Abstract:
There is provided an improved ultraviolet lamp assembly using an ultraviolet lamp with a vented closed end quartz tube having improved and increased ultraviolet lamp intensity output for increased germicidal and bactericidal effect for use in purification, sterilizing, sanitizing and cleaning systems. The ultraviolet lamp assembly comprises an ultraviolet lamp, a tube operative to house the ultraviolet lamp and comprising a closed end, an open end able to allow insertion of said ultraviolet lamp and having a plurality of vents that allow air into and out of an air space between the ultraviolet lamp and the surrounding tube, a tube divider operatively disposed between said UV lamp and said tube to thereby divide said air space into at least two air space compartments enabling air to circulate through said tube, and an air displacer operatively connected to at least one of said vents and able to produce air flow in said tube.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention generally relates to an ultraviolet lamp assembly for killing germs or bacteria in air ventilation systems. Specifically, the present invention relates to an ultraviolet lamp including a quartz sleeve having a vented open end which results in increased or improved germicidal and bactericidal effect in systems and apparatus using ultraviolet lamps for purification or cleaning of air.  
         BACKGROUND OF THE INVENTION  
         [0002]    The use of ultraviolet (“UV”) light or radiation for its purification, germicidal and bactericidal effect is well known. UV light is commonly used to control the growth of and kill impurities in septic, water and air systems. For example, UV light or UV lamps are commonly used in heating, ventilation, and air conditioning (“AC” or “HVAC”) systems for purification or air cleaning purposes. UV lamps are typically installed or mounted in the air ducts of AC systems in such a manner that the UV light emitted by the lamp floods the interior of the air duct. Air flowing through that duct will be irradiated with UV radiation which will have a germicidal or bactericidal affect on the moving air thereby reducing the impurities in the air flow.  
           [0003]    Existing air cleaning systems or devices commonly employ UV lamps similar to those shown in FIG. 1A. FIG. 1A shows a standard lamp  5  and a sealed lamp  10  with a quartz sleeve  15  built right onto the UV lamp  10 . FIG. 1A also shows a typical external quartz sleeve  20  that is often used to house standard UV lamps  5 . The quartz sleeve  20  can be used, for example, to physically separate the standard UV lamp  5  from a contaminated medium, i.e. the liquid or air to be cleaned, that is being irradiated with UV radiation.  
           [0004]    Existing air cleaning devices typically employ the standard or sealed UV lamps  5  and  10  alone or in combination with a closed end outer quartz sleeve  20 . A drawback of the UV lamps  5  and  10  used in existing cleaning devices or assemblies is that the UV lamps  5  and  10  typically have diminished UV radiation output intensity over time that results in reduced germicidal and bactericidal affect of the UV lamp cleaning device. For example, FIG. 1B illustrates a typical plot of a standard UV lamp output intensity  50  over time for a typical UV lamp  5  in still air. FIG. 1B indicates that the UV lamp output  50  typically reaches its maximum rated output intensity  53 , at about 56.1 mWatts/cm 2 , after the first few minutes of operation after an initial heat up period of the UV lamp  5 . The UV lamp output  50  then typically decreases over time to a generally steady lamp intensity output  56  of about 44.6 mWatts/cm 2  as the lamp continues to operate. The steady state output  56  is about 20% less that the maximum output  53  obtained during the first few minutes of UV lamp  5  operation. The drop in UV lamp output intensity  50  is typically due to the inconsistent and variable temperature around the UV lamp  5  that does not allow proper and uniform UV lamp  5  cooling. The diminished UV lamp output  50  shown in FIG. 1B is even more pronounced when air or water is circulated around the lamp which causes a higher rate of cooling as is well know to those of skill in the art.  
           [0005]    Moreover, inconsistent and variable temperatures present around the standard UV lamp  5  result in a cooling affect that does not allow proper and uniform UV lamp  5  cooling. In the long term, this cooling effect can adversely affect the UV lamp&#39;s  5  germicidal or bactericidal effect by causing the inside of the lamp to blacken or darken which in turn causes or results in a reduced UV lamp output intensity level  50 . FIG. 1C graphically illustrates the loss of UV lamp output intensity  50  throughout the effective life of the UV lamp  5  as a result of the cooling effect. FIG. 1C indicates that throughout the effective life of the UV lamp  5 , the percent of 100 hour rated output of the UV lamp  5  experiences a fairly steep decrease from about 100% when first operated to about 80% at about 1300-1325 hours of UV lamp  5  operation, and to about 65% at about 9000 hours of UV lamp  5  operation. The UV lamp output intensity  50  loss experienced throughout the life of the UV lamp  5  is another drawback of existing standard UV lamps  5 .  
