AIR PROCESSING UNITS FOR VENTILATION SYSTEMS

Abstract

An air ventilation system for an indoor space includes an air processing unit that includes a housing that receives air from the indoor space and discharges treated air, a microbial deactivation channel provided within the housing and defining a serpentine pathway that causes the air to navigate one or more directional changes as it circulates through the housing, and one or more ultraviolet (UV) light sources arranged within the microbial deactivation channel to emit UV light that impinges on and disinfects the air. One or more light reflection features are provided on one or more interior surfaces of the microbial deactivation channel, the one or more light reflection features comprising flat, mirror-like structures that receive and redirect the UV light within the microbial deactivation channel.

Claims

1. An air ventilation system for an indoor space, comprising: an air processing unit (APU) that includes: a housing that receives air from the indoor space and discharges treated air; a microbial deactivation channel provided within the housing and defining a serpentine pathway that causes the air to navigate one or more directional changes as it circulates through the housing; one or more ultraviolet (UV) light sources arranged within the microbial deactivation channel to emit UV light that impinges on and disinfects the air; and one or more light reflection features provided on one or more interior surfaces of the microbial deactivation channel, the one or more light reflection features comprising flat, mirror-like structures that receive and redirect the UV light within the microbial deactivation channel.

2. The air ventilation system of claim 1, wherein the indoor space is selected from the group consisting of a multi-passenger vehicle, an interior room or section of a building, an elevator carriage, a store check-out aisle, security checkpoints or check-ins, a greenhouse facility, a vegetation grow room or facility, and any combination thereof.

3. The air ventilation system of claim 1, wherein the housing comprises a microbial deactivation portion that houses the microbial deactivation channel, and wherein the housing further comprises an HVAC portion in fluid communication with the sterilization portion.

4. The air ventilation system of claim 3, wherein the HVAC and sterilization portions are operatively coupled at a seam and thereby cooperatively form integral portions of the housing.

5. The air ventilation system of claim 3, further comprising: an input provided on the HVAC portion to receive the air from the indoor space; and an output provided on the to discharge the treated air from the APU, wherein the air is conveyed from the HVAC portion to the microbial deactivation portion.

6. The air ventilation system of claim 3, wherein the HVAC portion provides an HVAC passageway that houses one or more of: one or more fans operable to draw the air into the HVAC passageway; one or more filters operable to filter the air; a heater operable to increase a temperature of the air; and a cooler operable to decrease the temperature of the air.

7. The air ventilation system of claim 1, wherein the microbial deactivation channel is defined by one or more sidewalls contiguously connected to one or more curved endwalls.

8. The air ventilation system of claim 7, wherein at least one of the one or more UV light sources is arranged at an apex of a corresponding one of the one or more curved endwalls.

9. The air ventilation system of claim 1, wherein at least one of the one or more UV light sources comprises a UV-C light source configured to emit germicidal far UV-C light.

10. The air ventilation system of claim 1, wherein at least one of the one or more UV light sources comprises an elongate bulb that exhibits a length L1 slightly shorter than a height of the microbial deactivation channel.

11. The air ventilation system of claim 10, wherein the housing includes a top panel detachable from the housing to expose the microbial deactivation channel, and wherein the one or more UV light sources are installed and removed lengthwise into/from the microbial deactivation channel with the top panel detached.

12. The air ventilation system of claim 1, wherein the one or more light reflection features are formed directly on the one or more interior surfaces of the microbial deactivation channel.

13. The air ventilation system of claim 1, wherein the one or more light reflection features comprise separate structures operatively coupled to the one or more interior surfaces of the microbial deactivation channel.

14. A method for ventilating an indoor space, comprising: conveying air from the indoor space to an air processing unit (APU) that includes: a housing; a microbial deactivation channel provided within the housing and defining a serpentine pathway; one or more ultraviolet (UV) light sources arranged within the microbial deactivation channel; and one or more light reflection features provided on one or more interior surfaces of the microbial deactivation channel and comprising flat, mirror-like structures; circulating the air through the microbial deactivation channel and thereby causing the air to navigate one or more directional changes within the housing; emitting UV light from the one or more UV light sources; receiving and redirecting the UV light within the microbial deactivation channel with the one or more light reflection features; and impinging the UV light on the air and thereby disinfecting the air.

