Systems and methods for cleaning air

An air cleaning system has a field charger comprising a plurality of bars comprising a conductive inner core and a non-conductive overmold, and a plurality of pins attached to the bars and extending out of the non-conductive overmold. The conductive inner core is molded over the plurality of pins, conductively connecting the pins, and the non-conductive overmold is molded over the conductive inner core. A method of manufacturing the field charger includes placing a plurality of metal pins in a mold, placing contact points in the mold, molding a conductive resin over at least a portion of the plurality of pins and contact points, molding an insulating resin over the inner core, plurality of pins, and contact points, wherein at least a portion of the pins and contact points extend from the non-conductive overmold, and mounting an earthplate to the conductive overmold.

Not applicable.

REFERENCE TO A MICROFICHE APPENDIX

Not applicable.

BACKGROUND

Indoor air pollution may lessen enjoyment of an indoor space as well as present a health hazard. Indoor air pollution may comprise airborne pollutants such as dust, smoke, pollen, animal dander, mold, and mildew which may be present in indoor spaces in quantities sufficient to present a health hazard to occupants of the indoor space. Some heating, ventilation, and air conditioning (HVAC) systems comprise an air cleaner to filter pollutants from air circulated through the HVAC systems.

SUMMARY

In some embodiments of the disclosure, an air cleaning system is provided that comprises a field charger, wherein the field charger comprises: a plurality of bars comprising a conductive inner core and a non-conductive overmold, and a plurality of pins attached to the bars and extending out of the non-conductive overmold; at least one collection cell; and a cabinet operable to house the field charger and at least one collection cell. The conductive inner core may be molded over the plurality of pins, conductively connecting the pins, and the non-conductive overmold may be molded over the conductive inner core.

In yet other embodiments of the disclosure, a field charger for use with a clean air system is disclosed. The field charger comprises a plurality of metal pins; a conductive resin molded over a portion of the metal pins, wherein the molded conductive resin forms a grid shape, and wherein the conductive resin conductively connects the plurality of metal pins; an insulating resin molded over the conductive resin and a portion of the metal pins; contact points molded into the conductive resin and insulting resin, wherein any voltage applied to the contact points is therefore applied to the conductive resin and the metal pins; and an earthplate coupled to the grid shape operable to provide a ground connection.

In other embodiments of the disclosure, a method of manufacturing a field charger for use in a clean air system is disclosed. The method comprises placing a plurality of metal pins in a mold; placing contact points in the mold; molding a conductive resin over at least a portion of each of the plurality of pins and contact points, wherein the conductive resin forms an inner core; molding an insulating resin over the inner core, plurality of pins, and contact points, wherein the insulating resin forms a non-conductive overmold, and wherein at least a portion of the pins and contact points extend from the non-conductive overmold; and mounting an earthplate to the conductive overmold.

DETAILED DESCRIPTION

Air cleaners used in HVAC systems, and possibly other applications, may comprise a field charger and collection cells operable to charge and collect particles in the air that flows through the air cleaner. Field chargers may comprise pins that create a current in the air around the pins that ionizes particles in the air. The collection cells are oppositely charged relative to field charger and may attract and collect the charged particles. In some field chargers comprising pins that are conductively connected by welding to metal bars, the metal bars are housed in a non-conductive covering or case. In wet conditions, carbon deposits may form in the field charger, causing electrical tracking that reduces the effectiveness of the field charger. The current disclosure provides an improved design for a field charger that may reduce the risk of carbon deposits forming in the field charger. Additionally, the embodiments of the current disclosure may provide a more homogeneously conductive bar core that more evenly distributes power through the bar core so that an efficiency of each pin connected to the conductive bar core is more uniform. The disclosure further provides methods for manufacturing the improved field charger using injection molding.

Referring now toFIG. 1, a schematic diagram of an HVAC system100according to an embodiment of this disclosure is shown. HVAC system100comprises an indoor unit102, an outdoor unit104, and a system controller106. In some embodiments, the system controller106may operate to control operation of the indoor unit102and/or the outdoor unit104. As shown, the HVAC system100is a so-called heat pump system that may be selectively operated to implement one or more substantially closed thermodynamic refrigeration cycles to provide a cooling functionality and/or a heating functionality.

