoor heat exchanger 40.
Heating unit 44 in exemplary embodiments includes one or more heater banks 60. Each heater bank 60 may be operated as desired to produce heat. In some embodiments as shown, three heater banks 60 may be utilized. Alternatively, however, any suitable number of heater banks 60 may be utilized. Each heater bank 60 may further include at least one heater coil or coil pass 62, such as in exemplary embodiments two heater coils or coil passes 62. Alternatively, other suitable heating elements may be utilized.
The operation of air conditioner unit 10 including compressor 34 (and thus refrigeration loop 48 generally) indoor fan 42, outdoor fan 32, heating unit 44, expansion device 50, and other components of refrigeration loop 48 may be controlled by a processing device such as a controller 64. Controller 64 may be in communication (via for example a suitable wired or wireless connection) to such components of the air conditioner unit 10. As described in more detail below with respect to
Unit 10 may additionally include a control panel 66 and one or more user inputs 68, which may be included in control panel 66. The user inputs 68 may be in communication with the controller 64. A user of the unit 10 may interact with the user inputs 68 to operate the unit 10, and user commands may be transmitted between the user inputs 68 and controller 64 to facilitate operation of the unit 10 based on such user commands. A display 70 may additionally be provided in the control panel 66, and may be in communication with the controller 64. Display 70 may, for example be a touchscreen or other text-readable display screen, or alternatively may simply be a light that can be activated and deactivated as required to provide an indication of, for example, an event or setting for the unit 10.
Referring briefly to
As shown in
In some cases, it may be desirable to treat or condition make-up air flowing through vent aperture 80 prior to blowing it into the room. For example, outdoor air which has a relatively high humidity level may require treating before passing into the room. In addition, if the outdoor air is cool, it may be desirable to heat the air before blowing it into the room. Therefore, as illustrated in
As illustrated, make-up air module 90 includes auxiliary fan 92 that is configured as part of auxiliary sealed system 90 and may be configured for urging a flow of air through auxiliary sealed system 90. Auxiliary sealed system 90 may further include one or more compressors, heat exchangers, and any other components suitable for operating auxiliary sealed system 90 similar to refrigeration loop 48 described above to condition make-up air. For example, auxiliary system 90 can be operated in a dehumidification mode, an air conditioning mode, a heating mode, a fan only mode where only auxiliary fan 92 is operated to supply outdoor air, an idle mode, etc.
Referring now to
According to the illustrated embodiment, control system 100 includes a packaged terminal air conditioner unit, such as unit 10, positioned on an exterior wall of a room 102. Unit 10 is configured for conditioning air within room 102 and supplying a flow of make-up air into room 102. In addition, control system 100 includes an occupancy system 104 generally configured for obtaining a room occupancy status. As used herein, “room occupancy status” may be used to refer to an indication that the room is occupied or unoccupied, to the number of room occupants, to the target make-up air flow rate, or any other information that may be used by the packaged terminal air conditioner unit 10 or make-up air module 90 to determine the proper make-up air flow rate.
Occupancy system 104 may include an identification reader such as a keycard reader 106 that is generally configured for reading an occupancy identification source, such as a keycard 108. More specifically, according to the exemplary illustrated embodiment, keycard reader 106 is positioned within room 102 near the door and keycard 108 includes a magnetic strip 110 that is configured to be read by the keycard reader 106. Upon entering the room, the guest puts keycard 108 into a slot of keycard reader 106. Keycard 108 may be encoded with information regarding the reserved room information as well as the number of guests staying in the room 102. The room occupancy status may be relayed to unit 10 and/or make-up air module 90 in any suitable manner.
The exemplary embodiment described above describes the room occupancy status and other information being relayed to make-up air module 90 using magnetic strip 110 on keycard 108. However, it should be appreciated that this information may be relayed using any other suitable method. For example, the room occupancy status may be entered by the guest using a keypad when they enter room 102, may be encoded in a barcode and read by a barcode scanner, may be communicated using a mobile phone application, may be transmitted using an RFID chip, or may be relayed in any other manner.
Occupancy system 104, including keycard reader 106 may be coupled to unit 10 through any suitable wired or wireless connection, as described in more detail below. For example, as illustrated, occupancy system 104 includes an occupancy system controller 120, e.g., housed within keycard reader 106, that is in operative communication with controller 64 of unit 10. More specifically, according to the illustrated embodiment, controller 64 and occupancy system controller 120 may be in communication with through a direct or indirect, wired or wireless connection, such as via a network 122.
After the room occupancy status is received by unit 10, controller 64 determines a target make-up air flow rate. For example, according to one exemplary embodiment, the target make-up air flow rate is based on a user setting which is determined from building code calculations factoring in expected room occupancy, room size, and any other combination of suitable factors. Notably, tying the target make-up air flow rate to occupancy system 104 and the number of room occupants, unit 10 may deliver the appropriate amount of air to meet government regulations and building codes, keep the noise created by auxiliary fan 92 to a minimum, and maintain guest comfort and satisfaction at a maximum.
