INDOOR AIR QUALITY APPLIANCE

Abstract

A self-regulating appliance operable as an air-exchanger, humidifier, dehumidifier, air scrubber, and air sterilizer. The appliance includes a cabinet defining an interior with a plurality of fluid passageways, a first inlet configured to receive a first air flow from a dwelling interior, a second inlet configured to receive a second air flow from a dwelling exterior, a first outlet configured to deliver a third air flow to the dwelling interior, and a second outlet configured to deliver a fourth air flow to the dwelling exterior. At least one blower is fluidically coupled to the first and second outlets to expel the third air flow to the dwelling interior and the fourth air flow to the dwelling exterior. The cabinet also includes an energy exchange core and a desiccant wheel. The desiccant wheel configured to rotate to transfer moisture and sensible energy between at least two air streams.

Claims

1. A self-regulating appliance operable as an air-exchanger, a humidifier, a dehumidifier, an air scrubber, and an air sterilizer, comprising: a cabinet defining an interior with a plurality of fluid passageways, the cabinet comprising a first inlet configured to receive a first air flow from a dwelling interior, a second inlet configured to receive a second air flow from a dwelling exterior, a first outlet configured to deliver a third air flow to the dwelling interior, and a second outlet configured to deliver a fourth air flow to the dwelling exterior; at least one blower fluidically coupled to the first and second outlets configured to expel the third air flow to the dwelling interior and the fourth air flow to the dwelling exterior; an energy exchange core fluidically coupled to the first and second inlets and outlets within the interior of the cabinet, the energy exchange core configured to transfer sensible energy between at least two air streams; and a desiccant wheel fluidically coupled to the core and first and second inlets and outlets, the desiccant wheel configured to rotate to transfer moisture and sensible energy between at least two air streams.

2. The self-regulating appliance of claim 1, further comprising: a sterilization source coupled to the cabinet interior configured to emit a prescribed amount of light to kill airborne viruses.

3. The self-regulating appliance of claim 2, wherein the sterilization source comprises at least one UV-C light source configured to emit ultraviolet light with a wavelength between 200 and 280 nanometers to kill the airborne viruses.

4. The self-regulating appliance of claim 2, further comprising: a filtration subsystem coupled to the housing interior configured to filter out unwanted airborne particulates from an air stream within the appliance.

5. The self-regulating appliance of claim 4, wherein the filtration subsystem comprises a first upstream pre-filter for removing large particulates and a second downstream filter for removing at least 99.7% of particulates greater than 0.3 microns in size.

6. The self-regulating appliance of claim 4, further comprising: a heating subsystem coupled to the cabinet interior for heating an air stream and reactivating desiccant wheel media.

7. The self-regulating appliance of claim 6, wherein the heating subsystem comprises at least one humidifier heater configured to heat an air stream and lower a relative humidity of the air and at least one reactivation heater for heating air adjacent to the desiccant wheel to reactivate the desiccant wheel media.

8. The self-regulating appliance of claim 6, further comprising: a humidifying subsystem coupled to the cabinet interior configured to receive a flow of water and provide moisture to an air stream within the appliance.

9. The self-regulating appliance of claim 8, wherein the humidifying subsystem comprises a water pad with a mesh substrate and a water wicking material for retaining and transferring moisture to the air stream within the appliance.

10. The self-regulating appliance of claim 9, wherein the humidifying subsystem further comprises a pad tray for positioning and holding the water pad within the appliance, a fill tube for receiving and metering a flow of water through the water pad, a water valve coupled to an external water source for controlling the flow of water, and a water filter for removing impurities from the flow of water prior to being provided to the water pad.

11. The self-regulating appliance of claim 9, further comprising: a plurality of external ducts coupled to the first and second inlets and outlets configured to provide the first and second air flows to the first and second inlets and receive the third and fourth air flows from the first and second outlets.

12. The self-regulating appliance of claim 11, further comprising: a plurality of dampers coupled to the plurality of external ducts for regulating air flow within the plurality of external ducts.

13. The self-regulating appliance of claim 12, further comprising: a control system configured to operate the appliance in a plurality of operating modes, wherein, in a first operating mode, the appliance receives the first airflow from the dwelling interior and sequentially passes the first airflow through the filtration subsystem, a bottom half of the desiccant wheel, the sterilization source, the energy exchange core, the humidifier heaters, and the humidifying subsystem prior to delivery into the first outlet.

14. The self-regulating appliance of claim 13, wherein, in a second operating mode, the appliance receives the first airflow from the dwelling interior, splits the first airflow into a fifth and sixth airflows within the cabinet interior, combines the fifth airflow and the second airflow from the dwelling exterior into a combined airflow, and passes the combined airflow sequentially through the filtration subsystem, a bottom half of the desiccant wheel, the sterilization source, the energy exchange core, the humidifier heaters, and the humidifying subsystem prior to delivery into the first outlet and the sixth airflow through the energy exchange core, the reactivation heaters, and a top half of the desiccant wheel prior to delivery into the second outlet.

15. The self-regulating appliance of claim 14, wherein over 80% of a temperature differential is transferred between the combined airflow and the sixth airflow within the energy exchange core.

16. The self-regulating appliance of claim 14, wherein, in a fourth operating mode, the appliance receives the first airflow from the dwelling interior and the second airflow from the dwelling exterior, passes the first airflow through the energy exchange core, the reactivation heaters, and the top of the desiccant wheel prior to delivery to the second outlet and the second airflow through the filtration subsystem, the bottom half of the desiccant wheel, the sterilization source, the energy exchange core, the humidifier heaters, and the humidifying subsystem prior to delivery into the first outlet.

17. The self-regulating appliance of claim 16, wherein, during the fourth operating mode, the desiccant wheel rotates at 30 revolutions per minute and over 80% of an enthalpy differential is transferred between the first and second airflows by the desiccant wheel.

18. The self-regulating appliance of claim 13, wherein, in a fifth operating mode, the at least one blower operates in a high-speed mode to expel airflow through the second outlet, the plurality of external ducts, a by-pass duct, and an intake screen of an exterior port.