           [0006]    In another typical UV lamp configuration, the UV lamp  10  is mounted inside a quartz tube as an attempt to counter act know lamp-cooling issues or problems. However, this configuration, when operated in still air, results in a larger drop in UV lamp intensity output  60  that that shown in FIG. 1B. FIG. 1D illustrates a typical plot of UV lamp output intensity  60  over time for a typical UV lamp with a quartz outer tube  10  in still air. FIG. 1D shows that the UV lamp output  60  typically reaches its maximum rated output intensity  63 , at about 52.7 mWatts/cm 2 , after a few minutes of operation after the initial heat-up or warm-up period of the UV lamp with a quartz outer tube  10 . Again, the UV lamp output  60  will typically decrease to a generally steady lamp intensity output  66  of about 34.5 mWatts/cm 2  as the lamp continues to operate. In this configuration, the steady state output  66  is about 35% less that the maximum output  63  obtained during the first few minutes of UV lamp  10  operation. Thus, the quartz outer tube results in a greater loss of UV lamp output intensity  60 .  
           [0007]    There is thus a need for an improved ultraviolet UV lamp assembly having increased and/or improved UV radiation intensity output for improved germicidal and bactericidal effect in purification, sterilization, cleaning of airflow systems.  
         SUMMARY OF THE INVENTION  
         [0008]    The present invention provides an improved ultraviolet lamp assembly using an ultraviolet (UV) lamp with a vented closed end quartz sleeve or tube having improved and increased UV lamp intensity output for increased germicidal and bactericidal effect. The UV lamp assembly of the present invention can be used in systems and applications with the goal to purify, sterilize, clean and sanitize a medium, object or apparatus.  
           [0009]    The ultraviolet lamp assembly comprises a UV lamp housed in a vented closed end quartz sleeve or tube. The quartz sleeve further comprises a closed end and an open end through which the UV lamp is inserted into and secured to the tube. The open end of the quartz sleeve comprises a plurality of inlet and outlet venting slots or ports that allow the air between the UV lamp and the sleeve wall to enter and exit the quartz sleeve or tube. The UV lamp assembly also comprises a sleeve divider operatively disposed between the UV lamp and the sleeve wall that divides the interior of the sleeve into two interior compartments that allow air to circulate through the quartz sleeve. The ultraviolet lamp assembly further comprises an air displacer or fan operatively connected to at least one of the venting slots for production of air flow into and out of the quartz tube.  
           [0010]    It is an object of the present invention to provide an ultraviolet lamp assembly that can be used in an AC or HVAC systems, and air ducts for purification and cleaning of air flowing in the AC or HVAC system and air ducts.  
           [0011]    It is an object of the present invention to provide a UV lamp assembly with a vented closed end quartz sleeve to provide improved and constant UV radiation intensity output.  
           [0012]    It is an object of the present invention to provide a divider in the vented closed end quartz sleeve resulting at least two compartments in the sleeve that allow air to circulate through the sleeve resulting in normalized or constant UV lamp temperature.  
           [0013]    It is an object of the present invention to increase UV lamp life by producing more consistent and stable UV lamp temperature.  
           [0014]    It is an object of the present invention to provide a UV lamp assembly with a vented closed end quartz sleeve and a sleeve fan that provides air flow in the sleeve in the range of about 0.5 cfm to 10 cfm when an associated sleeve fan is operating.  
           [0015]    It is an object of the present invention to provide a UV lamp assembly with a vented closed end quartz sleeve where the UV radiation intensity output is substantially uniform and constant about 100-110 mWatts/cm 2  when an associated sleeve fan is operating.  
           [0016]    It is an object of the present invention to provide a UV lamp assembly having an effective germicidal and bactericidal affect in a wavelength bandwidth of about 240 nm to 360 nm.  