15. The method of claim 14, wherein the housing comprises a microbial deactivation portion that houses the microbial deactivation channel, the housing further comprising an HVAC portion in fluid communication with the microbial deactivation portion, the method further comprising at least one of: drawing the air into the HVAC passageway with one or more fans arranged in the HVAC passageway; filtering the air with one or more filters arranged in the HVAC passageway; increasing a temperature of the air with a heater arranged in the HVAC passageway; and decreasing the temperature of the air with a cooler arranged in the HVAC passageway.

16. The method of claim 14, wherein the microbial deactivation channel is defined by one or more sidewalls contiguously connected to one or more curved endwalls, the method further comprising arranging at least one of the one or more UV light sources at an apex of a corresponding one of the one or more curved endwalls.

17. The method of claim 14, wherein at least one of the one or more UV light sources comprises a UV-C light source, and wherein emitting UV light from the one or more UV light sources comprises emitting germicidal far UV-C light.

18. The method of claim 14, wherein at least one of the one or more UV light sources comprises an elongate bulb that exhibits a length L1 slightly shorter than a height of the microbial deactivation channel, the method further comprising: installing the elongate bulb lengthwise into the housing; and removing the elongate bulb lengthwise from the housing.

19. The method of claim 14, wherein the one or more light reflection features are formed directly on the one or more interior surfaces of the microbial deactivation channel.

20. The method of claim 14, wherein the one or more light reflection features comprise separate structures operatively coupled to the one or more interior surfaces of the microbial deactivation channel.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0005] The accompanying drawings, which are incorporated into and constitute a part of this specification, illustrate one or more examples of embodiments and, together with the description of example embodiments, serve to explain the principles and implementations of the embodiments.

[0006] FIG. 1 is a schematic diagram of an example air ventilation system, according to one or more embodiments of the present disclosure.

[0007] FIG. 2 is a schematic plan view of the APU of FIG. 1, according to one or more embodiments of the present disclosure.

[0008] FIG. 3 is a top view of the APU of FIG. 1, according to one or more embodiments.

DETAILED DESCRIPTION

[0009] Embodiments of the present disclosure will now be described in detail with reference to the accompanying Figures. Like elements in the various figures may be denoted by like reference numerals for consistency. Further, in the following detailed description of embodiments of the present disclosure, numerous specific details are set forth in order to provide a more thorough understanding of the claimed subject matter. However, it will be apparent to one of ordinary skill in the art that the embodiments disclosed herein may be practiced without these specific details. In other instances, well-known features have not been described in detail to avoid unnecessarily complicating the description. Additionally, it will be apparent to one of ordinary skill in the art that the scale of the elements presented in the accompanying Figures may vary without departing from the scope of the present disclosure.

[0010] The embodiments described herein are directed to air ventilation systems for indoor spaces and, more particularly, to air processing units used in air ventilation systems and designed to condition and sterilize air circulating within or through indoor spaces. One example air ventilation system for an indoor space includes an air processing unit that includes a housing that receives air from the indoor space and discharges conditioned air, a microbial deactivation channel provided within the housing and defining a serpentine pathway that causes the air to navigate one or more directional changes as it circulates through the housing, and one or more ultraviolet (UV) light sources arranged within the microbial deactivation channel to emit UV light that impinges on and disinfects the air. According to embodiments of the present disclosure, one or more light reflection features may be provided on one or more interior surfaces of the microbial deactivation channel. The light reflection features may comprise flat, mirror-like structures that receive and redirect the UV light within the microbial deactivation channel.

[0011] FIG. 1 is a schematic diagram of an example air ventilation system 100, according to one or more embodiments of the present disclosure. As illustrated, the air ventilation system 100 includes an air processing unit or APU 102 that can be fed a supply of air 104 from an indoor space 106. The indoor space 106 may comprise any enclosed or semi-enclosed area that can be occupied by one or more occupants (persons, passengers, tenants, inhabitants, etc.) and through which air is continuously, periodically, or intermittently circulated. Examples of the indoor space 106 include, but are not limited to, a multi-passenger vehicle (e.g., mass transportation vehicle, personal vehicle, commercial vehicle, public transportation bus, tour bus, aeronautical aircraft, a train, a subway car, etc.), an interior room or section of a building (e.g., a waiting room, a residence, an office, commercial building, restaurant, supermarket, etc.), an elevator carriage, a store check-out aisle, security checkpoints or check-ins (e.g., airport, etc.), a greenhouse facility, a vegetation grow room or facility, or any combination thereof.