19. A self-regulating appliance operable as an air-exchanger, a humidifier, a dehumidifier, an air scrubber, and an air sterilizer, comprising: a cabinet defining an interior with a plurality of fluid passageways, the cabinet comprising a first inlet configured to receive a first air flow from a dwelling interior, a second inlet configured to receive a second air flow from a dwelling exterior, a first outlet configured to deliver a third air flow to the dwelling interior, and a second outlet configured to deliver a fourth air flow to the dwelling exterior; at least one blower fluidically coupled to the first and second outlets configured to expel the third air flow to the dwelling interior and the fourth air flow to the dwelling exterior; an energy exchange core fluidically coupled to the first and second inlets and outlets within the interior of the cabinet, the energy exchange core configured to transfer sensible energy between at least two air streams; a desiccant wheel fluidically coupled to the core and first and second inlets and outlets, the desiccant wheel configured to rotate to transfer moisture and sensible energy between at least two air streams; and a sterilization source coupled to the cabinet interior configured to emit a prescribed amount of light to kill airborne viruses.

20. A self-regulating appliance operable as an air-exchanger, a humidifier, a dehumidifier, an air scrubber, and an air sterilizer, comprising: a cabinet defining an interior with a plurality of fluid passageways, the cabinet comprising a first inlet configured to receive a first air flow from a dwelling interior, a second inlet configured to receive a second air flow from a dwelling exterior, a first outlet configured to deliver a third air flow to the dwelling interior, and a second outlet configured to deliver a fourth air flow to the dwelling exterior; at least one blower fluidically coupled to the first and second outlets configured to expel the third air flow to the dwelling interior and the fourth air flow to the dwelling exterior; an energy exchange core fluidically coupled to the first and second inlets and outlets within the interior of the cabinet, the energy exchange core configured to transfer sensible energy between at least two air streams; a desiccant wheel fluidically coupled to the core and first and second inlets and outlets, the desiccant wheel configured to rotate to transfer moisture and sensible energy between at least two air streams; a sterilization source coupled to the cabinet interior configured to emit a prescribed amount of light to kill airborne viruses; and a control system configured to operate the appliance in a plurality of operating modes, wherein, in a first operating mode, the first air flow passes through a bottom half of the desiccant wheel, the sterilization source, the energy exchange core, and the at least one blower to the first outlet.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Subject matter hereof may be more completely understood in consideration of the following detailed description of various embodiments in connection with the accompanying figures, in which:

[0012] FIG. 1 shows an appliance and components thereof in accordance with embodiments of the present invention.

[0013] FIG. 2 shows reactivation heaters, water valves, and humidifier fill tube(s) and orifice(s) in accordance with embodiments of the present invention.

[0014] FIGS. 3 and 4 show a drain and water inlet/supply port in accordance with embodiments of the present invention.

[0015] FIGS. 5 and 6 show designated areas of an appliance in accordance with embodiments of the present invention.

[0016] FIG. 7 shows an air scrub/sterilization operating mode in accordance with embodiments of the present invention.

[0017] FIG. 8 shows a dehumidifying operating mode in accordance with embodiments of the present invention.

[0018] FIG. 9 shows a humidifying operating mode in accordance with embodiments of the present invention.

[0019] FIG. 10 shows an air exchange operating mode in accordance with embodiments of the present invention.

[0020] FIGS. 11 and 12 show a self-cleaning operating mode in accordance with embodiments of the present invention.

[0021] FIG. 13 shows an appliance and furnace coupling in accordance with an embodiment of the present invention.

[0022] While various embodiments are amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit the claimed inventions to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the subject matter as defined by the claims.

DETAILED DESCRIPTION

[0023] The present disclosure sets forth an appliance capable of simultaneously serving as a self-regulating air exchanger, humidifier, dehumidifier, air scrubber, and air sterilizer to efficiently and effectively maintain comfortable climate conditions and high IAQ levels without the drawbacks of having to install, operate, and maintain separate units having high energy and cost demands. Namely, as will be discussed below, an appliance of the present invention may include numerous mechanical and electro-mechanical components operable under differing conditions to carry out a humidifying, dehumidifying, sterilizing, scrubbing, and air exchanging operation. Such components may include a disinfection source, e.g., UV-C (Ultraviolet C range) sterilization lamp(s) for killing airborne viruses such as COVID-19, along with two sensible energy transfer components and a moisture transfer component, e.g., rotor and core combination, for highly efficient enthalpy recovery. In the present disclosure, sensible energy may be defined as the thermal energy that changes the temperature of a system without changing its phase. Sensible energy may also be referred to as sensible heat and measured via a thermometer or other temperature sensing device.

[0024] Currently, as noted above, ERVs are becoming more common. However, all ERVs and HRVs have tradeoffs. Either they capture more moisture and less sensible energy or vice versa. Alternatively, the present appliance does not have this trade off. Specifically, as noted above, an appliance of the present invention may include two separate components for transferring moisture and sensible energy from one stream to another. In combination, both components may allow for high levels of moisture and energy transfer. Such components may include a quality sensible energy only exchange core and a desiccant wheel for transferring both sensible energy and moisture. Generally, the more desiccant media, e.g., silica gel, the wheel possess, the more mass it has, and, as a result, the more sensible energy and moisture is transferred. With both components, the disclosed appliance may allow for highly efficient and effective sensible energy and moisture transfer. Specifically, at 80% enthalpy transfer efficiency, an appliance may achieve 96% total sensible efficiency with 80% moisture transfer efficiency.

[0025] Through the inclusion of a second sensible energy transfer component, e.g., desiccant wheel, a bulk of normally wasted sensible energy may be captured. Namely, a desiccant wheel may be better at transferring moisture than a single membrane that creates a path for moisture to move from one stream to the other. Specifically, a rotating wheel with desiccant media may be more efficient and effective as one tablespoon of desiccant media, e.g., silica gel, has the surface area of a football field giving the desiccant wheel significantly more surface area to transfer moisture than a membrane. Additionally, since general statements of transfer efficiency are inapplicable without knowing the input conditions, it is to be understood that input conditions are often provided and referred to.

[0026] A desiccant wheel may be constructed to accommodate both functions, e.g., moisture and sensible heat transfer. However, to achieve optimal performance, the wheel may need to spin at drastically different speeds. For example, an optimum rotational speed for a dehumidification operation may be about 15 revolutions per hour whereas, for a sensible energy transfer operation, an optimum rotational speed may be about 2250 revolutions per hour.

[0027] Outside of the type of mechanical and electrical subsystems included, it is to be understood that the order and encounter of air streams with these subsystems is crucial to maintaining an optimal performance of the appliance. For example, in addition a desiccant wheel rotational speed, there is also an optimum ratio of air flow through the desiccant wheel during a dehumidification mode. Moreover, during this mode, a bypass section of the appliance may be essential to allow for optimal performance without producing a potentially dangerous pressure imbalance within the target structure.

