Patent Publication Number: US-11649988-B2

Title: Temperature control system in a passenger service unit

Description:
CROSS REFERENCE 
     The present application is a divisional application and claims the benefit under 37 CFR § 120 of U.S. patent application Ser. No. 16/741,360 filed on Jan. 13, 2020. The U.S. patent application Ser. No. 16/741,360 filed on Jan. 13, 2020 is hereby incorporated by reference in its entirety. 
    
    
     BACKGROUND 
     The options for passengers to control the local ambient environment on commercial aircraft are limited. Typically, a passenger can control their local environment by accessing the overhead nozzle in the passenger service unit (PSU). The passenger can control the amount and direction of air flow by manipulation of the overhead nozzle. The passenger is not, however, able to control the temperature of the air flow from the nozzle. Therefore, there exists a need in the art for a system which cures one or more of the shortfalls of previous approaches identified above. 
     SUMMARY 
     A temperature control system in an aircraft passenger service unit is disclosed. In embodiments, the system includes a swirl chamber configured to receive an inlet air stream, and a vortex tube configured to receive the inlet air stream from the swirl chamber and separate the inlet air stream into a warmer air stream and a cooler air stream. In embodiments, the system further includes a nozzle configured to direct a temperature-controlled air stream into a passenger space of an aircraft; wherein the nozzle is configured to be selectably adjusted in order to selectively blend the warmer air stream and the cooler air stream in order to generate the temperature-controlled air stream. 
     In some embodiments of the system, the nozzle is configured to receive two or more air streams from the vortex tube. 
     In some embodiments of the system, the nozzle is configured to be selectively adjusted in order to: selectively decrease an air flow rate of the temperature-controlled air stream into the passenger space; selectively increase an air flow rate of the temperature-controlled air stream into the passenger space; selectively control a direction of airflow of the temperature-controlled air stream; and selectively blend the cooler air stream and the warmer air stream to generate the temperature-controlled air stream of a desired temperature. 
     In some embodiments of the system, the nozzle is selected from the group consisting of a multi-gas nozzle, eductor nozzle, spillback nozzle, solid stream nozzle, hollow cone nozzle, full cone nozzle, screw nozzle, air amplifier nozzle, air edge nozzle, co-annular nozzle or an air jet nozzle. 
     In some embodiments of the system, the vortex tube is fluidically coupled with a flow tube. 
     In some embodiments of the system, the vortex tube and the fluidically coupled flow tube are insulated. 
     In some embodiments of the system, the system further includes a second vortex tube. 
     In some embodiments of the system, the system further includes a valve configured to control a flow rate of the inlet air stream into the vortex tube. 
     In some embodiments of the system, the valve is controlled by selectively adjusting the nozzle. 
     In some embodiments of the system, the valve is selected from the group consisting of a solenoid valve, two-way solenoid valve, three-way solenoid valve, globe valve, ball valve, wafer valve, butterfly valve, plug valve, slow acting valve, slide valve, pilot valve, relieving valve, wedge valve, notched ball valve, needle valve, pneumatic valve, two-way directional pneumatic valve, or a three-way directional pneumatic valve. 
     In some embodiments of the system, the valve is configured to: receive the inlet air stream from an air compressor; direct a first portion of the inlet air stream to a first vortex tube; and direct a second portion of the inlet air stream to a second vortex tube, wherein the first portion of the inlet air stream and the second portion of the inlet air stream air are blended by selectively adjusting the nozzle in the passenger service unit. 
     In some embodiments of the system, the vortex tube includes an inner air passageway and an outer air passageway. 
     In some embodiments of the system, the inner air passageway and the outer air passageway are fluidically coupled. 
     In some embodiments of the system, the inner air passageway is configured to: receive the air inlet stream; direct the air inlet stream within the inner air passageway to a conical nozzle configured to separate the air inlet stream into a warmer air stream and a cooler air stream, wherein the conical nozzle directs the warmer air stream around the conical nozzle into the outer air passageway towards the nozzle, and directs the cooler air stream through the inner air passageway towards the nozzle, wherein the warmer air stream and the cooler air stream are blended by selectively adjusting the nozzle. 