Indoor unit102comprises an indoor heat exchanger108, an indoor fan110, and an indoor metering device112. Indoor heat exchanger108is a plate fin heat exchanger configured to allow heat exchange between refrigerant carried within internal tubing of the indoor heat exchanger108and fluids that contact the indoor heat exchanger108but that are kept segregated from the refrigerant. In other embodiments, indoor heat exchanger108may comprise a spine fin heat exchanger, a microchannel heat exchanger, or any other suitable type of heat exchanger.

The indoor fan110is a centrifugal blower comprising a blower housing, blower impeller at least partially disposed within the blower housing, and a blower motor configured to selectively rotate the blower impeller. In other embodiments, the indoor fan110may comprise a mixed-flow fan and/or any other suitable type of fan. The indoor fan110is configured as a modulating and/or variable speed fan capable of being operated at many speeds over one or more ranges of speeds. In other embodiments, the indoor fan110may be configured a multiple speed fan capable of being operated at a plurality of operating speeds by selectively electrically powering different ones of multiple electromagnetic windings of a motor of the indoor fan110. In yet other embodiments, the indoor fan110may be a single speed fan.

The indoor metering device112is an electronically controlled motor drive electronic expansion valve (EEV). In alternative embodiments, the indoor metering device112may comprise a thermostatic expansion valve, a capillary tube assembly, and/or any other suitable metering device. The indoor metering device112may comprise and/or be associated with a refrigerant check valve and/or refrigerant bypass for use when a direction of refrigerant flow through the indoor metering device112is such that the indoor metering device112is not intended to meter or otherwise substantially restrict flow of the refrigerant through the indoor metering device112.

Outdoor unit104comprises an outdoor heat exchanger114, a compressor116, an outdoor fan118, an outdoor metering device120, and a reversing valve122. Outdoor heat exchanger114is a microchannel heat exchanger configured to allow heat exchange between refrigerant carried within internal passages of the outdoor heat exchanger114and fluids that contact the outdoor heat exchanger114but that are kept segregated from the refrigerant. In other embodiments, outdoor heat exchanger114may comprise a spine fin heat exchanger, a plate fin heat exchanger, or any other suitable type of heat exchanger.

The compressor116is a multiple speed scroll type compressor configured to selectively pump refrigerant at a plurality of mass flow rates. In alternative embodiments, the compressor116may comprise a modulating compressor capable of operation over one or more speed ranges, the compressor116may comprise a reciprocating type compressor, the compressor116may be a single speed compressor, and/or the compressor116may comprise any other suitable refrigerant compressor and/or refrigerant pump.

The outdoor fan118is an axial fan comprising a fan blade assembly and fan motor configured to selectively rotate the fan blade assembly. In other embodiments, the outdoor fan118may comprise a mixed-flow fan, a centrifugal blower, and/or any other suitable type of fan and/or blower. The outdoor fan118is configured as a modulating and/or variable speed fan capable of being operated at many speeds over one or more ranges of speeds. In other embodiments, the outdoor fan118may be configured as a multiple speed fan capable of being operated at a plurality of operating speeds by selectively electrically powering different ones of multiple electromagnetic windings of a motor of the outdoor fan118. In yet other embodiments, the outdoor fan118may be a single speed fan.

The outdoor metering device120is a thermostatic expansion valve. In alternative embodiments, the outdoor metering device120may comprise an electronically controlled motor driven EEV, a capillary tube assembly, and/or any other suitable metering device. The outdoor metering device120may comprise and/or be associated with a refrigerant check valve and/or refrigerant bypass for use when a direction of refrigerant flow through the outdoor metering device120is such that the outdoor metering device120is not intended to meter or otherwise substantially restrict flow of the refrigerant through the outdoor metering device120.

The reversing valve122is a so-called four-way reversing valve. The reversing valve122may be selectively controlled to alter a flow path of refrigerant in the HVAC system100as described in greater detail below. The reversing valve122may comprise an electrical solenoid or other device configured to selectively move a component of the reversing valve122between operational positions.

