Bioeffluent consists of volatile organic compounds and other chemical substances naturally released by human occupants through respiration, perspiration, and bodily functions. These compounds include carbon dioxide, ammonia, volatile fatty acids, and complex organic molecules that accumulate in occupied spaces. Bioeffluent represents a baseline indoor air quality challenge distinct from material-related emissions.
Composition and Concentration
Each occupant generates approximately 0.004 cubic feet per minute of bioeffluent compounds. Common bioeffluent components include acetone, methane, dimethyl disulfide, and nitrogen-containing compounds. Bioeffluent concentrations increase with occupancy density, activity levels, and hygiene practices. Poorly ventilated spaces accumulate bioeffluent at 2-4 ppm CO₂ above outdoor baseline within 20-30 minutes.
Ventilation Requirements
ASHRAE 62.1 specifies 15-20 CFM per person outdoor air to manage bioeffluent and associated odor. Actual requirement depends on occupancy type and activity level: sedentary office work requires 15 CFM/person while physical activity requires 20 CFM/person. Proper ventilation design and maintenance ensure bioeffluent remains at acceptable concentrations, supporting occupant comfort and cognitive performance during work hours.