Patent Publication Number: US-2009227194-A1

Title: Method and apparatus for cabin air management in a vehicle

Description:
BACKGROUND 
     Climate control is important in vehicles such as automobiles. These systems affect comfort, energy efficiency, and perceived value for the customer. For example, consumers perceive improved adjustability as a feature that can provide comfort and that can merit a higher vehicle price. 
     Since manufacturers and consumers are cost conscious, systems that provide for lower cost are desired. Variables that affect systems, apparatus and methods related to climate control include cost to build, energy efficiency during operation, part weight, part size and reliability. Improving the performance of systems, apparatus and methods to impact these variables can lower costs and otherwise improve customer satisfaction. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a high level diagram of a vehicle, according to some embodiments. 
         FIG. 2  shows an exploded perspective view of a portion of a heating, ventilation and air conditioning unit, according to some embodiments. 
         FIG. 3  shows an assembled perspective view of the parts illustrated in  FIG. 2 . 
         FIG. 4A  shows a cross section of a shell and a fluid distribution unit, according to some embodiments. 
         FIG. 4B  shows a cross section of a shell and a fluid distribution unit, according to some embodiments. 
         FIG. 4C  shows a cross section of a shell and a fluid distribution unit, according to some embodiments. 
         FIG. 4D  shows a cross section of a shell and a fluid distribution unit, according to some embodiments. 
         FIG. 4E  shows a cross section of a shell and a fluid distribution unit, according to some embodiments. 
         FIG. 4F  shows a cross section of a shell and a fluid distribution unit, according to some embodiments. 
         FIG. 4G  shows a cross section of a shell and a fluid distribution unit, according to some embodiments. 
         FIG. 4H  shows a cross section of a shell and a fluid distribution unit, according to some embodiments. 
         FIG. 4I  shows a cross section of a shell and a fluid distribution unit, according to some embodiments. 
         FIG. 5  is a diagram showing opening orientation in a shell, according to some embodiments. 
         FIG. 6  is a diagram showing aperture orientation in a fluid distribution ring, according to some embodiments. 
         FIG. 7  illustrates a flow chart, according to some embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     In the following description, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration, specific embodiments which may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that structural, logical and electrical changes may be made without departing from the scope of the present invention. The following description of example embodiments is, therefore, not to be taken in a limited sense, and the scope of the present invention is defined by the appended claims. 
     Heating, ventilation and air conditioning (“HVAC”) fluid handling systems, apparatus and methods blow fluid around the interior of a cabin. In some examples, the fluid is air. In various embodiments, the fluid originates from outside the cabin, from inside the cabin, or originates from a mix of sources including the inside of the cabin and the outside of the cabin. Some examples include a filter to filter the air by removing particulates from the air. In various embodiments, the present subject matter is adapted to control climate in a cabin of a vehicle. Although the present subject matter recites HVAC, the present subject matter is not limited to embodiments including air conditioning. 
     In some instances, fluid is routed through baffles and/or blend doors to a number of vents. In some embodiments, vents are easily accessed by users such as persons driving or riding in a vehicle. Users can adjust vents in some examples, either adjusting the direction of fluid flow, or whether or not fluid flows through the vent. In some examples, vents are not easily accessible to users. In some of these examples, a vent directs fluid flow without input from a user. Examples of such vents include floor vents and defrost vents. 
     It is beneficial to reduce or eliminate blend doors and baffles, to reduce cost and improve reliability and performance. Elimination of one blend door from a system can reduce the number of associated adjustment mechanisms, such as adjustment cables, motor drives or other hardware and electronics. Further, if obstructions in fluid flow, such as blend doors and baffles, are reduced or eliminated, smaller fluid collecting and moving sources, such as exterior openings and blower motors, can be used. Reduction of such obstructions can additionally decrease noise. Simplified HVAC systems can provide for shorter development times, since temperature control, noise control, energy consumption, and other design objectives are more easily met. 
