Life-cycle cost simulation of in-duct ultraviolet germicidal irradiation systems

Ultraviolet Germicidal Irradiation (UVGI) systems use 254 nm UVC radiation to inactivate microorganisms in the air and on surfaces. In-duct UVGI systems are installed in air-handling units or air distribution systems to inactivate microorganisms “on the fly” and on surfaces.  The literature contains few investigations of the economic performance of UVGI. This study presents a simulation-based life-cycle cost analysis of in-duct UVGI in a hypothetical office building served by VAV systems. Three scenarios are considered: UVGI in the mixed air stream upstream of the cooling coil, UVGI downstream of the coil, and equivalent enhanced filtration without UVGI. The upstream location results in lower first and operating cost for UVGI due to a more favorable thermal environment for UV lamps. UVGI in either location is much lower in annualized cost than equivalent enhanced filtration. The methodology presented could serve as a model for an improved design process.