HVAC sales technicians help to sell and promote heating, ventilation, and cooling equipment (HVAC) that is industrial in size to commercial customers. A large portion of their work is finding the best match between equipment output and efficiency that are compatible with the interior and exterior work areas of buildings. The engineers are accountable to ensure that they provide the best equipment for controlling and ventilating climates in the specific setting, without causing unnecessary cost overruns for the contractor or buyer and ensuring that the recommendations for the system are in line with the requirements for the particular building.