     The present subject matter reduces pressure loss by reducing or eliminating blend doors. In some embodiments, the present subject matter provides for independent temperature control of fluid passing through two or more vents. The present subject matter provides for a reduction in pressure loss and reduces the noise and power consumption required to drive the airflow, in various embodiments. The present subject matter additionally reduces weight, as some embodiments reduced the number of baffles, blend doors, and associated devices used to control fluid flow. An added benefit of the present subject matter is that it provides occupants with an improved variety of fluid distribution and temperature settings. The present subject matter is applied to vehicles having 1 seat, one row of seats (e.g., 2 seats), 2 rows of seats (e.g., 4 seats), 3 rows of seats (e.g. 6 seats) and additional configurations. 
       FIG. 1  is a high level diagram of a system  100 . Vehicles contemplated include, but are not limit to, ground based vehicles, aquatic vehicles, and aircraft. The present subject matter includes, but is not limited to, electric vehicles, hybrid vehicles having series hybrid architecture (e.g., range extended vehicles), vehicles having parallel hybrid architecture and other vehicles. In various embodiments, the vehicle  102  includes a battery  104  and electric motor  106  coupled to propel the vehicle  102 , the battery  104  coupled to power the electric motor  106 . In various examples, the electric motor  106  is for converting battery energy of the battery  104  into mechanical motion, such as rotary motion. Some examples include components coupled to a battery  104  such that the battery  104  can be plugged in for charging, using energy from another source such as a municipal power grid. 
     The present subject matter includes examples in which the battery  104  is a subcomponent of an energy storage system (“ESS”). An ESS includes various components associated with transmitting energy to and from the battery  104  in various examples, including safety components, cooling components, heating components, rectifiers, etc. The inventors have contemplated several examples of ESSs and the present subject matter should not be construed to be limited to the configurations disclosed herein, as other configurations of a battery  104  and ancillary components are possible. 
     Various battery chemistries are contemplated for battery  104 . The present subject matter includes embodiments in which the battery  104  is a secondary battery that is rechargeable using electricity rather than chemicals or other materials. Various secondary battery chemistries are contemplated for battery  104 , including lithium ion battery chemistries, lithium cobalt oxide cells, lithium iron phosphate battery chemistries, nickel metal hydride chemistries, lead acid chemistries, and other chemistries. 
     In some examples, the battery  104  includes a plurality of lithium ion cells coupled in parallel and/or series. Some examples of battery  104  include cylindrical lithium ion cells. In certain examples, the battery  104  includes one or more cells compatible with the 18650 battery standard, but the present subject matter is not so limited. Some examples include a first plurality of cells connected in parallel to define a first brick of cells, with a second plurality of cells connected in parallel to define a second brick of cells, with the first brick and the second brick connected in series. Some examples connect 69 cells in parallel to define a brick. Battery voltage, and as such, brick voltage, often ranges from around 3.6 volts to about 4.2 volts in use. In part because the voltage of batteries ranges from cell to cell, some instances include voltage management systems to maintain a steady voltage. Some embodiments connect 9 bricks in series to define a sheet. Such a sheet has around 35 volts. Some instances connect 11 sheets in series to define the battery of the ESS. The ESS will demonstrate around 385 volts in various examples. As such, some examples include approximately 6,831 cells that are interconnected. 
     Additionally illustrated is an energy converter  108 . The energy converter  108  is part of a system which converts energy from the battery  104  into energy useable by the electric motor  106 . In certain instances, the energy flow is from the electric motor  106  to the battery  104 . As such, in some examples, the battery  104  transmits energy to the energy converter  108 , which converts the energy into energy usable by the electric motor  106  to propel the vehicle  102 . In additional examples, the electric motor  106  generates energy that is transmitted to the energy converter  108 . In these examples, the energy converter  108  converts the energy generated by the electric motor  106  into energy which can be stored in the battery  104 . In certain examples, the energy converter  108  includes transistors. Some examples include one or more field effect transistors. Some examples include metal oxide semiconductor field effect transistors. Some examples include one more insulated gate bipolar transistors. As such, in various examples, the energy converter  108  includes a switch bank which is to receive a direct current (“DC”) power signal from the battery  104  and to output a three-phase alternating current (“AC”) signal to power the electric motor  106 . In some examples, the energy converter  108  is to convert a three phase signal from the electric motor  106  to DC power to be stored in the battery  104 . Some examples of the energy converter  108  convert energy from the battery  104  into energy usable by electrical loads other than the electric motor  106 . Some of these examples switch energy from approximately 390 Volts DC to 14 Volts DC. 