[0028] Generally, as discussed above, the appliance may serve as a more efficient and effective enthalpy recovery device in which energy is captured from an outbound stream and placed into an incoming fresh air stream through the use of both a desiccant wheel and a heat exchanger core with defined internal air passageways. Further, along with the other appliance subsystems and air passageways, the appliance may operate in numerous modes as an efficient and effective air exchanger, humidifier, dehumidifier, air scrubber, and air sterilizer. In turn, this may result in a lower operating and installation cost, lack of required supervision, and high operating efficiency and effectiveness.

[0029] FIG. 1 shows an appliance and components and areas thereof in accordance with embodiments of the present invention. As noted above, appliance 100 may operate in numerous operating modes to efficiently and effectively condition or process the air. Generally, appliance 100 may operate in numerous modes as an efficient and effective air exchanger, humidifier, dehumidifier, air scrubber, and air sterilizer to increase occupant comfort, from a thermal and moisture level standpoint, and improve air quality while maximizing energy efficiency. Appliance 100 may be installed inside or outside provided that the necessary operating accommodations are met. For example, internal structures may include dwellings, mechanical rooms, etc. It is to be understood that appliance 100 may operate in virtually any setting that has the necessary power, ductwork, water supply, and drain for operating appliance 100.

[0030] Appliance 100 may be given its own dedicated ductwork or tied into an existing HVAC system ductwork. For example, if there is a priority of rooms, appliance 100 may be given a custom dedicated ductwork system. However, if the entire dwelling is desired, appliance 100 may be given an existing HVAC ductwork system. During operation, appliance 100 may, at all times, provide a dwelling with clean, sterilized air at an ideal temperature and humidity level. Such air may be circulated through a dwelling's existing or dedicated HVAC system for distribution throughout the dwelling. For example, with existing ductwork, a HVAC unit's blower may receive the conditioned air and circulate the air throughout a target structure.

[0031] As shown in FIG. 1, appliance 100 may include a housing or cabinet 102 for storing the components and subsystems thereof, inlet ports 104, 106 for receiving a flow of air along flow paths 186 and 188, outlet ports 108 and 110 for delivering a flow of air along flow paths 190 and 192, blower 112 for moving air from a target structure to a dwelling exterior, blower 114 for moving air from the outside to a dwelling interior, or potentially, recirculating air from a target structure interior back to the inside of the structure after a filtering, sterilization, and humidification operation, a core 116 for transferring energy from one air stream to another, a rotor 118 with a driving mechanism 120 and desiccant media (not shown) for rotating and conditioning the air, damper(s) 122, 124, and 126 for directing and controlling air flow, a filtration subsystem 128 with first 130 and second 132 filters for filtering out unwanted airborne particulates, a heating subsystem 134, e.g., reactivation heaters 204 (shown in FIG. 2) and humidifier heaters 182, for heating air and reactivating rotor media, a disinfection source 136, e.g., UV-C source, for killing airborne viral and bacterial organisms, a humidifier subsystem 138 with a filter 142, pad tray/fill tube 146, pad 148, etc. for providing air moisture, external ducts 154, 156, 158, and 160 coupled to inlets 104, 106 and outlets 108, 110 for receiving and expelling air, exterior ports 176 and 178 for preventing weather elements, e.g., snow and rain, from entering exterior ducts 154 and 160, and a control system 180 for controlling the components and subsystems thereof.

[0032] Housing or cabinet 102 may comprise steel, aluminum, plastic, etc. In accordance with the present invention, housing 102 may include any material capable of providing an airtight exterior while resisting an airstream pressure differential without collapse or excessive leakage.

[0033] Inlet ports 104 and 106 may be used as openings between an exterior of appliance 100 and internal areas, i.e., first 402 and fourth areas 408 shown in FIG. 5, respectively. However, in some embodiments, inlet ports 104 and 106 may serve as outlets as well. For example, it may be desirable to send a shot of air through ports 104 and 106, down ducts 154 and 158, and through intake screen(s) for cleaning purposes.

[0034] Outlet ports 108 and 110 may be used as openings between an exterior of appliance 100 and internal areas, i.e., third 406 and sixth areas 412 shown in FIG. 5, respectively. Similar to inlet ports 104 and 106, outlet ports 108 and 110 may also serve as inlets in some examples.

[0035] Blowers 112 and 114 may be motorized backward inclined blowers for moving exhaust air streams through ducts 156 and 160. A speed of blowers 112 and 114, and thus CFM, may be controllable via potentiometer(s) that allow for an installer to balance air flow without creating a positive or negative pressure condition on a target building. However, in some examples, it may be desirable to create a pressure condition. For example, it may be desirable to have an over pressurized or negative air situation in clean rooms, surgical suites, and other rooms with similar requirements. Alternatively, for residential dwellings, a balanced condition may be desirable without flue flow issues.

[0036] Blowers 112 and 114 may be any type of air moving device with a motor and impeller or blade. Additionally, instead of two separate blower motors, a single blower motor may be used to power blowers 112 and 114. A clutch and gearbox may be engaged with a blower motor to change the speeds of either blower 112 or 114. In some examples, airflow may also be controlled by dampers 122, 124, and 126 rather than modifying an operating speed of blower(s) 112 and 114.

[0037] Core 116 may be a sensible, concurrent flow, aluminum energy exchange device and comprise any material capable of efficiently transferring sensible energy from one air stream to another while keeping the streams separate. In exemplary embodiments, core 116 may be made of a material that will not support fungal or bacterial growth while also being durable enough to last for over a year. Core 116 may also be an enthalpy exchanger however, in this example, core 116 may be used in conjunction with a Heat Recovery Rotor and not a desiccant rotor, as will be discussed below, as appliance 100 transfers the moisture part of enthalpy twice and lowers the appliances recovery efficiency. In accordance with the present invention, core 116 may be a cross flow, concurrent flow or any other design which effectively transfers energy from one stream to another. Multiple cores 116 may also be used.

[0038] Rotor 118 may be a wheel made of a stable substrate with air passages which run from face to face impregnated with a desiccant media, e.g., silica gel. During a dehumidification operation, as will be discussed below, a rotor wheel may rotate on its axis around 12 revolutions per hour and, during enthalpy exchange operations, spin at a rate of 30 revolutions per minute. Seals may sweep the wheel and minimize transfer from one air stream to the other. In one example, the seals may split the wheel into two equal halves. Perimeter seals may also force the air to go through the air passageways instead of around the wheel.

