The present disclosure relates generally to air conditioner units, and more particularly to fan assemblies for providing make up air in packaged terminal air conditioner units.
Air conditioner or conditioning units are conventionally utilized to adjust the temperature indoors, e.g., 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 indoors that is connected to another portion located outdoors, e.g., by tubing or conduit carrying refrigerant. These types of units are typically used for conditioning the air in larger spaces.
Another type of air conditioner unit, commonly referred to as single-package vertical units (SPVU) or package terminal air conditioners (PTAC), may be utilized to adjust the temperature in somewhat smaller indoor spaces, for example, a single room or group of rooms of a structure. These units typically operate like split heat pump systems, except that the indoor and outdoor portions are defined by a bulkhead and all system components are housed within a single package that installed in a wall sleeve 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. Notably, it may be desirable to filter the outdoor air before introducing it into the indoor space. However, the make-up air subsystem is often limited by size constraints, cost constraints, labor constraints, and maintenance/serviceability constraints. Due to these constraints, conventional air filters used in such assemblies may be ineffective in properly filtering the make-up air, particularly at higher flow rates required to meet industry required standards for make-up air flow rate.
In this regard, 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, government regulations or building codes may specify the amount of make-up air required for each room occupant. In certain situations, conventional air filters may not be capable of properly filtering air at the target flow rates.
Accordingly, improved air conditioner units and systems for filtering make-up air would be useful. More specifically, a packaged terminal air conditioner unit that includes a filter assembly capable of filtering large flow rates of air while minimizing parts, assembly costs, and maintenance costs would be particularly beneficial.
Aspects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.
In one exemplary embodiment, an air conditioner unit is provided, including a bulkhead defining an indoor portion and an outdoor portion, a vent aperture defined in the bulkhead, and a fan assembly for urging a flow of make-up air from the outdoor portion through the vent aperture to the indoor portion. The fan assembly includes a fan housing defining a fan slot, a filter slot, and a make-up air duct in fluid communication with the vent aperture, an auxiliary fan positioned within the fan slot of the fan housing, and an air filter positioned within the filter slot.
In another exemplary embodiment, a fan assembly for urging a flow of make-up air through an air conditioner unit is provided. The fan assembly includes a fan housing defining a fan slot, a filter slot, and a make-up air duct, an auxiliary fan positioned within the fan slot of the fan housing, and an air filter positioned within the filter slot.
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.
Repeat use of reference characters in the present specification and drawings is intended to represent the same or analogous features or elements of the present invention.
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.
As used herein, the term “or” is generally intended to be inclusive (i.e., “A or B” is intended to mean “A or B or both”). The terms “first,” “second,” and “third” may be used interchangeably to distinguish one component from another and are not intended to signify location or importance of the individual components. The terms “upstream” and “downstream” refer to the relative flow direction with respect to fluid flow in a fluid pathway. For example, “upstream” refers to the flow direction from which the fluid flows, and “downstream” refers to the flow direction to which the fluid flows. Furthermore, as used herein, terms of approximation, such as “approximately,” “substantially,” or “about,” refer to being within a ten percent margin of error.
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, and a compressor 34 may be housed within the wall sleeve 26. A fan shroud 36 may additionally enclose outdoor fan 32, as shown.
Indoor portion 12 may include, for example, an indoor heat exchanger 40, a blower fan or indoor fan 42, and a heating unit 44. These components may, for example, be housed behind the room front 24. Additionally, a bulkhead 46 may generally support and/or house various other components or portions thereof of the indoor portion 12, such as indoor fan 42 and the heating unit 44. Bulkhead 46 may generally separate and define the indoor portion 12 and outdoor portion 14.
Outdoor and indoor heat exchangers 30, 40 may be components of a sealed system or refrigeration loop 48, which is shown schematically in
As is understood in the art, refrigeration loop 48 may be alternately 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.
Specifically, according to an exemplary embodiment, compressor 34 may be an inverter compressor. In this regard, compressor 34 may include a power inverter, power electronic devices, rectifiers, or other control electronics suitable for converting an alternating current (AC) power input into a direct current (DC) power supply for the compressor. The inverter electronics may regulate the DC power output to any suitable DC voltage that corresponds to a specific operating speed of compressor. In this manner compressor 34 may be regulated to any suitable operating speed, e.g., from 0% to 100% of the full rated power and/or speed of the compressor. This may facilitate precise compressor operation at the desired operating power and speed, thus meeting system needs while maximizing efficiency and minimizing unnecessary system cycling, energy usage, and noise.