     The electric motor  106  is, in some embodiments, a three phase alternating current (“AC”) electric motor. Some examples include a plurality of such motors. The present subject matter can optionally include a transmission  110  in certain examples. While some examples include a 1-speed transmission, other examples are contemplated, including a 2-speed transmission, and transmissions having more than 2 speeds. In some examples, manually clutched transmissions are contemplated, as are those with hydraulic, electric, or electrohydraulic clutch actuation. Some examples employ a dual-clutch system that, during shifting, phases from one clutch coupled to a first gear to another coupled to a second gear. Rotary motion is transmitted from the transmission  110  to wheels  112  via one or more axles  114 , in various examples. 
     A vehicle management system  116  is optionally provided to control one or more of the battery  104  and the energy converter  108 . In certain examples, the vehicle management system  116  is coupled to vehicle system which monitors a safety system such as a crash sensor. In some examples the vehicle management system  116  is coupled to one or more driver inputs, such as acceleration inputs. The vehicle management system  116  is to control power to one or more of the battery  104  and the energy converter  108 , in various embodiments. 
     External power  118  is provided to communicate energy with the battery  104 , in various examples. In various embodiments, external power  118  includes a connector that is coupled to a municipal power grid. In certain examples, the charging converts power from an 110V AC power source into power storable by the battery  104 . In some examples, such conversion is performed by components onboard of a vehicle. In additional examples, the connector converts power from a 120V AC power source into power storable by the battery  104 . Some embodiments include converting energy from the battery  104  into power usable by a municipal grid. The present subject matter is not limited to examples in which a converter for converting energy from an external source to energy usable by the vehicle  102  is located outside the vehicle  102 , and other examples are contemplated. 
     Some examples include a vehicle display system  126 . The vehicle display system  126  includes a visual indicator of information relating to the system  100  in some examples. In some embodiments, the vehicle display system  126  includes a monitor that includes information related to the system  100 . The vehicle display system can include a user interface relating to HVAC as disclosed herein. 
     Various embodiments include an HVAC  128  as described herein. The HVAC  128  can receive heat from an engine in some embodiments. In additional embodiments, the HVAC  128  uses electricity, such as from battery  104 , to provide heat. 
       FIG. 2  is an exploded perspective view of a portion of an HVAC system  200 , according to some embodiments.  FIG. 3  shows an assembled perspective view of the parts illustrated in  FIG. 2 . Various embodiments include an HVAC shell  202 . In various embodiments, the HVAC shell  202  includes a plurality of openings  204 A-N. In various embodiments, the plurality of openings  204 A-N are in fluid communication with an inner chamber  206 . The HVAC shell  202  can be constructed from various materials, including, but not limited to, plastics such as ABS, composites such as fiberglass and carbon fiber. Other materials and combinations of materials are additionally possible. 
     Various embodiments include a fluid distribution ring  208 . In various embodiments, the fluid distribution ring  208  is mounted for coaxial rotary movement within the HVAC shell  202 . In some embodiments, the fluid distribution ring  208  is concentric with the HVAC shell  202 . Some embodiments include an HVAC shell cover  222  to seal the fluid passing into the fluid distribution ring  208 . The fluid distribution ring  208 , in various examples, includes one or more apertures  210 A-N. 