           [0017]    It is an object of the present invention to provide an ultraviolet lamp assembly that can be used to purify air in an airflow system such as an air conditioning system in a home, hotel or building.  
           [0018]    It is an object of the present invention to provide an ultraviolet lamp assembly that can be used to purify liquids, such as water, in a liquid purification system, such as a water treatment plant.  
           [0019]    It is an object of the present invention to provide an ultraviolet lamp assembly that can be used to purify or sterilized objects or apparatus such as medical instruments and equipment.  
           [0020]    The following drawings and description set forth additional advantages and benefits of the invention. More advantages and benefits will be obvious from the description and may be learned by practice of the invention. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0021]    The present invention may be better understood when read in connection with the accompanying drawings, of which:  
         [0022]    [0022]FIG. 1A illustrates existing ultraviolet lamps and lamp housings used in existing ultraviolet lamp assemblies;  
         [0023]    [0023]FIG. 1B illustrates a typical plot of UV lamp output intensity over time for a typical UV lamp in still air;  
         [0024]    [0024]FIG. 1C illustrates typical loss of UV lamp output intensity throughout the effective life of a typical UV lamp due to cooling effect;  
         [0025]    [0025]FIG. 1D illustrates a typical plot of UV lamp output intensity over time for a typical UV lamp with a quartz outer tube in still air;  
         [0026]    [0026]FIG. 2A illustrates an embodiment of a novel ultraviolet lamp assembly in accordance with the present invention;  
         [0027]    [0027]FIG. 2B illustrates a cross-section of the ultraviolet lamp assembly of FIG. 2A showing in more detail an embodiment of a tube divider in accordance with the present invention;  
         [0028]    [0028]FIG. 2C illustrates in more detail a section of the ultraviolet lamp assembly of FIG. 2A showing an embodiment of vent ports in accordance with the present invention;  
         [0029]    [0029]FIG. 2D illustrates a plot of UV lamp output intensity over time for the UV lamp of FIG. 2A in still air;  
         [0030]    [0030]FIG. 3 illustrates ultraviolet output intensity and lamp temperature over a test period for the lamp assembly of FIG. 2 where a lamp fan is ON; and  
         [0031]    [0031]FIG. 4 illustrates ultraviolet output intensity and lamp temperature over a similar test period for the lamp assembly of FIG. 2 where a lamp fan is OFF. 
     
    
     DETAILED DESCRIPTION  
       [0032]    [0032]FIG. 2A shows an embodiment of the novel ultraviolet lamp assembly  200  according to the present invention that can be used in a cleaning, purification or sanitizing system. The UV lamp assembly  200  preferably comprises a UV lamp  205 , a closed end quartz sleeve  220 , a tube divider  210 , an air displacer or fan  240  and a plurality of air vents or ports  237  and  245 . The ultraviolet (UV) lamp ( 205 ) preferably has a bandwidth of about 240 nm to 360 nm for germicidal and bactericidal effect. Other bandwidths or a particular wavelength may be used for specific purification applications. The UV lamp  205  may be an ozone free UV lamp operatively housed in the elongated sleeve or tube  220 . However, other types of lamps may be used and the assembly may have one or more UV lamps  205 .  
         [0033]    The sleeve or tube  220  is preferably comprised of a quartz material, however other suitable UV transparent materials may used to make up the sleeve  220 . The sleeve  220  is preferably an elongated hollow tube with a proximal open end  223  having a plurality of venting orifices, air vents, slots or ports  237  and  245 , and a distal closed end  225 . The open end  223  preferably comprises a plurality of inlet and outlet vents or ports  237  and  245  that enable or allow air to enter and exit the quartz sleeve  220 . The sleeve  220  preferably houses the UV lamp  205  but could have other physical configurations to compliment and house a UV lamp  205  having other shapes and sizes.  
