Patent Publication Number: US-2006018807-A1

Title: Air conditioner device with enhanced germicidal lamp

Description:
CLAIM OF PRIORITY  
      The present application claims priority under 35 USC 119(e) to U.S. Patent Application No. 60/590,445, filed Jul. 23, 2004, entitled “Air Conditioner Device With Enhanced Germicidal Lamp” (Attorney Docket No. SHPR-01361USR), which is hereby incorporated by reference.  
     CROSS-REFERENCE APPLICATIONS  
      The present invention is related to the following patent applications and patents, each of which is incorporated herein by reference: 
          U.S. patent application Ser. No. 10/074,207, filed Feb. 12, 2002, entitled “Electro-Kinetic Air Transporter-Conditioner Devices with Interstitial Electrode” (Attorney Docket No. SHPR-01041USN);     U.S. Pat. No. 6,176,977, entitled “Electro-Kinetic Air Transporter-Conditioner”(Attorney Docket No. SHPR-01041 US0);     U.S. Pat. No. 6,544,485, entitled “Electro-Kinetic Device with Anti Microorganism Capability” (Attorney Docket No. SHPR-01028US0);     U.S. patent application Ser. No. 10/074,347, filed Feb. 12, 2002, and entitled “Electro-Kinetic Air Transporter-Conditioner Device with Enhanced Housing” (Attorney Docket No. SHPR-01028US5);     U.S. patent application Ser. No. 10/717,420, filed Nov. 19, 2003, entitled “Electro-Kinetic Air Transporter And Conditioner Devices With Insulated Driver Electrodes” (Attorney Docket No. SHPR-01414US1);     U.S. patent application Ser. No. 10/625,401, filed Jul. 23, 2003, entitled “Electro-Kinetic Air Transporter And Conditioner Devices With Enhanced Arcing Detection And Suppression Features” (Attorney Docket No. SHPR-01361USB);     U.S. Pat. No. 6,350,417 issued May 4, 2000, entitled “Electrode Self Cleaning Mechanism For Electro-Kinetic Air Transporter-Conditioner” (Attorney Docket No. SHPR-01041US1);     U.S. Pat. No. 6,709,484, issued Mar. 23, 2004, entitled “Electrode Self-Cleaning Mechanism For Electro-Kinetic Air Transporter Conditioner Devices (Attorney Docket No. SHPR-01041US5);     U.S. Pat. No. 6,350,417 issued May 4, 2000, and entitled “Electrode SelfCleaning Mechanism For Electro-Kinetic Air Transporter-Conditioner” (Attorney Docket No. SHPR-01041US1);     U.S. Patent Application No. 60/590,688, filed Jul. 23, 2004, entitled “Air Conditioner Device With Removable Driver Electrodes” (Attorney Docket No. SHPR-01361USA);     U.S. Patent Application No. 60/590,735, filed Jul. 23, 2003, entitled “Air Conditioner Device With Variable Voltage Controlled Trailing Electrodes” (Attorney Docket No. SHPR-01361 USG);     U.S. Patent Application No. 60/590,960, filed Jul. 23, 2003, entitled “Air Conditioner Device With Removable Interstitial Driver Electrodes” (Attorney Docket No. SHPR-01361USQ);     U.S. Patent Application No. ______, filed ______, entitled “Enhanced Germicidal Lamp” (Attorney Docket No. SHPR-01361USY);     U.S. Patent Application No. ______, filed ______, entitled “Air Conditioner Device With Removable Driver Electrodes” (Attorney Docket No. SHPR-01414US7);     U.S. Patent Application No. ______, filed ______, entitled “Air Conditioner Device With Variable Voltage Controlled Trailing Electrodes” (Attorney Docket No. SHPR-01414US8);     U.S. Patent Application No. ______, filed ______, entitled “Air Conditioner     U.S. patent application Ser. No. ______, filed ______, entitled “Air Conditioner Device With Removable Driver Electrodes” (Attorney Docket No. SHPR-01414USB).       

    
    
     FIELD OF THE INVENTION  
      The present invention is related generally to a system for conditioning and/or transporting air.  
     BACKGROUND OF THE INVENTION  
      The use of an electric motor to rotate a fan blade to create an airflow has long been known in the art. Although such fans can produce substantial airflow (e.g., 1,000 ft 3 /minute or more), substantial electrical power is required to operate the motor, and essentially no conditioning of the flowing air occurs.  
      It is known to provide such fans with a HEPA-compliant filter element to remove particulate matter larger than perhaps 0.3 μm. Unfortunately, the resistance to airflow presented by the filter element may require doubling the electric motor size to maintain a desired level of airflow. Further, HEPA-compliant filter elements are expensive, and can represent a substantial portion of the sale price of a HEPA-compliant filter-fan unit. While such filter-fan units can condition the air by removing large particles, particulate matter small enough to pass through the filter element is not removed, including bacteria, for example.  
      It is also known in the art to produce an airflow using electro-kinetic techniques whereby electrical power is converted into a flow of air without utilizing mechanically moving components. One such system is described in U.S. Pat. No. 4,789,801 to Lee (1988), depicted herein in simplified form as  FIGS. 1A and 1B , which is hereby incorporated by reference. System  10  includes an array of first (“emitter”) electrodes or conductive surfaces  20  that are spaced-apart from an array of second (“collector”) electrodes or conductive surfaces  30 . The positive terminal of a generator such as, for example, pulse generator  40  which outputs a train of high voltage pulses (e.g., 0 to perhaps+5 KV) is coupled to the first array  20 , and the negative pulse generator terminal is coupled to the second array  30  in this example.  
      The high voltage pulses ionize the air between the arrays  20 ,  30  and create an airflow  50  from the first array  20  toward the second array  30 , without requiring any moving parts. Particulate matter  60  entrained within the airflow  50  also moves towards the second electrodes  30 . Much of the particulate matter is electrostatically attracted to the surfaces of the second electrodes  30 , where it remains, thus conditioning the flow of air that is exiting the system  10 . Further, the high voltage field present between the electrode sets releases ozone  03 , into the ambient environment, which eliminates odors that are entrained in the airflow.  
      In the particular embodiment of  FIG. 1A , the first electrodes  20  are circular in cross-section, having a diameter of about 0.003″ (0.08 mm), whereas the second electrodes  30  are substantially larger in area and define a “teardrop” shape in cross-section. The ratio of cross-sectional radii of curvature between the bulbous front nose of the second electrode  30  and the first electrodes  20  exceeds 10:1. As shown in  FIG. 1A , the bulbous front surfaces of the second electrodes  30  face the first electrodes  20 , and the somewhat “sharp” trailing edges face the exit direction of the airflow. In another particular embodiment shown herein as  FIG. 1B , second electrodes  30  are elongated in cross-section. The elongated trailing edges on the second electrodes  30  provide increased area upon which particulate matter  60  entrained in the airflow can attach. 
    
    
     BRIEF DESCRIPTION OF THE FIGURES  
       FIG. 1A  illustrates a plan, cross-sectional view, of a prior art electro-kinetic air transporter-conditioner system.  
       FIG. 1B  illustrates a plan, cross-sectional view of a prior art electro-kinetic air transporter-conditioner system.  
       FIG. 2  illustrates a perspective view of the system in accordance with one embodiment of the present invention.  
       FIG. 3  illustrates a plan view of the electrode assembly in accordance with one embodiment of the present invention.  
       FIG. 4  illustrates an electrical block diagram of the high voltage power source of one embodiment of the present invention.  
       FIG. 5  illustrates an electrical block diagram of the high voltage power source in accordance with one embodiment of the present invention.  
       FIG. 6  illustrates an exploded view of the system shown in  FIG. 2  in accordance with one embodiment of the present invention.  
       FIG. 7  illustrates a perspective view of the rear of the system with the germicidal lamp exposed in accordance with one embodiment of the present invention.  
       FIG. 8  illustrates a top view of the germicidal lamp in accordance with one embodiment of the present invention.  
       FIGS. 9-11  illustrate the system with the germicidal lamp positioned in various locations in accordance with one embodiment.  
       FIG. 12A-12B  illustrate plan views of the germicidal lamp and engaging receptacle in accordance with one embodiment of the present invention.  
       FIG. 12C  illustrates a perspective view of the engaging receptacle in accordance with one embodiment of the present invention.  
       FIG. 12D  illustrates a perspective view of the germicidal lamp in accordance with one embodiment of the present invention.  
