A system for disinfecting an enclosed chamber may include a housing, an inlet and an outlet carried by the housing to be connected in a closed airflow path with the enclosed chamber. A dehumidification chamber, a blower, and an evaporation chamber may be carried by the housing and connected in the airflow path between the inlet and outlet. An atomizing nozzle may be positioned within the evaporation chamber and connected to a disinfectant fluid reservoir and an air compressor and configured to atomize disinfectant within the evaporation chamber. An airflow valve may be connected in the airflow path, and a controller may be configured to, during a treatment phase, operate the compressor to introduce atomized disinfectant into the airflow path, and during an evacuation phase, operate the airflow valve to divert the airflow path through the desiccation chamber to remove atomized disinfectant from the airflow path.