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 (“EEV”) that enables controlled expansion of refrigerant, as is known in the art. According to alternative embodiments, expansion device 50 may be a capillary tube or another suitable expansion device configured for use in a thermodynamic cycle.
More specifically, according to exemplary embodiments, electronic expansion device 50 may be configured to precisely control the expansion of refrigerant to maintain, for example, a desired temperature differential of the refrigerant across the evaporator (i.e., the outdoor heat exchanger 30 in heat pump mode). In other words, electronic expansion device 50 throttles the flow of refrigerant based on the reaction of the temperature differential across the evaporator or the amount of superheat temperature differential, thereby ensuring that the refrigerant is in the gaseous state entering compressor 34.
In general, the terms “superheat,” “operating superheat,” or the like are generally intended to refer to the temperature increase of the refrigerant past the fully saturated vapor temperature in the evaporator. In this regard, for example, the superheat may be quantified in degrees Fahrenheit, e.g., such that 1° F. superheat means that the refrigerant exiting the evaporator is 1° F. higher than the saturated vapor temperature. It should be appreciated that the operating superheat may be measured and monitored by controller 64 in any suitable manner. For example, controller 64 may be operably coupled to a pressure sensor for measuring the refrigerant pressure exiting the evaporator, may convert that pressure to the saturated vapor temperature, and may subtract that temperature from the measured refrigerant temperature at the evaporator outlet to determine superheat.
According to exemplary embodiments, expansion device or electronic expansion valve 50 may be driven by a stepper motor or other drive mechanism to any desirable position between a fully closed position (e.g., when no refrigerant passes through EEV 50) to a fully open position (e.g., when there is little or no restriction through the EEV 50). For example, controller 64 may be operably coupled to EEV 50 and may regulate the position of the EEV 50 through a control signal to achieve a target superheat, a target restriction/expansion, etc.
More specifically, the control signal communicated from controller 64 may specify the number of control steps (or simply “steps”) and a corresponding direction (e.g., counterclockwise toward the closed position or clockwise toward the open position). Each EEV 50 may have a physical stroke span equal to the difference between the fully open position and the fully closed position. In addition, the EEV 50 may include a step range or range of control steps that correspond to the number adjustment steps it takes for the EEV 50 to travel from the fully closed position to the fully open position.
Each “step” may refer to a predetermined rotation of the drive mechanism, e.g., such as a stepper motor, which may in turn move the EEV 50 a fixed linear distance toward the open or closed position (depending on the commanded step direction). For example, according to the exemplary embodiment, the EEV 50 may have a step range of 500 steps, with 0 steps corresponding to fully closed and 500 steps corresponding to fully open. However, it should be appreciated that according to alternative embodiments, any given electronic expansion valve may include a different number of control steps, and the absolute step adjustments described herein may be varied accordingly.
In addition, as used herein, the position of EEV 50 may be expressed as a percentage, e.g., where 0% corresponds to a fully closed position and 100% corresponds to a fully open position. According to exemplary embodiments, this percentage representation may also refer to the percentage of total control steps taken from the closed position, e.g., with 10% referring to 50 steps (e.g., 10% of the 500 total steps), 80% referring to 400 steps (e.g., 80% of 500 total steps), etc.
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, e.g., similar to variable speed compressor 34. 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. Controller 64 may include a memory and one or more processing devices such as microprocessors, CPUs or the like, such as general or special purpose microprocessors operable to execute programming instructions or micro-control code associated with operation of unit 10. The memory may represent random access memory such as DRAM, or read only memory such as ROM or FLASH. In one embodiment, the processor executes programming instructions stored in memory. The memory may be a separate component from the processor or may be included onboard within the processor.
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, according to an exemplary embodiment of the present subject matter, unit 10 may further include an auxiliary sealed system that is positioned over vent aperture 80 for conditioning make-up air. The auxiliary sealed system may be a miniature sealed system that acts similar to refrigeration loop 48, but conditions only the air flowing through vent aperture 80. According to alternative embodiments, such as that described herein, make-up air may be urged through vent aperture 80 without the assistance of an auxiliary sealed system. Instead, make-up air is urged through vent aperture 80 may be conditioned at least in part by refrigeration loop 48, e.g., by passing through indoor heat exchanger 40. Additionally, the make-up air may be conditioned immediately upon entrance through vent aperture 80 or sequentially after combining with the air stream induced through indoor heat exchanger 40.
