Patent Abstract:
A variable refrigerant package air conditioner is shown that is easy to install in new construction with a unique base that causes collected mixture that overflows to drain outside the building. A control system is shown that has motors and compressor that are pulse width modulated so the air conditioner is infinitely variable while maintaining the highest possible power factor. Dehumidification of outside air occurs as it is mixed with inside air. By gradually approaching a temperature set point and even reheating after dehumidification, moisture is removed from the room. A snorkel that delivers fresh air to be mixed with inside entering air in front of the evaporator for a maximum dehumidification is also shown.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation-in-part of application Ser. No. 14/975,166, filed Dec. 18, 2015. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    This invention relates to a variable refrigerant package (VRP), and more particularly, to a packaged terminal air conditioner that dehumidifies outside air added to air conditioned room, the outside air being added through a sound dampening snorkel. 
         [0004]    2. Description of the Prior Art 
         [0005]    A package terminal air conditioner (PTAC) and a vertical packaged air conditioner (VPAC) are types of self-contained heating and air conditioning systems commonly found in hotels or motels. Most PTAC and VPAC units are designed to go through a wall having vents and/or heat sinks both inside and outside. While PTACs and VPACs are commonly used to heat or cool a single living space, there are cooling only PTACs and/or VPACs with an external heating source. On some PTACs/VPACs condensate drain piping is not required because the condensate water extracted from the air by the evaporator coil is thrown by the condenser fan onto the condenser coil surface where it evaporates. Conventional PTACs/VPACs still require condensate drain piping to be installed. 
         [0006]    Through-the-wall units such as PTACs/VPACs have some basic problems. The through-the-wall units do not ventilate the space in which the air is being conditioned. If provisions are made to ventilate the space being conditioned, then humidity is introduced into the space being conditioned. For example, in coastal areas, motels/hotels have a tendency to have a musty smell due to the humidity. The problem is the unit does not run long enough to remove the moisture from the space being conditioned. Yet, building codes require ventilation of the areas being conditioned which PTAC/VPAC units do not normally provide. 
         [0007]    While there have been various attempts to reduce the humidity inside of the space being conditioned, such attempts normally require ancillary devices or systems other than the PTAC/VPAC unit. Some require separate dehumidifiers that have to be connected to a building drain. Others require separate dehumidified air being forced into the conditioned space. Each of these systems are either complicated, expensive, or do not work properly. 
         [0008]    The standard air conditioner as it is cooling a particular space only responds to the temperature inside the space. Once the space&#39;s temperature is satisfied, the active cooling and dehumidification of the space stops. Humidity in the space continues to build. One solution to address the dehumidification and ventilation that has been used in the hotel/motel industry was to have duct work connecting a source of dehumidified outside air to the enclosed spaced. The dehumidified outside air is forced through the duct work into the room. The increased pressure caused by forcing the dehumidified outside air into the room being conditioned escapes through leakage points such as around the entry door and through the room exhaust. However, this method requires the running of additional duct work and having a dehumidifier to remove moisture from the outside air. 
         [0009]    Another common method that was used was to have a flap inside of a PTAC unit that is opened to allow outside air to be brought in. However, the outside air was not dehumidified which adds humidity to the space and would many times cause a musty smell inside of the room. Many times after inspection the outside air flap was simply bolted shut. 
         [0010]    Another variation of the room air conditioner is what is called a variable refrigerant flow system (VRF). Those systems have very large outdoor condensers and multiple indoor evaporators with refrigerant tubing being run to every space being cooled. Still, the variable refrigerant flow systems continue to have problems with high humidity and lack of available ventilation air. 
       SUMMARY OF THE INVENTION 
       [0011]    It is an object of the present invention to provide a variable refrigerant package (VRP). 
         [0012]    It is another object of the present invention to provide effective dehumidification of a conditioned space using a variable refrigerant package. 
         [0013]    It is still another object of the present invention to provide variable, yet stable, power to the power consuming parts of a variable refrigerant package. 
         [0014]    It is yet another object of the present invention for a contractor when building a hotel/motel to install external connections for a variable refrigerant package so that a non-skilled person can install the variable refrigerant package to provide cooling of an enclosed space. 
         [0015]    It is another object of the present invention to provide a new base for a variable refrigerant package. 
         [0016]    It is still another object of the present invention to provide a control system for a variable refrigerant package, which control system dehumidifies the air inside of the closed space. 
