Summary:\nOxygen consumption and carbon dioxide production is measured using indirect calorimetry. The Columbus Instruments Oxymax Equal Flow System is an indirect open circuit calorimeter designed to simultaneously measure metabolic performance of multiple subjects that have similar ventilation needs. uses an open circuit calorimetry technique. This system allows sixteen animal cages to be simultaneously monitored. Variables provided by this measurement include VO2, VCO2, RQ, and HEAT.