Referring now to
According to the illustrated embodiment, auxiliary fan 102 is an axial fan positioned at an inlet of fan duct 104, e.g., upstream from vent aperture 80. However, it should be appreciated that any other suitable number, type, and configuration of fan or blower could be used to urge a flow of makeup air according to alternative embodiments. In addition, auxiliary fan 102 may be positioned in any other suitable location within air conditioner unit 10 and auxiliary fan 102 may be positioned at any other suitable location within or in fluid communication with fan duct 104. The embodiments described herein are only exemplary and are not intended to limit the scope present subject matter.
Referring now to
As illustrated, room front 24 of unit 10 generally defines an intake vent 110 and a discharge vent 112 for use in circulating a flow of air (indicated by arrows 114) throughout a room. In this regard, indoor fan 42 is generally configured for drawing in air 114 through intake vent 110 and urging the flow of air through indoor heat exchanger 40 before discharging the air 114 out of discharge vent 112. According to the illustrated embodiment, intake vent 110 is positioned proximate a bottom of unit 10 and discharge vent 112 is positioned proximate a top of unit 10. However, it should be appreciated that according to alternative embodiments, intake vent 110 and discharge vent 112 may have any other suitable size, shape, position, or configuration.
During a cooling cycle, refrigeration loop 48 is generally configured for urging cold refrigerant through indoor heat exchanger 40 in order to lower the temperature of the flow of air 114 before discharging it back into the room. Specifically, during a cooling operation, controller 64 may be provided with a target temperature, e.g., as set by a user for the desired room temperature. In general, components of refrigeration loop 48, outdoor fan 32, indoor fan 42, and other components of unit 10 operate to continuously cool the flow of air.
In order to facilitate operation of refrigeration loop 48 and other components of unit 10, unit 10 may include a variety of sensors for detecting conditions internal and external to the unit 10. These conditions can be fed to controller 64 which may make decisions regarding operation of unit 10 to rectify undesirable conditions or to otherwise condition the flow of air 114 into the room. For example, as best illustrated in
As used herein, “temperature sensor” or the equivalent is intended to refer to any suitable type of temperature measuring system or device positioned at any suitable location for measuring the desired temperature. Thus, for example, temperature sensor 120 may each be any suitable type of temperature sensor, such as a thermistor, a thermocouple, a resistance temperature detector, a semiconductor-based integrated circuit temperature sensor, etc. In addition, temperature sensor 120 may be positioned at any suitable location and may output a signal, such as a voltage, to a controller that is proportional to and/or indicative of the temperature being measured. Although exemplary positioning of temperature sensors is described herein, it should be appreciated that unit 10 may include any other suitable number, type, and position of temperature, and/or other sensors according to alternative embodiments.
As used herein, the terms “humidity sensor” or the equivalent may be intended to refer to any suitable type of humidity measuring system or device positioned at any suitable location for measuring the desired humidity. Thus, for example, humidity sensor 122 may refer to any suitable type of humidity sensor, such as capacitive digital sensors, resistive sensors, and thermal conductivity humidity sensors. In addition, humidity sensor 122 may be positioned at any suitable location and may output a signal, such as a voltage, to a controller that is proportional to and/or indicative of the humidity being measured. Although exemplary positioning of humidity sensors is described herein, it should be appreciated that unit 10 may include any other suitable number, type, and position of humidity sensors according to alternative embodiments.
Referring now to
For example, external communication system 170 permits controller 64 of air conditioner unit 10 to communicate with a separate device external to air conditioner unit 10, referred to generally herein as an external device 172. As described in more detail below, these communications may be facilitated using a wired or wireless connection, such as via a network 174. In general, external device 172 may be any suitable device separate from air conditioner unit 10 that is configured to provide and/or receive communications, information, data, or commands from a user. In this regard, external device 172 may be, for example, a personal phone, a smartphone, a tablet, a laptop or personal computer, a wearable device, a smart home system, or another mobile or remote device.
In addition, a remote server 176 may be in communication with air conditioner unit 10 and/or external device 172 through network 174. In this regard, for example, remote server 176 may be a cloud-based server 176, and is thus located at a distant location, such as in a separate state, country, etc. According to an exemplary embodiment, external device 172 may communicate with a remote server 176 over network 174, such as the Internet, to transmit/receive data or information, provide user inputs, receive user notifications or instructions, interact with or control air conditioner unit 10, etc. In addition, external device 172 and remote server 176 may communicate with air conditioner unit 10 to communicate similar information.