The system controller106may comprise a touchscreen interface for displaying information and for receiving user inputs. The system controller106may display information related to the operation of the HVAC system100and may receive user inputs related to operation of the HVAC system100. However, the system controller106may further be operable to display information and receive user inputs tangentially and/or unrelated to operation of the HVAC system100. In some embodiments, the system controller106may selectively communicate with an indoor controller124of the indoor unit102, with an outdoor controller126of the outdoor unit104, and/or with other components of the HVAC system100. In some embodiments, the system controller106may be configured for selective bidirectional communication over a communication bus128. In some embodiments, portions of the communication bus128may comprise a three-wire connection suitable for communicating messages between the system controller106and one or more of the HVAC system100components configured for interfacing with the communication bus128. Still further, the system controller106may be configured to selectively communicate with HVAC system100components and/or other device130via a communication network132. In some embodiments, the communication network132may comprise a telephone network and the other device130may comprise a telephone. In some embodiments, the communication network132may comprise the Internet and the other device130may comprise a so-called smartphone and/or other Internet enabled mobile telecommunication device.

The indoor controller124may be carried by the indoor unit102and may be configured to receive information inputs, transmit information outputs, and otherwise communicate with the system controller106, the outdoor controller126, and/or any other device via the communication bus128and/or any other suitable medium of communication. In some embodiments, the indoor controller124may be configured to communicate with an indoor personality module134, receive information related to a speed of the indoor fan110, transmit a control output to an electric heat relay, transmit information regarding an indoor fan110volumetric flow-rate, communicate with and/or otherwise affect control over an air cleaner136, and communicate with an indoor EEV controller138. In some embodiments, the indoor controller124may be configured to communicate with an indoor fan controller142and/or otherwise affect control over operation of the indoor fan110. In some embodiments, the indoor personality module134may comprise information related to the identification and/or operation of the indoor unit102.

In some embodiments, the indoor EEV controller138may be configured to receive information regarding temperatures and pressures of the refrigerant in the indoor unit102. More specifically, the indoor EEV controller138may be configured to receive information regarding temperatures and pressures of refrigerant entering, exiting, and/or within the indoor heat exchanger108. Further, the indoor EEV controller138may be configured to communicate with the indoor metering device112and/or otherwise affect control over the indoor metering device112.

The outdoor controller126may be carried by the outdoor unit104and may be configured to receive information inputs, transmit information outputs, and otherwise communicate with the system controller106, the indoor controller124, and/or any other device via the communication bus128and/or any other suitable medium of communication. In some embodiments, the outdoor controller126may be configured to communicate with an outdoor personality module140that may comprise information related to the identification and/or operation of the outdoor unit104. In some embodiments, the outdoor controller126may be configured to receive information related to an ambient temperature associated with the outdoor unit104, information related to a temperature of the outdoor heat exchanger114, and/or information related to refrigerant temperatures and/or pressures of refrigerant entering, exiting, and/or within the outdoor heat exchanger114and/or the compressor116. In some embodiments, the outdoor controller126may be configured to transmit information related to monitoring, communicating with, and/or otherwise affecting control over the outdoor fan118, a compressor sump heater, a solenoid of the reversing valve122, a relay associated with adjusting and/or monitoring a refrigerant charge of the HVAC system100, a position of the indoor metering device112, and/or a position of the outdoor metering device120. The outdoor controller126may further be configured to communicate with a compressor drive controller144that is configured to electrically power and/or control the compressor116.

The HVAC system100is shown configured for operating in a so-called cooling mode in which heat is absorbed by refrigerant at the indoor heat exchanger108and heat is rejected from the refrigerant at the outdoor heat exchanger114. In some embodiments, the compressor116may be operated to compress refrigerant and pump the relatively high temperature and high pressure compressed refrigerant from the compressor116to the outdoor heat exchanger114through the reversing valve122and to the outdoor heat exchanger114. As the refrigerant is passed through the outdoor heat exchanger114, the outdoor fan118may be operated to move air into contact with the outdoor heat exchanger114, thereby transferring heat from the refrigerant to the air surrounding the outdoor heat exchanger114. The refrigerant may primarily comprise liquid phase refrigerant and the refrigerant may be pumped from the outdoor heat exchanger114to the indoor metering device112through and/or around the outdoor metering device120which does not substantially impede flow of the refrigerant in the cooling mode. The indoor metering device112may meter passage of the refrigerant through the indoor metering device112so that the refrigerant downstream of the indoor metering device112is at a lower pressure than the refrigerant upstream of the indoor metering device112. The pressure differential across the indoor metering device112allows the refrigerant downstream of the indoor metering device112to expand and/or at least partially convert to gaseous phase. The gaseous phase refrigerant may enter the indoor heat exchanger108. As the refrigerant is passed through the indoor heat exchanger108, the indoor fan110may be operated to move air into contact with the indoor heat exchanger108, thereby transferring heat to the refrigerant from the air surrounding the indoor heat exchanger108. The refrigerant may thereafter reenter the compressor116after passing through the reversing valve122.