[0012] The air 104 provided to the APU 102 from the indoor space 106 may be considered contaminated or otherwise unconditioned for a variety of reasons, and the APU 102 may be designed or configured to condition the air 104 as appropriate for occupant comfort and safety. As used herein, the term condition or conditioning, as in conditioning the air 104, or any variation thereof, refers to a variety of processes or treatments undertaken by the APU 102 on the air 104. Example processes include, but are not limited to, heating, cooling, humidifying, dehumidifying, sterilizing, disinfecting, virus deactivation, ionizing, filtering, augmenting, replacing with exterior air, and any combination thereof. Accordingly, the term conditioning will thus be used herein to denote any of the foregoing processes or actions.

[0013] Circulating the air 104 through the APU 102 may condition the air 104 such that conditioned or treated air 108 is discharged from the APU 102 and conveyed back to the indoor space 106 for circulation. As illustrated, the APU 102 provides or defines an input 110a to receive the air 104 from the indoor space 106, and an output 110b where the treated air 108 is discharged from the APU 102 to be conveyed back to the indoor space 106 (or another location). In some embodiments, as illustrated, the airflow direction of the air into the input 110a, and the airflow direction of the treated air 108 discharged from the output 110b may be orthogonal to one another. In other embodiments, however, the airflow direction into the input 110a and discharged from the output 110b may be parallel or at any other angle relative to the other, without departing from the scope of the disclosure. While not specifically detailed in FIG. 1, appropriate plumbing, piping, and/or ductwork (collectively referred to herein as ductwork), may extend between the APU 102 and the indoor space 106 to convey the air 104 to the APU and convey the treated air 108 back to the indoor space 106.

[0014] The APU 102 may provide or include a housing 112 sized to contain the various component parts and mechanisms included in (forming part of) the APU 102 and required to suitably condition the air 104 as it is received. The input and output 110a, b are each provided on or defined by the housing 112.

[0015] In some embodiments, as illustrated, the housing 112 may comprise two or more sections or portions, shown as an HVAC portion 114 and a sterilization portion or microbial deactivation portion 116. In other embodiments, however, the HVAC portion 114 may be omitted and the housing 112 may include only the microbial deactivation portion 116. In embodiments that include both the HVAC and microbial deactivation portions 114, 116, the HVAC and microbial deactivation portions 114, 116 may be operatively coupled at a seam 118 and thereby cooperatively form integral portions of the housing 112. In other embodiments, however, the HVAC and microbial deactivation portions 114, 116 may comprise separate, distinct structures in fluid communication with each other via appropriate ductwork (not shown). In such embodiments, the air 104 may be transferred (conveyed) from one of the HVAC and microbial deactivation portions 114, 116 to the other via suitable ductwork.

[0016] In some embodiments, as illustrated, the air 104 may first be received at the HVAC portion 114, following which the air 104 is conveyed to the microbial deactivation portion 116 for further conditioning or treatment. In other embodiments, however, the air 104 may alternatively be first received at the microbial deactivation portion 116, following which the air 104 is conveyed to the HVAC portion 114 for further conditioning or treatment. In the HVAC portion 114, the air 104 may be conditioned by one or more of heating, cooling, humidifying, dehumidifying, filtering, or any combination thereof. In the microbial deactivation portion 116, the air 104 may be further treated by one or more of sterilizing, disinfecting, ionizing, virus deactivation, or any combination thereof.

[0017] As illustrated, a microbial deactivation channel 120 may be provided or defined within the housing 112, and the air 104 may be circulated through the microbial deactivation channel 120 to be treated and otherwise further conditioned. More specifically, the microbial deactivation channel 120 may be provided within the microbial deactivation portion 116, and the air 104 circulating through the microbial deactivation channel 120 may be sterilized, disinfected, etc. In some embodiments, the microbial deactivation channel 120 may provide a serpentine and tortuous pathway that agitates and mixes the air 104 as it circulates through the microbial deactivation channel 120. To accomplish this, the microbial deactivation channel 120 may provide a plurality of sidewalls 122 and curved endwalls 124 that are contiguously connected. As it traverses the microbial deactivation channel 120, the air 104 is required to navigate one or more directional changes, such as 180 changes in direction, and this causes the air 104 to be mixed and agitated.