[0039] A rotor wheel may be about 4 thick and comprise any number of materials and types of desiccant media. In operation, the wheel may spin at any speed to optimize efficiency for the selected modes and for the observed conditions. While, in one example, the wheel may be split into a 50/50 ratio, it is to be understood that any ratio may be used to fit the desired operating conditions. This may include dividing the wheel into more than two sections. Also, while the wheel may include a desiccant material, a nondesiccant material, which transfers sensible heat and not moisture, may be used as well. Further, in some embodiments, a non-rotating wheel may be used as well. For example, a stationary piece of desiccant laden media may be used along with dampers to route multiple air streams through it in different cycles.

[0040] Rotor driving mechanism 120 may include any type of motor with a pulley or sprocket that drives a belt or chain to turn rotor/wheel 118. A motor may be driven by direct drive, gears, belts, or chains and controlled in accordance with any number of control protocols or methods.

[0041] Dampers 122, 124, and 126 may be motorized or serve as gravity operated, passive back check valves. For example, damper 122 may be a motorized damper lying between external duct 154 and inlet port 104, damper 124 may be a motorized damper for opening an air pathway between internal areas, i.e., areas 408 and 402 via area 414 shown in FIG. 5, and damper 126 a passive back check valve operable by blower 112 in which, without airflow, damper 126 closes. Dampers 122 and 124 may remain open or closed depending on an operational mode of air quality appliance 100 while damper 126 operates to prevent unwanted back streaming into the appliance. Dampers 122, 124, and 126 may also be manually or pneumatically driven as well.

[0042] Filtration subsystem 128 may include any number of filters for filtering out unwanted particulates, odors, or catalysts from received airflow. In one example, as shown, subsystem 128 may include a first filter 130, e.g., a prefilter, and a second filter 132, e.g., a HEPA filter. In this example, filter 130 may include a light washable MERV 6-8 filter placed in front of second filter 132. Filter 130 may be washable, replaceable, or a reel-to-reel system with years' worth of filter media to extend a lifetime of filter 130. Further, it is contemplated that filter 130 may include special coatings or materials, e.g., carbon, to absorb odors or catalysts that will remove certain gases.

[0043] Alternatively, second filter 132 may include a field replaceable HEPA filter capable of removing at least 99.97% of particulates greater than 0.3 microns in size and take any number of sizes and shapes to handle the airflow within appliance 100. Similarly, filter 132 may also have special coatings or materials, e.g., carbon, to absorb odors, catalysts, or gases.

[0044] Control system 180 may include any control equipment required to operate appliance 100, and the components thereof, in accordance with the operating modes and HVAC equipment set forth herein. For example, control system 180 may include a thermostat, relay board, circuit breaker board, sensors, controller(s)/processor(s), input/output devices, software, hardware, communication systems, memory storage devices, etc. Such components may include a Honeywell thermostat with an interface board, a WIFI module, and outdoor wireless temperature and humidity sensors for appliance 100, furnace, and AC equipment.

[0045] In accordance with the present invention, any number of supplemental control systems and methods may be used as well. For example, system 180 may also include weather and air quality processing equipment for making energy efficient decisions based on user preferences. Additionally, in poor outdoor air quality environments, such equipment may direct appliance 100 to produce a constant over pressurization of clean filtered air to minimize an amount of low-quality air from entering a target structure.

[0046] Heating subsystem 134 may include any number of heaters for heating air and absorbent media. For example, heating subsystem 134 may include humidifier heaters 182 for heating air within an internal area, e.g., area 406, and reactivation heaters 184 for reactivating desiccant rotor media. Specifically, humidifier heaters 182 may include electric PTC (Positive Temperature Coefficient) heaters for heating the air just before it enters area 406. In turn, as a temperature of the air increases, a relative humidity level may decrease. However, appliance 100 may operate without heaters 182 as well. For example, as discussed below, while humidifying subsystem 138 may have an increased effectiveness with heaters 182, subsystem 138 may operate without heaters 182 in some examples.

[0047] Disinfection source 136 may include a UV-C source or other form of disinfecting source that, in operation, kills or eliminates bacterial or viral organisms. For example, a UV-C source may be positioned within a designed holder and internal area, e.g., area 504, and, in operation, emit a prescribed amount of ultraviolet light sufficient to kill 99.9+% of viruses, e.g., corona viruses, common cold viruses, etc. An emitted wavelength may be between 200 and 280 nanometers. While disinfection source 136 illustratively includes three UV-C sources, it is expressly contemplated that additional or fewer sources may be used as well. However, as shown, three UV-C sources may be mounted within UV stable plastic holders within cabinet 102. A turning vane and bulb placement may position UV-C sources within a close proximity of all air flowing through this section. In one embodiment, to increase a dwell time within the internal area, e.g., area 404, and UV-C sources, rotor 118 and core 116 may include sufficiently sized openings for elongated periods of UV-C exposure. For example, by having a core 116 opening larger than half of the area of rotor 118, airflow within the internal area may be slowed which, in turn, may increase a dwell time and amount of UV-C received.

[0048] Generally, three factors affect a sterilization dosage for airborne particulates. A strength of the source, distance from the source, and time spent at each distance away from the source. Typically, intensity of the light falls off at the inverse square of the distance from the source. To efficiently and effectively design an environment that will provide a target with a sufficient dosage of UV-C, disinfection source 136 and appliance 100 may take a variety of configurations. For example, a weaker bulb may be used along with a slower air passage rate or a grid of stronger UV-C emitting LEDs with a faster air flow rate. To maximize an effectiveness of disinfection source 136, it is contemplated that a combination of CFM to be processed, airstream load, airstream flow speed, disinfection distance, and exposure time may each be varied to ensure an adequate dosage is being achieved for a target particulate.

[0049] Humidifying subsystem 138 may include any number of components for providing air moisture and humidity within appliance 100, e.g., water inlet/supply port 140, filter 142, valve 144, pad tray/fill tube 146, pad 148, drain 150, humidifier fill tube and orifice 152, etc. Beginning with water pad 148, pad 148 may include a metal mesh substrate coated with a water wicking material, e.g., cellulose material, for providing air moisture. However, any number of moisture holding materials and substrates may be used. In operation, water wicking material of pad 148 may retain water while being suspended within a target air flow and allow for a minimum amount of resistance to the airflow traversing the material. In turn, any unused water may be directed to a drain pan and line coupled to pad 148.