     A method for generating a temperature-controlled air stream with a passenger service unit of an aircraft cabin is disclosed. In embodiments, the method includes: generating a compressed inlet air stream with an air compressor; receiving the compressed air inlet stream with a swirl chamber; directing the compressed air inlet stream from the swirl chamber to a conical nozzle disposed within a vortex tube; separating the compressed air inlet stream into a warmer air stream and a cooler air stream with the conical nozzle; directing at least one of the warmer air stream and the cooler air stream to a nozzle; and directing a temperature-controlled air stream into a passenger space of an aircraft with the nozzle, wherein the nozzle is configured to be selectively adjusted in order to selectively blend the warmer air stream and the cooler air stream in order to generate the temperature-controlled air stream. 
     It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not necessarily restrictive of the invention as claimed. The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and together with the general description, serve to explain the principles of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Implementations of the inventive concepts disclosed herein may be better understood when consideration is given to the following detailed description thereof. Such description makes reference to the included drawings, which are not necessarily to scale, and in which some features may be exaggerated, and some features may be omitted or may be represented schematically in the interest of clarity. Like reference numerals in the drawings may represent and refer to the same or similar element, feature, or function. In the drawings: 
         FIG.  1    illustrates a cross-sectional view of a vortex tube. 
         FIG.  2    illustrates a cross-sectional view of a portion of a conventional nozzle system in a passenger service unit (PSU). 
         FIG.  3 A  illustrates a cross-sectional view of a portion of a PSU including a nozzle equipped with a vortex tube, in accordance with one or more embodiments of the present disclosure. 
         FIG.  3 B  illustrates a cross-sectional view of a portion of a PSU including a nozzle equipped with a vortex tube, in accordance with one or more embodiments of the present disclosure. 
         FIG.  3 C  illustrates a cross-sectional view of a portion of a PSU including a nozzle equipped with a first vortex tube and second vortex tube, in accordance with one or more embodiments of the present disclosure. 
         FIG.  4 A  illustrates a cross-sectional view of a portion of a PSU including a nozzle equipped with a vortex tube, in accordance with one or more embodiments of the present disclosure. 
         FIG.  4 B  illustrates a cross-sectional overhead view of vortex tube in PSU, in accordance with one or more embodiments of the present disclosure. 
         FIG.  4 C  illustrates a cross-sectional view of a portion of a PSU including a nozzle equipped with a vortex tube, in accordance with one or more embodiments of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Before explaining at least one embodiment of the inventive concepts disclosed herein in detail, it is to be understood that the inventive concepts are not limited in their application to the details of construction and the arrangement of the components or steps or methodologies set forth in the following description or illustrated in the drawings. In the following detailed description of embodiments of the instant inventive concepts, numerous specific details are set forth in order to provide a more thorough understanding of the inventive concepts. However, it will be apparent to one of ordinary skill in the art having the benefit of the instant disclosure that the inventive concepts disclosed herein may be practiced without these specific details. In other instances, well-known features may not be described in detail to avoid unnecessarily complicating the instant disclosure. The inventive concepts disclosed herein are capable of other embodiments or of being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and should not be regarded as limiting. 
     As used herein, directional terms such as “top,” “bottom,” “over,” “under,” “upper,” “upward,” “lower,” “down,” “downward,” and similar terms, are intended to provide relative positions for purposes of description, and are not intended to designate an absolute frame of reference. Various modifications to the described embodiments will be apparent to those with skill in the art, and the general principles defined herein may be applied to other embodiments. Therefore, the present invention is not intended to be limited to the particular embodiments shown and described, but is to be accorded the widest scope consistent with the principles and novel features herein disclosed. 
     Additionally, as used herein, a letter following a reference numeral is intended to reference an embodiment of the feature or element that may be similar, but not necessarily identical, to a previously described element or feature bearing the same reference numeral (e.g., 1, 1A, 1B). Such shorthand notations are used for purposes of convenience only and should not be construed to limit the inventive concepts disclosed herein in any way unless expressly stated to the contrary. 