[0018] In some embodiments, one or more ultraviolet (UV) light sources 126 may be arranged within the microbial deactivation channel 120 and configured to emit UV light that impinges on the air 104 circulating through the serpentine microbial deactivation channel 120, and thereby sterilizes and disinfects the air 104. As used herein, the term impinge, as in impinging the UV light on the air 104, refers to the UV light penetrating the air 104 and interacting with the molecules and microorganisms entrained within the air 104 to disinfect the air 104. In at least one embodiment, one or more of the UV light sources 126 may comprise UV-C light sources configured to emit germicidal far UV-C light, which can penetrate the cell walls of microorganisms, including target pathogens related to Covid-19, and cause cellular or genetic damage. Upon being subjected to far UV-C light, the affected microorganisms are, therefore, killed, deactivated, or become unable to reproduce. Aside from the intensity of the UV-C light, their exposure time to the UV-C light is a key factor in determining how efficiently the microorganisms are disabled. Advantageously, the serpentine shape and path of the microbial deactivation channel 120 ensures that the microorganisms are exposed to the UV-C light for sufficient time to fully kill or disable them. As such, the treated air 108 exiting the APU 102 is substantially disinfected, that is, free of these harmful microorganisms, including target pathogens related to Covid-19.

[0019] The microbial deactivation channel 120 (i.e., the interconnected sidewalls 122 and curved endwalls 124) exhibits a height H1 that may extend along all or close to all of the height of an adjacent sidewall 128 of the housing 112 (e.g., the microbial deactivation portion 116). Moreover, one or more of the UV light sources 126 may comprise elongate UV-C bulbs that exhibit a length L1 that may be the same as or slightly shorter than the height H1. In such embodiments, the UV-C bulbs may be configured to emit UV-C light along the entire length L1 to ensure maximum exposure to the microorganisms and pathogens entrained in the air 104 circulating through the microbial deactivation channel 120.

[0020] The UV light sources 126 may be equidistantly or non-equidistantly spaced from each other within the microbial deactivation channel 120. In some embodiments, for example, the UV light sources 126 may be spaced from each along the serpentine pathway of the microbial deactivation channel 120 by a common distance (e.g., every 6 inches, 1 foot, 2 feet, etc.). In at least one embodiment, as illustrated, a UV light source 126 may be arranged at or near the apex of each curved endwall 124. Positioning the UV light sources 126 at the apex of each curved endwall 124 allows maximum exposure of the UV-C light to the air 104 circulating within the microbial deactivation channel 120, such as in both downstream and upstream directions.

[0021] In some embodiments, as illustrated, the housing 112 (e.g., the microbial deactivation portion 116) may provide a top panel 130 that may be detachable to expose the microbial deactivation channel 120. Once the top panel 130 is detached, the UV light sources 126 may be installed lengthwise into the microbial deactivation channel 120, or otherwise removed lengthwise from the microbial deactivation channel 120. In other embodiments, however, the top panel 130 may provide individual panels corresponding to each UV light source 126, and removing a given individual panel will allow a user (e.g., a technician, maintenance crew, operator, etc.) to access a corresponding one of the UV light sources 126. In at least one embodiment, the top panel 130 may provide tamper-proof access to the microbial deactivation channel 120, and may be equipped with a battle switch or circuit interrupter switch for safety of maintenance crew due to the dangers of exposure to UV-C lighting. Consequently, the housing 112 can operate like a black out box so that there is no possibility of occupants in the indoor space 106 being exposed to the UV-C lighting.

[0022] The microbial deactivation channel 120 may be sized and otherwise designed for maximum air exposure to the sterilizing UV light sources 126, and the UV-C bulbs may be designed to special wavelengths of nanometers depending on the targeted pathogens, such as Covid-19. Moreover, the number of UV-C bulbs and intensity may be selected for the required exposure given a particular flow rate of the air 104 through the microbial deactivation channel 120. Consequently, the microbial deactivation channel 120 may be designed to expose the air 104 in ratio to the proper UV-C lighting in order to implement an effective sterilization regime.

