RELATED APPLICATIONS This continuation-in-part application claims the priority of U.S. Provisional Patent Application Numbers 60/435,390 and 60/448,071, filed on December 20, 2002 and February 18, 2003, respectively and U.S. Utility Patent Application Number 10/733,904, filed on December 11, 2003.

BACKGROUND OF THE INVENTION The present invention relates to fungus abatement and more particularly to a system for use in preventing fungus from forming in a building structure such as a home or an office building. Fungus is increasingly a problem in homes and office buildings. The fungus typically develops in unconditioned areas of the building such as basements or crawl spaces and is then spread by a natural upward flow of air and/or by the HVAC system to conditioned areas of the building where it contaminates the conditioned areas and generates occupant discomfort and health hazards.

SUMMARY OF THE INVENTION The invention provides a method of maintaining a structure free of fungi. According to the invention method, a flow of air is created from an enclosed space within the structure, the flow of air is treated in a germicidal fashion, and the flow of air is treated in a dehumidifying fashion. This basic air handling and treating process results in a continual cleansing and dehumidifying of the air in the enclosed space to preclude contamination of other areas of the structure. According to a further feature of the invention methodology, the flow of air is returned to the enclosed space after the germicidal treating step and after the dehumidifying treating step. The germicidal cleansing and the dehumidifying of the air conditions the air to a point where it is suitable for return to the enclosed space. According to a further feature of the invention methodology, the germicidal treating step comprises creating a fungi killing zone in the enclosed space and passing the flow of air through the killing zone. This specific germicidal treating step effectively removes fungi from the air. According to a further feature of the invention methodology, the killing zone comprises a zone in which the flow of air is subjected to radiant energy. This methodology provides a convenient means of creating the killing zone to destroy the fungi. In the disclosed embodiments of the invention the radiant energy comprises ultraviolet radiation. In one embodiment of the invention methodology, the flow of air moves through the killing zone prior to its movement through the dehumidifier. In another version of the invention methodology, the air flows through the dehumidifier prior to its movement through the killing zone. The invention also provides an apparatus for abating fungi in a structure having boundary walls defining a first enclosed space intended for human occupancy and a second enclosed space proximate the first enclosed space. The abatement apparatus comprises a blower unit, a source of radiant energy, and a dehumidifier. The blower unit has an air inlet and an air exhaust and is adapted to be positioned within the structure with the air inlet communicating with the second enclosed space, actuation of the blower unit being operative to create a flow of air from the second enclosed space into the blower unit inlet and thereafter discharge the air through the blower unit air exhaust. The source of radiant energy is adapted to be positioned to establish a fungi killing zone to intercept the flow of air moving from the second enclosed space to the inlet of the blower unit, and the dehumidifier is adapted to be positioned to intercept the flow of air moving from the second enclosed space to the inlet of the blower unit. This apparatus provides a ready and continuous cleansing and dehumidifying of the air in the second enclosed space and insures that all of the exhausted air is thoroughly dehumidfied and throughly treated with radiant energy to remove the fungi from the air. In one embodiment of the invention apparatus, the radiant energy source comprises a series of ultraviolet lamps positioned in spaced locations within the second enclosed space and arranged to irradiate the air prior to its movement to the dehumidifier. In another embodiment of the invention apparatus, a housing is provided receiving the blower unit and the dehumidifier and the source of radiant energy is provided in the housing between the dehumidifier and the inlet of the blower unit so that the flow of air moving from the second enclosed space to the blower unit passes first through the dehumidifier and then through the killing zone established by the source of radiant energy. Other applications of the present invention will become apparent to those skilled in the art when the following description of the best mode contemplated for practicing the invention is read in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS The description herein makes reference to the accompanying drawings wherein like reference numerals refer to like parts throughout the several views, and wherein: Figure 1 is a perspective, fragmentary view of building having a crawl space employing a fungus abatement system according to the invention; Figures 2, 3, 4 and 5 are perspective, plan, side elevation, and end views of a blower unit employed in the fungus abatement system; Figure 6 is a plan view of the fungus abatement system; Figures 7 and 8 are cross-sectional views of germicidal lamp assemblies utilized in the fungus abatement system; Figure 9 is a wiring diagram for a fungus abatement system according to the invention; Figure 10 is a perspective view showing the fungus abatement system of the invention utilized in a building having a full unfinished basement; Figures 11-13 are fragmentary views showing the fungus abatement system of the invention utilized in a building having a full finished basement; Figures 14, 15 and 16 are plan, side elevational, and perspective views of a modified form of the invention employing a dehumidifying apparatus; and Figures 17 and 18 are side elevational and cross-sectional views of a further modified form of the invention also employing a dehumidifying apparatus.