         [0017]    It is yet another object of the present invention to dehumidify outside air before it is added to the air in the enclosed space. 
         [0018]    It is still another object of the present invention to modulate the power being supplied to the compressor and/or fans of a variable refrigerant package. 
         [0019]    It is another object of the present invention to use pulse width modulation on the compressor and motors contained within a variable refrigerant package, which pulse width modulation is used to slowly bring the variable refrigerant package slowly to the inside temperature set in the room sensor to allow for increased dehumidification of the inside air. 
         [0020]    It is yet another object of the present invention to provide a reheat system to provide extra dehumidification by the evaporator. 
         [0021]    It is a further object of the present invention to actively control the power factor of the variable refrigerant package for reduced power consumption. 
         [0022]    It is another object of the present invention to reduce the amount of outside noise that reaches conditional space while simultaneously dehumidifying outside air being introduced to the conditional space. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0023]      FIG. 1  illustrates a variable refrigerant package fitting inside a closet. 
           [0024]      FIG. 2  is an exploded perspective showing how a plenum and base are installed in a framed (but not enclosed) closet for receiving a variable refrigerant package. 
           [0025]      FIG. 3  is an exploded pictorial illustration showing how the variable refrigerant package is inserted into a framed (but not enclosed) closet. 
           [0026]      FIG. 4  is an exploded perspective view of a variable refrigerant package. 
           [0027]      FIG. 5  is a sectional view illustrating air flow in the variable refrigerant package. 
           [0028]      FIG. 6  is an enlarged partial sectional view of  FIG. 5  illustrating how outside air entering the room being conditioned is dehumidified. 
           [0029]      FIGS. 7A and 7B  are pictorial block diagrams of controls for a variable refrigerant package. 
           [0030]      FIGS. 8A and 8B  are expanded block diagrams of the motor control system shown in  FIG. 7B . 
           [0031]      FIG. 9  is an expanded block diagram of the power factor correction shown in  FIG. 8A . 
           [0032]      FIG. 10  is an exploded perspective view of a base for the variable refrigerant package. 
           [0033]      FIG. 11  shows alternative perspective views of three different bases that can be used with the variable refrigerant package. 
           [0034]      FIG. 12  is a horizontal cross-sectional view of an alternative embodiment of the present invention. 
           [0035]      FIG. 13  is a vertical sectional view of the alternative embodiment shown in  FIG. 12 . 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0036]    A preferred embodiment of the present invention will be given herein below in conjunction with the illustrations shown in the attached figures. A variable refrigerant package  21  is shown in  FIG. 1  installed in a closet  23  formed by frame  25  on floor  27  of a space to be cooled. Frame  25  extends to the outside  29  of the space being cooled. For illustration purposes, the sheetrock or other covering material for the frame  25  has been removed. 
         [0037]    Inside of the closet  23  is installed a base  31  on which the variable refrigerant package  21  sits. A duct adapter  33  is installed near the top of the closet  23  for connection to the top of the variable refrigerant package  21  to direct the conditioned air to a desired location. The variable refrigerant package  21  is inserted into the closet  23  through door opening  35 . 
         [0038]    Referring now to  FIG. 2 , the variable refrigeration package  21  has been removed. During construction of the closet  23  by the contractor building the hotel/motel, a plenum  37  is installed that has an interior wall plenum  39  that telescopes inside of exterior wall plenum  41 . The lower portion of both the interior wall plenum  39  and exterior wall plenum  41  slopes downward toward the outside  29 . A plenum divider baffle  43  is located inside of the interior wall plenum  39  and exterior wall plenum  41 . 
         [0039]    The plenum  37  extends from the outside  29  to the inside of closet  23 . Because of the telescoping feature of the plenum  37 , varying widths of the outside wall  45  can be accommodated with typical widths being between four to eight inches. An outdoor louvre grill  47  covers the outside opening of plenum  37 . The outdoor louvre grill  47  has downwardly sloped louvres  49  to keep rain from entering through plenum  37   
         [0040]    In addition to installing the plenum  37  through outside wall  45 , a contractor building the hotel/motel will install base  31  inside of closet  23 . The outer portion of the base  31  will extend over the inside lower edge of interior wall plenum  39  in a manner as will be subsequently described. 
         [0041]    To provide good sealing contact with the variable refrigeration package  21  (shown in  FIG. 1 ), a plenum gasket  51  is located on the inside of interior wall plenum  39 . 