[0050] Water filter 142 may include a water filter with water softening and carbon filter elements for collectively removing impurities from water placed within a target air stream, e.g., pad 148, for increasing air stream humidity. In turn, softened and filtered water may extend a life of humidifier pad 148 by reducing scale, a buildup of materials, and impurities capable of being entrained within an airflow. In some examples, filtered and softened water may also prevent humidifier orifices from clogging which meter a flow of water through pad 148 and keep a drain line clean. In accordance with the present invention, water filter 142 may take a relatively simple or complex configuration and include a screened intake as well. In operation, without filter 142, pad 148 may need to be changed more frequently while air flowing into a target structure remains full of impurities.

[0051] Water pad tray and fill tube 146 may include any number of devices for holding pad 148 and controlling a flow rate therethrough, respectively. Generally, tray 146 holds pad 148 and includes a bottom in the form of a drain pan connected to a drain line. A top of tray 146 may include a reservoir and a water dispersal system for directing water to flow evenly down through pad 148. Fill tube 146 may include a metering orifice to control a flow rate of water. Tray and fill tube 146 may take any number of configurations for holding pad 148 and dispersing water therethrough. Further, it is contemplated that a fill tube orifice may be changed to optimize flow for different conditions or available water pressures.

[0052] Turning now to external ducts, it is to be understood that appliance 100 may include any number of external ducts. Specifically, while appliance 100 is shown with four ducts 154, 156, 158 and 160, it is to be understood that additional or fewer ducts may be used as well. As shown in FIG. 1, duct 154 may travel from a screened fresh air intake through damper 122 and into inlet port 104. Duct 156 may travel from outlet port 108 to a downstream port in a HVAC system's return duct or a supply inlet of a dedicated ductwork system. Duct 158 may travel from an upstream port in a HVAC system's return duct or from a dedicated ductwork system return to inlet port 106.

[0053] Finally, duct 160 may travel from an outlet of damper 126, which is mounted in the outlet of outlet port 110, to an exhaust outlet of a dwelling's exterior wall. Ducts 154, 156, 158, and 160 may hook into different locations based on a type of desired system for appliance 100 and comprise any suitable material such as insulated or uninsulated flexible HVAC tubing or metal rigid piping.

[0054] Appliance 100 may further include exterior ports 176 and 178 for preventing unwanted debris or weather elements from entering external ducts 154 and 160. Specifically, ports 176 and 178 may include through-the-wall exit and intake ports, respectively, with a bird/rodent screen and weather hood to prevent weather elements, e.g., snow, rain, etc., from filling ducts 154 and 160. Ports 176 and 178 may be made of any number of materials and, in some embodiments, include back-check dampers as well.

[0055] Turning now to FIG. 2, as shown, an appliance 200 may include a heating subsystem 202 with reactivation heaters 204 for heating air around desiccant rotor material and a humidifier subsystem 206 with water valves 208, humidifier fill tube(s), and orifices 210 for controlling a flow of water to humidifier subsystem 206.

[0056] Reactivation heaters 204 may include electric PTC heaters for heating air just before it enters a rotor, e.g., rotor 118, to reactivate the desiccant media located on the rotor. Specifically, as noted above, a rotor may include desiccant media for adsorbing moisture and dehumidifying an incoming air stream. Once the desiccant media has reached its maximum moisture holding capacity, heaters 204 may heat the surrounding air to regenerate (dry) the media. Specifically, heaters 204 may increase the temperature of the air and, in turn, lower a relative humidity as well. Heated air may then give energy to the adsorbed moisture and cause it to vaporize, enter the air stream, and exit appliance 200 as exhaust. In accordance with the present invention, rather than electric heaters, reactivation heaters 204 and humidifier heaters, e.g., humidifier heaters 182, may also include direct fired clean burning fuel, indirect fired fuels, liquid to air heat exchangers, etc.

[0057] Water valve 208 may include a normally closed electric solenoid valve for controlling water flow to a humidifier water pad, e.g., pad 148. However, other pneumatic, electric, or alternatively controlled valves may be used as well.

[0058] Humidifier fill tube and orifice 210 may include plastic tubing for bringing water from a water supply valve to a top of a water pad tray, e.g., tray 146. In one example, tube and orifice 210 may include a piece of plastic with a small opening that, in operation, couples to an end of the tube and serves as a metering device. Tube 210 may comprise plastic, copper, aluminum, etc. Depending on a desired volume of water, an orifice hole may include any number of sizes and shapes.

[0059] As shown in FIGS. 3 and 4, a humidifier subsystem 302 of an appliance 300 may further include a drain 304 and water inlet/supply port 306. Water drain 304 may include a plastic drain pan affixed to a drain line going to a bulkhead water fitting with a hose barbed outlet and a vinyl drain line going to a dwelling's floor drain. A drain line may include any number of materials. In some examples, if appliance 300 is installed far from a drain, a large tank or pump could be used to move the water to a suitable drain. In other examples, a tank with a filter and pump may also be used to reuse the water by sending it back through a water pad, e.g., pad 148.

[0060] Water inlet/supply port 306 may be where an external water supply connects with appliance 100. Water inlet/supply port 306 may include a quick connect fitting mounted within a dwelling, e.g., a cabinet wall. In exemplary examples, a hot water supply may be used, however, appliance 100 may operate with either hot or cold water. Further, in exemplary examples, supply water may be potable to prevent unwanted substances from entering an air stream and target structure. In some examples, water inlet/supply port 306 may include a hole where a hose is routed through and hooked directly to a water filter, e.g., filter 142. In turn, the hose may need to be sealed to an outer wall, e.g., an outer cabinet wall.

[0061] FIGS. 5 and 6 show indoor air quality appliance areas in accordance with embodiments of the present invention. While seven areas are shown, it is contemplated an appliance may include additional or fewer areas as well. However, as shown in FIGS. 5 and 6, appliance 400 includes seven designated areas 402, 404, 406, 408, 410, 412, and 414 where air travels within appliance 400 and undergoes processing or is otherwise expelled to downstream area(s). Beginning with area 402, area 402 represents a first area where incoming fresh air is received from an outside environment, e.g., through an inlet 416, and where air is brought from a target structure to be reprocessed, e.g., along area 414. As shown, area 402 lies between a pre-filter 418, a damper 420, inlet port 416, internal barriers of a cabinet 422, and access panels of a control system, e.g., system 180.