       FIG. 13  illustrates a perspective view of the front grill with trailing electrodes thereon in accordance with one embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PRESENT INVENTION  
      An air transporting and/or conditioning system comprising a housing, an emitter electrode configured within the housing, a collector electrode configured within the housing and positioned downstream from the emitter electrode, and a integrally shielded germicidal lamp to selectively direct UV light emitted therefrom. The system preferably includes a driver electrode which is preferably removable from the housing through a side portion of the housing. Preferably, the driver electrode is insulated with a dielectric material and/or a catalyst. Preferably, a removable trailing electrode is configured within the housing and downstream of the collector electrode. Preferably, a first voltage source electrically is coupled to the emitter electrode and the collector electrode, and a second voltage source electrically is coupled to the trailing electrode. The second voltage source is independently and selectively controllable of the first voltage source.  
       FIG. 2  depicts one embodiment of the air transporter-conditioner system  100  whose housing  102  preferably includes a removable rear-located intake grill  104 , a removable front-located exhaust grill  106 , and a base pedestal  108 . Alternatively, a single grill provides both an air intake and an air exhaust with an air inlet channel and an air exhaust channel communicating with the grill and the air movement system within. The housing  102  is preferably freestanding and/or upstandingly vertical and/or elongated. The general shape of the housing  102  in the embodiment shown in  FIG. 2  is that of an oval cross-section. Alternatively, the housing  102  includes a differently shaped cross-section such as, but not limited to, a rectangular shape, a figure-eight shape, an egg shape, a tear-drop shape, or circular shape.  
      Internal to the transporter housing  102  is an air movement system which preferably includes an ion generating unit  220  ( FIG. 3 ), also referred to as an electrode assembly. The ion generating unit  220  ( FIG. 3 ) is self-contained in that, other than ambient air, nothing is required from beyond the housing  102 , save external operating potential, for operation of the present invention. In one embodiment, the air movement system includes a fan utilized to supplement and/or replace the movement of air caused by the operation of the ion generator  220 . The system  100  includes a germicidal lamp ( FIG. 4 ) which reduces the amount of microorganisms exposed to the lamp when passed through the system  100 . The germicidal lamp  290  ( FIG. 4 ) is effective in diminishing or destroying bacteria, germs, and viruses to which it is exposed.  
      The ion generating unit  220  is preferably powered by an AC:DC power supply. The AC:DC power supply is energizable or excitable using a switch S 1 . S 1  is conveniently located at the top  124  of the housing  102 . The function dial  218  enables a user to operate the germicidal lamp  290  (FIG.  4 ). In particular, the user can select the dial  218  to “ON,” “ON/GP,” or “OFF.” In the “ON” setting, the germicidal lamp  290  does not operate or emit UV light, although the electrode assembly  220  operates. In the “ON/GP” setting, the germicidal lamp  290  operates to remove or kill bacteria within the airflow while the electrode assembly  220  operates. The electrode assembly  220  as well as the germicidal lamp  290  do not operate when the function dial  218  is set to the “OFF” setting. In addition, located preferably on top  124  of the housing  102  is a boost button  216  which can boost the ion output of the ion generator  220 , as will be discussed below.  
      Both the inlet and the outlet grills  104 ,  106  are covered by fins  134 , also referred to as louvers. In accordance with one embodiment, each fin  134  is a thin ridge spaced-apart from the next fin  134 , so that each fin  134  creates minimal resistance as air flows through the housing  102 . As shown in  FIG. 2 , the fins  134  are vertical and are directed along the elongated vertical upstanding housing  102  of the system  100 , in one embodiment. Alternatively, the fins  134  are perpendicular to the elongated housing  102  and are configured horizontally. In one embodiment, the inlet and outlet fins  134  are aligned to give the unit a “see through” appearance while preventing an individual from viewing the UV light directly emitted from the germicidal lamp  290 , as discussed below. Thus, a user can safely “see through” the system  100  from the inlet  104  to the outlet  106  or vice versa. The user will see no moving parts within the housing, but just a quiet unit that cleans the air passing therethrough.  
      There is preferably no distinction between grills  104  and  106 , except their location relative to the collector electrodes  242  ( FIG. 3 ). Alternatively, the grills  104  and  106  are configured differently and are distinct from one another. The grills  104 ,  106  serve to ensure that an adequate flow of ambient air is drawn into or made available to the system  100  and that an adequate flow of ionized air that includes appropriate amounts of ozone flows out from the system  100  via the exhaust grill  106 . Thus, the IN flow preferably enters via grill(s)  104  and that the OUT flow exits via grill(s)  106  as shown in  FIG. 2 .  
      When the system  100  is energized by activating switch S 1 , high voltage or high potential output by the ion generator  220  produces at least ions within the system  100 . The “IN” notation in FIG.  2  denotes the intake of ambient air with particulate matter  60  through the inlet grill  104 . The “OUT” notation in  FIG. 2  denotes the outflow of cleaned air through the exhaust grill  106  substantially devoid of the particulate matter  60 .  
       FIG. 3  illustrates a plan view of the electrode assembly in accordance with one embodiment of the present invention. The electrode assembly  220  is shown to include the first electrode set  230 , having the emitter electrodes  232 , and the second electrode set  240 , having the collector electrodes  242 , preferably downstream from the first electrode set  230 . In the embodiment shown in  FIG. 3 , the electrode assembly  220  also includes a set of driver electrodes  246  located interstitially between the collector electrodes  242 . It is preferred that the electrode assembly  220  additionally includes a set of trailing electrodes  222  downstream from the collector electrodes  242 . It is preferred that the number N 1  of emitter electrodes  232  in the first set  230  differ by one relative to the number N 2  of collector electrodes  242  in the second set  240 . Preferably, the system  100  includes a greater number of collector electrodes  242  than emitter electrodes  232 . However, if desired, additional emitter electrodes  232  are alternatively positioned at the outer ends of set  230  such that N 1 &gt;N 2 , e.g., five emitter electrodes  232  compared to four collector electrodes  242 . Alternatively, instead of multiple electrodes, single electrodes or single conductive surfaces are substituted. It is apparent that other numbers and arrangements of emitter electrodes  232 , collector electrodes  242 , trailing electrodes  222  and driver electrodes  246  are alternatively configured in the electrode assembly  220  in other embodiments.  
      The material(s) of the electrodes  232  and  242  should conduct electricity and be resistant to the corrosive effects from the application of high voltage, but yet be strong and durable enough to be cleaned periodically. In one embodiment, the emitter electrodes  232  are preferably fabricated from tungsten. Tungsten is sufficiently robust in order to withstand cleaning, has a high melting point to retard breakdown due to ionization, and has a rough exterior surface that promotes efficient ionization. The collector electrodes  242  preferably have a highly polished exterior surface to minimize unwanted point-to-point radiation. As such, the collector electrodes  242  are fabricated from stainless steel and/or brass, among other appropriate materials. The polished surface of electrodes  232  also promotes ease of electrode cleaning. The materials and construction of the electrodes  232  and  242 , allow the electrodes  232 ,  242  to be light weight, easy to fabricate, and lend themselves to mass production. Further, electrodes  232  and  242  described herein promote more efficient generation of ionized air, and appropriate amounts of ozone.  
      As shown in  FIG. 3 , one embodiment of the present invention includes a first high voltage source (HVS)  170  and a second high power voltage source  172 . The positive output terminal of the first HVS  170  is coupled to the emitter electrodes  232 , and the negative output terminal of first HVS  170  is coupled to the collector electrodes  242 . This coupling polarity has been found to work well and minimizes unwanted audible electrode vibration or hum. It is noted that in some embodiments, one port, such as the negative port, of the high voltage power supply can in fact be the ambient air. Thus, the electrodes  242  in the second set  240  need not be connected to the first HVS  170  using a wire. Nonetheless, there will be an “effective connection” between the collector electrodes  242  and one output port of the first HVS  170 , in this instance, via ambient air. Alternatively, the negative output terminal of first HVS  170  is connected to the first electrode set  230  and the positive output terminal is connected to the second electrode set  240 .  
      When voltage or pulses from the first HVS  170  are generated across the first and second electrode sets  230  and  240 , a plasma-like field is created surrounding the electrodes  232  in first set  230 . This electric field ionizes the ambient air between the first and the second electrode sets  230 ,  240  and establishes an “OUT” airflow that moves towards the second electrodes  240 , which is herein referred to as the ionization region.  