         [0042]    To seal with the bottom of the variable refrigeration package  21 , a base gasket  53  is provided on the top edge of base  31 . 
         [0043]    In  FIG. 3 , the installation of the variable refrigeration package  21  inside of the closet  23  is illustrated. The variable refrigeration package  21  is inserted through the door opening  35 . Installation rails  55  are mounted on the bottom of the variable refrigeration package  21  to slide in grooves in the top of base  31  until the variable refrigeration package  21  slides through and presses against the plenum gasket  51  to provide a good seal between the plenum  37  and the variable refrigeration package  21 . 
         [0044]    The bottom of the variable refrigeration package  21  rests on the base gasket  53 . After the variable refrigeration package  21  is in place, duct adapter  33  moves downward to enclose supply duct flanges  57 . 
         [0045]    While not shown in  FIGS. 1 through 3 , closet  23  will be wired by the contractor with electricity so the variable refrigerant package may be plugged in for power. Also, a connection (not shown) is provided in closet  23  to the room sensor. By installing the return air door  59  in the door opening  35  of the closet  23  and plugging into power and the room sensor, the variable refrigerant package  21  as shown in  FIG. 3  is ready for operation. The installation of the variable refrigerant package  21  can be completed by non-certified personnel. 
         [0046]      FIG. 4  shows an exploded perspective view of the mechanical parts of the variable refrigerant package  21 . The condenser base assembly  61  has a drain tray  63  in the bottom thereof, which rests on base  65 . Below base  65  are located the installation rails  55 . Compressor  67  rests on the drain tray  63 , which is supported by the base  65 . 
         [0047]    Extending upward from the base  65  are corner posts  69 . On the top of corner posts  69  is located the condenser top cover  71 . Connected to the underside of the condenser top cover  71  are fresh air modules  73 , which will be discussed in more detail subsequently. Control box  75  is located between corner posts  69 . Adjacent the control box  75  is control box cover  77 . Located below the control box cover  77  is condenser access panel  79 . Lower side covers  81  enclose the sides of the condenser base assembly  61 . Upper side covers  83  enclose the upper sides of the variable refrigeration package  21 . Any return air coming back into the variable refrigerant package  21  has to enter through the return air filter  85 . 
         [0048]    Located within the condenser base assembly  61  are the condenser  87  and the condenser shroud  89 . The condenser fan assembly  91  is located within the condenser shroud  89  and blows air through the condenser  87 . Condenser drain pan  93  will collect any moisture that drips off of condenser  87  or the evaporator drain pan  103 . Located above the compressor  67  is the reversing valve assembly  95 . 
         [0049]    Located above the condenser top cover  71  is an insulation plate  97 , which is mounted between the condenser top cover  71  and the evaporator base  99 . Located above the evaporator base  99  is evaporator  101  with an evaporator drain pan  103  there below. Connecting from the evaporator drain pan  103  to the bottom of the variable refrigeration package  21  is evaporator drain tube  105 . 
         [0050]    To draw air through the evaporator  101 , a blower assembly  107  draws air through blower inlet panel  109 . Between the blower inlet panel  109  and the evaporator  101  is located electric heater  111 . Allowing access to the electric heater  111  is heater access panel  113 . 
         [0051]    Conditioned air after flowing through evaporator  101 , electric heater  111 , blower inlet panel  109  and blower assembly  107  leaves through supply duct flanges  57  as previously described in conjunction with  FIG. 3 . A reheat coil  115  is located behind the evaporator  101 . 
         [0052]    Referring now to  FIG. 5 , a pictorial cross-sectional view of the variable refrigerant package  21  is shown. The same numbers as applied to prior component parts described in  FIGS. 1 through 4  will be used in  FIG. 5 . The blower assembly  107  brings indoor entering air across the return air filter  85 , evaporator coil  101 , reheat coil  115  and out blower inlet panel  109  to give indoor leaving air. Any moisture that is collected drains out through evaporator drain tube  105 . 
         [0053]    Outdoor entering air is drawn in through outdoor air inlet  117  by the condenser fan assembly  91  with the majority of the air blowing out through the condenser shroud  89  and through condenser  87  to give outdoor leaving air. The flow of the outdoor air provides cooling for the control box  75  as well as removing heat from condenser  87 . 
