Chilled water, DX, and evaporative cooling options are also available for combination heating and cooling requirements. The DGX is designed for providing make-up air to commercial and industrial facilities. Airflow volumes range from 800 to 48,000 cfm with heating output capacities up to 4,800,000 Btu/hr. Durable Construction Designed for maximum weather resistance, DGX housings are constructed of heavy gauge G90 galvanized steel. Lifting lugs are standard. Direct Gas-Fired System • High quality