     Finally, as used herein any reference to “one embodiment,” or “some embodiments” means that a particular element, feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the inventive concepts disclosed herein. The appearances of the phrase “in some embodiments” in various places in the specification are not necessarily all referring to the same embodiment, and embodiments of the inventive concepts disclosed may include one or more of the features expressly described or inherently present herein, or any combination of sub-combination of two or more such features, along with any other features which may not necessarily be expressly described or inherently present in the instant disclosure. 
     Broadly, embodiments of present disclosure are directed to temperature control in a PSU system in an aircraft. More particularly, embodiments of the present disclosure are directed to a temperature control system embedded in a PSU that can be manipulated (e.g., selectively actuated, selectively adjusted) by a passenger to control the temperature of the air flow coming out of the overhead vent. Further embodiments of the present disclosure are directed to a system based on a vortex tube which can be integrated into a PSU that separates cabin air into hot and cold streams of air. 
     It is contemplated herein that the temperature control system of the present disclosure may provide a number of advantages over conventional air vent nozzles in PSUs. First, a passenger can control the temperature of the air coming out of the air nozzle, not just the air flow. This may lead to an increased level of comfort for the passenger. Additionally, each passenger in the cabin can control their own local heating or cooling. This reduces the need for mass conditioning of the larger cabin environment resulting in more efficient operation of the aircraft. The temperature control system has no moving parts (other than the passenger manipulated nozzle), electricity or refrigerant and uses cabin air that is separated into cold and hot streams of air. 
     Referring generally to  FIGS.  1 A- 4 C , a temperature control system in a PSU is described, in accordance with example embodiments of the present disclosure. 
       FIG.  1    illustrates a cross-sectional view of a vortex tube  100 . It is noted herein that vortex tube  100  is presented to generally illustrate the physical principles by which the temperature control system described herein is based on such that the inventive concepts of the present disclosure may be more clearly understood. 
     Vortex tube  100  is a device that separates compressed gas into hot and cold streams of gas. A conventional vortex tube  100  includes a tube  102  with an air inlet  104 , a swirl chamber  106 , a conical nozzle  108  on one end of the tube  102 , and an air outlet  110  on an opposite end of the tube  102 . 
     In operation, a compressed air stream  112  is injected tangentially into the swirl chamber  106 . Air stream  112  is accelerated to a high rate of rotation in the swirl chamber. The larger diameter, outer shell of air  116  rotating at the higher speed with a higher temperature travels along the length of tube  102  and escapes through the conical nozzle  108  located at one end of tube  102  as a warmer air stream  118 . The inner vortex of air  120  with smaller diameter and of cooler temperature is forced to the opposite end of tube  102  where air  120  exits outlet  110  as a cooler air stream  122 . The inner vortex of air  120  and outer vortex of air  116  flow in opposite directions in a counterflow manner within vortex tube  100 . This phenomenon is the basis of the inventive concepts disclosed herein. Tube  102 , inlet  104 , swirl chamber  106 , conical nozzle  108  and air outlet  110  are generally fluidically coupled. 
       FIG.  2    illustrates a cross-sectional view of a portion of a conventional nozzle system in a passenger service unit (PSU). The conventional PSU  200  in  FIG.  2    is described for comparative illustration to the embodiments described herein. PSU  200  may include a substrate  202  that supports and is embedded with various functionalities accessible by a passenger in a passenger space in an aircraft cabin. PSU  200  may further include a light  204 , an emergency call button  206  and an air nozzle  208 . A PSU may include other functionalities not shown in  FIG.  2   . 
