An air disinfection module for use in a HVAC system comprises a first and second housing, each of the housings including at least one support member adjustably coupled with the other to form a framework for varying the lateral distance between the first and second housings. The housings further comprise a lamp assembly that includes at least one ultraviolet radiation source communicating with and projecting from its respective housing towards its opposite housing, and a radiation pervious protective sleeve disposed about the radiation source. Electric transmission means are also included which communicates with the ultraviolet radiation source(s) and with at least one source of electrical power to provide electricity to the ultraviolet radiation sources. At least one cross support member communicating with the protective sleeves and the support members is provided for supporting the sleeves and their corresponding ultraviolet radiation sources between the first and second housings.