     Various embodiments include a mechanism coupled to the HVAC shell  202  and the fluid distribution ring  208  to rotate the ring relative to the HVAC shell between selected rotary positions to provide fluid flow paths through those openings  204 A-N in the HVAC shell that are aligned with the one or more apertures  210 A-N in the fluid distribution ring  208 . In various embodiments, the mechanism includes a worm drive. In various embodiments a worm drive includes a worm gear mated to teeth  228  to move the teeth  228  relative to the worm gear. The present subject matter additionally includes other drive systems to change the orientation of the fluid distribution ring  208  with respect to the HVAC shell  202 . 
     In various embodiments, the plurality of openings  204 A-N and apertures  210 A-N have a circular cross-section. In some embodiments, the plurality of openings  204 A-N and apertures  210 A-N are like sized. Embodiments in which apertures  210 A-N are shaped differently from the plurality of openings  204 A-N are contemplated. Regular shapes and irregular shapes in addition to circular shapes are possible for each of the plurality of openings  204 A-N and apertures  210 A-N. The present configuration is provided for explanation, and should not be construed as limiting of the possible configurations. 
     The depth of one or more of the HVAC shell  202  and the fluid distribution ring  208  are adjustable depending on fluid volume required for an application. Airflow can additionally be adjusted by varying the size of one or more of the plurality of openings  204 A-N and apertures  210 A-N. Diameter likewise can impact the volume of fluid passing through the system  200 . Embodiments disclosed herein include one or more modes in which an opening of the plurality of openings  204 A-N is coextensive with an aperture of the apertures  210 A-N, but the present subject matter includes embodiments in which an aperture of the apertures  210 A-N is only partially mated with an opening of the plurality of openings  204 A-N. The present subject matter provides for adjustability of airflow and temperature by varying the degree to which an aperture of the apertures  210 A-N and an opening of the plurality of openings  204 A-N are aligned in some embodiments. The specific location of openings  204 A-N and apertures  210 A-N is not limited to those orientations provided herein, and additional orientations are possible. 
     Various embodiments include a blower  212 . In various embodiments, the blower is concentric with one or more of the HVAC shell  202  and the fluid distribution ring  208 , but the present subject matter is not so limited. In various embodiments, the blower  212  is located upstream of the evaporator  216 . The blower  212  is not limited to a concentric orientation with the HVAC shell  202 . Additionally illustrated is a blower motor  214 . In various embodiments, the blower  212  is spun by the blower motor  214  to force fluid from the inner chamber  206  through those of the plurality of openings  204 A-N in the HVAC shell  202  that are aligned with the one or more apertures  210 A-N in the fluid distribution ring  208 . In various embodiments, the blower  212  is coupled to a vehicle, such as the vehicle associated with  FIG. 1 . Blower types include, but are not limited to, fans, radial fans, axial fans, fans including a shroud, squirrel cages, and other fans. In some embodiments, the blower motor  214  is a variable speed blower motor. In some instances, motor speed is controlled via switching one or more resistors into and out of series with a voltage to supply a plurality of voltages to the blower motor  214  according to several embodiments. In additional examples, motor speed is controlled via pulse width modulation of a voltage supplying energy to the blower motor  214 . Additional control configurations are also possible. The size of blower  212  is selected to fit various applications. For example, diameter and width are variable depending on the volume or air that is desired to flow over time. 
     Various embodiments include a heat exchanger such as evaporator  216 . Additionally illustrated is a thermal expansion valve  234 . In various embodiments, the evaporator  216  is coupled to contact fluid passing through those openings of the plurality of openings  204 A-N in the HVAC shell  202  that are aligned with the one or more apertures  210 A-N in the fluid distribution ring  208 . In various embodiments, fluid is drawn through the evaporator  216  and the evaporator  216  extracts heat and condenses moisture from the incoming fluid. In various examples, the evaporator  216  dehumidifies fluid. 