[0062] Internal area 404 represents a second area where air is received from area 402 after traveling through prefilter 418, a filter 424, and lower half of a rotor 426. Area 404 lies between rotor 426, turning vane, a core 428, interior barriers of cabinet 422, and access panels. As shown, a disinfection source 430 is also located within this area. Turning to internal area 406, this is where air arrives from area 404 after traveling through core 428 and humidifier heaters 432. Area 406 lies between core 428, humidifier heaters 432, a blower 434, internal barriers of cabinet 422, and access panels. As shown, a water pad 436 and water pad tray and fill tube 438 are within area 406.

[0063] Area 408 is where incoming stale air from a target building arrives within appliance 400, e.g., via an inlet 440. Area 408 lies between core 428, inlet port 440, internal barriers of cabinet 422, and access panels. Water filter 442 lies within area 408 as well as control system components, e.g., components 480. In turn, air within area 408 may pass into either, or both of, areas 410 or 402 via area 414. Area 410 is where air is received from area 408 after passing through core 428. As shown, area 410 lies between core 428, rotor 426, reactivation heaters 444, turning vane, internal barriers of cabinet 422, and access panels.

[0064] Area 412 is where air arrives after traveling through reactivation heaters 444 and rotor 426. Area 412 lies between rotor 426, a blower 446, internal barriers of cabinet 422, and access panels. Finally, as shown in FIGS. 5 and 6, area 414 is where air from area 408 travels to area 402 during certain operating modes of appliance 400. Area 414 lies between internal barriers of cabinet 422 and access panels.

[0065] FIGS. 7-12 show flows paths and operating modes of an appliance in accordance with embodiments of the present invention. Specifically, FIG. 7 shows appliance 500 operating in an air scrub/sterilization operating mode, FIG. 8 shows a dehumidifier operating mode, FIG. 9 a humidification operating mode, FIG. 10 an air exchange operating mode, and FIGS. 11 and 12 a self-cleaning operating mode. However, it is to be understood that an appliance may operate in additional or fewer modes as well.

[0066] Beginning with FIG. 7, as shown, during an air scrub/sterilization, or first, mode of operation, a damper 502 closes to stop incoming outside air, a damper 504 opens to allow airflow through an area 506, a rotor 508 is not rotating, a blower 510 is off, and a blower 512 is running at a standard speed. As shown, air 514 is taken from a return duct of a target structure, routed through an area 506, around a core 516, and brought to an area 518. The air then proceeds through a prefilter 520 to remove larger particulates, a HEPA filter 522 where 99.7% of all particulates larger than 0.3 microns are removed, rotor 508, and finally to area 524 where it is sterilized via a UV-C emitting source 526. After which, the air passes through core 516 and humidifier heaters 528 and arrives to an area 530. From area 530, air 514 goes through humidifier pad 532, blower 512, and through return ductwork to a downstream location from which air 514 is first picked up. In some embodiments, if the humidification mode is turned on, air 514, after passing through humidification heater 528, is warmed up and its relative humidity lowered prior to picking up water from water pad 532 to increase its absolute humidity.

[0067] In some examples, an air scrub/sterilization mode may be the primary mode of operation. Specifically, a scrub/sterilization operating mode may be the default mode if no other mode is called on, or, in some instances, may operate simultaneously with the other modes. However, if a user wishes to save energy, appliance 500 may remain inoperative. In some examples, the UV sterilization source 526 may be operative any time air is brought into or back from a target structure.

[0068] Turning to a dehumidifier or, second, mode of operation, as shown in FIG. 8, a dehumidifier mode of operation may be its own stand-alone mode. In this mode, appliance 600 may run in an air exchange, or fourth, mode of operation at about 50% of a normal level and an air scrub/sterilization, or first, mode of operation at about 50% of its normal level. Specifically, during a dehumidifier mode, a humidification, or third, mode of operation is locked out, reactivation heaters 602 are turned on, a blower 604 is turned on to move half of the normal CFM as it moves during the air exchange mode, a blower 606 is turned on and runs at the same speed (once set by an installer), a rotor 608 starts to run at an approximate speed of 12 RPH (revolutions per hour), and both dampers 610 and 612 are opened.

[0069] As shown, air 614 enters appliance 600 through inlet port 616 into area 618. Approximately 50% of air 614 then flows through area 620, through damper 612, and into area 622. Similarly, approximately 50% of air 624 also enters area 622 via external duct 626 after passing through damper 610. Both streams of air 614 and 624 combine in area 622. The combined air then proceeds through prefilter 628 where any large particulates are removed and HEPA filter 630 where 99.97% of all particulates larger than 0.3 microns are removed. In turn, the combined air passes through rotor 608 to remove moisture and lower a specific humidity level. Simultaneously, an air temperature of the air may increase due to a heat of reactivation and a latent heat of evaporation. The combined air then arrives in area 632 where it comes into close proximity with UV-C emitting source 634 to be sterilized. After which, the air passes through core 636 where over 80% of its temperature differential is transferred with the other air stream flowing through core 636. From core 636, the air travels through humidifier heaters 638 (which are off), arrives in area 640, passes through humidifier pad 642, and into an intake of blower 606 to return to ductwork and a downstream location from which half of the combined air was initially picked up.

[0070] Simultaneously, a second half of air 614 entering area 618 of appliance 600 splits from the first half and goes through core 636 where it either gives up or receives over 80% of the temperature differential it has with the combined air stream flowing through core 636. From core 636, this stream arrives in area 644 and flows through reactivation heaters 602 to increase its temperature and lower its relative humidity prior to passing through a top half of spinning rotor 608 to pick up moisture. Finally, the air arrives in area 646 where it enters an intake of blower 604 and is pushed out of appliance 600 through an outlet 648, damper 650, and into duct 652 and a target building exterior. As noted above, rotor 608 is a wheel with a substrate material laden with a desiccant media, e.g., silica gel, etc. In operation, part of desiccant rotor 608 may be drying while the other part is being reactivated.