      Ozone and ions are generated simultaneously by the first electrodes  232  as a function of the voltage potential from the HVS  170 . Ozone generation is increased or decreased by respectively increasing or decreasing the voltage potential at the first electrode set  230 . Coupling an opposite polarity voltage potential to the second electrodes  242  accelerates the motion of ions from the first set  230  to the second set  240 , thereby producing the airflow in the ionization region. Molecules as well as particulates in the air thus become ionized with the charge emitted by the emitter electrodes  232  as they pass by the electrodes  232 . As the ions and ionized particulates move toward the second set  240 , the ions and ionized particles push or move air molecules toward the second set  240 . The relative velocity of this motion is increased, by way of example, by increasing the voltage potential at the second set  240  relative to the potential at the first set  230 . Therefore, the collector electrodes  242  collect the ionized particulates in the air, thereby allowing the system  100  to output cleaner, fresher air.  
      As shown in the embodiment in  FIG. 3 , at least one output trailing electrode  222  is electrically coupled to the second HVS  172 . The trailing electrode  222  generates a substantial amount of negative ions, because the electrode  222  is coupled to relatively negative high potential. In one embodiment, the trailing electrode(s)  222  is a wire positioned downstream from the second electrodes  242 . In one embodiment, the electrode  222  has a pointed shape in the side profile (e.g., a triangle) as described in U.S. patent application Ser. No. 10/074,347 which is incorporated by reference above.  
      The negative ions produced by the trailing electrode  222  neutralize excess positive ions otherwise present in the output airflow, such that the OUT flow has a net negative charge. The trailing electrodes  222  are preferably made of stainless steel, copper, or other conductor material. The inclusion of one electrode  222  has been found sufficient to provide a sufficient number of output negative ions. However, multiple trailing wire electrodes  222  are utilized in another embodiment. More details regarding the trailing electrode  222  are described in the 60/590,735 application, which is incorporated by reference above.  
      The use of the driver electrodes  246  increase the particle collection efficiency of the electrode assembly  220  and reduces the percentage of particles that are not collected by the collector electrode  242 . This is due to the driver electrode  246  pushing particles in air flow toward the inside surface  244  of the adjacent collector electrode(s)  242 , which is referred to herein as the collecting region. The driver electrode  246  is preferably insulated which further increases particle collection efficiency.  
      As stated above, the system of the present invention will also produce ozone (O 3 ). In accordance with one embodiment of the present invention, ozone production is reduced by preferably coating the internal surfaces of the housing with an ozone reducing catalyst. Exemplary ozone reducing catalysts include manganese dioxide and activated carbon. Commercially available ozone reducing catalysts such as PremAir™ manufactured by Englehard Corporation of Iselin, New Jersey, is alternatively used. Some ozone reducing catalysts are electrically conductive, while others are not electrically conductive (e.g., manganese dioxide). Preferably the ozone reducing catalysts should have a dielectric strength of at least 1000 V/mil (one-hundredth of an inch).  
      The insulated driver electrode  246  includes an electrically conductive electrode  253  that is coated with an insulating dielectric material  254 . In embodiments where the driver electrode  246  is not insulated, the driver electrode  246  simply includes the electrically conductive electrode  253 . In accordance with one embodiment of the present invention, the insulating dielectric material  254  is a heat shrink material (e.g. flexible polyolefin material). In another embodiment, the dielectric material  254  is an insulating varnish, lacquer or resin. Other possible dielectric materials  254  that can be used to insulate the driver electrode  253  include, but are not limited to, ceramic, porcelain enamel or fiberglass.  
      In one embodiment, the driver electrodes  246  are electrically connected to ground as shown in  FIG. 3 . Although the grounded drivers  246  do not receive a charge from either the first or second HVS  170 ,  172 , the drivers  246  may still deflect positively charged particles toward the collector electrodes  242 . In another embodiment, the driver electrodes  246  are positively charged. In yet another embodiment, the driver electrodes  246  are electrically coupled to the negative terminal of either the first or second HVS  170 ,  172 , whereby the driver electrodes  246  are preferably charged at a voltage that is less than the negatively charged collector electrodes  242 . More details regarding the insulated driver electrodes  246  are described in the 60/590,960 application, which is incorporated by reference above.  
       FIG. 4  illustrates an electrical circuit diagram for the system  100 , according to one embodiment of the present invention. The system  100  has an electrical power cord that plugs into a common electrical wall socket that provides a nominal 110 VAC. An electromagnetic interference (EMI) filter  110  is placed across the incoming nominal 110 VAC line to reduce and/or eliminate high frequencies generated by the various circuits within the system  100 , such as the electronic ballast  112 . In one embodiment, the electronic ballast  112  is electrically connected to a germicidal lamp  290  (e.g. an ultraviolet lamp) to regulate, or control, the flow of current through the lamp  290 . A switch  218  is used to turn the lamp  290  on or off. The EMI Filter  110  is well known in the art and does not require a further description. In another embodiment, the system  100  does not include the germicidal lamp  290 , whereby the circuit diagram shown in  FIG. 4  would not include the electronic ballast  112 , the germicidal lamp  290 , nor the switch  218  used to operate the germicidal lamp  290 .  
      The EMI filter  110  is coupled to a DC power supply  114 . The DC power supply  114  is coupled to the first HVS  170  as well as the second high voltage power source  172 . The high voltage power source can also be referred to as a pulse generator. The DC power supply  114  is also coupled to the micro-controller unit (MCU)  130 . The MCU  130  can be, for example, a Motorola 68HC908 series micro-controller, available from Motorola. Alternatively, any other type of MCU is contemplated. The MCU  130  can receive a signal from the switch S 1  as well as a boost signal from the boost button  216 . The MCU  130  also includes an indicator light  219  which specifies when the electrode assembly is ready to be cleaned.  
      The DC Power Supply  114  is designed to receive the incoming nominal 110 VAC and to output a first DC voltage (e.g., 160 VDC) to the first HVS  170 . The DC Power Supply  114  voltage (e.g., 160 VDC) is also stepped down to a second DC voltage (e.g., 12 VDC) for powering the micro-controller unit (MCU)  130 , the HVS  172 , and other internal logic of the system  100 . The voltage is stepped down through a resistor network, transformer or other component.  
      As shown in  FIG. 4 , the first HVS  170  is coupled to the first electrode set  230  and the second electrode set  240  to provide a potential difference between the electrode sets. In one embodiment, the first HVS  170  is electrically coupled to the driver electrode  246 , as described above. In addition, the first HVS  170  is coupled to the MCU  130 , whereby the MCU receives arc sensing signals  128  from the first HVS  170  and provides low voltage pulses  120  to the first HVS  170 . Also shown in  FIG. 4  is the second HVS  172  which provides a voltage to the trailing electrodes  222 . In addition, the second HVS  172  is coupled to the MCU  130 , whereby the MCU receives arc sensing signals  128  from the second HVS  172  and provides low voltage pulses  120  to the second HVS  172 .  
      In accordance with one embodiment of the present invention, the MCU  130  monitors the stepped down voltage (e.g., about 12 VDC), which is referred to as the AC voltage sense signal  132  in  FIG. 4 , to determine if the AC line voltage is above or below the nominal 110 VAC, and to sense changes in the AC line voltage. For example, if a nominal 110 VAC increases by 10% to 121 VAC, then the stepped down DC voltage will also increase by 10%. The MCU  130  can sense this increase and then reduce the pulse width, duty cycle and/or frequency of the low voltage pulses to maintain the output power (provided to the HVS  170 ) to be the same as when the line voltage is at 110 VAC. Conversely, when the line voltage drops, the MCU  130  can sense this decrease and appropriately increase the pulse width, duty cycle and/or frequency of the low voltage pulses to maintain a constant output power. Such voltage adjustment features of the present invention also enable the same system  100  to be used in different countries that have different nominal voltages than in the United States (e.g., in Japan the nominal AC voltage is 100 VAC).  
       FIG. 5  illustrates a schematic block diagram of the high voltage power supply in accordance with one embodiment of the present invention. For the present description, the first and second HVSs  170 ,  172  include the same or similar components as that shown in  FIG. 5 . However, it is apparent to one skilled in the art that the first and second HVSs  170 ,  172  are alternatively comprised of different components from each other as well as those shown in  FIG. 5 . The various circuits and components comprising the first and second HVS  170 ,  172  can, for example, be fabricated on a printed circuit board mounted within housing  210 . The MCU  130  can be located on the same circuit board or a different circuit board.  
