Greenheck make-up air models DGX and MSX can be configured with a direct drive, mixed flow plenum supply fan for low to medium pressure applications. With performance capacities from 800 to 16,000 cfm, Models DGX-P-MF and MSX-P-MF reduce horsepower requirements, resulting in lower operating costs. The direct drive, mixed flow impellers contribute to lower sound levels; sound power reduction of up to 8 decibels can be achieved. The preprogrammed variable frequency drive provides a soft-start for the supply fan, while the absence of belts and sheaves also reduces maintenance and simplifies air balancing in the field. Multi-directional discharge contributes to installation flexibility. Heating options include direct gas-fired, electric heat, hot water and steam coils; cooling options include packaged direct expansion, split direct expansion, chilled water and evaporative cooling. Models DGX-P-MF and MSX-P-MF are ideal for a variety of commercial and industrial facilities where low sound and energy efficiency are required.