Recently, a much younger engineer than I asked if we could meet and discuss an energy retrofit project she was working on but was not familiar with the application. The existing HVAC exhaust system served lab exhaust and the system was a vane axial, controllable-pitch fan with a discharge duct extending straight up 10 ft above the roof.
Standard 1950-1960 hospital HVAC central air system design. 100% outdoor air, 100% exhaust air, and constant volume supply air system. Really?