      In the embodiment shown in  FIG. 5 , the HVSs  170 ,  172  include an electronic switch  126 , a step-up transformer  116  and a voltage multiplier  118 . The primary side of the step-up transformer  116  receives the DC voltage from the DC power supply  114 . For the first HVS  170 , the DC voltage received from the DC power supply  114  is approximately 160 Vdc. For the second HVS  172 , the DC voltage received from the DC power supply  114  is approximately 12 Vdc. An electronic switch  126  receives low voltage pulses  120  (of perhaps 20-25 KHz frequency) from the MCU  130 . Such a switch is shown as an insulated gate bipolar transistor (IGBT)  126 . The IGBT  126 , or other appropriate switch, couples the low voltage pulses  120  from the MCU  130  to the input winding of the step-up transformer  116 . The secondary winding of the transformer  116  is coupled to the voltage multiplier  118 , which outputs the high voltage pulses to the electrode(s). For the first HVS  170 , the electrode(s) are the emitter and collector electrode sets  230  and  240 . For the second HVS  172 , the electrode(s) are the trailing electrodes  222 . In general, the IGBT  126  operates as an electronic on/off switch. Such a transistor is well known in the art and does not require a further description.  
      When driven, the first and second HVSs  170 ,  172  receive the low input DC voltage from the DC power supply  114  and the low voltage pulses from the MCU  130  and generate high voltage pulses of preferably at least 5 KV peak-to-peak with a repetition rate of about 20 to 25 KHz. The voltage multiplier  118  in the first HVS  170  outputs between 5 to 9 KV to the first set of electrodes  230  and between −6 to −18 KV to the second set of electrodes  240 . In the preferred embodiment, the emitter electrodes  232  receive approximately 5 to 6 KV whereas the collector electrodes  242  receive approximately −9 to −10 KV. The voltage multiplier  118  in the second HVS  172  outputs approximately −12 KV to the trailing electrodes  222 . In one embodiment, the driver electrodes  246  are preferably connected to ground. It is within the scope of the present invention for the voltage multiplier  118  to produce greater or smaller voltages. The high voltage pulses preferably have a duty cycle of about 10%-15%, but may have other duty cycles, including a 100% duty cycle.  
      The MCU  130  is coupled to a control dial S 1 , as discussed above, which can be set to a LOW, MEDIUM or HIGH airflow setting as shown in  FIG. 4 . The MCU  130  controls the amplitude, pulse width, duty cycle and/or frequency of the low voltage pulse signal to control the airflow output of the system  100 , based on the setting of the control dial S 1 . To increase the airflow output, the MCU  130  can be set to increase the amplitude, pulse width, frequency and/or duty cycle. Conversely, to decrease the airflow output rate, the MCU  130  is able to reduce the amplitude, pulse width, frequency and/or duty cycle. In accordance with one embodiment, the low voltage pulse signal  120  has a fixed pulse width, frequency and duty cycle for the LOW setting, another fixed pulse width, frequency and duty cycle for the MEDIUM setting, and a further fixed pulse width, frequency and duty cycle for the HIGH setting.  
      In accordance with one embodiment of the present invention, the low voltage pulse signal  120  modulates between a predetermined duration of a “high” airflow signal and a “low” airflow signal. It is preferred that the low voltage signal modulates between a predetemmined amount of time when the airflow is to be at the greater “high” flow rate, followed by another predetermined amount of time in which the airflow is to be at the lesser “low” flow rate. This is preferably executed by adjusting the voltages provided by the first HVS to the first and second sets of electrodes for the greater flow rate period and the lesser flow rate period. This produces an acceptable airflow output while limiting the ozone production to acceptable levels, regardless of whether the control dial S 1  is set to HIGH, MEDIUM or LOW. For example, the “high” airflow signal can have a pulse width of 5 microseconds and a period of 40 microseconds (i.e., a 12.5% duty cycle), and the “low” airflow signal can have a pulse width of 4 microseconds and a period of 40 microseconds (i.e., a 10% duty cycle).  
      In general, the voltage difference between the first set  230  and the second set  240  is proportional to the actual airflow output rate of the system  100 . Thus, the greater voltage differential is created between the first and second set electrodes  230 ,  240  by the “high” airflow signal, whereas the lesser voltage differential is created between the first and second set electrodes  230 ,  240  by the “low” airflow signal. In one embodiment, the airflow signal causes the voltage multiplier  118  to provide between 5 and 9 KV to the first set electrodes  230  and between −9 and −10 KV to the second set electrodes  240 . For example, the “high” airflow signal causes the voltage multiplier  118  to provide 5.9 KV to the first set electrodes  230  and −9.8 KV to the second set electrodes  240 . In the example, the “low” airflow signal causes the voltage multiplier  118  to provide 5.3 KV to the first set electrodes  230  and −9.5 KV to the second set electrodes  240 . It is within the scope of the present invention for the MCU  130  and the first HVS  170  to produce voltage potential differentials between the first and second sets electrodes  230  and  240  other than the values provided above and is in no way limited by the values specified.  
      In accordance with the preferred embodiment of the present invention, when the control dial S 1  is set to HIGH, the electrical signal output from the MCU  130  will continuously drive the first HVS  170  and the airflow, whereby the electrical signal output modulates between the “high” and “low” airflow signals stated above (e.g. 2 seconds “high” and 10 seconds “low”). When the control dial S 1  is set to MEDIUM, the electrical signal output from the MCU  130  will cyclically drive the first HVS  170  (i.e. airflow is “On”) for a predetermined amount of time (e.g., 20 seconds), and then drop to a zero or a lower voltage for a further predetermined amount of time (e.g., a further 20 seconds). It is to be noted that the cyclical drive when the airflow is “On” is preferably modulated between the “high” and “low” airflow signals (e.g. 2 seconds “high” and 10 seconds “low”), as stated above. When the control dial S 1  is set to LOW, the signal from the MCU  130  will cyclically drive the first HVS  170  (i.e. airflow is “On”) for a predetermined amount of time (e.g., 20 seconds), and then drop to a zero or a lower voltage for a longer time period (e.g., 80 seconds). Again, it is to be noted that the cyclical drive when the airflow is “On” is preferably modulated between the “high” and “low” airflow signals (e.g. 2 seconds “high” and 10 seconds “low”), as stated above. It is within the scope and spirit of the present invention the HIGH, MEDIUM, and LOW settings will drive the first HVS  170  for longer or shorter periods of time. It is also contemplated that the cyclic drive between “high” and “low” airflow signals are durations and voltages other than that described herein.  
      Cyclically driving airflow through the system  100  for a period of time, followed by little or no airflow for another period of time (i.e. MEDIUM and LOW settings) allows the overall airflow rate through the system  100  to be slower than when the dial S 1  is set to HIGH. In addition, cyclical driving reduces the amount of ozone emitted by the system since little or no ions are produced during the period in which lesser or no airflow is being output by the system. Further, the duration in which little or no airflow is driven through the system  100  provides the air already inside the system a longer dwell time, thereby increasing particle collection efficiency. In one embodiment, the long dwell time allows air to be exposed to a germicidal lamp, if present.  
      Regarding the second HVS  172 , approximately 12 volts DC is applied to the second HVS  172  from the DC Power Supply  114 . The second HVS  172  provides a negative charge (e.g. −12 KV) to one or more trailing electrodes  222  in one embodiment. However, it is contemplated that the second HVS  172  provides a voltage in the range of, and including, −10 KV to −60 KV in other embodiments. In one embodiment, other voltages produced by the second HVS  172  are contemplated.  
      In one embodiment, the second HVS  172  is controllable independently from the first HVS  170  (as for example by the boost button  216 ) to allow the user to variably increase or decrease the amount of negative ions output by the trailing electrodes  222  without correspondingly increasing or decreasing the amount of voltage provided to the first and second set of electrodes  230 ,  240 . The second HVS  172  thus provides freedom to operate the trailing electrodes  222  independently of the remainder of the electrode assembly  220  to reduce static electricity, eliminate odors and the like. In addition, the second HVS  172  allows the trailing electrodes  222  to operate at a different duty cycle, amplitude, pulse width, and/or frequency than the electrode sets  230  and  240 . In one embodiment, the user is able to vary the voltage supplied by the second HVS  172  to the trailing electrodes  222  at any time by depressing the button  216 . In one embodiment, the user is able to turn on or turn off the second HVS  172 , and thus the trailing electrodes  222 , without affecting operation of the electrode assembly  220  and/or the germicidal lamp  290 . It should be noted that the second HVS  172  can also be used to control electrical components other than the trailing electrodes  222  (e.g. driver electrodes and germicidal lamp).  