     Various embodiments include an evaporator housing  218  (also referred to as a heat exchanger housing) coupled to the evaporator  216  to constrain fluid flow from an inlet  220  of the evaporator housing  218  to the inner chamber  206 . In various embodiments, the evaporator housing  218  is coupled to a vehicle such as the vehicle illustrated in  FIG. 1 , and the inlet  220  is inside a cabin of the vehicle. Some embodiments include an evaporator housing cover  224  to seal fluid into the evaporator housing  218 . In various embodiments, the inlet  220  is adapted to switch between or blend between a recirculating fluid inlet  230  and a fresh fluid inlet  232 . In various embodiments, switching is assisted by an inlet blend door  226 . In various embodiments, in a fresh fluid mode, the inlet blend door  226  is adjusted to direct fluid from outside of the vehicle into the inner chamber  206 . In additional embodiments, in a recirculating fluid mode, the inlet blend door  226  is adjusted to direct fluid from inside a cabin of a vehicle into the inner chamber  206 . 
     Various embodiments include a heat exchanger that includes a heating element. The evaporator  216  in some embodiments is coupled with a heating element, such as a heater core or an electronic heating element. Heating and cooling can be provided alone or in combination. Some examples include positive temperature coefficient (“PTC”) heat exchangers to provide heating. In some embodiments, a single PTC heater is disposed proximal to the evaporator  216 , such as downstream of the evaporator  216 . In some of these embodiments, the PTC heater is disposed in the evaporator housing  218 . Some embodiments include a temperature blend door to regulate the amount of total airflow through the heater. Some embodiments include a PTC heater that uses between 3 and 5 kW, but the present subject matter is not so limited. Additional embodiments position a heat exchanger such as a PTC heater in one or more of the plurality of openings  204 A- 204 N. In some embodiments, these heat exchangers each use from 0 to 1 kW during heating, but the present subject matter is not so limited. In still further embodiments, heat exchangers are positioned proximal to vents that are coupled to the plurality of openings  204 A- 204 N, such as through ductwork. Various embodiments include a heat exchanger housing for one or both of an evaporator  216  and a heating element. 
     The heating, ventilation and system  200 , in various embodiments, include ducts. Ducts are attached to the plurality of openings  204 A-N in the HVAC shell  202 . Ducts extend around a vehicle, in various examples. In some examples, ducts exit near the driver window (e.g. the left front window), the front passenger window (e.g. the right front window), near the floor of the driver and the front passenger, and in some embodiments near the floor of rear occupants. In some embodiments, a valve is coupled to at least one of the plurality of openings  204 A-N in the HVAC shell  202  to further control airflow. Such a valve can include a manual flute coupled to a vent that is flush mounted with an instrument panel, but the present subject matter is not so limited. These configurations are provided for illustration, and the present subject matter includes additional configurations. In various embodiments, one or more ducts include temperature sensors that relay temperature information to a controller controlling one or more of the blower motor  214 , a mechanism to adjust orientation of the fluid distribution ring  208  with respect to the HVAC shell  202 , and one or more secondary heat exchangers. 
     Control of the system  200  is accomplished according to several configurations, including manual configurations and automatic configurations. Various embodiments allow a user to input a desired temperature change from the driver position. In some embodiments, temperature control is determined by occupant demand, and regulated via an electronic automatic temperature control (“EATC”) controller. In some of these examples, evaporator outlet temperature is determined by various temperature sensors mounted to heat exchangers, openings, ducts and wherever else temperature knowledge is useful. In various embodiments, a controller monitors the temperature of fluid entering a heat exchanger and fluid exiting a heat exchanger. In some embodiments, a controller adjusts one or more components of the system  200  to address user input in view of the lowest temperature measured across multiple sensors. For example, if an occupant passenger temperature demand is lower than a driver temperature demand in a dual zone climate control configuration, the system  200  is adjusted to provide air for the cooler zone, and one or more heat exchangers such as PTC heaters warm the air for the remaining zones. 