To operate the HVAC system100in the so-called heating mode, the reversing valve122may be controlled to alter the flow path of the refrigerant, the indoor metering device112may be disabled and/or bypassed, and the outdoor metering device120may be enabled. In the heating mode, refrigerant may flow from the compressor116to the indoor heat exchanger108through the reversing valve122, the refrigerant may be substantially unaffected by the indoor metering device112, the refrigerant may experience a pressure differential across the outdoor metering device120, the refrigerant may pass through the outdoor heat exchanger114, and the refrigerant may reenter the compressor116after passing through the reversing valve122. Most generally, operation of the HVAC system100in the heating mode reverses the roles of the indoor heat exchanger108and the outdoor heat exchanger114as compared to their operation in the cooling mode.

While HVAC system100are shown as a so-called split system comprising an indoor unit102located separately from the outdoor unit104, alternative embodiments of an HVAC system100may comprise a so-called package system in which one or more of the components of the indoor unit102and one or more of the components of the outdoor unit104are carried together in a common housing or package. The HVAC system100is shown as a so-called ducted system where the indoor unit102is located remote from the conditioned zones, thereby requiring air ducts to route the circulating air. However, in alternative embodiments, an HVAC system100may be configured as a non-ducted system in which the indoor unit102and/or multiple indoor units102associated with an outdoor unit104is located substantially in the space and/or zone to be conditioned by the respective indoor units102, thereby not requiring air ducts to route the air conditioned by the indoor units102.

It will be appreciated that a so-called clean air delivery rate (CADR) of HVAC system100may be defined as the product of a volumetric flow-rate (sometimes expressed in units of cubic feet per minute or CFM) of air passing through air cleaner200multiplied by a so-called air cleaner efficiency of air cleaner200. Accordingly, a relatively higher CADR may generally be accomplished by adjusting the volumetric flow-rate of air through the air cleaner200and/or by adjusting the air cleaner efficiency so that the product of the two is relatively increased. In this embodiment, air cleaner200may operate to clean air using a so-called electrostatic precipitation process. In some embodiments, the air cleaner200may comprise an electrically powered field charger configured to enable the electrostatic precipitation process. In some embodiments, varying an electrical supply to the field charger may vary a resultant performance and/or air cleaner efficiency of the air cleaner200. For example, in some embodiments, providing a relatively higher voltage to the field charger may increase a performance and/or air cleaner efficiency of the air cleaner200as compared to a performance and/or air cleaner efficiency of the air cleaner200when a relatively lower voltage is provided to the field charger. In some embodiments, the air cleaner200may be configured to operate at one of three power level settings, high, medium, and low, each setting being indicative of relative voltage levels provided to the field charger.

In alternative embodiments, an air cleaner200may be configured to selectively modulate and/or vary a power level setting over one or more ranges of power levels. For example, the air cleaner200may even be capable of adjusting a voltage supplied to a field charger so that the air cleaner efficiency of the air cleaner200is adjustable over a relatively large range of values at which the air cleaner200may be effectively operated. Still further, in alternative embodiments of an air cleaner200, the air cleaner200may comprise other components that affect air cleaner performance and/or an air cleaner efficiency of the air cleaner200in addition to or instead of a field charger. During subsequent discussion of a so-called air cleaner power setting and/or field charger power setting, it will be appreciated that it is intended that operating an air cleaner200at a relatively higher power setting is meant to control the air cleaner200and/or one or more of the components of the air cleaner200to have a first or higher rate of performance and/or air cleaner efficiency while operating the air cleaner200at a relatively lower power setting is meant to control the air cleaner200and/or one or more of the components of the air cleaner200to have a second or relatively lower rate of performance and/or air cleaner efficiency as compared to the first or higher rate of performance and/or air cleaner efficiency.