         [0034]    The UV lamp  205  is preferably positioned and secured on the sleeve  220  at the proximal open end  223  of the sleeve  220 . When the UV lamp  205  is operatively positioned in the sleeve  220  there is formed or results an air space  207  between the UV lamp&#39;s  205  outer or exterior surface and the interior surface or wall of the sleeve  220 . Further, there is preferably a tube or sleeve divider  210  operatively positioned or disposed in the sleeve  220  interior or air space  207  between the UV lamp  205  and sleeve  220 . The tube divider  210  preferably separates the air space  207  into two air space compartments  207 A and  207 B. Those of skill in the art will readily recognize that additional dividers  210  could be used resulting in a different number of air space compartments  207 . The tube divider  210  and the resulting two air space compartments  207 A and  207 B in conjunction with the venting ports  237  and  245  comprise or form an airflow path for the circulation of air or air flow through the interior of the quartz sleeve  220 . This will allow or enable air, or other medium, e.g., a gas or liquid, to preferably be displaced and to circulate down  213 A on one side of the tube  220  and back up  213 B the other side of the tube  220 . Alternatively, the airflow could be reversed if desired for or dictated by a certain application or system that uses the UV lamp assembly  200 .  
         [0035]    The preferred embodiment shown in FIG. 2A comprises an air displacer or fan  240  that is used as the driver to force or move air into and/or out of the interior or air space  207  between the UV lamp  205  and sleeve  220 . The air displacer or fan  240  is preferably cooperatively and operatively connected to at least one of the sleeve vents or ports  237  and  245  to provide for air flow in the UV lamp  205  and sleeve  220  combination. In this embodiment, the air displacer or fan  240  is positioned in a port designated as an intake port  237  such that in operation, the fan  240  will force air, or another selected medium, into the space  207  between the UV lamp  205  and the sleeve  220 . The second port  245  is open such that it provides an exit way for the air being forced in by the fan  240 . In this manner air will traverse or circulate into and out of the space  207  between the UV lamp  205  and the sleeve  220 . Those of skill in the art will readily recognize that the fan could be placed in the other vent port  245  instead, or that two cooperative fans  240  could be used to move or circulate air, gas or another medium into and out of the space  207  between the UV lamp  205  and the sleeve  220 .  
         [0036]    Thus, as shown in FIG. 2A, the fan  240  will preferably provide air flow into the space  207  between the UV lamp  205  and the sleeve  220  and the air will exit at the second vent port  245 , which in this embodiment does not have a fan  240 . In a preferred embodiment, the fan or air mover  240  can provide a flow rate in the range of 0.5 to 10 cubic feet per min (cfm) to preferably maintain a consistent temperature outside or around the UV lamp of between 85° F. to 95° F. This will allow the UV lamp intensity output to be maintained near its maximum output. Those of skill in the art will readily recognize that the flow rate and temperature will vary for different length UV lamps  205  and lamps with varying power ratings depending on a particular application or usage of the UV lamp assembly  200 .  
         [0037]    As briefly discussed previously, when the fan  240  is in operation, air is introduced into the space  207  between the UV lamp  205  and the sleeve  220  via the vent intake  237  into the first  207 A of two compartments created by the sleeve divider  210 . The air then travels from the first  207 A compartment to the second  207 B compartment. From the second compartment  207 B, the air will then be forced out of the quartz sleeve  220  through the vent outlet  245 . The forced airflow  213 A and  213 B provided by the fan  240  allows air to circulate through the quartz sleeve which will result in substantially normalized or constant UV lamp temperature which in turn results in a constant UV intensity output that is closer to the maximum UV output for the UV lamp  205 . The improved UV intensity output will allow the UV lamp assembly  200  to provide better and increased germicidal and bactericidal effect. This will enable a system that uses the UV lamp assembly to better purify, sterilize, clean, or sanitize a medium, such as air or liquid, or an object, such as a medical instrument or apparatus. In the case of an air conditioning system (AC), for example as might be used in a home, hotel or commercial or industrial application, use of the UV assembly  200  will result in cleaner air moving or flowing in the air ducts of the AC system.  
         [0038]    [0038]FIG. 2B shows a cross-section of the ultraviolet lamp assembly of FIG. 2A showing in more detail an embodiment of a tube divider in accordance with the present invention. As shown in FIG. 2B, the tube or sleeve divider  210  is preferably comprised of a first  210 A and a second  210 B tube divider which are operatively positioned or disposed in the interior space  207  between the UV lamp  205  and sleeve  220 . The tube dividers  210 A and  210 B preferably separate the air space  207  into a first and second interior space compartment  207 A and  207 B. Those of skill in the art will readily recognize that additional dividers  210 ,  210 A and  210 B could be used resulting in a different number of interior space compartments  207 ,  207 A and  207 B. The number of tube dividers  210  can vary depending on the specific application or use of the UV lamp assembly  200 . The tube divider  210  and the resulting two air space compartments  207 A and  207 B provide an airflow path for the circulation of air or air flow through the interior of the sleeve  220 .  