      As mentioned above, the system  100  includes a boost button  216 . In one embodiment, the trailing electrodes  222  as well as the electrode sets  230 ,  240  are controlled by the boost signal from the boost button  216  input into the MCU  130 . In one embodiment, as mentioned above, the boost button  216  cycles through a set of operating settings upon the boost button  216  being depressed. In the example embodiment discussed below, the system  100  includes three operating settings. However, any number of operating settings are contemplated within the scope of the invention.  
      The following discussion presents methods of operation of the boost button  216  which are variations of the methods discussed above. In particular, the system  100  will operate in a first boost setting when the boost button  216  is pressed once. In the first boost setting, the MCU  130  drives the first HVS  170  as if the control dial S 1  was set to the HIGH setting for a predetermined amount of time (e.g., 6 minutes), even if the control dial S 1  is set to LOW or MEDIUM (in effect overriding the setting specified by the dial S 1 ). The predetermined time period may be longer or shorter than 6 minutes. For example, the predetermined period can also preferably be 20 minutes if a higher cleaning setting for a longer period of time is desired. This will cause the system  100  to run at a maximum airflow rate for the predetermined boost time period. In one embodiment, the low voltage signal modulates between the “high” airflow signal and the “low” airflow signal for predetermined amount of times and voltages, as stated above, when operating in the first boost setting. In another embodiment, the low voltage signal does not modulate between the “high” and “low” airflow signals.  
      In the first boost setting, the MCU  130  will also operate the second HVS  172  to operate the trailing electrode  222  to generate ions, preferably negative, into the airflow. In one embodiment, the trailing electrode  222  will preferably repeatedly emit ions for one second and then terminate for five seconds for the entire predetermined boost time period. The increased amounts of ozone from the boost level will further reduce odors in the entering airflow as well as increase the particle capture rate of the system  100 . At the end of the predetermined boost period, the system  100  will return to the airflow rate previously selected by the control dial S 1 . It should be noted that the on/off cycle at which the trailing electrodes  222  operate are not limited to the cycles and periods described above.  
      In the example, once the boost button  216  is pressed again, the system  100  operates in the second setting, which is an increased ion generation or “feel good” mode. In the second setting, the MCU  130  drives the first HVS  170  as if the control dial S 1  was set to the LOW setting, even if the control dial S 1  is set to HIGH or MEDIUM (in effect overriding the setting specified by the dial S 1 ). Thus, the airflow is not continuous, but “On” and then at a lesser or zero airflow for a predetermined amount of time (e.g. 6 minutes). In addition, the MCU  130  will operate the second HVS  172  to operate the trailing electrode  222  to generate negative ions into the airflow. In one embodiment, the trailing electrode  222  will repeatedly emit ions for one second and then terminate for five seconds for the predetermined amount of time. It should be noted that the on/off cycle at which the trailing electrodes  222  operate are not limited to the cycles and periods described above.  
      In the example, upon the boost button  216  being pressed again, the MCU  130  will operate the system  100  in a third operating setting, which is a normal operating mode. In the third setting, the MCU  130  drives the first HVS  170  depending on the which setting the control dial S 1  is set to (e.g. HIGH, MEDIUM or LOW). In addition, the MCU  130  will operate the second HVS  172  to operate the trailing electrode  222  to generate ions, preferably negative, into the airflow at a predetermined interval. In one embodiment, the trailing electrode  222  will repeatedly emit ions for one second and then terminate for nine seconds. In another embodiment, the trailing electrode  222  does not operate at all in this mode. The system  100  will continue to operate in the third setting by default until the boost button  216  is pressed. It should be noted that the on/off cycle at which the trailing electrodes  222  operate are not limited to the cycles and periods described above.  
      In one embodiment, the present system  100  operates in an automatic boost mode upon the system  100  being initially plugged into the wall and/or initially being turned on after being off for a predetermined amount of time. In particular, upon the system  100  being turned on, the MCU  130  automatically drives the first HVS  170  as if the control dial S 1  was set to the HIGH setting for a predetermined amount of time, as discussed above, even if the control dial S 1  is set to LOW or MEDIUM, thereby causing the system  100  to run at a maximum airflow rate for the amount of time. In addition, the MCU  130  automatically operates the second HVS  172  to operate the trailing electrode  222  at a maximum ion emitting rate to generate ions, preferably negative, into the airflow for the same amount of time. This configuration allows the system  100  to effectively clean stale, pungent, and/or polluted air in a room which the system  100  has not been continuously operating in. This feature improves the air quality at a faster rate while emitting negative “feel good” ions to quickly eliminate any odor in the room. Once the system  100  has been operating in the first setting boost mode, the system  100  automatically adjusts the airflow rate and ion emitting rate to the third setting (i.e. normal operating mode). For example, in this initial plug-in or initial turn-on mode, the system can operate in the high setting for 20 minutes to enhance the removal of particulates and to more rapidly clean the air as well as deodorize the room.  
      In addition, the system  100  will include an indicator light which informs the user what mode the system  100  is operating in when the boost button  216  is depressed. In one embodiment, the indicator light is the same as the cleaning indicator light  219  discussed above. In another embodiment, the indicator light is a separate light from the indicator light  219 . For example only, the indicator light will emit a blue light when the system  100  operates in the first setting. In addition, the indicator light will emit a green light when the system  100  operates in the second setting. In the example, the indicator light will not emit a light when the system  100  is operating in the third setting.  
      The MCU  130  provides various timing and maintenance features in one embodiment. For example, the MCU  130  can provide a cleaning reminder feature (e.g., a 2 week timing feature) that provides a reminder to clean the system  100  (e.g., by causing indicator light  219  to turn on amber, and/or by triggering an audible alarm that produces a buzzing or beeping noise). The MCU  130  can also provide arc sensing, suppression and indicator features, as well as the ability to shut down the first HVS  170  in the case of continued arcing. Details regarding arc sensing, suppression and indicator features are described in U.S. patent application Ser. No. 10/625,401 which is incorporated by reference above.  
      In addition, the MCU  130  includes a lamp timing feature which notifies the user that the lamp  290  is in need of replacement. In particular, upon the timing feature counting a predetermined duration (e.g. 8000 operating hours), the MCU  130  will notify the user that the lamp  290  should be replaced. It is preferred that the timing feature of the MCU  130  tolls the counting while the unit is off or unplugged. In one embodiment, the MCU  130  notifies the user using the indicator light  219  discussed above, whereby the indicator light turns a different color and/or begins flashing. In another embodiment, the system  100  includes a separate indicator. The lamp timing feature of the MCU  130  is preferably set by the manufacturer to the normal operating life of the lamp  290 .  
      The timing feature of the MCU  130  is preferably reset by the user. In one embodiment, the timing feature is reset by performing a combination of steps. This prevents the user from inadvertently resetting the timer. For example only, the timing feature is able to be reset by simultaneously pressing the boost button  216  and turning the S 1  switch to HIGH while the unit is off. The “high” airflow signal and the boost button signal enter the MCU  130  to thereby reset the timer circuit. In another embodiment, the timer feature is reset by a mechanical switch in the receptacle  300  ( FIG. 7 ), whereby simply removing and/or inserting the lamp  290  into the receptacle  300  resets the timer circuit.  
       FIG. 6  illustrates an exploded view of the system  100  in accordance with one embodiment of the present invention. In particular,  FIG. 6  illustrates the housing  102 , the rear intake grill  104  (also referred to as inlet), the front exhaust grill  106  (also referred to outlet), the collector electrodes  242 , the driver electrodes  246  and the germicidal lamp  290 . The system  100  also includes one or more trailing electrodes  222  ( FIG. 13 ). As shown in the embodiment in  FIG. 6 , the upper surface ofhousing  102  includes a user-liftable handle member  112  to lift the collector electrodes  242  from the housing  102 . In the embodiment shown in  FIG. 6 , the lifting member  112  lifts the collector electrodes  242  upward, thereby causing the collector electrodes  242  to telescope out of the aperture  126  in the top surface  124  of the housing  102  and, and if desired, out of the system  100  for cleaning. In addition, the driver electrodes  246  are removable from the housing  102  horizontally, as shown in  FIG. 6 , when the exhaust grill  106  is removed from the housing  102 . Alternatively or additionally, the driver electrodes are removable vertically from the housing  102  as further discussed in U.S. Patent Application No. 60/590,688, which is incorporated by reference above.  