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention fungus abatement system is seen in Figures 1 and 6 installed in a building 10 of the type including an upper enclosed living area space 12, bounded by a floor 14, and a lower enclosed crawl space 16 beneath the upper enclosed space. Upper enclosed space 12 is defined by walls 12a and 12b as well as by floor 14 and crawl space 16 is defined by walls 16a and 16b as well as by a ground surface 18. The fungus abatement system, broadly considered, includes a blower assembly 20, a plurality of air inlet conduits 22, 24, 26 and 28, a pair of exhaust conduits 30 and 32, and a plurality of germicidal units 34, 36, 38 and 40. Blower assembly 20 includes a housing 42 and a pair of squirrel cage blowers 44 and 46. Housing 42 (Figure 2-5) has a sheet metal construction and is secured to the underface of floor 14 centrally within the crawl space 16. Housing 42 includes a main body portion 42a defining exhaust ports 42b and 42c, and a plenum chamber 42d positioned against main body portion 42a and defining intake ports 42e, 42f, 42g and 42h. Squirrel cage blowers 44 and 46 are commonly driven by a central electric motor 48 positioned in housing main body portion 42a and may each comprise a unit available from Penn Zepher as Part Number Z 102. Each blower 44, 46, will be understood to have an exhaust communicating with a respective exhaust port 42b, 42c and an intake communicating with plenum chamber 42d. Blower assembly 20 is preferably provided with a germicidal filter 49 positioned at the interface of plenum chamber 42d and the intakes of the blowers 44 and 46. Intake conduits 22, 24, 26 and 28 each have an outlet end 22a, 24a, 26a, and 28a connected respectively to a housing port 42e, 42f, 42g and 42h; an inlet end 22b, 24b, 26b and 28b positioned respectively in the four corners of the crawl space; and an intermediate portion 22c, 24c, 26c and 28c interconnecting the inlet end and the outlet end of each conduit. Inlet ends 22b, 24b, 26b and 28b will be seen to be vertically disposed and will be seen to terminate in an inlet port 22d, 24d, 26d and 28d positioned proximate but spaced slightly above the ground surface 18. Intermediate portions 22c, 24c, 26c and 28c will be seen to comprise horizontal runs extending beneath floor 14 and interconnecting the respective inlet end and the respective outlet end of the respective conduit. Exhaust conduits 30, 32 each define an inlet end 30a and 32a connected to a respective port 42b, 42c of housing 42 and an outlet end 30b and 32b communicating with a register or vent 50 positioned in opposite crawl space sidewalls 16b. Germicidal units 34, 36, 38 and 40 are positioned on the underface of floor 14 in association with the inlet port of a respective intake conduit. Each germicidal unit may comprise, for example, a 15 watt ultraviolet germicidal lamp of the type available from Sylvania company as Part Number GI5T8. Each germicidal lamp in known manner emits ultraviolet radiation in the wave length of 254 nm which has the effect of establishing a killing zone around each germicidal unit which will effectively kill any fungi carried by air passing through the killing zone. Each germicidal lamp comprises an elongated tube 51 and a base 52 to which the tube is suitably mounted. If desired, an overhead directional reflector may be provided with respect to at least certain of the lamps. The reflector may, for example, have an inverted trough configuration as seen at 53 in Figure 7 or a gull wing configuration as seen at 54 in Figure 8, depending upon the shape and size of the killing field that it is desired to establish in the vicinity of the tube 51. Preferably, however, no reflectors would be utilized in the crawl space embodiment of Figures 1-6. Rather, sufficient germicidal lamps would be provided to essentially flood the crawl space area with radiant energy. The fungus abatement system of the invention further includes a motion detector 58, a control panel 60, a plurality of humidistats 62, and a controller 64. Motion detector 58 may be installed in the crawl space 16 beneath the floor 14 and preferably has a 180° sweep. The detector may be of the type available from Desa International as Part Number 5411-ASL-5407A. This is a motion-on detector and is therefore used with a relay 65 to reverse the action of the motion detector to a motion-off detector. Relay 65 may be a 5 pin 6C895-7 type and may snap into a 5 pin base of the 6C898-1 type. Control panel 60 may be positioned in upper enclosed living space 12 on wall 12a for ready access by occupants of living space 12. A humidistat or humidistat trigger 62 may be installed in crawl space 16 proximate the inlet port 22d, 24d, 26d and 28d of each of the intake conduits whereby to sense the humidity of the air entering each of the intake conduits. Controller 64 may be mounted, for example, in a controller housing 68 secured to a side face of blower housing 42. As seen in the wiring diagram of Figure 9, a lead 64 interconnects lamp 34 and motion detector 58; a lead 66 interconnects lamp 36 and lamp 40; a lead 68 interconnects lamp 40 and motion detector 60; a lead 70 interconnects lamp 38 and motion detector 60; a lead 72 interconnects motion detector 60 and controller 64; leads 74 and 76 interconnect thermostats 62 and controller 64; and a lead 78 interconnects control panel 60 and controller 64.