         [0039]    [0039]FIG. 2C shows the open end section  223  of the ultraviolet lamp assembly of FIG. 2A and shows the vent ports  237  and  235  and the fan  240  used force or move air into the interior space  207  between the UV lamp  205  and sleeve  220 . In this embodiment, the air displacer or fan  240  is positioned in the intake or inflow port designated as an intake port  237  such that in operation, the fan  240  will force air, or another selected medium, into the space  207  between the UV lamp  205  and the sleeve  220 . The second port  245  is open or unobstructed, and is shown without a fan  240 , such that it provides an exit path for the air being force in by the fan  240  at the intake port  237 . In this manner air will traverse or circulate into and out of the space  207  between the UV lamp  205  and the sleeve  220 . Those of skill in the art will readily recognize that the fan  240  could be placed in the other vent port  245  instead to move air into or out of the space  207  between the UV lamp  205  and the sleeve  220 , or that two cooperative fans  240  could be used to move or circulate air, gas or another medium into and out of the space  207  between the UV lamp  205  and the sleeve  220 .  
         [0040]    [0040]FIG. 2D shows the resultant plot of UV lamp output intensity over time for the UV lamp assembly  200  of FIG. 2A that uses the UV lamp  205  with the tube divider  210  in still air. FIG. 2D shows that the UV lamp output  250  typically reaches its maximum rated output intensity  253 , at about 57.7 mWatts/cm2, after the first few minutes of operation after an initial heat up period of the UV lamp  205 . FIG. 2D shows the improvement in UV lamp intensity output  250  of the UV lamp assembly  200  compared to prior art UV lamps  5  and  10  that do not have a divider  210  or air mover  240  (see FIGS. 1B and 1D). Unlike prior art UV lamps  5  and  10 , the UV lamp output  250  of the present invention does not experience a significant decrease in UV lamp output  250  over time as the UV lamp  205  continues to operate. The UV lamp assembly  200  with the divider  210  and air mover  240  substantially maintains the UV intensity output  250  of the UV lamp  205  at or above the rated output of the UV lamp  205 . In another embodiment, the UV lamp assembly  200  maintains the UV intensity output  250  of the UV lamp  205  within 3% of the rated output of the UV lamp  205  as shown in FIG. 2D. The steady state output  256  is about 56.2 mWatts/cm2, only about a 3% drop from the maximum UV lamp intensity output  253  obtained during the first few minutes of UV lamp  205  operation.  
         [0041]    Comparing the UV lamp intensity output of FIG. 2D to those of FIGS. 1B and 1D, the UV lamp assembly  200  apparatus and method of the present invention increases the maximum UV lamp output  253  by 2.8% verses the standard UV lamp  5 , and by 9.4% verses the sealed quartz lamp  10 . The biggest change experienced with the novel UV lamp assembly  200  is clearly seen in the steady state operation of the UV lamp  205 . The UV lamp assembly  200  apparatus and method increased the UV lamp output  250  and  256  by 26% verses the standard lamp  5  and by 62.8% verses the sealed quartz lamp  10 . Further, the novel UV lamp assembly  200  apparatus and method of the present invention results in consistent and more stable UV lamp  205  temperature which improves or increases the life of the UV lamp  205 .  
         [0042]    [0042]FIGS. 3 and 4 illustrate ultraviolet output intensity and UV lamp temperatures over a test period for an embodiment of the UV lamp assembly  200  used in an air conditioning (AC) system where the lamp venting fan  240  is ON (FIG. 3) and where the lamp fan  240  is OFF (FIG. 4). FIGS. 3 and 4 depict various operating conditions I, II, III, IV and V of both the AC system and the UV lamp assembly  200 .  
