A UV disinfectant system may include a chamber having a wall that is transparent to a disinfecting radiation. Liquid may be flowed through the chamber for treatment by exposure to the radiation. The chamber may include a static mixer having vanes to impede laminar flow of the liquid during treatment. The vanes extend into the flow path of the liquid through the chamber. A gap is defined between the vanes and the transparent wall. A cabinet may house the chamber and radiation emitting bulbs. Blowers may be operably coupled to a temperature sensor and flow meter and positioned at a lower end and upper end of the cabinet to urge air out of the cabinet. The temperature sensor may include a thermocouple. The blowers may be variable speed blowers. The system may include a controller to control system operations. The controller may be remotely accessible to monitor or control operations.