      The housing  102  is preferably made from a lightweight inexpensive material, ABS plastic for example. Considering that a germicidal lamp  290  is located within the housing  102 , the material must be able to withstand prolonged exposure to class UV-C light. Non- “hardened” material will degenerate over time if exposed to light such as UV-C. By way of example only, the housing  102  may be manufactured from CYCLOLAC7 ABS Resin (material designation VW300(f2)), which is manufactured by General Electric Plastics Global Products, and is certified by UL Inc. for use with ultraviolet light. It is within the scope of the present invention to manufacture the housing  102  from other UV appropriate materials.  
       FIG. 7  illustrates a rear perspective view of the system  100  with the intake grill  104  removed from the housing  102 . In one embodiment, the removable intake grill  104  allows a user to easily remove and replace the germicidal lamp  290  from the receptacle  300  in the housing  102  when the lamp  290  expires. In the embodiment in which the grill  104  is removable, the grill  104  has locking tabs  120  located on each side, along the entire length of the grill  104 . The locking tabs  120 , as shown in  FIG. 7 , are “L”-shaped. Each tab  120  extends away from the grill  104 , inward towards the housing  102 , and then projects downward, parallel with the edge of the grill  104 . It is also within the spirit and scope of the invention to have differently-shaped tabs  120 . Each tab  120  individually and slidably interlocks with recesses  122  formed within the housing  102 . The grill  104  is preferably slid vertically upward until the tabs  120  disengage the recesses  122 . The grill  104  is then pulled away from the housing  102  in a lateral direction, as shown in  FIG. 7 . Removing the grill  104  exposes the lamp  290  within the housing  102 . In one embodiment, the grill  104  includes a safety mechanism, such as a rear projecting tab removed from a receiving slot, to shut the system  100  off when the grill  104  is removed.  
      In another embodiment, the germicidal lamp  290  is removable from the housing  102  by vertically lifting the germicidal lamp  290  out through the top surface  124 . The lamp  290  is mounted to a lamp fixture that has circuit contacts which engage the circuit  320  ( FIG. 4 ), such that the lamp  290  will shut the entire system  100  off when lifted out of the housing. In similar, but less convenient fashion, the lamp  290  may be designed to be removed from the bottom of the housing  102 . More details regarding removing the lamp  290  telescopically from the housing  102  are discussed in U.S. patent application Ser. No. 10/074,347 which is incorporated by reference above.  
       FIG. 8  illustrates a plan view of the preferred germicidal lamp  290  in accordance with one embodiment of the present invention. As shown in  FIG. 8 , the ends of the lamp  290  preferably include two lamp pins  292  which electrically connect the lamp  290  to the electronic ballast ( FIG. 5 ). However, as discussed below, one or more ends of the lamp  290  may alternatively have additional pins.  
      The germicidal lamp  290  is preferably a UV-C lamp that preferably emits viewable light and radiation (in combination referred to as radiation or light  280 ) having wavelength of about 254 nm. This wavelength is effective in diminishing or destroying bacteria, germs, and viruses to which it is exposed. As shown in  FIG. 8 , the lamp  290  includes a shield  294  integrally configured which selectively directs UV light and radiation emitted by the lamp  290 . Lamps  290  are commercially available. For example, the lamp  290  may be a Phillips model TUV 15W-R, a 15 W tubular lamp measuring about 25 mm in diameter by about 43 cm in length. Other lamps that emit the desired wavelength are alternatively used.  
      The lamp  290  shown in  FIG. 8  includes two distinct shielded regions  294  as well as two distinct non-shielded regions  296 . Any number of shielded or non-shielded regions, including only one, are alternatively contemplated. The shielded regions  294  of the lamp  290  are preferably coated with a shielding material  291  which prevents UV light and radiation emitted by the lamp  290  from passing therethrough. In one embodiment, the shielding material  291  is a coating which is disposed on the inner and/or outer surface of the germicidal lamp  290 . In another embodiment, the shielding material  291  is formed within the glass housing between the inner and outer surfaces of the lamp body. The shielding material  291  of the lamp  290  is preferably made of titanium dioxide. However, it is within the scope of the present invention that the shielding material  291  be any appropriate material which blocks emission of UV light and radiation from the lamp  290 . In one embodiment, the interior of the lamp  290  is lined with a reflective material in the areas where the shielding material  291  is disposed to increase the UV intensity through the non-shielded regions  296 . Alternatively, the reflective material is configured to be elsewhere within the lamp body. In another embodiment, the interior of the lamp  290  is not lined with a reflective material. The shielding material  291  is applied to the lamp  290  by known methods which are not discussed in detail herein.  
      As shown in the Figures, the shielding material  291  is disposed on predetermined locations of the lamp  290  such that the shielded regions  294  face the inlet and outlets  104 ,  106  and the non-shielded regions  296  face the inner walls  101  of the housing  102  when the lamp is positioned within the housing  102 . Where the shielded regions are disposed on the body  290  depend on the location as well as the orientation of the lamp  290  within the housing  102  as discussed in more detail below. It is preferred that the shielded regions  294  extend continuously from the lamp&#39;s top end to the lamp&#39;s bottom end. Alternatively, the shielded regions  294  are not continuous from the top end to the bottom end of the lamp  290 .  
      As stated above, the non-shielded regions  296  of the lamp  290  allow UV light and radiation to pass through. It is preferred that the lamp  290  is configured and oriented such that non-shielded regions  296  allow UV light and radiation to be emitted onto the inner surface  111  of the housing  102  away from the view of the user. Thus, the non-shielded regions  296  do not allow UV light and radiation to pass directly from the lamp to the inlet and outlet  104 ,  106  of the housing  102 . The lamp  290  is thus oriented such that the shielded regions  294  face the inlet  104  and outlet  106 , thereby preventing UV light and radiation from being directly emitted toward the inlet  104  and/or outlet  106  in which a user would be able to view the directly emitted light. In addition, the configuration of the louvers  134  as well as placement of the shielded regions  294  prevent an individual looking into the inlet  104  and/or outlet  106  from directly viewing the undesired UV light and radiation emitted directly by the lamp  290 . The integrally shielded lamp  290  of the present invention thus eliminates the need for light deflecting baffles or other housings which can simplify manufacturing of the system  100 . Without such baffles and other housing shields, there is less structure in the housing that can potentially impede the flow of air from the inlet  104  to the outlet  106 . In addition, the use of an integrally shielded lamp can provide the ability to specifically direct light to a desired location in the housing (e.g. collector electrodes), while preventing the UV light from being viewed through the inlet and/or outlet in a non airflow-restrictive manner.  
      As shown in  FIG. 9 , the system includes the ion generator  220  along with the germicidal lamp  290  of  FIG. 8  positioned upstream of the ion generator  220 . In particular, the electrode assembly  220  is positioned near the outlet grill  106 , whereas the germicidal lamp  290  is positioned near the inlet grill  104 , preferably along line A-A. The germicidal lamp  290  is also shown placed directly in-line with both the inlet  104  and outlet  106 . The housing  102  of the present system  100  is preferably designed to optimize the reduction of microorganisms within the airflow, whereby the efficacy of radiation  280  upon microorganisms depends upon the length oftime such organisms are subjected to the radiation  280 . Thus, the lamp  290  is preferably located within the housing  102  where the airflow is the slowest which is along line A-A. Line A-A designates the largest width and cross-sectional area of the housing  102 , which is perpendicular to the airflow. By positioning the lamp  290  substantially along line A-A, the air will have the longest dwell time as it passes through the radiation  280  emitted by the lamp  290 . It is, however, within the scope of the present invention to locate the lamp  290  anywhere within the housing  102 , preferably upstream of the electrode assembly  220   
      It is desired to provide the inner surface of the housing  102  with an electrostatic shield to reduce detectable electromagnetic radiation. In one embodiment, a metal shield or metallic paint is preferably disposed within the housing  102 , or regions of the interior of the housing  102 . In one embodiment, the inner surface  111  has a non-smooth finish or a non-light reflecting finish or color. In general, when the UV rays emitted by the lamp  290  strikes the interior surface  111  of the housing  102 , the radiation  280  is shifted from its emitted UV spectrum to an appropriate viewable spectrum. Thus, the potentially undesired UV portion of the light and radiation  280  which strikes the interior surface  111  will be absorbed by the surface  111 , whereas the harmless UV portion of the radiation  280  will be disbursed as viewable light.  
      As discussed above in one example, the louvers  134  covering the inlet  104  and the outlet  106  also limit any angle of sight for the individual looking into the housing  102 . The depth D of each fin  134  is preferably sufficient to prevent an individual from directly viewing the interior wall  111  when looking into the inlet and/or outlet grill  104 ,  106 . Instead, the user will be to “see through” the device upon looking through the inlet and the outlet. It is to be understood that it is acceptable to see light or a glow coming from within housing  102  if the wavelength of the light renders it acceptable for viewing. Therefore, the configuration of the fins  134  as well as the lamp  290  allow an individual to look into the inlet  104  or the outlet  106  and be able to see light or glow which is not harmful to the individual.  