     Nozzle  208  directs inlet air  210  that enters in the space above the PSU  200 . Nozzle  208  is typically capable of being manipulated or selectively adjusted by a passenger. For example, nozzle  208  may be directional such that a passenger may control the direction of inlet air  210  that enters and exits nozzle  208  as exiting air  212 . Additionally, a passenger can typically control (e.g., selectively adjust) the amount of flow of exiting air  212 . A passenger can selectively increase and/or decrease the air flow rate to the passenger space. For example, the nozzle may be configured to be selectively adjusted in order to selectively decrease or completely shut off the flow of exiting air  212 , selectively increase or completely open the flow of exiting air  212  or somewhere in between. The amount of flow of exiting air  212  (air flow rate)depends on the passenger&#39;s desired comfort. The flow of exiting air  212  is controlled by manipulation of nozzle  208 . A common air nozzle design is a screw nozzle commonly equipped in PSUs. As the passenger turns the nozzle  208  head in a clockwise manner, the nozzle  208  gradually closes and decreases or completely shuts off the exiting air  212  flow to the passenger space. The nozzle  208  head can be turned in a counter-clockwise manner to selectively increase and open the nozzle  208  and increase the flow of exiting air  212 . A passenger though cannot control the actual temperature of inlet air  210  that is emitted into the passenger space, only the flow rate. 
       FIG.  3 A  illustrates a cross-sectional view of a portion of a PSU including a nozzle equipped with a vortex tube, in accordance with one or more embodiments of the present disclosure. 
     In embodiments, PSU  300  may be configured to be disposed in a passenger space. In an embodiment, PSU  300  includes a substrate  302 , a light  304 , an emergency call button  306 , a nozzle  308 , vortex tube  314 , air inlet  316 , swirl chamber  318 , conical nozzle  320 , air flow tube  322 , and exhaust air outlet  324 . In some embodiments, PSU  300  may further include an air compressor  326  to compress inlet air stream  310  for more efficient and effective operation of vortex tube  314  to separate inlet air  310  into cooler and warmer air streams. In embodiments, vortex tube  314  may be continuous with air flow tube  322 . In some embodiments, vortex tube  314  may be fluidically coupled with air flow tube  322 . In other embodiments, vortex tube  314  may be fluidically coupled to air flow tube  322  by a U-shaped tube as illustrated in  FIG.  3 A . Nozzle  308 , vortex tube  314 , air inlet  316 , swirl chamber  318 , conical nozzle  320 , air flow tube  322 , and exhaust outlet  324  may be fluidically coupled. 
     In operation, a compressed air stream  310  is injected into and received by air inlet  316  and into swirl chamber  318 . The air is directed in an upward direction towards conical nozzle  320  where the warmer air stream  328  passes around conical nozzle  320  towards flow tube  322 . The warmer air stream  328  (solid line) passes through the U-shaped tube into flow tube  322  towards nozzle  308 . The cooler air stream  330  (dotted line) moves downwards towards swirl chamber  318  and onward towards nozzle  308 . A passenger may then selectively adjust nozzle  308  in such a way as to blend the cool air stream  330  and warm air stream  328  to attain a desired temperature of temperature-controlled air stream  312  to be allowed into the passenger space. A passenger may also selectively adjust the nozzle  308  in order to adjust an air flow rate of the temperature-controlled air stream  312  entering the passenger space. For example, a passenger may completely shut off the flow of any air stream into the passenger space by selectively decreasing and completely closing the nozzle or selectively increasing and completely open up the nozzle to allow all air to flow out. Any unused air during blending or if the passenger completely closes nozzle  308 , may exit out exhaust outlet  324  as exhausted air stream  332 . In other embodiments, a passenger may also control the flow rate of temperature-controlled air stream  312 . 
       FIG.  3 B  illustrates a cross-sectional view of a portion of a PSU including a nozzle equipped with a vortex tube, in accordance with one or more embodiments of the present disclosure. 
     In embodiments, PSU  350  is configured to be disposed in a passenger space in an aircraft. In an embodiment, PSU  350  includes a nozzle  308 , a vortex tube  314 , an air inlet  316 , a swirl chamber  318 , a conical nozzle  320 , a flow tube  322  and an exhaust outlet  324 . In this embodiment, vortex tube  314  is reversed in comparison to PSU embodiment  300  in  FIG.  3 A . In PSU  350 , air inlet  316  is toward the top and nearest the U-shaped tube bend and air flow tube  322 . In embodiments, vortex tube  314  may be continuous with air flow tube  322 . In some embodiments, vortex tube  314  may be fluidically coupled with air flow tube  322 . In other embodiments, vortex tube  314  may be fluidically coupled with air flow tube  322  by a U-shaped tube as illustrated in  FIG.  3 B . In some embodiments, PSU  350  may further include an air compressor  326  to compress inlet air stream  310 . Nozzle  308 , vortex tube  314 , air inlet  316 , swirl chamber  318 , conical nozzle  320 , air flow tube  322 , and air exhaust outlet  324  may be fluidically coupled. 
