This decision tree can be used to provide general guidance on calf barn ventilation system evaluation. Calf ventilation systems are evaluated to provide ideal air exchange in the calf nose zone, located at the same level above the bedding as the calf’s nose would be when in a lying position. Please note this is a guidance for performing a first-line assessment of the ventilation in a specific facility. Further evaluation is likely needed to conclude if the barn is adequately ventilated.