[0023] FIG. 2 is a schematic, plan view of the APU 102, according to one or more embodiments of the present disclosure. As illustrated, the APU 102 includes the housing 112, which can comprise the HVAC and microbial deactivation portions 114, 116, and is sized to contain various component parts and mechanisms required to suitably condition and treat the air 104. In the illustrated embodiment, the air 104 is received into the housing 112 at the input 110a, which fluidly communicates with the HVAC portion 114. In other embodiments, however, as mentioned above, the input 110a could alternatively be provided on the microbial deactivation portion 116, without departing from the scope of the disclosure.

[0024] As illustrated, the HVAC portion 114 provides or otherwise defines an HVAC passageway 202 in which one or more component parts or mechanisms may be housed to condition the air 104 as it is received at the input 110a. In particular, one or more fans 204 may be arranged within the HVAC passageway 202 and may be operable to draw the air 104 into the HVAC passageway 202 via the input 110a. In some embodiments, one or more filters 206 may be arranged within the HVAC passageway 202 to filter the air 104 from particles and dust of a predetermined size and entrained in the air 104. In some embodiments, the filter(s) 206 may be arranged upstream from the fans 204, but could alternatively be arranged downstream from the fans 204, without departing from the scope of the disclosure. The filters 206 may comprise one or more slide-in filter banks, as generally known to those skilled in the art. In at least one embodiment, the filters may comprise high efficiency particulate air (HEPA) air filters.

[0025] In some embodiments, the HVAC portion 114 may include at least one of a heater 208 and a cooler 210. The heater 208 may comprise a heat coil or element or the like, and flowing the air 104 through the heater 208 will increase the temperature of the air 104. The cooler 210 may comprise an air conditioning coil, or the like, and flowing the air 104 through the cooler 210 will decrease the temperature of the air 104. In embodiments that include the cooler 210, a drip pan 212 may be arranged to catch generated or accumulated water from operating the cooler 210, and the accumulated water may be evacuated from the drip pan 212 via a drain 214, and if needed, an overflow drain 216.

[0026] While not shown in FIG. 2, the HVAC portion 114 may include additional component parts or mechanisms to further condition the air 104. For example, it is contemplated herein that the HVAC portion 114 further include at least one of a humidifier and a dehumidifier. Moreover, in at least one embodiment, one or more of the UV light sources 126 may also be arranged within the HVAC passageway 202 adjacent the heater 208 and may be operable to help prevent growth of mold or other organic material on the heat coil or element.

[0027] The end of the HVAC passageway 202 may include an endwall 218 that diverts the air 104 toward the microbial deactivation portion 116 and into the microbial deactivation channel 120. In some embodiments, as illustrated, the endwall 218 may be curved to smoothly change the flow direction of the air 104. In the illustrated embodiment, the HVAC and microbial deactivation portions 114, 116 of the housing 112 are operatively coupled at the seam 118, as generally described above, and the HVAC passageway 202 feeds directly into the microbial deactivation channel 120 at a transfer aperture 220 defined in the seam 118. In embodiments where the HVAC and microbial deactivation portions 114, 116 comprise separate structures, however, the air 104 may be transferred from the HVAC passageway 202 to the microbial deactivation channel 120 via suitable ductwork (not shown).

[0028] As mentioned above, the microbial deactivation channel 120 may provide a serpentine and tortuous pathway defined by a plurality of sidewalls 122 and curved endwalls 124 that are contiguously connected and configured to agitate and mix the air 104 as it circulates (flows) through the microbial deactivation channel 120. As illustrated, the sidewalls 122 may be substantially straight and transition into the curved endwalls 124, which transition back to additional straight sidewalls 122. Consequently, the air 104 is required to navigate one or more 180 directional changes or switchbacks, which causes the air 104 to be mixed and agitated. In at least one embodiment, the microbial deactivation channel 120 does not have any dead corners (e.g., angled corners), which may reduce turbulence and increases flow efficiency.

[0029] As also mentioned above, the UV light sources 126 may be arranged within the microbial deactivation channel 120 to emit UV light that sterilizes and disinfects the air 104 circulating through the serpentine microbial deactivation channel 120. As illustrated, one or more of the UV light sources 126 may be arranged at or near the apex 221 of a corresponding curved endwall 124, thus allowing the emitted UV light to impinge in multiple directions around structural features of the microbial deactivation channel 120 (e.g., portions of the sidewalls 122 and endwalls 124), such as in both the downstream and upstream directions.