     In operation, a compressed inlet air stream  310  is injected into and received by air inlet  316  and into swirl chamber  318 . The air is directed in a downward direction towards conical nozzle  320  where the warmer air stream  328  (solid line) passes around conical nozzle  320  towards nozzle  308 . The cooler air stream  330  (dotted line) moves upwards towards swirl chamber  318 , into U-shaped tube bend and flow tube  322 . The cooler air stream  330  then flows onward towards nozzle  308 . The passenger may manipulate nozzle  308  in such a way as to selectively blend the cooler air stream  330  and warmer air stream  328  to attain a desired temperature of a temperature-controlled air stream  312  that is released into the passenger space. Any unused air during blending or if the passenger completely closes nozzle  308 , may exit out exhaust outlet  324  as exhausted air stream  332 . In other embodiments, the passenger may also control the flow rate of the temperature-controlled air stream  312  that is released into the passenger space. 
       FIG.  3 C  illustrates a cross-sectional view of a portion of a PSU  360  including a nozzle  308  equipped with a first vortex tube  362  and a second vortex tube  364 , in accordance with one or more embodiments of the present disclosure. 
     In embodiments, PSU  360  may be configured to be in a passenger space in an aircraft. In an embodiment, PSU  360  includes a first vortex tube  362  and a second vortex tube  364 . Generally, first vortex tube  362  and second vortex tube  364  are fluidically coupled. This contrasts with embodiments  300 ,  350  illustrated in  FIGS.  3 A- 3 B  that include a single vortex tube  314 . Vortex tubes  362 ,  364  in PSU  360  may be arranged in an opposing manner wherein the air inlet  366  for first vortex tube  362  is arranged near nozzle  308  and air inlet  368  of second vortex tube  364  is arranged away from nozzle  308 . The embodiment in  FIG.  3 C  shows air inlets  366 ,  368  are arranged to receive compressed air to the left of first vortex tube  362 . In other embodiments, air inlet  368  may be facing the opposite direction of inlet  366  such that air inlets  366 ,  368  may receive compressed air from opposing directions. Vortex tubes  362 ,  364 , air inlets  366 ,  368 , swirl chambers  370 ,  378  and conical nozzles  372 ,  380  may be fluidically coupled. In some embodiments, PSU  360  may further include an air compressor  326  to compress inlet air stream  310 . 
     In dual vortex tube operation, a compressed inlet air stream  310  is injected and received simultaneously into air inlet  366  and swirl chamber  370  of first vortex tube  362  and air inlet  368  and swirl chamber  378  of second vortex tube  364 . Air that enters inlet  366  of first vortex tube  362  flows in an upward manner towards conical nozzle  372  where the warmer air stream  374  flows out of vortex tube  362 . The cooler air stream  376  of first vortex tube  362  flows in a downward manner towards nozzle  308 . Air that enters inlet  368  and swirl chamber  378  of second vortex tube  364  flows in a downward manner towards conical nozzle  380 . The warmer air stream  382  passes around conical nozzle  380  and onwards towards nozzle  308 . The cooler air stream  384  flows upward towards swirl chamber  378  and exits vortex tube  364 . A passenger may then be able to control the temperature of the temperature-controlled air stream  386  by selectively adjusting nozzle  308  in a way to selectively decrease and/or shut off the flow or blend warmer air stream  382  and cooler air stream  376  to a desired temperature to be released into the passenger space. In other embodiments, a passenger may also control the flow rate of temperature-controlled air stream  386  released into the passenger space. 