In some embodiments, the system controller106may be operated to allow a user to control the HVAC system100to meet a user's demand for air cleaned by the air cleaner200. In some embodiments, the user's demand for the provision of cleaned air may comprise controlling one or more of (1) a volumetric flow-rate of air passing through the air cleaner200, (2) a performance and/or air cleaner efficiency of the air cleaner200, and (3) a duration of operation of the air cleaner200and/or indoor fan110that moves air through the air cleaner200.

Referring now toFIG. 2A, an exploded view of the air cleaner200is shown. The air cleaner200may comprise a cabinet202that houses the other components of the air cleaner200. The air cleaner200may also comprise a pre-filter206operable to trap large particles such as hair and lint. The air cleaner200may also comprise a field charger208(as described above) and collection cells204and205operable to remove and collect small impurities from the air. The field charger208may be operable to ionize the air close to the cells204and205, thereby charging particles that pass through the pre-filter206in the air flow. Then, the particles are collected by the collection cells204and205which have an opposite charge of the particles in the air. Additionally, the air cleaner200may comprise a power door212operable to supply power to the air cleaner200and allow for control of the components of the air cleaner200.FIG. 2Billustrates an orthogonal front view of the air cleaner200ofFIG. 2Awith door212removed, and the direction of the air flow220through the air cleaner200. In some embodiments, the air cleaner200may comprise additional components and features not listed here, such as additionally power control components, for example. Additionally, although the air cleaner200is shown as a part of an HVAC system100, embodiments may include stand-alone air cleaners comprising a field charger.

Referring now toFIGS. 3A-3B, an oblique schematic view of the field charger208is shown. In some embodiments, the field charger208may comprise a grid of interconnected bars300. In some embodiments, the grid shape may be formed by molding bars300individually and then connecting the bars. In other embodiments, the bars300of the grid shape may be molded together, forming at least a portion of the total grid. In some embodiments, subsections of the grid may be formed and then connected. In some embodiments, the bars300forming the grid may comprise an inner core302and an outer overmold304. In some embodiments, the inner core302may be made of a conductive plastic material and the outer overmold304may be made of a non-conductive insulating plastic material. In some embodiments, the grid shape of the field charger208may be coupled to an earth plate306to create a ground connection. The earth plate306may also provide stability for the grid of the field charger208.

Referring now toFIGS. 4A-4C, an alternative embodiment of a bar400is shown. Bar400is substantially similar to bar300at least insofar as it may be incorporate into the field charger208.FIG. 4Aillustrates a side view. The bar400may comprise an inner conductive core402, a plurality of pins408, and an outer non-conductive overmold404. The pins408may be operable to ionize the air around the pins408when a voltage is distributed to the pins408. In some embodiments, the pins408may be molded into the inner conductive core402, wherein the conductive core402may supply the voltage to each of the pins408. Then, the non-conductive overmold404may be molded over the inner core402and the pins408, such that the pins408are conductively connected via the conductive core402. In some embodiments, one or more contact points412may be molded into the conductive core402and overmold404to allow for a voltage to be applied to the inner core402and therefore the pins408. In some embodiments, the inner conductive core402may comprise one or more of carbon powder or carbon fiber filled nylon having a minimum thickness of about 0.06 inches and a minimum filler percentage of 8% carbon powder or 5% carbon fiber. Alternatively, the core402may comprise stainless steel filled nylon comprising a minimum thickness of about 0.06 inches and a minimum filler percentage of about 10% stainless steel filler. In some embodiments, the overmold404material may be configured to electrically insulate against transmission of electricity of approximately 8000 to 9000 volts. In some embodiments, the non-conductive overmold404may comprise glass filled acetyl or polypropylene comprising a minimum thickness of about 0.06 inches and comprising a minimum glass filler percentage of about 10%. In some embodiments, the required properties of the conductive core402and the non-conductive overmold404may depend on their shape.