         [0043]    In a first operating condition I, the UV lamp  205  with the closed end vented quartz sleeve or tube  220  is ON and an air system blower or system fan is OFF. The first operating condition could be referred to as or called a “still air condition”. In this operating condition I and with the UV lamp venting fan ON, as shown in FIG. 3, the UV lamp intensity output  310  is steady at about 110 mW/cm 2  about 10.5 minutes after the UV lamp  205  is turned ON. During the same time period, the temperature outside the UV lamp  320 , i.e., external to the vented quartz sleeve or tube  220 , is substantially constant at about 78° F., while the temperature inside the UV lamp  330 , i.e., the air space between the UV lamp  205  and the tube or sleeve  220  interior, increases from about 78° F. to 150° F.  
         [0044]    In contrast, when the UV lamp fan  240  is OFF in the first operating condition I, as shown in FIG. 4, the UV lamp intensity output  410  initially increases to about 110 mW/cm 2  at 3 minutes after the UV lamp  205  is turned ON and then drops to about 50 mW/cm 2  at 15 minutes before stabilizing at about 60 mW/cm 2 . During the same time period, the temperature outside the UV lamp  420  increases to a constant 85° F., while the temperature inside the UV lamp  430  increases from about 75° to 145° F. The first operating condition I, shown in FIGS. 3 and 4, illustrates that the air flow provided by the UV lamp fan  240  increases the UV intensity output  310  of the UV lamp to about a constant 110 mW/cm 2  resulting in improved germicidal and bactericidal effect.  
         [0045]    In a second operating condition II, the UV lamp  205  with the closed end vented quartz sleeve or tube  220  is ON and an air system blower or system fan is also ON. In this operating condition II and with the UV lamp venting fan  240  ON, as shown in FIG. 3, the UV lamp intensity output  310  is maintained steady at about 110 mW/cm 2 . During the same time period, the temperature inside the UV lamp  330  decreases from about 150° F. to a steady 95° F., while the temperature outside the UV lamp  320  stays substantially constant at about 80° F. The decrease in the temperature inside the UV lamp  330  is mainly due to the air flow introduced in the air system by the system blower or fan. The novel UV lamp assembly  200  maintains the UV lamp intensity output  310  steady at about 110 mW/cm 2  thereby maintaining its increased germicidal and bactericidal effect at substantially normalized or constant internal UV lamp temperature  330 .  
         [0046]    In contrast, when the UV lamp fan  240  is OFF in the second operating condition II, as shown in FIG. 4, the UV lamp intensity output  410  steadily ramp up from about 70 mW/cm 2  to about 90 mW/cm 2 . During the same time period, the temperature inside the UV lamp  430  decreases from about 145° F. to about 95° F., while the temperature outside the UV lamp  420  decreases to about 85° F. The second operating condition II, shown in FIGS. 3 and 4, again illustrates that the UV lamp assembly  200  of the present invention with air flow provided by the UV lamp fan  240  has improved UV intensity output  310  of about 110 mW/cm 2  at a normalized temperature of about 95° F. resulting in improved germicidal and bactericidal effect.  
         [0047]    In a third operating condition III, the UV lamp  205  with the closed end vented quartz sleeve or tube  220  is ON, the air system blower or system fan is also ON and the AC unit is ON. In this operating condition III and with the UV lamp venting fan  2400 N, as shown in FIG. 3, the UV lamp intensity output  310  is substantially steady at about 110 mW/cm 2 . During the same time period, the temperature inside the UV lamp  330  decreases from about 95° F. to a steady 75° F., while the temperature outside the UV lamp  320  decreases to about 55° F. The decrease in the temperature inside the UV lamp  330  can be attributed to the AC unit being turned ON which introduces cool air that is forced through the air duct system by the system blower or fan. The novel UV lamp assembly  200  maintains the UV lamp intensity output  310  steady at about 110 mW/cm 2  providing increased germicidal and bactericidal effect at substantially constant internal UV lamp temperature  330 .  
         [0048]    In contrast, when the UV lamp fan  240  is OFF in the third operating condition III, as shown in FIG. 4, the UV lamp intensity output  410  continues to increase from about 90 mW/cm 2  to about 100 mW/cm 2 . During the same time period, the temperature inside the UV lamp  430  decreases from about 95° F. to about 75° F., while the temperature outside the UV lamp  420  decreases to about 55° F. The third operating condition III, shown in FIGS. 3 and 4, again illustrates that the UV lamp assembly  200  of the present invention with air flow provided by the UV lamp fan  240  has improved UV intensity output  310  of about 110 mW/cm 2  at a normalized temperature of about 75° F. resulting in improved germicidal and bactericidal effect.  