[0030] In some embodiments, one or more interior surfaces 224 of the microbial deactivation channel 120 may be faceted and otherwise provide light reflection features 222. The light reflection features 222 may comprise flat, mirror-like structures capable of receiving and redirecting light waves; e.g., the light emitted from the UV light sources 126. For example, light emitted from the UV light sources 126 will impinge upon a given light reflection feature 222 at a first angle, but reflect off the given light reflection feature 222 at a second angle different from the first angle, thereby propagating the UV light in multiple directions within the microbial deactivation channel 120. Accordingly, the light reflection features 222 convert the microbial deactivation channel 120 into a faceted structure or pathway that advantageously scatters the emitted UV light, and scattering the UV light may enhance the process of disinfecting the air 104 as it will penetrate the air 104 in effectively every direction.

[0031] In some embodiments, the light reflection features 222 may be provided only on select portions of the interior surfaces 224 of the microbial deactivation channel 120. In such embodiments, for example, the light reflection feature 222 may be provided at or near the UV light sources 126, thereby being able to receive and redirect the UV light emitted from the UV light sources 126. In other embodiments, however, the light reflection features 222 may be provided on the entire inner surface 224 of the microbial deactivation channel 120 from the transfer aperture 222 to the outlet 110b, without departing from the scope of the disclosure. Exaggerated

[0032] In some embodiments, the light reflection features 222 are formed directly on the inner surface 224 of the microbial deactivation channel 120, and thus form an integral part of the sidewalls 122 and/or endwalls 124. In such embodiments, the structural material forming the sidewalls 122 and the curved end walls 124 may be machined, bent, deformed, and otherwise manipulated to form the light reflection features 222. The light reflection features 222 shown in FIG. 2 are exaggerated in shape, but may comprise short (width-wise) and segmented portions of the sidewalls 122 and/or endwalls 124 along some or all of the microbial deactivation channel 120. In some embodiments, for example, the width of each light reflection feature 222 may be about 0.25 inches, about 0.50 inches, about 1.00 inch, or more, and may extend the entire height H.sub.1 (FIG. 1) of the housing 112. Moreover, in such embodiments, the exposed surfaces of the light reflection features 222 may be treated, processed, or polished such that a reflective or mirror-like surface results. Example processes that result in reflective surfaces include, but are not limited to, polishing, etching, coating with a reflective substance (e.g., a paint, a metal deposition, etc.), or any combination thereof.

[0033] In other embodiments, however, the light reflection features 222 may comprise separate structures or devices (e.g., plates, panels, etc.) operatively coupled (attached) to the inner surface 224 of the microbial deactivation channel 120. In such embodiments, the light reflection features 222 may be attached to the inner surfaces 224 of the sidewalls 122 and the curved endwalls 124 in a variety of orientations and directions, thereby ensuring that the UV light emitted from the UV light sources 126 is redirected in a variety of directions and pathways. Moreover, in such embodiments, the light reflection features 122 may be made of a variety of materials capable of being secured to the inner surfaces of the sidewalls 122 and the curved endwalls 124. For example, the light reflection features 122 may be made of a metal (e.g., stainless steel, aluminum, etc.), but could alternatively be made of plastic or a composite material. The exposed surfaces of the light reflection features 222 may be treated or processed with any of the example processes mentioned above such that a reflective or mirror-like surface results.

[0034] In some embodiments, each light reflection feature 222 may exhibit the same shape, and may be generally the same size. In such embodiments, for example, the light reflection features 222 may be square and exhibit a length and a width of about inch, but could alternatively exhibit a length/width smaller or greater than inch. In other embodiments, however, the light reflection features 222, may exhibit other polygonal shapes including, but not limited to, triangular, rectangular, pentagonal, etc. In yet other embodiments, the light reflection features 222 may be circular, oval, or ovoid, or a combination of polygonal and circular, without departing from the scope of the disclosure.

[0035] FIG. 3 is a top view of the APU 102, according to one or more embodiments. More specifically, FIG. 3 provides a top view of the top panel 130 included in the microbial deactivation portion 116. In some embodiments, the top panel 130 may define or provide the outlet 110b. In other embodiments, however, the outlet 110b may penetrate the top panel 130. The top panel 130 may be removably attached to the housing 112 using one or more mechanical fasteners 302. As indicated above, the top panel 130 may be removed to access the interior of the APU 102, thereby allowing a user to replace the UVC light sources 126 as needed. In other embodiments, however, that top panel 130 may provide individual, smaller panels 303 corresponding to each UV light source 126, and removing a given individual panel 303 will allow a user (e.g., a technician, maintenance crew, operator, etc.) to access a corresponding one of the UV light sources 126.