Computing device(s) 130 can include one or more processor(s) 130A and one or more memory device(s) 130B. The one or more processor(s) 130A can include any suitable processing device, such as a microprocessor, microcontroller, integrated circuit, an application specific integrated circuit (ASIC), a digital signal processor (DSP), a field-programmable gate array (FPGA), logic device, one or more central processing units (CPUs), graphics processing units (GPUs) (e.g., dedicated to efficiently rendering images), processing units performing other specialized calculations, etc. The memory device(s) 130B can include one or more non-transitory computer-readable storage medium(s), such as RAM, ROM, EEPROM, EPROM, flash memory devices, magnetic disks, etc., and/or combinations thereof.
The memory device(s) 130B can include one or more computer-readable media and can store information accessible by the one or more processor(s) 130A, including instructions 130C that can be executed by the one or more processor(s) 130A. For instance, the memory device(s) 130B can store instructions 130C for running one or more software applications, displaying a user interface, receiving user input, processing user input, etc. In some implementations, the instructions 130C can be executed by the one or more processor(s) 130A to cause the one or more processor(s) 130A to perform operations, as described herein (e.g., one or more portions of method 200). More specifically, for example, the instructions 130C may be executed to transmit and/or receive occupancy status information, determine a target make-up air flow rate, and adjust the speed of an indoor or auxiliary fan. The instructions 130C can be software written in any suitable programming language or can be implemented in hardware. Additionally, and/or alternatively, the instructions 130C can be executed in logically and/or virtually separate threads on processor(s) 130A.
The one or more memory device(s) 130B can also store data 130D that can be retrieved, manipulated, created, or stored by the one or more processor(s) 130A. The data 130D can include, for instance, data indicative of target make-up air flow rates for a given number of room occupants. The data 130D can be stored in one or more database(s). The one or more database(s) can be connected to controller 64 and/or controller 120 by a high bandwidth LAN or WAN, or can also be connected to controller through network(s) 122. The one or more database(s) can be split up so that they are located in multiple locales. In some implementations, the data 130D can be received from another device.
The computing device(s) 130 can also include a communication module or interface 130E used to communicate with one or more other component(s) of control system (e.g., controllers 64 and 120) over the network(s) 122. The communication interface 130E can include any suitable components for interfacing with one or more network(s), including for example, transmitters, receivers, ports, controllers, antennas, or other suitable components.
The network(s) 122 can be any type of communications network, such as a local area network (e.g. intranet), wide area network (e.g. Internet), cellular network, or some combination thereof and can include any number of wired and/or wireless links. The network(s) 122 can also include a direct connection between one or more component(s) of control system 100. In general, communication over the network(s) 122 can be carried via any type of wired and/or wireless connection, using a wide variety of communication protocols (e.g., TCP/IP, HTTP, SMTP, FTP), encodings or formats (e.g., HTML, XML), and/or protection schemes (e.g., VPN, secure HTTP, SSL).
The technology discussed herein makes reference to servers, databases, software applications, and other computer-based systems, as well as actions taken and information sent to and from such systems. It should be appreciated that the inherent flexibility of computer-based systems allows for a great variety of possible configurations, combinations, and divisions of tasks and functionality between and among components. For instance, computer processes discussed herein can be implemented using a single computing device or multiple computing devices (e.g., servers) working in combination. Databases and applications can be implemented on a single system or distributed across multiple systems. Distributed components can operate sequentially or in parallel. Furthermore, computing tasks discussed herein as being performed at the computing system (e.g., a server system) can instead be performed at a user computing device. Likewise, computing tasks discussed herein as being performed at the user computing device can instead be performed at the computing system.
Now that the construction of air conditioner unit 10 and the configuration of control system 100 according to exemplary embodiments has been presented, an exemplary method 200 of operating a packaged terminal air conditioner unit will be described. Although the discussion below refers to the exemplary method 200 of operating air conditioner unit 10, one skilled in the art will appreciate that the exemplary method 200 is applicable to the operation of a variety of other air conditioning appliances. In exemplary embodiments, the various method steps as disclosed herein may be performed by controller 64 or a separate, dedicated controller.
In general, unit 10 controls the delivery of make-up air into indoor portion 12 through vent aperture 80. More specifically, when vent door 82 is open, indoor fan 42 and auxiliary fan 92 operate to urge make-up air into the room. More specifically, indoor fan 42 may be referred to herein as urging a flow of primary make-up air at a primary flow rate and auxiliary fan 92 may be referred to as urging a flow of auxiliary make-up air at an auxiliary flow rate. According to the exemplary embodiment, the total flow rate of make-up air is the sum of the primary flow rate and the auxiliary flow rate. It should be appreciated that the terms “primary” flow and flow rate and “auxiliary” flow and flow rate are only intended to refer to the relative proportions/amounts of make-up air passing through vent aperture 80. Each of indoor fan 42 and auxiliary fan 92 may be operated independently of each other or collectively to urge a flow of make-up air through vent aperture 80.