[0071] FIG. 9 shows a humidification, or third, mode of operation in accordance with an embodiment of the present invention. Appliance 700 may operate in a humidification mode of operation during an air exchange or air scrub/sterilization modes of operation. In one example, appliance 700 may not operate in a standalone humidification mode. Rather, appliance 700 may operate in a humidification mode during a default air scrub/sterilization mode of operation. This may be advantageous as one or more blower(s) 702 and 704 are already running and air to undergo humidification is already providing 100% of the air to a humidifier portion of appliance 700 during an air scrub/sterilization mode. As discussed below, during an air exchange mode, air is being exchanged with fresh outside air while the inside air is still the determining party as to whether a humidifier portion of appliance 700 is running. However, the incoming fresh air may also meet humidity levels that would call for humidification.

[0072] During a humidification mode of operation, humidifier heaters 716 are turned on, water valve(s), e.g. valves 208 are opened, and water starts flowing downward through water pad 708 and out to an external drain (not shown). Air 710 from area 712 flows through core 714 and humidifier heaters 716 to increase an air temperature while lowering a relative humidity level of air 710. After arriving in area 706, air 710 proceeds through water pad 708 to pick up water vapor from pad 708 and, in turn, increase a specific humidity of air 710. Air 710 then flows into an intake of blower 704, down external duct 718, and into downstream ductwork of a HVAC or into a supply inlet of a dedicated ductwork system (not shown).

[0073] FIG. 10 shows an air exchange, or fourth, mode of operation in accordance with an embodiment of the present invention. In one example, appliance 800 may operate in a stand-alone air exchange mode of operation. In this mode, air is being scrubbed, sterilized, and may also be humidified. However, the air coming into appliance 800 from outside a target structure is the amount of air coming into appliance from inside the target structure. Specifically, damper 802 (bypass damper) is closed and, thus, other than a small amount of leakage, appliance 800 is exchanging stale air from inside the target structure with fresh outside air in a one-to-one ratio.

[0074] In this mode, blower 804 is turned on and operating at its normal speed, blower 806 is turned on and operating at its normal full speed, damper 802 is closed, damper 808 is opened, damper 810 (back check damper) is opened by airflow from blower 806, and rotor 812 rotates at a speed of about 30 RPM (revolutions per minute). At this speed, rotor 812 is operating at approximately 150 times the speed as compared to a dehumidification mode to widely spread each function and maximize an operating efficiency as an enthalpy transfer device.

[0075] During operation, two counterflowing streams 814 and 816 move through appliance 800. Air 814 enters external duct 818 through an outside fresh air intake, travels through damper 808, and enters area 820 of appliance 800. Air 814 then passes through prefilter 822 to remove large particulates, HEPA filter 824 to remove 99.97% of all particulates larger than 0.3 microns, and rotor 812 where over 80% of its enthalpy differential with stream 826 is transferred to stream 826. After which, air 814 arrives in area 828 and comes into close proximity with UV-C emitting source 830 to be sterilized. After being sterilized, air 814 passes through core 832 where it exchanges over 80% of its current sensible energy differential with stream 816. Air 814 then travels through humidifier heaters 834, area 836, humidifier pad 838, and into an intake of blower 804, through external duct 840 and into a downstream location of a HVAC's return ductwork or to a supply inlet of a dedicated ductwork system. In one example, air 814, in a humidification operation, may also be warmed up to lower its relative humidity and pick up water from water pad 838 to increase its absolute humidity.

[0076] Air 816 enters external duct 842 through an upstream port on a HVAC return duct or via a dedicated duct work system return. Air 816 then enters appliance 800 through inlet 844 and arrives in area 846. After which, air 816 goes through core 832 exchanging over 80% of its sensible energy differential with air 814. Air 816 then enters area 854, passes through reactivation heaters 848 (which are off) and spinning rotor 812 where it exchanges over 80% of its enthalpy differential with air 814. Finally, air 816 arrives in area 850 where it enters an intake of blower 806 and is pushed out of appliance 800 through an outlet, back check damper 810, and into external duct 852 to an exterior of a target building.

[0077] FIGS. 11 and 12 show an appliance self-cleaning mode of operation in accordance with an embodiment of the present invention. Often, homeowners or dwelling inhabitants fail to clean their appliances with the frequency needed to ensure their optimal efficiency and effectiveness. As such, in some examples, appliance 900 may operate in a self-cleaning, or fifth, mode of operation. There may be two main aspects of this system. First, there may be an occasional redirecting of exhaust through a fresh air intake to clear the intake. This may be accomplished by adding a bypass duct 902 between external ducts 904 and 906. As shown, bypass 902 may be after damper 908 (back check damper) and after, or before, damper 910. An additional damper, damper 912, may be positioned in the middle of bypass 902 and include a motorized damper.

[0078] In operation, appliance 900 may begin by closing damper 910, opening damper 908, and operating blower 914 in a high-speed mode. In turn, this may shoot air down both external duct 906 and external duct 904 to clear an intake screen of the fresh air intake. As a result, a small pressure differential may be created between the target structure and outside air. However, if damper 908 is motorized, bypass 902 may be installed before it and damper 910. After which, dampers 910 and 908 may be closed and damper 912 opened. Blower 914 may then operate at a high speed to create a stronger force to clear an intake screen. However, this may also create a stronger pressure differential between the target structure and outside air.

[0079] Second, the self-cleaning mode of appliance 900 may eliminate monthly prefilter cleanings/replacements. For example, a reel-to-reel system (not shown) may be added to prefilter media 916. Reel one may have feet of prefilter media wound on it. Reel two may have a drive motor that occasionally winds the used prefilter media onto itself and, in turn, moves fresh filter media into position in front of HEPA filter 918. A frequency of winding may be determined by run time, a unit region, time of year, and estimated debris load. An amount of media in the appliance may be enough to last a year assuming normal operating conditions and climates. In turn, an appliance maintenance frequency may be reduced to once a year along with the other main components of appliance 900, e.g., HEPA filter, UV source, rotor drive belt, water filter, and water pad.

[0080] While five operating modes have been discussed, it is also contemplated that an appliance may simultaneously operate in multiple modes as well. For example, an appliance may operate in an air scrub/sterilization and humidification mode of operation, an air exchange and humidification mode of operation, and a dehumidification mode of operation as a combination of air exchange and air scrub/sterilization modes under varying parameters. Further, in some examples, an appliance may include a heat exchanger within an external duct, e.g., duct 160, for recovering air stream heat during a dehumidification or other mode of operation. However, additional energy recovering devices may be used as well.