[0036] A power feed 304 may be attached to the APU 102, such as at or near the top panel 130. The power feed 304 may provide a location to provide electrical power to the electrical component of the APU 102, including the UVC light sources 126. As illustrated, power provided to the power feed 304 may be conveyed to an inverter 306, which converts the power (e.g., DC to AC) and distributes the electrical power to one or more UVC transistors or lights ballasts 308 to drive the UVC light sources 126. From the UVC transistors 308, electrical power is conveyed to the UVC light sources 126.

[0037] In some embodiments, the top panel 130 may include or otherwise be equipped with one or more safety battle switches 312 (two shown). The safety battle switches 312 may comprise circuit interrupter switches operable to cut power to the UVC light sources 126 once the top panel 130 is removed. This may be a safety feature for maintenance crew (or anyone for that matter) to protect them from the dangers of exposure to UV-C lighting used for sterilization.

[0038] In some embodiments, one or more UVC sight glasses 310 (four shown) may be provided on the top panel 130. The UVC sight glasses 310 are protected viewports that include a covering or film that allows technicians and users to check the operational status of the UVC light sources 126 (FIG. 2) while being shielding from harmful UV-C rays.

[0039] Embodiments disclosed herein include: [0040] A. An air ventilation system for an indoor space that includes an air processing unit (APU) that includes a housing that receives air from the indoor space and discharges treated air, a microbial deactivation channel provided within the housing and defining a serpentine pathway that causes the air to navigate one or more directional changes as it circulates through the housing, one or more ultraviolet (UV) light sources arranged within the microbial deactivation channel to emit UV light that impinges on and disinfects the air, and one or more light reflection features provided on one or more interior surfaces of the microbial deactivation channel, the one or more light reflection features comprising flat, mirror-like structures that receive and redirect the UV light within the microbial deactivation channel. [0041] B. A method for ventilating an indoor space includes conveying air from the indoor space to an air processing unit (APU) that includes a housing, a microbial deactivation channel provided within the housing and defining a serpentine pathway, one or more ultraviolet (UV) light sources arranged within the microbial deactivation channel, and one or more light reflection features provided on one or more interior surfaces of the microbial deactivation channel and comprising flat, mirror-like structures. The method further including circulating the air through the microbial deactivation channel and thereby causing the air to navigate one or more directional changes within the housing, emitting UV light from the one or more UV light sources, receiving and redirecting the UV light within the microbial deactivation channel with the one or more light reflection features, and impinging the UV light on the air and thereby disinfecting the air.

[0042] Each of embodiments A and B may have one or more of the following additional elements in any combination: Element 1: wherein the indoor space is selected from the group consisting of a multi-passenger vehicle, an interior room or section of a building, an elevator carriage, a store check-out aisle, security checkpoints or check-ins, a greenhouse facility, a vegetation grow room or facility, and any combination thereof. Element 2: wherein the housing comprises a microbial deactivation portion that houses the microbial deactivation channel, and wherein the housing further comprises an HVAC portion in fluid communication with the sterilization portion. Element 3: wherein the HVAC and sterilization portions are operatively coupled at a seam and thereby cooperatively form integral portions of the housing. Element 4: further comprising an input provided on the HVAC portion to receive the air from the indoor space, and an output provided on the to discharge the treated air from the APU, wherein the air is conveyed from the HVAC portion to the microbial deactivation portion. Element 5: wherein the HVAC portion provides an HVAC passageway that houses one or more of one or more fans operable to draw the air into the HVAC passageway, one or more filters operable to filter the air, a heater operable to increase a temperature of the air, and a cooler operable to decrease the temperature of the air. Element 6: wherein the microbial deactivation channel is defined by one or more sidewalls contiguously connected to one or more curved endwalls. Element 7: wherein at least one of the one or more UV light sources is arranged at an apex of a corresponding one of the one or more curved endwalls. Element 8: wherein at least one of the one or more UV light sources comprises a UV-C light source configured to emit germicidal far UV-C light. Element 9: wherein at least one of the one or more UV light sources comprises an elongate bulb that exhibits a length L1 slightly shorter than a height of the microbial deactivation channel. Element 10: wherein the housing includes a top panel detachable from the housing to expose the microbial deactivation channel, and wherein the one or more UV light sources are installed and removed lengthwise into/from the microbial deactivation channel with the top panel detached. Element 11: wherein the one or more light reflection features are formed directly on the one or more interior surfaces of the microbial deactivation channel. Element 12: wherein the one or more light reflection features comprise separate structures operatively coupled to the one or more interior surfaces of the microbial deactivation channel.