         [0049]    In a fourth operating condition IV, the UV lamp  205  with the closed end vented quartz sleeve or tube  220  is ON, the air system blower or system fan is also ON and the AC unit is now OFF. In this operating condition IV and with the UV lamp venting fan  240  ON, as shown in FIG. 3, the UV lamp intensity output  310  decreases slightly when the AC unit is turned OFF but then returns to a substantially steady intensity output of about 110 mW/cm 2 . During the same time period, the temperature inside the UV lamp  330  increases from about 75° F. back to about 95° F., while the temperature outside the UV lamp  320  increases to about 75° F. The increase in the temperature inside the UV lamp  330  can be attributed to the AC unit being turned OFF which takes away the cool air being forced through the air duct system by the system blower or fan. The novel UV lamp assembly  200  maintains the UV lamp intensity output  310  steady at about 110 mW/cm 2  providing increased germicidal and bactericidal effect.  
         [0050]    In contrast, when the UV lamp fan  240  is OFF in the fourth operating condition IV, as shown in FIG. 4, the UV lamp intensity output  410  decreases continually from about 100 mW/cm 2  to about 90 mW/cm 2 . During the same time period, the temperature inside the UV lamp  430  increases from about 75° F. to about 95° F., while the temperature outside the UV lamp  420  increases to about 75° F. The fourth operating condition IV, shown in FIGS. 3 and 4, again illustrates that the UV lamp assembly  200  of the present invention with air flow provided by the UV lamp fan  240  has improved UV intensity output  310  of about 110 mW/cm 2  resulting in improved germicidal and bactericidal effect.  
         [0051]    In a fifth operating condition V, the UV lamp  205  with the closed end vented quartz sleeve or tube  220  is ON, the air system blower or system fan is now OFF and the AC unit is also OFF. In this operating condition V and with the UV lamp venting fan  240  ON, as shown in FIG. 3, the UV lamp intensity output  310  remains substantially at about 110 mW/cm 2 . During the same time period, the temperature inside the UV lamp  330  increases from about 95° F. up to about 140° F., while the temperature outside the UV lamp  320  increases to about 90° F. The increase in the temperature inside the UV lamp  330  can be attributed to the system blower or fan being turned OFF which takes away the air flow in the air duct system by the system blower or fan. The novel UV lamp assembly  200  maintains the UV lamp intensity output  310  steady at about 110 mW/cm 2  providing increased germicidal and bactericidal effect.  
         [0052]    In contrast, when the UV lamp fan  240  is OFF in the fifth operating condition V, as shown in FIG. 4, the UV lamp intensity output  410  continues to decreases from about 95 mW/cm 2  to about 85 mW/cm 2 . During the same time period, the temperature inside the UV lamp  430  increases from about 95° F. to about 140° F., while the temperature outside the UV lamp  420  increases to about 90° F. The increase in the temperature inside the UV lamp  430  can be attributed to the UV lamp fan  240  and the system blower fan being turned OFF which results in loss of circulation or air flow into and out of the vented quartz sleeve  220  and loss of the air flow in the air duct system provided by the system blower or fan. The increased internal UV lamp temperature  430  in turn decreases the UV lamp intensity output. The fifth operating condition V, shown in FIGS. 3 and 4, again illustrates that the UV lamp assembly  200  of the present invention with air flow provided by the UV lamp fan  240  has improved UV intensity output  310  of about 110 mW/cm 2  resulting in improved germicidal and bactericidal effect.  
         [0053]    The invention has been described and illustrated with respect to certain preferred embodiments by way of example only. Those skilled in that art will recognize that the preferred embodiments may be altered or amended without departing from the true spirit and scope of the invention. For example, the UV lamp assembly could be used in or with devices used to sterilize medical instruments, equipment, apparatus and facilities. Therefore, the invention is not limited to the specific details, representative devices, and illustrated examples in this description. The present invention is limited only by the following claims and equivalents.