     In some embodiments, a controller such as an EATC contains sensing, logic and control algorithms to allow automatic temperature control, with zone biasing to enhance human comfort perception. Zone biasing, in various embodiments, allows warmer temperature for the feet and cooler temperature toward the head or breath level simultaneously. In various embodiments, the EATC contains sensing, logic and control algorithms to sense the occupied zones and set temperature and distribution settings to provide comfort with minimal power consumption. Such behavior can be activated automatically, or via user selection of an economy mode. In some embodiments, outlet duct temperature settings and fan blower speed are manually controlled in addition to the EATC and Economy Mode settings. In some embodiments, the controller includes a thermostat and automatically controls one or more mechanisms to adjust the orientation of the to the fluid distribution ring  208  with respect HVAC shell  202 . 
     In various embodiments, system  200  is preassembled. For example, in some embodiments, system  200  is shipped to a final assembly manufacturing plant for installation into a vehicle. In some of these examples, the system  200  is a module for assembly into a vehicle. 
       FIG. 4A-I  show various cross sections of a shell and a fluid distribution unit, according to some embodiments. Various modes are contemplated. In a first mode, illustrated in  FIG. 4A , the HVAC shell  402  and the fluid distribution ring  404  are aligned such that fluid is free to pass through a driver vent, a front passenger vent and a rear or aft occupant vent. For the purposes of explanation, the left side of the vehicle is termed the driver side, and the right side of the vehicle is termed the passenger side, but other coordinate systems are possible. 
     In a second mode, illustrated in  FIG. 4B , the HVAC shell  402  and the fluid distribution ring  404  are aligned such that fluid is free to pass through a driver vent and a forward floor vent. The forward floor vent directs fluid toward the feet of a driver and a front seated passenger, but the present subject matter is not so limited. In various embodiments, the mode illustrated in  FIG. 4B  is a driver preferred mode. 
     In a third mode, illustrated in  FIG. 4C , the HVAC shell  402  and the fluid distribution ring  404  are aligned such that fluid is free to pass through a defrost vent and to a forward floor vent. In various embodiments, the mode illustrated in  FIG. 4C  is a warm-up mode that can be engaged during warming and defrosting of the vehicle. 
     In a fourth mode, illustrated in  FIG. 4D , the HVAC shell  402  and the fluid distribution ring  404  are aligned such that fluid is free to pass through a defrost vent and a rear occupant vent. In various embodiments, the mode illustrated in  FIG. 4D  could be used to defrost while providing heat for rear occupants, such as when a baby is seated in a rear seat. 
     In a fifth mode, illustrated in  FIG. 4E , the HVAC shell  402  and the fluid distribution ring  404  are aligned such that fluid is free to pass through a driver vent and a front passenger vent. 
     In a sixth mode, illustrated in  FIG. 4F , the HVAC shell  402  and the fluid distribution ring  404  are aligned such that fluid is free to pass through a driver vent, a front passenger vent and a forward floor vent. 
     In a seventh mode, illustrated in  FIG. 4G , the HVAC shell  402  and the fluid distribution ring  404  are aligned such that fluid is free to pass through a defrost vent. In various embodiments, the mode illustrated in  FIG. 4G  is a maximum defrost mode, useful when visibility through glass is impaired by moisture. 
     In an eighth mode, illustrated in  FIG. 4H , the HVAC shell  402  and the fluid distribution ring  404  are aligned such that fluid is free to pass through a forward floor vent and a front passenger vent. This mode is termed a passenger preferred mode. In various embodiments, the forward floor vent includes the forward floor around the front passenger area and the forward floor around the driver area, but the present subject matter is not so limited. In various embodiments a baffle in the floor vent ducting is included to direct all or a portion of the fluid flow to the driver side or the passenger side, for additional control of driver preferred and passenger preferred modes. 
     In a ninth mode, illustrated in  FIG. 4I , the HVAC shell  402  and the fluid distribution ring  404  are aligned such that fluid is free to pass through a rear floor vent. A rear floor vent, in various embodiments, includes the rear floor area used by occupants sitting in the rear seat (e.g., 2nd row or 3rd row seating), but the present subject matter is not so limited. In some embodiments, a demist mode for windshield and side glass demisting is accomplished concurrently with other modes using a demist outlet, in-duct electric heater, and actuated door located in the HVAC shell  402  and ducted to the base of the defrost panel duct. In some embodiments, control of fluid outlet open/close position via a mode selection reduces the need for manually operated vents. 
