the present invention may be understood more readily by reference to the following detailed description of the invention taken in connection with the accompanying drawing figures , which form a part of this disclosure . it is to be understood that this invention is not limited to the specific devices , methods , conditions or parameters described and / or shown herein , and that the terminology used herein is for the purpose of describing particular embodiments by way of example only and is not intended to be limiting of the claimed invention . any and all patents and other publications identified in this specification are incorporated by reference as though fully set forth herein . also , as used in the specification including the appended claims , the singular forms “ a ,” “ an ,” and “ the ” include the plural , and reference to a particular numerical value includes at least that particular value , unless the context clearly dictates otherwise . ranges may be expressed herein as from “ about ” or “ approximately ” one particular value and / or to “ about ” or “ approximately ” another particular value . when such a range is expressed , another embodiment includes from the one particular value and / or to the other particular value . similarly , when values are expressed as approximations , by use of the antecedent “ about ,” it will be understood that the particular value forms another embodiment . the present invention includes a number of ion generator carrier and mounting assemblies for application and control of delivery of ionization to an airflow , including bipolar ionization . fig1 a and 1 b show an exemplary embodiment of an assembly 200 for mounting to the exterior of a duct , housing , or other conduit for airflow . the assembly includes a housing 210 or other enclosure , such as for example a nema 4x enclosure or similar configuration , an internal panel 212 within the housing 210 , and an external arm 214 projecting from the back side of the housing . the external arm 214 includes mountings 248 and electrical contacts 250 for receiving one or more ion generators 240 for delivery of bipolar ionization to airflow within a conduit . alternatively , the arm 214 may be disposed adjacent a cooling coil . such ion generator 240 can include the sterionizer device that may be purchased from filt - air , a beth - el group , israel , and includes a pair of electrodes that disperse ions . the mountings 148 securely engage the ion generator 240 or ion generators 240 and maintain them in an orientation having their electrodes axially aligned with the arm 214 and generally perpendicular to the airflow . the panel 212 optionally comprises one or more pluggable terminal blocks for wiring connection to the ion generators 240 via the contacts 250 on the arm 214 , a connection for power input , and one or more indicators such as leds 242 to indicate the presence / absence and operational state ( on / off , ion output , etc .) of the ion generators 240 . optionally , a power converter or transformer is provided in the housing 210 for converting the input power to the power required to operate the ion generators 240 . one or more connectors are optionally provided for mounting the housing 210 to the exterior of a duct or housing , with the arm 214 extending into the duct or housing through an opening formed therein . sealing means such as a gasket are optionally provided on the back of the housing 210 around the arm 214 for sealing around the opening . fig2 and 4 show a device 200 according to an alternate embodiment , having a housing 210 with an arm 214 extending therefrom . the length of the arm 214 may vary depending on the size of the conduit it is to be applied to and the number of ion generators to be installed , and in example embodiments is between 2 ″- 24 ″, for example about 10 ″ in length . the arm 214 is generally elongate and extends outwardly from the housing 210 and has a top side , a bottom side , a first side , and a second side . the arm 214 contains at least one opening 244 contained therein in . the arm 214 includes mountings 248 and electrical contacts 250 for receiving one or more ion generators 240 for delivery of ionization to an airflow within the conduit . such ion generator can include the sterionizer device that may be purchased from filt - air , a beth - el group , israel , and includes a pair of electrodes that disperse ions . the mountings 248 securely engage the ion generators 240 and maintain them in an orientation having their electrodes axially aligned with the arm 214 and generally perpendicular to the airflow . the panel 212 optionally comprises one or more pluggable terminal blocks for wiring connection to the ion generators 220 via the contacts on the arm 214 , a connection for power input , and one or more indicators such as leds 242 to indicate the presence / absence and operational state ( on / off , ion output , etc .) of the ion generators 220 . optionally , a power converter or transformer is provided in the housing 210 for converting the input power to the power required to operate the ion generators 240 . one or more connectors are optionally provided for mounting the housing 210 to the exterior of a duct or housing , with the arm 214 extending into the duct or housing through an opening formed therein . sealing means such as a gasket are optionally provided on the back of the housing 210 around the arm 214 for sealing around the opening . the electrodes of the ion generators 240 are placed in close proximity to the opening 220 on the arm 214 , thus allowing the ions to disperse through the arm 214 . as illustrated in fig5 , the electrodes are recessed within the arm 214 . in other words , the electrodes of the ion generators 240 do not break the horizontal plane of the external of the top side of the arm 214 and are located equal to or beneath the horizontal plane of the arm 214 for allowing the ions to disperse through the openings 244 in the arm 214 . as illustrated in fig2 , and 4 , the arm 214 contains two openings 244 for each ion generator 220 . in another alternative embodiment , the electrodes of the ion generator 220 may protrude through the openings 244 and extend above the horizontal plane of the arm 214 . the housing 210 includes a base 212 that extends to an outer edge . first and second pairs of opposed sidewalls 214 , 216 extend from the outer edge of the base 212 to an upper edge 218 . the sidewalls 214 , 216 each have an inner and outer sidewall surfaces 220 , 222 . as shown in fig6 and 7 , each of the second pair of sidewalls 216 interconnects the first pair of sidewalls 214 to define corners 224 and an interior storage compartment 226 . at least one retention member 228 extends from a first or second sidewall 214 , 216 or the base 212 . a top portion 230 may be selectively secured to the base 212 . as illustrated , the top portion 230 is hingedly connected to the base 212 and includes a latch 246 for selectively securing the top portion 230 to the base 212 . although the present invention has been illustrated and described herein with reference to preferred embodiments and specific examples thereof , it will be readily apparent to those of ordinary skill in the art that other embodiments and examples may perform similar functions and / or achieve like results . all such equivalent embodiments and examples are within the spirit and scope of the present invention and are intended to be covered by the following claims .