OPERATION With control panel 60 calling for operation of the fungus abatement system, and assuming that the motion detector 58 does not detect the presence of anyone in the crawl space, the controller 64 functions to turn on the system and specifically functions to turn on the blowers 44, 46 and the lamps 34, 36, 38 and 40. Actuation of the blowers has the effect of drawing air from the crawl space 16 into the inlet ports 22d, 24d, 26d and 28d of the intake conduits for passage through the conduits to the plenum chamber 42d and thence through the squirrel cage blowers for discharge via the conduits 30 and 32 through the grills 50 to the exterior of the building. As the air moves respectively toward the inlet ports 22d, 24d, 26d and 28d of the intake conduits, the air passes through killing zones 80 established around each of the lamps 34, 36, 38, 40 so that effectively all of the air entering the inlet ports 22d of all of the conduits is first passed through a killing zone where the air is irradiated by the germinating lamp to kill any fungus or other contaminants carried by the air. The air passing through the intake conduits in turn passes through germicidal filter 49. The air thereafter moved outwardly through the exhaust conduits is thus essentially free of fungus and the air in the crawl space 16 is continuously purged of fungus so that the crawl space air, rather than rising upwardly laden with fungal contaminants into the conditioned air living area space above the crawl space, is cleansed within the crawl space and carried to a location outside of the building. Alternatively, the system may be programmed to cycle on and off dependent upon the readings provided by the humidistats 62. Specifically, as the humidity of one or more of the humidistats reaches a predetermined upper limit the controller functions to turn on the system and as the humidity reaches a predetermined lower limit as determined by the humidistats the blowers are turned off. Desirably, the ultraviolet lights remain on for a measured period of time following cessation of blower operation to insure that the stagnant air remaining in the crawl space is cleansed of fungi. It will be understood that, depending upon the construction and porosity of the building, air will also be sucked downwardly from the conditioned air space 12 into the crawl space for discharge through the intake conduits and the exhaust conduits to the exterior of the building, thereby reversing the normal flow of air within the building. It will further be understood that the efficiency of ultraviolet radiation is directly proportional to the density or the humidity of the air being treated. The denser or more humid the air, the slower the ultraviolet travel. Accordingly, by lowering humidity the efficiency of the germicidal units increases. In some scenarios involving exceptionally high humidity, it may be necessary to provide a separate dedicated dehumidifier to assist the invention system in maintaining a desired humidity level. It will further be understood that, if the motion detector 58 detects movement in the crawlspace, the controller is appropriately signaled to turn off the system to preclude harm to living creatures in the crawlspace. ALTERNATE EMBODIMENTS The fungus abatement system seen in Figure 10 is intended for use with a building 10' having a full unfinished basement 82 including a floor 84. The system of Figure 12, for use with a full unfinished basement, is identical to the system of Figure 1, for use with a crawl space, except that the intake conduit lower ends 22b', 24b1, 26b1, and 28b' are extended vertically downwardly to position the conduit inlet ports 22d', 24d', 26d' and 28d' proximate the floor 84, and the humidistats 62 are moved downwardly to retain their positions proximate the inlet ports of the respective intake conduits whereby to monitor the humidity of the air entering the respective conduits. As with the crawl space configuration, sufficient germicidal lamps would be provided to essentially flood the basement area with radiant energy or, alternatively, at least certain of the ultraviolet lamps would be provided with directional reflectors. Lamps 34, 36, 38 and 40 are preferably mounted on the underface of floor 14. Figures 11-13 illustrate an arrangement for use in a full finished basement including a drop ceiling 86, studs 88 mounted against foundation wall 90, and dry wall or other paneling 92 mounted on the studs and defining dead air spaces 94 between the paneling and the foundation wall. Suitable FIVAC equipment is provided so that the lower area within the paneling is provided year round with conditioned air, either heated or cooled. The fungus abatement system for the full finished basement of Figures 11-13 includes a plurality of vertical intake conduits 96 positioned between selected studs 88 with the open lower ends 96a spaced above the sills 98 and a plurality of germicidal lamp units 100 positioned above the drop ceiling proximate to the perimeter of the basement. For example, and as shown, intake conduits 96 may be positioned around the perimeter of the basement on 48" centers and a germicidal lamp 