         [0054]    A small amount of the outdoor entering air flows through the fresh air module  73 . Rectangular openings  121  and honeycomb openings  119  (see  FIG. 4 ) in evaporator base  99  allows the fresh air to flow there through. From the honeycomb openings  119 , the fresh air flows to the inlet side of evaporator  101 . Therefore, excess moisture in the fresh air is removed as the fresh air flows through the evaporator  101 . To ensure that an appropriate amount of fresh air is being drawn into the space being cooled, each of the fresh air modules  73  have fans inside of them to control the fresh air flow, as will be described in more detail subsequently. The fresh air entering through the fresh air module  73  is cooled and dehumidified by the evaporator  101 . The fresh air is mixed with the indoor entering air, cooled and dehumidified with the evaporator  101  with any moisture being collected by evaporator drain panel  103  and discharged out the evaporator drain tube  105 . 
         [0055]    During the heating mode for the variable refrigerant package  21 , electric heaters  111  may be turned ON to heat the indoor entering air. If humidity needs to be removed from the fresh air, the evaporator  101  is operated just enough to remove the humidity. The reheat coil  115  will provide any reheating necessary due to the operation of the evaporator  101  in removing humidity. 
         [0056]    Referring to  FIGS. 5 and 6  in combination,  FIG. 6  shows an enlarged, cross-sectional view of one of the fresh air modules  73 . The fresh air module  73  has an outdoor air fan  123  for drawing air into fresh air chamber  125 . The outdoor air fan  123  has a housing, fan blade and motor very similar to a computer-style fan. From the fresh air chamber  125  fresh air flows through outdoor air filter  127 . Rectangular openings  121  and honeycomb openings  119  allows some of the outdoor entering air to be mixed with indoor entering air in front of the evaporator coil  101 . The mixed air streams of outdoor entering air and indoor entering air are then conditioned to whatever condition the variable refrigerant package  21  is set. The mixed air can be cooled, dehumidified or heated. If dehumidified, the evaporator drain pan  103  will collect the moisture which is subsequently discharged out evaporator drain tube  105  (see  FIGS. 4 and 6 ). Any air entering the air conditioned space is filtered by the outdoor air filter  127  or, upon recirculation, by the return air filter  85 . 
         [0057]    Traditional air conditioners simply control the temperature of the space being cooled. They turn ON or OFF based upon the temperature set point inside the space being conditioned. The traditional air conditioner may not run long enough to remove moisture from the space. Most traditional air conditioners do not bring fresh air into the space being cooled. Fresh air is required for the occupants to breathe and to displace noxious fumes, plus bring oxygen into the space being conditioned. 
         [0058]    The present invention brings fresh air into the space being conditioned and by a sophisticated control system that coordinates the motors and compressor allows the variable refrigerant package  21  to run longer so that it will cause more dehumidification of the air. As the space being conditioned gets closer and closer to the desired temperature, the motors and compressor are slowed down so that the unit will run longer to dehumidify the space being conditioned. 
         [0059]    The variable refrigerant package  21  varies its ability to cool the enclosed space by two distinct methods. In the first method, the variable refrigerant package  21  reduces its capacity or ability to cool by varying the speeds of the motors or compressor as the conditioned space approaches the desired temperature. The second method is to add some reheat back to the space being cooled as is provided by the re-heater coil  115 . 
         [0060]    In the reheat method, the evaporator  101  is allowed to continue to run and remove moisture from the air, but heat is then added back through re-heater coil  115 . In this method the conditioned space is being actively dehumidified. 
         [0061]    The electrical controls for the variable refrigerant package  21  are illustrated in  FIG. 7 . A wall controller  129 , commonly called a thermostat, sets the desired temperature inside of enclosed space. The wall controller  129  may be communicated with through an external communications module  131 . Also, setting up the operating parameters of the variable refrigerant package  21  may be done with SD card  133 . The wall controller  129  communicates with the main controller  135 . The main controller  135  has a wall controller communications  137  for communicating with the wall controller  129 . The main controller  135  has a processor  136  in which provisional data may be programmed by data switches  138 . 
         [0062]    The main controller  135  communicates with motor control system  139  via MCS communication  141 . Also, main controller  135  communicates with heater board  143  via heater communication  145 . The main controller  135  could be referred to as the master unit with the motor control system  139  and/or the heater board  143  being referred to as slave units. Both the motor control system  139  and the heater board  143  receive commands from the processor  136  in the main controller  135 . If a problem is detected in either the motor control system  139  or the heater board  143 , the message is communicated back through the main controller  135  and is displayed on the wall controller  129 . The wall controller  129  may receive commands or send commands back and forth with the main controller  135 , plus having an external communications module  131 . 