FIG. 4Billustrates an orthogonal end view of the bar400. In some embodiments, the bar400may comprise an octagonal or tapered shape, as illustrated inFIG. 4B, while in other embodiments, the bars may comprise other shapes, such as rectangular, round, oval, T-shaped, etc. In some embodiments, the tapered edges of the bar400illustrated inFIG. 4Bmay reduce air-flow disruption over the bar400. In some embodiments, the inner core402may be concentric with the outer overmold404, wherein the shape formed by the edges of the core402may be similar to the shape formed by the edges of the overmold404. In other embodiments, the shape of the core402may be different from the shape of the overmold404. In some embodiments, the pin408may extend through the overmold404into the conductive core402. In some embodiments, the pin408may be embedded (or extend) all the way through the inner core402, as shown inFIG. 4B, which may provide stability for the pin(s)408held in place by the core402and overmold404. In other embodiments, the pin408may extend though only a portion of the inner core402, such as one-quarter of the way, half-way, or three-quarters of the way into the core402, for example. The conductive connection between the conductive core402and the pins408may not depend on the depth that the pin408penetrates into the core402.

In the specific embodiment shown inFIGS. 4A-4C, a height420of the bar400including the pin408may be approximately 0.713 inches. As shown inFIG. 4C, a height422of the bar400, not including the pin408, may be approximately 0.375 inches. A width424of the bar400may be approximately 0.250 inches. A thickness426of the outer overmold404(between the core402and the edges of the overmold) may be approximately 0.063 inches.

Referring now toFIGS. 5A-5D, orthogonal views of the inner core402of the bar400are shown. The inner core402may be injection molded around a plurality of pins408, which may be spread along the length of the core402. In the specific embodiment shown inFIG. 5A, the total length520of the core402may be approximately 19.250 inches. In some embodiments, the first pin408along the length of the core402may be at a distance521of approximately 1.121 inches from the end403of the core402. A distance522between each of the pins408may be approximately 2.126 inches. The core402may comprise a plurality of cut-outs502. The cut-outs502may be located on either side of the pins408and at the ends of the bar400. In some embodiments, a first set of cut-outs504may be at a distance525of approximately 0.200 inches from the end403of the core402. Depths523and524of all of the cut-outs502may be approximately 0.050 inches. A width526of the cut-outs502may be approximately 0.200 inches. Additionally, distances527and528between the pin408and the cut-outs502may be approximately 0.200 inches.

In the specific embodiment shown inFIGS. 5C and 5D, a height530of the inner core402and the pin408may be approximately 0.650 inches. Additionally, a height531of the inner core402(not including the pin408) may be approximately 0.250 inches. In the embodiment shown, a total width532of the inner core402may be approximately 0.125 inches. The shape may comprise tapered edges, wherein widths533and534at the top and bottom of the inner core402, respectively, may be approximately 0.016 inches. In the embodiments shown, angles535and536of the tapered edges relative to a side may be approximately 30 degrees, wherein the cross-section of the core402may be approximately symmetrical about vertical and horizontal axes.

Referring now toFIGS. 6A-6B, orthogonal views of the insulating overmold404are shown. In the specific embodiment, a total length602of the bar400may be approximately 19.375 inches. A distance604between the edge601of the overmold404and an edge603of the inner core402may be approximately 0.063 inches. A height606of the overmold404may be approximately 0.375 inches. A total width608of the overmold404may be approximately 0.250 inches. A thickness610of the overmold404may be approximately 0.063 inches. The overmold404may also comprise tapered edges similar to those of the inner core402.

Referring now toFIGS. 7A-7B, orthogonal views of the pin408are shown. A length702of the pin408may be approximately 0.650 inches. A diameter704of the pin408may be approximately 0.016 inches.

Referring now toFIG. 8, a flow chart of a method800of manufacturing a field charger is shown. The method800starts at block802, where a plurality of metal pins is placed in a mold. Then, at block804, contact points are also placed in the mold. At block806, a conductive resin is molded over at least a portion of each of the plurality of pins, wherein the conductive resin forms an inner core. At block808, an insulating resin is molded over the inner core, plurality of pins, and contact points, wherein the insulating resin forms a non-conductive overmold, and wherein at least a portion of the pins and contact points extend from the non-conductive overmold. At block810, an earthplate is mounted to the non-conductive overmold. In some embodiments, the shape of the mold comprises at least one bar. In some embodiments, the shape of the mold comprises a grid with horizontal and vertical bars.