100 may be provided in association with each intake conduit. Each germicidal lamp 100 may include an elongated tube 102, a base 104, and a reflector 106. Each lamp may be centered on a stud 88 and the reflector 106 may be notched at 106a to fit over the stud. Each reflector 100 may be of the type available from Simkar Corporation as Part Number ARW20-SR and will be seen to provide an angled reflector surface 106b which is operative to direct rays from the tube 102 downwardly into the dead air spaces 94 on either side of the stud over which the reflector is fitted so as to establish germicidal killing zones in the dead air spaces on either side of the stud over which the reflector is fitted. It will be understood that the blower unit 20 in this finished basement embodiment is positioned centrally above the drop ceiling, that each conduit 96 is suitably connected to the intake of the blower unit, and that suitable humidistats (not shown) might be provided proximate the intake of the various conduits 96. In operation, following actuation of the blower unit and the germicidal lamps, any fungal matter in the dead air spaces 94 is killed by exposure to the ultraviolet killing zones established in the dead air spaces and the cleansed air is sucked upwardly through conduits 96 for discharge by the blower unit outside of the building. Since the studs 88 do not sealingly interface with the foundation wall but rather define significant spacing at the interface, air is free to move laterally from the dead air spaces in which a conduit is not positioned into a dead air space in which a conduit is positioned for entry into that conduit and discharge from the building. As the air moves laterally toward the intake of a conduit, it moves through a killing zone and is cleansed of fungal matter. The forms of the invention heretofore described are open systems in which the conditioned air is exhausted outside of the associated building structure. The modified form of the invention seen in Figures 14-16 employs a dehumidifying apparatus to allow the unit to operate in a closed loop fashion with the blower discharge being returned to the enclosed space defined by a finished basement, for example, rather than being exhausted outside of the building structure. The apparatus seen in Figures 14-16 is generally similar to the apparatus seen in Figure 10 and as such includes intake conduits 22, 24, 26 and 28 defining intake conduit lower ends 22b', 24b', 26b' and 28b' positioned proximate the floor of the associated enclosed space (for example a finished basement of a housing structure); a plurality of ultraviolet lamps 34, 36, 38 and 40 mounted at spaced locations on the underface of the floor of the enclosed space of the housing structure overlying the finished basement and establishing respective killing zones 80 positioned to intercept air moving from the finished basement space into the respective intake conduit lower ends, and a housing 42' receiving the outlet ends of the intake conduits 22, 24, 26 and 28 and housing the blowers 44 and 46. However, and as best seen in Figure 15, housing 42' also receives a dehumidifying apparatus 1 10 positioned within the housing between filter 49 and blowers 44, 46. Dehumidirying apparatus 110 includes an evaporator 112, a compressor 114, and a condenser 116. Evaporator 112, in known manner, may comprise a single continuous smooth wall tube 112a extending in sinusoidal fashion within the housing 120b of the evaporator and condenser 116, in known manner, may comprise a single continuous finned tube 116a extending in sinusoidal fashion within the housing 116b of the condenser. Compressor 114 may, for example, comprise a unit available from Danfoss as Model Number SE 15FPX; condenser 116 may, for example, comprise a unit available from Tecumseh as Model Number 508; the evaporator 112 may be formed of a length of 5/16" OD copper tubing received in a suitable housing; and the refrigerant may be R 134a. The refrigerant moves through the dehumidifier apparatus as indicated by the arrows and, specifically, leaves the outlet 114a of the compressor as a high pressure vapor, moves through a conduit 120 to the inlet of the condenser, is transformed in the condenser to a liquid, flows as a liquid through a conduit 122 to the inlet of the evaporator, is transformed in the evaporator to a low pressure vapor, and moves through a conduit 118 to the inlet 114b of the compressor to complete the refrigerant loop. In the operation of the embodiment of Figures 14-16, a flow of irradiated air from the enclosed space defined by the finished basement is delivered to plenum chamber 42d' of the housing 42' via intake conduits 22, 24, 26 and 28; thereafter moves through the filter 49; thereafter moves through evaporator 1 12 where it is cooled by the evaporation of the refrigerant and the resulting condensate collected in a drain pan 124 for discharge and collection via a drain tube 126; the cooled and dehumidified air thereafter moves through the condenser 116 where it serves to extract the superheat from the refrigerant and is heated; and the irradiated and dehumidified air flow is thereafter delivered