         [0063]    The main controller  135  has a USB interface  147  for communicating with a personal computer  149 . The personal computer  149  may be programmed to set data points in the main controller  135 , retrieve data, send commands, or remotely control the entire variable refrigerant package  21 . Also, the personal computer  149  may be used to do monitor control tests to make sure the variable refrigerant package  21  is operating properly. Any error history in the main controller  135  may be downloaded and observed in the personal computer  149 . The personal computer  149  may be used for troubleshooting or upgrading software in the main controller  135 . The parameters set in the main controller  135  can be changed through the personal computer  149 . 
         [0064]    Inside of the motor control system  139 , processor  151  controls fan driver  153  that operates the indoor fan  155 . By providing pulse width modulation to the indoor fan  155 , the speed of the indoor fan  155  and its power consumption is controlled. Also, processor  151  controls the fan driver  157  for the outdoor fan  159 . The indoor fan  155  is the same as blower assembly  107  shown in  FIGS. 4 and 5 . Outdoor fan  159  is the same as condenser fan assembly  91  shown in  FIGS. 4 and 5 . 
         [0065]    Processor  161  inside of motor control system  139  operates a compressor driver  163  that in turn operates the compressor  67 . By pulse width modulation from the processor  161  via the compressor driver  163 , the speed of the compressor  67  may be varied. 
         [0066]    Outside power feeds through power input lines  165  and fuses  167  to the power supply  169 . The power supply  169  has power factor correction therein as will be subsequently described in conjunction with  FIGS. 8 and 9 . 
         [0067]    Service personnel that may work on the variable refrigerant package  21  will probably not have a personal computer  149  to connect through USB interface  147 . Therefore, an SD socket  171  is provided to receive SD card  173 . The SD card  173  may be used to upgrade the program or firmware inside of the main controller  135 . Also, the SD card  173  may be used for troubleshooting or downloading the history of the operation of the variable refrigerant package  21 . The SD card  173  can also provide extra memory for the main controller  135 . 
         [0068]    The motor control system  139  may have its own SD card  175 . By having the SD card  173  in the main controller  135  and SD card  175  in the motor control system  139 , extra memory is provided for a remote upgrade. If the motor control system  139  is being upgraded from the wall controller  129 , SD card  175  needs to be installed to provide as a temporary memory storage space while the motor control system  139  is being upgraded. Similarly, to upgrade the main controller  135  through the wall controller  129 , SD card  173  must be installed to provide temporary memory storage. 
         [0069]    The main controller  135  also controls a stepper driver  177  that operates electronic expansion valve  179 . The electronic expansion valve  179  controls the flow of the refrigerant inside the system. The operation of the electronic expansion valve  179  is controlled by the temperature entering the evaporator  101  and the temperature entering the compressor  67  (see  FIG. 5 ). The electronic expansion valve  179  is opened or closed to maintain a certain temperature range between the evaporator inlet and the compressor inlet. The electronic expansion valve  179  acts like a modulating valve. 
         [0070]    As an alternative to the motor control system  139  operating the indoor fan  155 , an indoor fan  181  may be pulse width modulated by motor control  183  inside of main controller  135 . 
         [0071]    The heater board  143  energizes and de-energizes the reversing valve  185 . Assuming the variable refrigerant package  21  has been in the cooling mode and is switched to the heating mode, the main controller  135  will cause the heater board  143  to switch the reversing valve  185 . Communication between the main controller  135  and the heater board  143  is provided by heater communication  145  with the microcontroller  187 . From the microcontroller  187 , a signal is sent to the reversing valve triac  189  to switch the reversing valve relay  191 . A microcontroller  187  that could be used is a Freescale KL02. 
         [0072]    Since the microcontroller  187  provides pulse width modulation, the zero cross-detector  193  lets the microcontroller  187  know when the alternating current provided in power input lines  165  crosses the zero axis. If heat is being called for, the microcontroller  187  will operate heater relay drivers  194  to switch heater relays  195  and/or  197 , which controls heaters  199  and  201 , respectively. A heater silicon controlled rectifier  203  completes the circuit for heaters  199  and/or  201  and is operated by microcontroller  187 . A 3.3 volt regulator  192  is provided internally in a heater board  143 . 
         [0073]    Internally within the main controller  135  are a +3.3 volt regulator  205  and a +5 volt regular  207 . Feeding into microcontroller  135  is a number of temperature sensors  209  of the variable refrigerant package  21 . 
