Engineers at Pennsylvania State University have devised an air conditioning system that is more efficient than current standards and is highly resistant to dangerous airborne microbes such as anthrax. Because the Dedicated Outdoor Air System (DOAS) does not use recirculated air, a letter contaminated with anthrax would not spread throughout the building. A detailed technical overview of the concept is given on the DOAS home page, as well as an assessment of its benefits over traditional air conditioning. A collection of over twenty research papers and five presentations related to the system's development is also provided.