     The assignment of the openings to areas or zones of a car are variable according to several embodiments. For example, sports cars having no rear occupants can direct the openings labeled “rear occupant” to another portion of a vehicle, such as individual floor outlets, to seats, or to a trunk space. These and other configurations are possible without departing from the present subject matter. Air distribution rings  404  having more or less apertures, or apertures at different locations are possible in various embodiments. HVAC shells  402  having more or less openings, or openings at different locations are possible in additional embodiments. In some embodiments, mass customization is possible by inventorying multiple air-distribution rings. For example, in some embodiments, a first air distribution ring having no aperture for alignment with the rear occupant opening is provided at a first price level, and a second air distribution ring having an aperture for alignment with the rear occupant opening is provided at a second price level higher than the first price level. The present subject matter&#39;s customization options are not limited to the rear occupant opening, and other openings can be withheld or provided according to pricing schemes or vehicle configuration in additional embodiments. 
       FIG. 5  is a diagram showing vent orientation in a shell, according to some embodiments.  FIG. 6  is a diagram showing vent orientation in a fluid distribution ring, according to some embodiments. In various embodiments, the HVAC shell  402  includes a front passenger opening having a front passenger opening centerline, a rear occupant opening having a rear occupant opening centerline approximately 90 degrees from the front passenger opening centerline around the axis, a front passenger floor opening having a front passenger floor opening centerline approximately 150 degrees from the front passenger opening centerline around the axis, a driver opening having a driver opening centerline approximately 240 degrees from the front passenger opening centerline around the axis and a defrost opening having a defrost opening centerline approximately 300 degrees from front passenger opening centerline around the axis. 
     In additional embodiments, the fluid distribution ring  404  includes a first opening having a first opening centerline, a second opening having a second opening centerline approximately 120 degrees from the first opening centerline around the axis, a third opening having a third opening centerline approximately 210 degrees from the first opening centerline around the axis, a fourth opening having a fourth opening centerline approximately 240 degrees from the first opening centerline around the axis and a fifth opening having a fifth opening centerline approximately 330 degrees from first opening centerline around the axis. 
       FIG. 7  illustrates a flow chart, according to some embodiments. At  702 , the method  700  includes coaxially rotating a fluid distribution ring inside an HVAC shell such that one or more apertures of the fluid distribution ring align with one or more openings of the HVAC shell such that fluid flows through the aligned opening and aperture. The method  700  includes coaxially rotating the fluid distribution ring in relation to the HVAC shell to switch between a defrost venting mode, a front passenger venting, driver venting and forward floor venting mode and a front passenger venting and driver venting mode. At  704 , the method  700  optionally includes coaxially rotating the fluid distribution ring in relation to the HVAC shell to switch between a front passenger venting and forward floor venting mode and a driver venting and forward floor venting mode. At  706 , the method  700  optionally includes coaxially rotating the fluid distribution ring in relation to the HVAC shell to switch to a front passenger venting, a driver venting and a rear occupant venting mode. At  708 , the method  700  optionally includes coaxially rotating the fluid distribution ring in relation to the HVAC shell to switch to a defrost venting and a rear occupant venting mode. At  710 , the method  700  optionally includes coaxially rotating the fluid distribution ring in relation to the HVAC shell to switch to a rear occupant venting mode. At  712 , the method  700  optionally includes coaxially rotating the fluid distribution ring in relation to the HVAC shell to switch to a defrost venting and a forward floor venting mode. One or more of the methods optionally includes coaxially rotating the fluid distribution ring with respect to the HVAC via a worm drive. 
     The Abstract is provided to comply with 37 C.F.R. §1.72(b) to allow the reader to quickly ascertain the nature and gist of the technical disclosure. The Abstract is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.