      Referring back to  FIG. 8 , specific areas of the lamp  290  are configured to include the shielding material  291  such that UV light is directed toward the inner surface  111  and away from the inlet  104  and the outlet  106 . The particular lamp  290  in  FIG. 8  is shown placed in the housing  102  in  FIG. 9 . The specific angles, arc lengths, and locations of the shielded regions  294  as well as the non-shielded regions  296  of the particular lamp  290  are discussed in relation to the Y 0  axis. The shielded and non-shielded regions of the lamp  290  shown for the embodiment in  FIGS. 8 and 9  are preferably symmetrical about the Y axis. The lamp  290  has a front shielded region  294 A which faces the outlet  106  when positioned in the housing as well as a rear shielded region  294 B which faces the inlet  104  of the housing, as shown in  FIGS. 8 and 9 . A portion of the front shielded region  294 A preferably has an arc-length of about 30 degrees clockwise from the Y 0  axis, shown as angle D, whereby Y 0  is the reference point of the angles discussed herein. As shown in  FIG. 8 , the remaining portion of the front shielded region  294 A has an arc length of 30 degrees counterclockwise from the Y 0  axis (i.e. 330 degrees clockwise with respect to Y 0 ). Thus, for the embodiment of the lamp  290  shown in  FIG. 8 , the front shielded region  294 A extends 60 degrees (shown as angle D′) from the left end  295 A to the right end  295 B, whereby the left end  295 A is approximately at 330 degrees from the Y 0  axis and the right end  295 B is approximately at 30 degrees from the Y 0  axis. It should be noted that the angles and arc-lengths discussed above are for one embodiment and are not to be construed to be limited thereto.  
      The rear shielded region  294 B is shown in  FIG. 8  extending between a right end  297 A and a left end  297 B which preferably faces the inlet of the housing. As shown in  FIG. 8 , the right end  297 A of the rear shielded region  294 B is located approximately at 80 degrees from the Y 0  axis (angle B is preferably 10 degrees). Additionally, the left end  297 B of the rear shielded region  294 B is approximately located at 280 degrees from the Y 0  axis. Thus, the rear shielded region  294 B of the embodiment shown in  FIG. 8  preferably has an arc-length of about 100 degrees (angle C) and an overall arc-length of approximately 200 degrees (angle C′). It should be noted that the angles and arc-lengths discussed above are for one embodiment and are not to be construed to be limited thereto.  
      The right non-shielded region  296 A of the lamp  290  is located adjacent to the front and rear shielded regions and preferably has an arc-length of about 50 degrees with respect to the center of the lamp  290 , which is shown as angle A. Thus, as shown in  FIG. 8 , the right non-shielded region  296 A extends between the right end  295 B of the front shielded region and the right end  297 A of the rear shielded region  294 B. Considering that the lamp  290  is symmetrical about the Y-axis, the lamp  290  also includes a left non-shielded region  296 B has an arc-length of about 50 degrees with respect to the center. The non-shielded region  296 A is located between the left end  295 A of the front shielded region  294 A and the left end  297 B of the rear shielded region  294 B in the embodiment shown in  FIG. 8 . As shown in  FIG. 8 , the right non-shielded region  296 A has boundaries approximately at 30 degrees clockwise from the Y axis (adjacent to front shielded region  294 A) and 80 degrees (adjacent to rear shielded region  294 B) clockwise from the Y axis. As stated above, the lamp  290  in  FIG. 8  is symmetrical about the Y axis. Therefore, the boundaries of the left non-shielded region  296 B is located at approximately 30 degrees counter clockwise from the Y axis (adjacent to the rear shielded region  294 B) and 80 degrees (adjacent to the front shielded region  294 A) counter clockwise with respect to the Y axis. As stated above, it should be noted that the angles, locations and numbers of shielded and non-shielded regions discussed in relation to  FIG. 8  are examples and are not meant to be limiting. It should also be noted that any other angles, locations and numbers of the shielded and non-shielded regions are contemplated.  
      The particular angles and locations of the shielded regions  294  as well as the non-shielded regions controls where as well as how much UV light and radiation  280  is disbursed by the lamp  290  within the housing  102 . In particular, the front shielded region  294 A is located to face the outlet grill  106 , whereby the angle of the front shielded region  294 A (i.e. angle D) radially covers the lamp  290  to prevent undesirable UV light from being dispersed directly at the outlet grill  106 . In addition, the rear shielded region  294 B is located to face the inlet grill  104 , whereby the angle of the rear shielded region  294 B (i.e. angle C) radially covers the lamp  290  to prevent undesirable UV light to be dispersed directly at the inlet grill  104 . The non-shielded regions  296 A and  296 B are oriented to face the inner walls  111  of the housing and away from the inlet and outlet grill  104 ,  106  such that an individual looking into the system  100  through the inlet  104  or outlet  106  would not be able to view UV light directly emitted by the lamp  290 . The angles of the non-shielded regions  296  (i.e. angle A) are such that sufficient UV light is able to be emitted out of the lamp  290  to adequately neutralize microorganisms in the airflow.  
      In the embodiment shown in  FIG. 10 , the lamp  390  is located along the side of the housing  102 . As the air enters the housing  102 , the air is immediately exposed to the light  280  emitted by the lamp  390 . In  FIG. 10 , the lamp  390  is configured and oriented such that the shielded regions  394 A,  394 B block UV light  280  from being directed toward the inlet  104  and outlet  106 . The shape and depth D of the louvers  134  prevent an individual from seeing the lamp at an angle into the housing  102 . Thus, the top shielded region  394 A covers the portion of the lamp  390  which is viewable by an individual looking into the housing through the space between the louvers  134  in the outlet  106 . Similarly, the rear shielded region  394 B shields light emitted from the lamp  390  from being emitted or viewed through the space between the louvers  134  in the inlet  104 .  
      Additionally, the non-shielded regions  396  of the lamp  390  are located to face the interior walls  111  of the housing  102 . In particular, the non-shielded region  396 A (about 50 degrees arc length) is oriented and has an appropriate radial width to direct light toward the inner wall  111  on the left side of the housing  102  without allowing undesired UV light from the lamp  290  to be viewed by an individual looking into the housing  102 . Similarly, the non-shielded region  396 B (about 160 degree in arc-length) is oriented and has an appropriate radial width to direct light toward the inner wall  111  on the right side of the housing  102 . As shown in  FIG. 10 , a substantial portion  396 B of the lamp  390  is out of the direct line of sight through the inlet  104  and the outlet  106 , and the portion  396 B is located near the right side of the housing  101 . The portion  396 B is thus not shielded, since almost all the light and radiation  280  emitted through the non-shielded portion  396 B is immediately directed onto the inner wall  111  on the right side of the housing  102 . In one embodiment, one non-shielded region  296  of the lamp  290  faces several light guides which further prevent the light  280  from shining directly towards the inlet  104  and the outlet  106  and also guide the light toward the opposing wall  111 . More details of the light guides are described in the U.S. application Ser. No. 10/074,347 which is incorporated by reference above. It should be noted that the angles, locations and numbers of shielded and non-shielded regions discussed in relation to  FIG. 10  are examples and are not meant to be limiting. It should also be noted that any other angles, locations and numbers of the shielded and non-shielded regions are contemplated.  
      As shown in  FIG. 11 , the inlet grill  104  includes multiple vertical slots  136  located along each side of a rear wall  138 , whereby the slots  136  face in a direction perpendicular to the louvers  134  of the exhaust grill  106  and the general direction of the airflow through the system  100 . Thus, air outside of the housing  102  travels in toward the inlet grill  104  and then enters the housing  102  in a perpendicular direction. The rear wall  138  is preferably a solid, opaque structure which does not allow light to pass through it. In one embodiment, the rear wall  138  of the inlet grill  104  is coated with the same material as the rest of the interior  111  of the housing to absorb and/or disburse the UV light emitted by the lamp  490 . The lamp  490  in the embodiment in  FIG. 11  has only one shielded region  494  which covers a substantial portion of the radial surface of the lamp  490  which faces the exhaust grill  106 . In one embodiment, the shielded region  494  has an arc-length of about 70 degrees with respect to the center as with the lamp  290  discussed in  FIG. 8 . Since the rear wall  138  does not allow light to pass through and has the inlets  136  facing perpendicular to the outlet  106  and toward the inner walls  111  of the housing, an individual cannot see the non-shielded region of the lamp  490  by looking into the housing  102  through the inlet slots  136 . Thus, the side of the lamp  490  which faces toward the inlet  106  is not shielded. The UV light is emitted through the non-shielded region to shine toward the inner surface  111  of the housing  102  as well as the rear wall  138  of the inlet  104 . Nonetheless, an individual is not exposed to undesired UV rays, because the non-shielded region  494  is not viewable from the outlet  106 . It should be noted that the angles, locations and numbers of shielded and non-shielded regions discussed in relation to  FIG. 11  are examples and are not meant to be limiting. It should also be noted that any other angles, locations and numbers of the shielded and non-shielded regions are contemplated.  