     In some embodiments, PSU  360  may further include a valve  388 . For example, valve  388  may be a three-way valve as illustrated in  FIG.  3 C . Valve  388  may be operated by a control device accessible by a passenger near nozzle  308 . Valve  388  may be used to control the temperature of the temperature-controlled air stream  386  released into the passenger space. Valve  388  may be selected from the group consisting of a solenoid valve, two-way solenoid valve, three-way solenoid valve, globe valve, ball valve, wafer valve, butterfly valve, plug valve, slow acting valve, slide valve, pilot valve, relieving valve, wedge valve, notched ball valve, needle valve, pneumatic valve, two-way directional pneumatic valve or a three-way directional pneumatic valve. 
     In operation, compressed inlet air stream  310  may enter valve  388 . Depending on the desired temperature of air stream  386  by the passenger, a valve  388  may allow inlet air stream  310  to pass into inlets  366  of the first vortex tube  362  and air inlet  368  of second vortex tube  364  substantially equally. This may lead to a relatively moderate temperature level of temperature-controlled air stream  386 . 
     In some situations, a passenger may desire a colder air stream exiting from the nozzle  308 . In this situation, valve  388  may be controlled by a passenger to close off air flow to inlet  368  of second vortex tube  364 . This shuts off the warmer air stream  382  from the second vortex tube  364  and allows cooler air stream  376  from first vortex tube  362  to enter nozzle  308  and exit as temperature-controlled air stream  386  into the passenger space. 
     In some situations, a passenger may desire a warmer air stream exiting from the nozzle  308 . In this situation, valve  388  may be controlled by a passenger to close off air flow to inlet  366  of first vortex tube  362 . This shuts off the cooler air stream  376  from the first vortex tube  362  and allows warmer air stream  382  from the second vortex tube  364  to enter nozzle  308  and exit as temperature-controlled air stream  386  into the passenger space. 
     In some embodiments, PSU  360  may include three or more vortex tubes. In some embodiments, nozzle  308  may be configured to receive two or more air streams. The two or more air streams may be of different temperatures. 
       FIG.  4 A  illustrates a cross-sectional view of a portion of a PSU including a nozzle equipped with a vortex tube, in accordance with one or more embodiments of the present disclosure. 
     In some embodiments, PSU  400  includes a substrate  402  that supports and is embedded with various functionalities accessible by a passenger in a passenger space in an aircraft cabin. PSU  400  may include a light  404 , an emergency call button  406  and an air nozzle  408 . PSU  400  may include other functionalities not shown in  FIG.  4 A . Nozzle  408  directs air that enters in the space above PSU  400 . Nozzle  408  is typically capable of being manipulated by a passenger. For example, nozzle  408  may be directional such that a passenger may control the direction of air that enters and exits nozzle  408  and into the passenger space. Additionally, a passenger may also control the amount of flow of air exiting nozzle  408  and into the passenger space. 
     In embodiments, PSU  400  includes a vortex tube  410 , an air inlet  412 , a swirl chamber  414 , a conical nozzle  416  and an exhaust air outlet  418 . The vortex tube  410  further includes an inner air passageway  420  and an outer air passageway  422 . In an embodiment, outer air passageway  422  surrounds inner air passageway  420 . In some embodiments, PSU  400  may further include an air compressor  434 . In some embodiments, inner air passageway  420  is fluidically coupled with outer air passageway  422  as illustrated in PSU embodiment  400  in  FIG.  4 A . Vortex tube  410 , nozzle  408 , air inlet  412 , swirl chamber  414 , conical nozzle  416 , exhaust air outlet  418 , inner air passageway  420  and outer air passageway  422  may be fluidically coupled. 
