University of Minnesota
University of Minnesota: Department of Mechanical Engineering


Thomas H. Kuehn

Professor Emeritus

Office: ME 3101C
Phone: 612-625-4520

Ph.D. 1976, M.S. 1973, B.S. 1971, Mechanical Engineering, University of Minnesota



Research interests include basic studies of fluid mechanics and heat and mass transfer, bioaerosols, and other topics related to energy use and indoor environments in buildings.

Experimental measurements are being performed in the laboratory to test how efficiently building ventilation filters remove airborne particles of biological origin including viruses and fungal and bacterial spores. Fungal growth on loaded filters is also being investigated to determine the influence of environmental parameters such as temperature, humidity and air flow, and to quantify the efficacy of various antimicrobial methods. Protocols have been developed to use loaded ventilation filters to determine background levels of selected airborne bacteria and viruses in buildings. Analytical methods include culturing and identifying viable bacteria and live viruses and screening for selected microorganisms using PCR and RT-PCR.

A significant amount of research has been conducted on commercial kitchen equipment. Particulate and vapor effluents from various commercial cooking appliances and corresponding food products have been characterized. The rate of grease particle and vapor deposition inside exhaust ducts has been determined at various exhaust velocities. The results showed that lower velocities are better than the widely used minimum design value of 1500 ft/min. The minimum exhaust velocity in NFPA 96 was changed as a result of our work. A recent study developed a test protocol for the particulate capture performance of commercial grease filters. This was adopted by ASTM as a standard method of test and has been published as ASTM F2519-05.


Aerosol and Particle Measurement Short Course

Bioaerosol Measurement Short Course

Air and Gas Filtration Short course

Health Care Facility Short Course


Thermal Environmental Engineering Laboratory

Center for Filtration Research