      It is also contemplated that the integrally shielded lamp  290  is able to be used in other air movement devices not specifically mentioned herein. For example, the integrally shielded lamp  290  is able to be utilized in an electrostatic precipitator system described in the U.S. patent application Ser. No. 10/774,759 which is incorporated by reference above. In addition, the values provided above for the angles and arc-lengths of the shielded and non-shielded regions are examples and should not be limited thereto. Thus, other angles and arc-lengths of the shielded and non-shielded regions are contemplated.  
      As stated above, the integrally shielded lamp  290  has shielded and non-shielded regions which are to be properly oriented within the housing  102  to prevent undesired UV rays from being directed at the inlet  104  and outlet  106 .  FIGS. 12A and 12B  illustrate plan views of the lamp  290  and receptacle  300  in accordance with one embodiment. As stated above, the integrally shielded lamp  290  couples to a lamp holding receptacle  300 , whereby the lamp  290  is selectively removable from the receptacle  300 . Preferably, the system  100  includes two receptacles  300 , each receptacle to engage an end of the lamp  290 . It is preferred that the lamp  290  and/or receptacle  300  be designed such that the lamp  290  can be engaged to the receptacle  300  in only one manner. This ensures that the lamp  290  is oriented properly within the housing  102 .  
      As shown in  FIG. 12A , the receptacle housing  300  includes an outer receptacle  310  and an inner receptacle  306  positioned within the outer receptacle  310 . The outer receptacle  310  is stationary and mounted to the interior of the housing  102 , whereas the inner receptacle  306  is preferably rotatable about its center in the outer receptacle  310 . In one embodiment, the inner receptacle  306  is rotated clockwise to a locked position ( FIG. 12B ). In contrast, the inner receptacle  306  is rotated counterclockwise to be in an unlocked position ( FIG. 12A ). The lamp  290  is insertable and removable from the receptacle housing  300  through the opening  308  in the outer receptacle  310 .  
      The lamp  290  in  FIG. 12A  includes the two pins  292  as well as an additional third pin  298  which extends from the end of the lamp  290 . Although the terminal pins  292  are aligned along the center at the end of the lamp  290 , the third pin  298  is preferably slightly off-center and adjacent to the terminal pins  292 . The inner receptacle  306  includes a first recess  302 , which receives the two pins  292  as well as a second recess  304  which is slightly off-center to simultaneously receive the off-center third pin  298  of the lamp  290 . The offset second recess  304  forces the lamp  290  to be properly inserted in the housing, thereby ensuring that the user properly orients the lamp  290  when engaging the lamp  290  to the receptacle housing  300 . Upon properly inserting the pins  292 ,  298  into their respective recesses  302 ,  304 , the lamp  290  is able to be rotated clockwise approximately 90 degrees to lock the lamp  290  as shown in  FIG. 12B . As shown in  FIG. 12B , the integrally shielded lamp  290  is oriented in the manner as in  FIG. 9  when in the locked position. It is preferred that the pins  292  come into electrical connect with the voltage source when in the secured position shown in  FIG. 12B . Removal of the lamp  290  is performed in the opposite manner as that described above. It is preferred that only one of the opposed receptacles  300  includes the second recess  304  to ensure that the lamp  290  is not inserted upside down. However, it is noted that both receptacles  300  can have the design described in  FIGS. 12A and 12B .  
      It should be noted that the above is only one example of how the lamp  290  and receptacle housing  300  are configured and is not to be limited thereto. For example,  FIG. 12C  illustrates another embodiment of the receptacle housing  300 ′, whereby the housing  300 ′ includes the outer receptacle  312  and the rotatable inner receptacle  314 . The receptacle housing  300 ′ is configured to receive the lamp  290 ′ shown in  FIG. 12D . The lamp  290 ′ in  FIG. 12D  includes a recess  293  in line with the pins  292  on only one side of the lamp  290 ′. In the embodiment shown in  FIG. 12C , the inner receptacle  314  includes one recess  316  which receives the two pins  292  of the lamp  290 ′. Within the recess  316  is also a protrusion  318  which serves to mate with the recess  293  ( FIG. 12D ) of the lamp  290  when the detent  293  end of the lamp  290  is inserted first into the receptacle  300 ′. For instance, if the non-detent side of the end of the lamp  290  is inserted into the receptacle first, the lamp  290 ′ will not be able to be completely inserted into the receptacle  300 . It is within the scope of the present invention that the present invention utilizes any alternative design to ensure that the lamp  290  operates in the system  100  in the proper orientation such that UV light directly emitted from the lamp  290  does not exit nor is viewed through the inlet and/or outlet grills  104 ,  106 .  
       FIG. 13  illustrates a perspective view of the front grill with trailing electrodes thereon in accordance with one embodiment of the present invention. As shown in  FIG. 13 , the trailing electrodes  222  are coupled to an inner surface of the exhaust grill  106 . This arrangement allows the user to clean the trailing electrodes  222  from the housing  102  by simply removing the exhaust grill  106 . Additionally, placement of the trailing electrodes  222  along the inner surface of the exhaust grill  106  allows the trailing electrodes  222  to emit ions directly out of the system  100  with the least amount of airflow resistance. More details regarding cleaning of the trailing electrodes  222  are described in U.S. Patent Application No. 60/590,735 which is incorporated by reference above.  
      The operation of replacing the germicidal lamp  290  and cleaning the electrodes of the present system  100  will now be discussed. In one embodiment, the inlet grill  104  is first removed from the housing  102 . This is done by lifting the inlet grill  104  vertically and then pulling the grill  104  horizontally away from the housing  102 , as discussed above in relation to  FIG. 7 . Additionally, the exhaust grill  106  is removable from the housing  102  in the same manner. In one embodiment, once the inlet grill  104  is removed from the housing  102 , the germicidal lamp  290  is exposed. The user is able to remove the germicidal lamp  290  by preferably twisting the lamp in predetermined direction to unlock the lamp  290  from the lamp receptacle  300 . Once unlocked, the, user preferably pulls the lamp  290  laterally outward from within the housing  102 . The user is then able to couple a replacement lamp  290  to the housing  102  by inserting the lamp  290  into the receptacle  300  in the correct manner discussed above. Upon locking the lamp  290  within the housing  102 , the inlet grill  104  is preferably coupled to the housing  102  in a manner opposite of the grill  104  removal process.  
      In one embodiment, the user is also able to clean the trailing electrodes  222  on the interior of the grill  106  ( FIG. 13 ). In one embodiment, the user is able to clean the collector and driver electrodes  242 ,  246  while the electrodes  242 ,  246  are positioned within the housing  102 . In another embodiment, the user is able to pull the collector electrodes  242  telescopically out through an aperture  126  in the top end  124  of the housing  106  as shown in  FIG. 6 . In one embodiment, the driver electrodes  246  are removed from the housing  102  along with the collector electrodes  242 . In another embodiment, the driver electrodes are laterally removable from the housing, either along with removal of the exhaust grill  106  or independently of the removal of the exhaust grill  106 . Upon removing the collector and driver electrodes  242 ,  246 , the user is preferably able to clean the electrodes  242 ,  246  by wiping them with a cloth. Once the collector and driver electrodes  242 ,  246  are cleaned, the user then inserts the collector and driver electrodes  242 ,  246  back into the housing  102  in a manner opposite of the removal of the electrodes  242 ,  246 . More detail regarding the insertion and removal of the driver electrodes and collector electrodes are discussed in the 60/590,688 and 60/590,960 application, which are incorporated by reference above.  
      The foregoing description of the above embodiments of the present invention has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many modifications and variations will be apparent to one of ordinary skill in the relevant arts. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, thereby enabling others skilled in the art to understand the invention for various embodiments and with various modifications that are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims and their equivalence.