     In operation, compressed air  424  is injected into and received by the air inlet  412  and enters the swirl chamber  414 . The air is directed in an upward manner towards the conical nozzle  416 . The outer shell of warmer air  426  passes around the conical nozzle  416  and exits inner air passageway  420  and enters outer air passageway  422 . Warmer air stream  426  (solid line) is forced in a downward direction towards nozzle  408 . The inner shell of cooler air  428  (dotted line) is forced in a downward direction in inner air passageway  420  towards nozzle  408 . Both the warmer air stream  426  and cooler air stream  428  enters nozzle  408  where a passenger may manipulate and selectively adjust nozzle  408  in such a manner as to selectably blend air streams  426 ,  428  to regulate the temperature of exiting temperature controlled air  430  into the passenger space. Excess exhaust air  432  may exit the vortex tube  410  out of exhaust outlet  418 . If a passenger chooses to selectively decrease and completely shut off nozzle  408 , all air from inner air passageway  420  and outer air passageway  422  may exit exhaust outlet  418 . 
       FIG.  4 B  illustrates a cross-sectional overhead view of vortex tube in PSU, in accordance with one or more embodiments of the present disclosure. 
       FIG.  4 B  attempts to more clearly illustrate vortex tube design  410  in PSU embodiment  400 . This view looks down on top of the PSU  400  near the conical nozzle  416 .  FIG.  4 B  shows a substantially circular vortex tube  410 .  FIG.  4 B  further illustrates the inner air passageway  420 , the outer air passageway  422 , the swirl chamber  414 , the air inlet  412  and the exhaust outlet  418 . This design shows the air inlet  412  and air outlet  418  on opposing sides of vortex tube  410 . In other embodiments, the air inlet  412  and the air outlet  418  may be on the same side. Other designs of the locations of the air inlet  412  and air outlet  418  may be possible depending on the application. 
       FIG.  4 C  illustrates a cross-sectional view of a portion of a PSU including a nozzle equipped with a vortex tube, in accordance with one or more embodiments of the present disclosure. 
     Vortex tube  442  in PSU  440  includes an inner air passageway  444 , an outer air passageway  446 , a compressed air inlet  448 , a swirl chamber  450 , a conical nozzle  452  and an exhaust air outlet  454 . PSU  440  is similar to embodiment PSU  400  but the air inlet  444  and swirl chamber  450  are located near the top of vortex tube  442 . In embodiment PSU  400 , the air inlet  412  and swirl chamber  414  are located near the bottom of the vortex tube  410 . In some embodiments, inner air passageway  444  is fluidically coupled with outer air passageway  446  as illustrated in the PSU  440 . In some embodiments, PSU  440  may further include an air compressor  434 . The vortex tube  442 , the nozzle  408 , the inner air passageway  444 , the outer air passageway  446 , the air inlet  448 , the swirl chamber  450 , the conical nozzle  452  and the exhaust air outlet  454  may be fluidically coupled. 
     In operation, compressed air  424  is injected into and received by the air inlet  448  and enters the swirl chamber  450 . Inlet air  424  is directed in a downward manner towards the conical nozzle  452 . The outer shell of warmer air  456  (solid line) passes around the conical nozzle  452  towards nozzle  408 . The cooler air stream  458  (dotted line) is forced upward where the cooler air stream  458  exits inner air passageway  444  and enters outer air passageway  446 . The cooler air stream  458  and the warmer air stream  456  flow in opposite directions in a counterflow manner within the vortex tube  442 . The cooler air stream  458  is forced in a downward direction towards the nozzle  408 . Both the warmer air stream  456  and the cooler air stream  458  enters nozzle  408  where a passenger may manipulate and selectively adjust nozzle  3408  in such a manner as to blend the air streams  456 ,  458  to regulate the temperature of exiting temperature controlled air  430  that is released into the passenger space. The excess exhaust air  432  may leave the vortex tube  442  out the exhaust outlet  454 . If a passenger chooses to completely shut off the nozzle  408 , all air from the inner passageway  444  and the outer passageway  446  may exit the exhaust outlet  454 . 
     The embodiments illustrated in  FIGS.  3 A- 4 C  are depicted as monolithic units that include components necessary to receive inlet air and separate the inlet air into cooler and warmer air streams. The temperature and flow of the air streams may be controlled by a passenger that are released into the passenger space to a desired comfort level. In other embodiments, the units may be modular in design. For example, PSUs comprising conventional systems illustrated in  FIG.  2    may be retrofitted with temperature control systems illustrated in embodiments  300 ,  350 ,  360 ,  400  or  440 . 