         [0074]      FIG. 8  is a more in-depth review of the motor control system  139 . The power input lines  165  connect from an alternating current source  211 , which may vary from 180 to 293 volts AC, into the motor control system  139 . The alternating current source  211  feeds through an EMI filter  213  prior to connecting to 2-phase interleaved active power factor correction  215 . The 2-phased interleaved active power factor correction  215  has a current sensor  217  and a voltage sensor  219 . With the current sensor  217  and voltage sensor  219 , the power being consumed can continually be determined. 
         [0075]    From the 2-phase interleaved active power factor correction  215 , a 430 volt DC bus  221  is generated. From the 430 volt DC bus  221 , an isolated auxiliary power supply  223  generates +12 volts DC at 2.5 amps. 
         [0076]    Inside of motor control system  139  is processor  161  as previously explained in connection with  FIG. 7 . Processor  161  controls the compressor motor  67  through compressor driver  163 . The 430 volt DC bus  221  supplies DC voltage to the compressor driver  163 . 
         [0077]    Processor  151  controls outdoor fan motor  159  through outdoor fan driver  157  and indoor fan motor  155  through indoor fan driver  153 . The processor  151  provides pulse width modulated power via outdoor fan driver  157  to outdoor fan motor  159 . Likewise, processor  151  provides pulse width modulated power to indoor fan  155  via indoor fan driver  153 . 
         [0078]    The motor control system  139  shown in  FIG. 8  has an active power factor correction which is provided in part by the 2-phase interleaved active power factor correction  215 . 
         [0079]    The signal being delivered to the compressor motor  67  through the compressor driver  163  from the processor  161  senses the rotor position inside the compressor  67 . The signal being received from the 430 volt DC bus  221  is chopped and converted into a simulated three-phase AC signal to make the motor axis of the compressor  67  spin at the desired rate. The outdoor fan driver  157  for the outdoor fan motor  159  is doing essentially the same thing by taking the signal from the 430 volt DC bus  221 , chopping it and providing a simulated three-phase AC current to the outdoor fan motor  159 . Likewise, the indoor fan driver  153  does essentially the same thing for the indoor fan motor  155 . While the compressor driver  163  is being controlled by processor  161 , outdoor fan driver  157  and indoor fan driver  153  are being controlled by processor  151 . 
         [0080]    A bias power supply  225  receives voltage from 430 volts DC bus  221  and generates +15 volts DC and +3.3 volts DC, which is used to supply power to any part of the variable refrigerant package  21  that may need those voltage levels. The +3.3 volt DC is used to operate processors  161  and processor  151 . 
         [0081]    All of the conditioning of the power received and converted to DC signals is done inside of the motor control system  139 . While the bias power supply  225  generates +15 volts and +3.3 volts, multiplexer  227  has an isolated RS-485 duplexer  229  for connection to an external device. The external device may be similar to the personal computer  149  shown in  FIG. 7 . The isolated RS-485 duplexer  229  allows for external connections and controls to the motor control system  139 . Also, the motor control system  139  has an isolated serial peripheral interface  231  that may connect to a micro SD card  175 . The SD card  175  may be used to update the motor control system  139 , check error messages and exchange information therewith. 
         [0082]    The motor control system  139  is where all of the power conversion is done. This is where the drivers  163 ,  157  and  153  are all located. This is where regulated power is generated from a highly unregulated source. 
         [0083]    When the variable refrigerant package  21  is turned OFF so the alternating current source  211  no longer connects through the EMI filter  213  to the 2-phase interleaved active power factor correction  215 , inductive or capacitive charges may still remain in the circuit. A bleeder circuit  220  is provided through which the inductive and/or capacitive charges may drain down. The LED  222  will remain lit until the bleeder circuit  220  has fallen below a predetermined current. 
         [0084]    Turning now to  FIG. 9 , a schematic view is shown of the 2-phase interleaved active power factor correction  215 . The alternating current source  211  feeds through the EMI filter  213  to the 2-phase interleaved active power factor correction  215 . Within the 2-phase interleaved active power factor correction  215 , the alternating current is changed by a full wave rectifier  301  to a rectified AC signal. The rectified AC signal from the full wave rectifier  301  feeds through inductors  303  and  305 . The inductors  303  and  305  are connected to current sensors  307  and  309 , respectively. Each current sensor  307  and  309  connects to MOSFETs  311  and  313 , respectively. 