to the blower units 44, 46 for discharge through exhaust conduits 32' which, rather than extending as in the Figure 10 embodiment to registers 50 for discharge outside of the building, are configured to deliver the dehumidified and irradiated air back to the enclosed space via exhaust tube outlet ends 32a'. The modified apparatus as seen in Figure 17 and 18 corresponds to the apparatus of Figures 14-16 with the exception that the killing zone for irradiation is established within the housing 42" between the dehumidifying apparatus 110 and the blower units 44, 46. Specifically, the dehumidifying air leaving the dehumidifying unit 110, rather than flowing directly to the blowers 44, 46 as in the Figures 14-16 embodiment, instead is directed through a reduced diameter housing conduit 42a" where it is exposed to a series of ultraviolet lamps positioned within the conduit 42a ' so that the flow of air arriving at the blowers 44, 46 is irradiated to remove fungi with the irradiation in this case taking place within the housing of the blower unit rather than taking place outside of the housing within the general area of the enclosed space as in the previous embodiments. Specifically, the flow of air leaving the dehumidifying unit first passes through a first killing zone established by a first series of circumferentially spaced ultraviolet lamps 128 positioned within the conduit 42a" and thereafter passes through a second killing zone established by a second series of circumferentially spaced ultraviolet lamps 130 positioned within the conduit 42a". As in the case of the 14-16 embodiment, the irradiated and dehumidified air leaving the blowers 44, 46 is returned via conduits 32' to the enclosed space rather than being discharged outside of the building. As noted, in the embodiment of Figures 17 and 18 the ultraviolet lamp 34, 36, 38 and 40 and their associated killing zones 80, are eliminated since the irradiation is now performed within the blower unit housing. SPECIFICATIONS The number sizing and location of the various components of the mold abatement system will of course depend on whether a crawl space is being treated or a full basement is being treated and will of course in each case further depend on the size of the crawl space or the full basement. As an example, for a crawl space with dimensions of 26' wide by 42' long and 36" deep for a total of 3,276 cubic feet, the blower assembly 20 would have a 638 cfm capacity and would serve to establish a system static pressure of .375 inches, and would operate on 3.6 amps. This arrangement would serve to change the air within the crawl space ten times per hour. As previously noted, blowers 44 and 46 in this crawl space configuration may comprise units available from Perm Zepher as Part Number Z 102. These blower units would also be satisfactory for use in the full finished basement embodiment of Figures 11-13. As a further example, for a mil unfinished basement 8' deep by 26' wide by 42' long, resulting in 8,736 cubic feet of space, a 950 cfm blower assembly 20 would be required operating at .8375 inches system static pressure. This arrangement would serve to change the air within the basement 5.868 times per hour. Blowers 44 and 46 in this full basement configuration may comprise units available from Perm Zepher as Part Number Z 121. The invention would seem to provide an efficient and inexpensive means of precluding the contamination of the living areas of a building by fungi. The embodiments of the invention illustrated in Figures 1-13, where the irradiated air is exhausted to a location outside of the building structure, are best suited for crawl space applications or applications where the basement, while full size, is not primarily used for human habitation, and the embodiments seen in Figures 14-18, where the air is dehumidified prior to discharge from the blower units, are best suited for use in full basements that are finished and where regular human habitation is contemplated. While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention is not to be limited to the disclosed embodiments but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims, which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures as is permitted under the law. For example, the term fungi as used in the specification and appended claims will be understood to include germs, parasites, spores, bacteria, mold, rust, mildew, smuts, mushrooms and other airborne contaminants. As a further example, the particular reflector configuration, if any, employed in association with the ultraviolet lamps will vary depending upon the nature and configuration of the space being treated. As a yet further example, although the invention has been described with reference to the germicidal treatment of air in a lower enclosed space of a building, it also has applicability in certain situations to the germicidal treatment of air in an upper enclosed space of a building. As a yet further example, although the invention has been described with reference to treatment of air in a building, it may also have applicability to the treatment of air in structures other than buildings.