     In some embodiments, any of the components may be insulated. This may help to retain the temperature of the separated warmer and cooler air streams that exit the nozzle and into the passenger space. This may allow for more efficient operation of a temperature control device in a PSU. 
     A variety of nozzles may be acceptable for blending of warm and cool air streams and integrated into PSUs comprising a vortex tube. In some embodiments, the nozzle  308 ,  408  may include a multi-gas nozzle. Nozzle  308 ,  408  may include one or more of an eductor nozzle, spillback nozzle, solid stream nozzle, hollow cone nozzle, full cone nozzle, screw nozzle, air amplifier nozzle, air edge nozzle, co-annular nozzle or an air jet nozzle. 
     In some embodiments, a single nozzle for use in a PSU comprising a vortex tube may be able to be manipulated and selectively adjusted by a passenger to control the air flow and the temperature of the airflow that is released into the passenger space. In other embodiments, a PSU may include a first nozzle that may be manipulated by a passenger to selectively adjust the temperature of the air flow and a second nozzle that may be manipulated and selectively adjusted by a passenger to control the amount and direction of air flow. 
     Any of the components in the temperature control systems described herein may be composed of metal, polymer, glass or a combination thereof. 
     One skilled in the art will recognize that the herein described components (e.g., operations), devices, objects, and the discussion accompanying them are used as examples for the sake of conceptual clarity and that various configuration modifications are contemplated. Consequently, as used herein, the specific exemplars set forth and the accompanying discussion are intended to be representative of their more general classes. In general, use of any specific exemplar is intended to be representative of its class, and the non-inclusion of specific components (e.g., operations), devices, and objects should not be taken as limiting. 
     The previous description is presented to enable one of ordinary skill in the art to make and use the invention as provided in the context of a particular application and its requirements. As used herein, directional terms such as “top,” “bottom,” “over,” “under,” “upper,” “upward,” “lower,” “down,” and “downward” are intended to provide relative positions for purposes of description, and are not intended to designate an absolute frame of reference. Various modifications to the described embodiments will be apparent to those with skill in the art, and the general principles defined herein may be applied to other embodiments. Therefore, the present invention is not intended to be limited to the particular embodiments shown and described, but is to be accorded the widest scope consistent with the principles and novel features herein disclosed. 
     With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations are not expressly set forth herein for sake of clarity. 
     It is further contemplated that each of the embodiments of the method described above may include any other step(s) of any other method(s) described herein. In addition, each of the embodiments of the method described above may be performed by any of the systems described herein. 
     The herein described subject matter sometimes illustrates different components contained within, or connected with, other components. It is to be understood that such depicted architectures are merely exemplary, and that in fact many other architectures can be implemented which achieve the same functionality. In a conceptual sense, any arrangement of components to achieve the same functionality is effectively “associated” such that the desired functionality is achieved. Hence, any two components herein combined to achieve a particular functionality can be seen as “associated with” each other such that the desired functionality is achieved, irrespective of architectures or intermedial components. Likewise, any two components so associated can also be viewed as being “connected,” or “coupled,” to each other to achieve the desired functionality, and any two components capable of being so associated can also be viewed as being “couplable,” to each other to achieve the desired functionality. Specific examples of couplable include but are not limited to physically mateable and/or physically interacting components and/or wirelessly interactable and/or wirelessly interacting components and/or logically interacting and/or logically interactable components. 
     Furthermore, it is to be understood that the invention is defined by the appended claims. It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” and the like). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, and the like” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, and the like). In those instances where a convention analogous to “at least one of A, B, or C, and the like” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, and the like). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B.” 
     It is believed that the present disclosure and many of its attendant advantages will be understood by the foregoing description, and it will be apparent that various changes may be made in the form, construction and arrangement of the components without departing from the disclosed subject matter or without sacrificing all of its material advantages. The form described is merely explanatory, and it is the intention of the following claims to encompass and include such changes. Furthermore, it is to be understood that the invention is defined by the appended claims.