In general, communication between air conditioner unit 10, external device 172, remote server 176, and/or other user devices or appliances may be carried using any type of wired or wireless connection and using any suitable type of communication network, non-limiting examples of which are provided below. For example, external device 172 may be in direct or indirect communication with air conditioner unit 10 through any suitable wired or wireless communication connections or interfaces, such as network 174. For example, network 174 may include one or more of a local area network (LAN), a wide area network (WAN), a personal area network (PAN), the Internet, a cellular network, any other suitable short-or long-range wireless networks, etc. In addition, communications may be transmitted using any suitable communications devices or protocols, such as via Wi-Fi®, Bluetooth®, Zigbee®, wireless radio, laser, infrared, Ethernet type devices and interfaces, etc. In addition, such communication may use a 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).
External communication system 170 is described herein according to an exemplary embodiment of the present subject matter. However, it should be appreciated that the exemplary functions and configurations of external communication system 170 provided herein are used only as examples to facilitate description of aspects of the present subject matter. System configurations may vary, other communication devices may be used to communicate directly or indirectly with one or more associated appliances, other communication protocols and steps may be implemented, etc. These variations and modifications are contemplated as within the scope of the present subject matter.
Referring now specifically to
As explained above, fan assembly 100 may generally be configured for using auxiliary fan 102 to urge a flow of makeup air 190 (
According to the illustrated embodiment, fan slot 210 and/or filter slot 212 may be defined by one or more walls 220 that extend from lower portion 202 and upper portion 204 into makeup air duct 104. In this regard, auxiliary fan 102 may slide into fan slot 210 defined between walls 220 and a front panel 222 of fan housing 200. By contrast, filter slot 212 may be defined between two adjacent and spaced apart walls 220. According to example embodiments, auxiliary fan 102 may be installed in fan housing 200 by positioning auxiliary fan 102 into one half of fan slot 210 (e.g., within lower portion 202) before joining the other half of fan housing 200 (e.g., upper portion 204).
According to example embodiments, fan housing 200 may further define a filter aperture 230 for inserting and/or removing air filter 214 from filter slot 212. In this regard, as illustrated for example in
It should be appreciated that air filter 214 may be any suitable type, size, or rating of filter. For example, air filter 214 may be a pleated filter media, a mesh filter media, a sponge, a HEPA filter, an electrostatic filter, a spun glass filter, or any other suitable type and size of filter medium. In addition, air filter may have any suitable minimum efficiency reporting value (MERV) rating.
As best illustrated in
It should be appreciated that the shape of filter slot 212 may take any suitable profile or series of profiles. For example, according to the illustrated embodiment, filter slot 212 is curved across an entire width of makeup air duct 104. By contrast, according to alternative embodiments, filter slot 212 may be a series of straight segments and curved segments. According to still other embodiments, the shape of filter slot 212 may be zig-zag, sinusoidal, or any other suitable shape.
Notably, the filtration area may be improved by varying the radius of the arcuate portion of filter slot 212. Accordingly, filter slot 212 may generally define a radius of curvature 240 and fan slot 210 may define a fan slot width 242. According to example embodiments, the radius of curvature 240 may be smaller than fan slot width 242. For example, fan slot width 242 may be 1.1 times, 1.3 times, 1.5 times, 2 times, 4 times, 10 times, or greater than radius of curvature 240.
According to the illustrated example embodiment, air filter 214 is positioned downstream of auxiliary fan 102, e.g., such that air filter 214 is positioned within makeup air duct 104 between auxiliary fan 102 and vent aperture 80. However, it should be appreciated that air filter 214 may be positioned at other locations within the air flow while remaining within the scope of the present subject matter. In addition, according to the illustrated embodiment, filter slot 212 (e.g., and thus air filter 214) may be concave as viewed from fan slot 212.
As explained herein, aspects of the present subject matter are generally directed to a fan assembly having a clam-shell design of the duct of a PTAC makeup air supply system. The duct may include an integrated fan capturing an auxiliary fan (e.g., a muffin axial fan) and a filter. A filter capturing feature of the fan housing allows use of filters with complex shapes thereby allowing the filter to have maximum surface area with respect to the fan flow zone. The proposed design may eliminate the need for a dedicated fan bracket, filter bracket, and mounting fasteners, thereby simplifying assembly and reducing costs. Further, the fan and the filter can be easily accessed for servicing by removing the upper part of the duct.
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.