[0081] Through the various operating modes, an appliance, e.g., appliance 100, may serve as an efficient and effective air exchanger, humidifier, dehumidifier, scrubber and sterilizer. By way of example only, an appliance may be used in a family home and operate to effectively and efficiently deal with allergens, viruses, etc. More specifically, a user may be able to set appliance preferences via a control system, e.g., system 180, in easy-to-understand terms, e.g., wetter, dryer, more fresh air, less fresh air, etc., and once set, the appliance may, while maintaining condensation free windows, selectively perform an air exchange operation during optimal outdoor conditions. Such operation may occur at numerous times through a day or week, e.g., 4-6 per day each week. As a result, a risk of accruing allergens and viruses in a home is mitigated. Further, during periods of elevated heat and humidity, an appliance may maintain an internal structure at a comfortable level with reduced humidity to better assist an air conditioning (AC) unit with maintaining a comfortable temperature. In these conditions, without the assistance of the appliance, the excessive humidity may render the AC unit ineffective due to a high humidity load. Another possible benefit may be reduced accumulation of off gassed contaminants from construction. Cost savings may also be observed running appliance the 24 hours a day, 7 days a week, 365 days a year due to the high enthalpy recovery efficiency of the appliance.

[0082] In accordance with the present invention, it is to be understood that an appliance, e.g., appliance 100, may take any number of different configurations. For example, appliance and the components thereof may be scalable to accommodate any sized dwelling without any design limits. Further, an appliance may be modified to meet individual customer demands and used in any residential, commercial, and industrial property and environment. For example, a desiccant laden rotor, e.g., rotor 118, may be replaced with a sensible energy transfer only model and a sensible core with an enthalpy exchanging core instead. Multiple cores may also be used to increase an overall efficiency of an appliance. Appliance blowers may also be modified to handle additional static pressure placed on the appliance to achieve previous air flow levels.

[0083] In some iterations, if a steam source is available and free of hazardous chemicals or particles, the steam source may be used in place of a humidification subsystem, e.g., subsystem 138. Additionally, if a warm dry air source is available, a purge section may be added to a dehumidifier mode of operation in which dry air sweeps some moisture from a rotor prior to reactivation. An appliance may also include a performance indicator package. For example, a particle counter may also be positioned before and after a HEPA filter indicating a total number or percentage of particles removed. Such package may further include a UV light indicator to verify enough UV light is being emitted to kill viruses and bacteria. Finally, a package may include a VOC meter as well.

[0084] FIG. 13 shows an indoor air quality appliance and furnace in accordance with an embodiment of the present invention. As shown, an appliance 1000 may connect to a furnace 1002 with a return duct 1004 and, in operation, receive air flow through an upstream return port 1006. In turn, processed or otherwise conditioned air may be returned to furnace 1002 through downstream return port 1008. Within furnace 1002, air 1010 may travel upwards to any number of downstream applications. It is to be understood that ports 1008 and 1006 may couple to furnace 1002 using any number of connection mechanisms.

Examples

[0085] Below, Tables 1-6 set forth example operating parameters and characteristics of appliance 100. Specifically, Table 1 sets forth example physical characteristics of appliance 100, Table 2 sets forth Air Cleaning and Handling data, Table 3 AHRI Standard Winter Test Efficiencies, Table 4 AHRI Standard Summer Test Efficiencies, Table 5 Power Consumption with Three UV Bulbs On, and Table 6 Dehumidification/Humidification rates.

TABLE-US-00001 TABLE 1 Physical Characteristics Overall Dimensions 39 20.5 21.5 (L W H) Weight 203 lbs.

TABLE-US-00002 TABLE 2 Air Cleaning and Handling Virus Kill Rate >99.99% (Single Pass) HEPA Filtration 99.97% of 0.3 m particles Process Air 150 cfm

TABLE-US-00003 TABLE 3 Efficiencies AHRI Standard Winter Test Simulated Conditions Field Test* Sensible Efficiency (Apparent) 96% 112% Enthalpy Efficiency 87% 97% Moisture Transfer Efficiency 73% 64% AHRI winter test standard calls for 70 F. 53 gr/lb. house side and 35 F. 24 gr/lb. outside, tests were conducted at 70 F. 54 gr/lb. house side and 38 F. 22 gr/lb. outside. *Field test conditions were (68 F.-74 F.) and (48 gr/lb.-58 gr/lb.) house side and (34 F.-42 F.) and (30 gr/lb.-33 gr/lb.) outside.

TABLE-US-00004 TABLE 4 Efficiencies AHRI Standard Summer Test* Sensible Efficiency (Apparent) 81% Enthalpy Efficiency 83% Moisture Transfer Efficiency 82% *AHRI summer test standard calls for 75 F. 67 gr/lb. house side and 95 F. 119 gr/lb. outside, tests were conducted at 80 F. 36 gr/lb. house side and 98 F. 111 gr/lb. outside.

TABLE-US-00005 TABLE 5 Power by Mode with Three UV Bulbs On Mode Power (240 V AC) Percent Time * Air Scrubbing 362 W 62% Ventilation 643 W 34% Dehumidification 3960 W 1% Humidification & Air Scrubbing 3096 W 3% Humidification & Ventilation 3192 W <1% *Field tests ran from May 19.sup.th to October 25.sup.th. A field test home was kept at comfortable temperatures (70 F.) and humidity (40% RH-50% RH).

TABLE-US-00006 TABLE 6 Dehumidification/Humidification Rates Dehumidification @ AHAM* 6.0 lbs/hr., 17.26 (80 F. @ 60% RH) Gallons/Day, 138 Pints/Day Humidification 0.56 Gallons/Hour, 13.6 gpd

[0086] Various embodiments of systems, devices, and methods have been described herein. These embodiments are given only by way of example and are not intended to limit the scope of the claimed inventions. It should be appreciated, moreover, that the various features of the embodiments that have been described may be combined in various ways to produce numerous additional embodiments. Moreover, while various materials, dimensions, shapes, configurations and locations, etc. have been described for use with disclosed embodiments, others besides those disclosed may be utilized without exceeding the scope of the claimed inventions.

[0087] Persons of ordinary skill in the relevant arts will recognize that the subject matter hereof may comprise fewer features than illustrated in any individual embodiment described above. The embodiments described herein are not meant to be an exhaustive presentation of the ways in which the various features of the subject matter hereof may be combined. Accordingly, the embodiments are not mutually exclusive combinations of features; rather, the various embodiments can comprise a combination of different individual features selected from different individual embodiments, as understood by persons of ordinary skill in the art. Moreover, elements described with respect to one embodiment can be implemented in other embodiments even when not described in such embodiments unless otherwise noted.