         [0085]    Resistor network on the front of the N-phase interleaved active PFC  215  are resistors  315  and  317 . While resistors  315  and  317  provide sensing on the front end of the two-phase interleaved active PFC  215 , resistors  319  and  321  provide a feedback  323  to a controller  325 . The controller  325  also receives a current sense  327  from current sensor  307  and current sense  329  from current sensor  309 , respectively. Further, the controller  325  receives the input voltage  333  as developed across input resistors  315  and  317 . 
         [0086]    Diodes  335 ,  337  and  339  insure that current only flows in one direction to capacitor  341 . 
         [0087]    The controller  325  monitors the input voltage  333 , feedback voltage  323 , along with current sense  327  and  329  to decide if the power factor needs to be corrected. 
         [0088]    The controller  325  controls the point at which each of the MOSFETs  311  and/or  313  are fired to get the maximum power factor. The maximum power factor is when the current and the voltage are in phase with each other. An example of such a controller  325  that can control the firing of MOSFETs  311  and  313  is a Texas Instrument, Part No. UCC-2807. 
         [0089]    The controller  325  is taking the feedback voltage  323  and the input voltage  333  and comparing them with the current sense  327  and  329  and firing the MOSFETs  311  and  313  to get a power factor as close to 1 as possible. 
         [0090]    “Power factor” in an AC electrical power system is the ratio of real power flowing to the load versus apparent power in the circuit. A power factor of less than 1 means the voltage and current wave forms are not in phase. Real power is the capacity of the circuit for performing work in a particular time. Apparent power is the product of the current load of the circuit. In an electrical power system, a load with a low power factor draws more current than a load with a high power factor. Higher currents increase the energy loss in the system. The present system uses an active power factor which is built into the power consuming portion of the variable refrigerant package  21 . In the 2-phase interleaved active power factor correction  215 , there is continuous “ebb-and-flow” of the reactants (capacitive and inductive). The power factor will continue to change unless there are corrections in the power factor. The present invention uses a 2-phase interleaved active factor correction  215 , but could use a single phase or other multi-phase configurations. 
         [0091]    In  FIG. 9 , the unregulated AC voltage being received from alternating current source  211  is taken and converted into a regulated DC output voltage by using a switched mode power supply. The DC voltage is regulated even though the AC voltage may vary over a broad range. For example, the AC voltage can vary from 180 volts AC to 293 volts AC, yet the DC bus will be maintained at 430 volts DC. 
         [0092]    Referring to  FIG. 10 , and exploded perspective view of the base  31  is shown. The base  31  has a hard plastic top  257  which is fairly thin. The hard plastic top  257  has ribs  259  formed on either side thereof. The ribs define a channel  261  on each side of the hard plastic top  257  of the base  31 . 
         [0093]    A drain basin  263  is provided in the internal trough  265  provided inside of raised rib seat  267 . One end of the internal trough  165  provides outdoor drain access  269 . Sealing the top of the raised rim seat  267  to the underside of the variable refrigerant package  21  is chassis seal  271 . 
         [0094]    On the underside of the base  31  is located bottom cover  273 . Between the bottom cover  273  and the hard plastic top  257  is located a three-way tee  275  that connects to drain hole  277  of drain basin  263  via drain connecting tube  279  which connects to retaining rings  281 . Connected to the lower side of the three-way tee  275  are building drain tubes  283  ( a ), ( b ) and ( c ). Building drain tubes  283  are held into slots  285  ( a ), ( b ) and ( c ), respectively, by retaining rings  287  ( a ), ( b ), and ( c ), respectively. The ends of the filling drain tubes  283  are temporarily sealed by end caps  289  ( a ), ( b ) and ( c ), respectively. 
         [0095]    When assembled, a two-part expanding foam is injected between hard plastic top  257  and bottom cover  273  through injection port  291  until a portion of the two-part expanding foam can be seen at each of the outlet ports  293 . The two-part expanding foam (not shown) gives rigidity to the base  31  so that it can support the variable refrigerant package  21 . 
         [0096]    When installed, the installation rails  55  (see  FIG. 3 ) will rest inside of channels  261 . When installing the base  31 , the end cap  289  ( a ), ( b ), or (c) that is the most convenient to the building drain system is removed and the appropriate building drain tube  283 ( a ), ( b ) or ( c ) is connected to the building drain system (not shown). By having the drain basin  263  drain to any of three sides of the base  31 , it is more convenient for the construction crew to connect to the building drain system. 