Referring now to
Method 200 further includes, at step 220, operating an indoor fan to urge a flow of primary make-up air through a vent aperture to an indoor portion at a primary flow rate. In this regard, for example, when the vent door is closed and indoor fan is operating according to an air conditioning mode, air from within the room is circulated through indoor fan. However, when the vent door of the packaged terminal air conditioner unit is open, operation of the indoor fan also has a tendency to draw in make-up air through the vent aperture at a flow rate (i.e., the primary flow rate) roughly proportional to the fan speed. According to alternative embodiments, other means can be used to assist in drawing the primary make-up air through the vent aperture, such as a bathroom exhaust fan, which generates a negative pressure within the room, resulting in additional make-up air entering through the vent aperture.
Method 200 further includes, at step 230, operating an auxiliary fan to urge a flow of auxiliary make-up air through the vent aperture to the indoor portion at an auxiliary flow rate. Notably, a sum of the primary flow rate and the auxiliary flow rate is substantially equivalent to the target make-up air flow rate so that the room receives the necessary flow rate of make-up air. In other words, according to aspects of the present subject matter, the indoor fan and the auxiliary fan work together to supply make-up air at the target make-up air flow rate.
According to alternative embodiments, method 200 may further be used to operate a packaged terminal air conditioner unit to achieve various alternative goals. For example, according to an alternative embodiment, the auxiliary fan may have a maximum flow rate or it may be desirable to select and arbitrary maximum flow rate which the auxiliary fan should not exceed. The maximum flow rate could be a flow rate where the auxiliary fan operates at its most energy efficient operating point or at a specific energy consumption level.
According to such an embodiment, the PTAC controller may be configured for determining that the target make-up air flow rate is greater than the maximum flow rate of the auxiliary fan. The controller may operate the auxiliary fan to urge the flow of auxiliary make-up air at the maximum flow rate. Finally, in order to meet the target make-up air flow rate, the controller may be configured for operating the indoor fan such that the primary flow rate is substantially equivalent to the target make-up air flow rate minus the maximum flow rate. In this manner, a predetermined operating threshold such as the maximum flow rate of the auxiliary fan may be maintained while the indoor fan is controlled as necessary to achieve the target make-up air flow rate.
It should be appreciated that such a control method may also be used to place limits on the operation of the indoor fan. More specifically, controller may set a maximum primary flow rate and auxiliary fan may be selectively operated to supply auxiliary make-up air at an auxiliary flow rate sufficient to meet the target make-up air flow rate. In addition, the predetermined operating threshold, whether it is selected for the indoor fan or the auxiliary fan, may be set for any particular purpose. For example, the auxiliary fan may be operated at a noise-limiting flow rate where the noise generated by the auxiliary fan reaches, but does not exceed a predetermined noise threshold. In this manner, when auxiliary fan begins to generate too much noise, the indoor fan can begin to supply the extra make-up air without the operation of the unit exceeding an undesirable noise level.
For example, according to one exemplary embodiment, the occupancy system may determine that there are three room occupants and that the target make-up air flow rate is about fifty cubic feet per minute (CFM) in order to satisfy guest comfort and government regulations. The controller may determine that the indoor fan is currently operating, and based on the indoor fan speed, may determine that the primary flow rate is about fifteen CFM. The controller will then calculate that the auxiliary flow rate which must be supplied by the auxiliary fan to achieve the target make-up air flow rate is about thirty-five CFM, and will adjust the speed of the auxiliary fan accordingly. By contrast, if the occupancy system determines that the room is unoccupied, e.g., such that the target make-up air flow rate is zero, the controller may pivot the vent door to the closed position and turn the auxiliary fan off to conserve energy. It should be appreciated that these are only exemplary manners of operating the packaged terminal air conditioner unit and are not intended to limit the scope of the present subject matter.
The construction of packaged terminal air conditioner unit 10, control system 100, and methods 200 described above provide a means for ensuring that indoor fan 42 and auxiliary fan 92 work together to ensure that the necessary amount of make-up air is provided while minimizing noise and energy usage. Thus, for example, if the target make-up air flow rate is higher than a maximum flow rate of the auxiliary fan or the auxiliary fan is operating at a noise level that is above a predetermined threshold, the indoor fan may operate to boost the make-up air flow rate, thereby reducing the load placed on the auxiliary fan. In addition, decreasing the auxiliary fan speed when the indoor fan is operating in a cooling mode can save energy while maintaining the target make-up air flow rate. Thus, coordinated operation of the indoor fan and the auxiliary fan may result in improved guest comfort, minimized energy usage, and the elimination of unnecessary noise from an auxiliary fan operating at higher than necessary speeds.
In this manner, unit 10 and auxiliary fan 92 provide the appropriate amount of air to meet government regulations and building codes, keeps the noise created by make-up air module 90 to a minimum, and maintains guest comfort and satisfaction at a maximum. In addition, by operatively connecting unit 10 with control system 100 and its associated occupancy system 104, the target make-up air flow rate may be automatically adjusted to provide the required amount of make-up air without requiring a facility operator to make a manual change to the setting in each unit 10 when each guest or guests check into their room.
This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.