[0043] Element 13: wherein the housing comprises a microbial deactivation portion that houses the microbial deactivation channel, the housing further comprising an HVAC portion in fluid communication with the microbial deactivation portion, the method further comprising at least one of drawing the air into the HVAC passageway with one or more fans arranged in the HVAC passageway, filtering the air with one or more filters arranged in the HVAC passageway, increasing a temperature of the air with a heater arranged in the HVAC passageway, and decreasing the temperature of the air with a cooler arranged in the HVAC passageway. Element 14: wherein the microbial deactivation channel is defined by one or more sidewalls contiguously connected to one or more curved endwalls, the method further comprising arranging at least one of the one or more UV light sources at an apex of a corresponding one of the one or more curved endwalls. Element 15: wherein at least one of the one or more UV light sources comprises a UV-C light source, and wherein emitting UV light from the one or more UV light sources comprises emitting germicidal far UV-C light. Element 16: wherein at least one of the one or more UV light sources comprises an elongate bulb that exhibits a length L1 slightly shorter than a height of the microbial deactivation channel, the method further comprising installing the elongate bulb lengthwise into the housing, and removing the elongate bulb lengthwise from the housing. Element 17: wherein the one or more light reflection features are formed directly on the one or more interior surfaces of the microbial deactivation channel. Element 18: wherein the one or more light reflection features comprise separate structures operatively coupled to the one or more interior surfaces of the microbial deactivation channel.

[0044] By way of non-limiting example, exemplary combinations applicable to A, B, and C include: Element 2 with Element 3; Element 2 with Element 4; Element 2 with Element 5; Element 6 with Element 7; and Element 9 with Element 10.

[0045] Therefore, the disclosed systems and methods are well adapted to attain the ends and advantages mentioned as well as those that are inherent therein. The particular embodiments disclosed above are illustrative only, as the teachings of the present disclosure may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular illustrative embodiments disclosed above may be altered, combined, or modified and all such variations are considered within the scope of the present disclosure. The systems and methods illustratively disclosed herein may suitably be practiced in the absence of any element that is not specifically disclosed herein and/or any optional element disclosed herein. While compositions and methods are described in terms of comprising, containing, or including various components or steps, the compositions and methods can also consist essentially of or consist of the various components and steps. All numbers and ranges disclosed above may vary by some amount. Whenever a numerical range with a lower limit and an upper limit is disclosed, any number and any included range falling within the range is specifically disclosed. In particular, every range of values (of the form, from about a to about b, or, equivalently, from approximately a to b, or, equivalently, from approximately a-b) disclosed herein is to be understood to set forth every number and range encompassed within the broader range of values. Also, the terms in the claims have their plain, ordinary meaning unless otherwise explicitly and clearly defined by the patentee. Moreover, the indefinite articles a or an, as used in the claims, are defined herein to mean one or more than one of the elements that it introduces. If there is any conflict in the usages of a word or term in this specification and one or more patent or other documents that may be incorporated herein by reference, the definitions that are consistent with this specification should be adopted.

[0046] As used herein, the phrase at least one of preceding a series of items, with the terms and or or to separate any of the items, modifies the list as a whole, rather than each member of the list (i.e., each item). The phrase at least one of allows a meaning that includes at least one of any one of the items, and/or at least one of any combination of the items, and/or at least one of each of the items. By way of example, the phrases at least one of A, B, and C or at least one of A, B, or C each refer to only A, only B, or only C; any combination of A, B, and C; and/or at least one of each of A, B, and C.

[0047] The use of directional terms such as above, below, upper, lower, upward, downward, left, right, and the like are used in relation to the illustrative embodiments as they are depicted in the figures, the upward direction being toward the top of the corresponding figure and the downward direction being toward the bottom of the corresponding figure.