Four commercially available sidewall air inlets and one sharp-edged rectangular opening were tested in a full-scale building section under similar isothermal conditions. Large differences were found between inlets for airjet spread, axial velocity decay, airjet throw, and entrainment ratio. A criterion was derived for evaluating inlets utilizing airjet throw, airjet spread, entrainment ratio, and animal-level velocity. The criterion developed highlighted some deficiencies of the commercially available inlets at a recommended building operating pressure of 12.4 Pa.