This chart shows the frequency spectrum of the noise emissions at the East Air Intake area of the L-1 Vertical Wind Tunnel located at Appalachian Amusement Center with the fan blades removed for inspection. Comparing this to the same test with the fan blades will help to isolate which part of the emission is generated by mechanical noise, and which is generated by air moving though the intake and fan. This will help to determine what improvements can be made. When these measurements were made there was intermittent wind and background noises such as passing vehicles and distant power tools. These may have slightly increased some readings even though great care was taken to make the measurements between occurrences. This may explain why the ambient reading is higher than with the HVAC below 160 Hz. The zero readings were below the meter range used and so didn't register. The meter was located 56 feet to the side of the fan centerline near the transformer. Some hum from the transformer may have contributed to the readings.