         [0097]    If the building drain system becomes clogged, the outdoor drain access  269  extends over the inside edge of the plenum  37  so that any accumulated moisture will drain outside the building. Thereafter, if service personnel sees the drainage flowing through the plenum  37  to outside the building, the service personnel will know that the drain system for that particular room is clogged and needs to be cleaned. However, no damage will have been caused inside the room. 
         [0098]    When installing the variable refrigerant package  21 , a notch  295  is provided in the raised rib seat  267 . This notch  295  allows the lower end of the evaporator drain tube  105  to move there through when being installed until the lower end of the evaporator drain tube  105  is just above the drain basin  263 . After installation of the variable refrigerant package  21  a piece of foam may be placed inside of notch  295 . 
         [0099]    Because hotel/motel rooms may be different, the shape of the base  31  may need to be different to accumulate different plenum  37  and door openings  35  being located on different sides of the closet  23 . Referring to  FIG. 11 , base  31  in  FIG. 11( a )  is the straight install base.  FIG. 11( b )  is the right install base  297 .  FIG. 11( c )  is the left install base  299 . Each of the bases  31 ,  297  and  299  allows for access water to drain outside of the building if the normal drain line is plugged. At the time of construction, the contractor will decide which style base  31 ,  297  or  299  will be used. 
         [0100]    Many hotels/motels are located in high humidity areas such as along the coast, which hotels/motels use package terminal air conditioners (PTACs). A standard PTAC unit is 42 inches wide and 16 inches tall. The depth may change to some degree. 
         [0101]    Referring to  FIGS. 12 and 13  in combination, a PTAC unit  400  that introduces fresh air is illustrated. Assuming the PTAC unit  400  is in the cooling mode, condenser fan  402  will draw outside entering air through condenser  404 . As can be seen in  FIG. 12 , outside leaving air passes through the condenser  404  prior to discharge to the atmosphere. 
         [0102]    Meanwhile, inside entering air is drawn in through the return air filter  406  to a mixing chamber  408  in front of the evaporator  410 . A fresh air fan  412  draws some outside entering air from the outside air chamber  414 , through a dividing wall  422 , and forces the fresh air through a snorkel  416  to the mixing chamber  408 . 
         [0103]    Inside of the mixing chamber  408 , the fresh air is mixed with indoor entering air and drawn through the evaporator  410  by the blower  418 . The mixed fresh air and indoor entering air combine to give indoor leaving air. 
         [0104]    Inside of the snorkel  416  is a fresh air filter  420  to remove any particles that may be in the fresh air. The inside of the snorkel  416  is lined with sound-deadening material to keep sound outside of a hotel/motel room from reaching the inside of the hotel/motel room. 
         [0105]    The volume of the fresh air flowing through the snorkel  416  in the PTAC unit  400  is approximately 5% to 10% of the outdoor entering air, which is approximately 30 to 50 cubic feet per minute (CFM). 
         [0106]    By taking the fresh air in through the mixing chamber  408  and mixing it with indoor entering air, the entire capacity of the evaporator  410  may be used to remove moisture from the fresh air being introduced into the conditioned space. By using the entire capacity of the evaporator  410  to remove humidity, musty indoor smells that occur in many hotel/motel rooms along the coast can be eliminated. By reducing the humidity inside the hotel/motel room, it eliminates the growth of mold and hence, the musty smell commonly referred to as “sick building syndrome.” 
         [0107]    If additional run times of the PTAC unit  400  using techniques described herein above are needed for further dehumidification, such techniques can be used in the PTAC unit  400 . 
         [0108]    By having the shape of the duct work between the fresh air fan  212  to the mixing chamber  408  in the shape of the snorkel, noises occurring outside of the hotel/motel room do not have a direct path to the inside. Also, by lining of the snorkel  416  with sound-deadening materials helps ensure the attenuation of any outside noise that might reach the inside of the hotel/motel room through the snorkel  416 . 
         [0109]    In addition to having the fresh air fan  412  with the snorkel  416 , the alternative embodiment may have any of the additional features such as infinitely variable speeds and reheating as described herein above. 
         [0110]    By decreasing the humidity inside the hotel/motel room, especially in high humidity areas, the period of time between the refurbishing of the rooms can be extended due to eliminating or reducing the sick building syndrome.

Technology Classification (CPC): 5