PTAC Wind Noise

[spedprof]

I live in a 3rd floor condo facing the West, with no blocking buildings. Had a new (replacement) PTAC professionally installed this summer. Last evening, while the highest wind was said to be 25 mph for a few hours, when there was a gust, I heard a short but annoying loud noise, deeper than a whistle, almost a hum. Such wind happens occasionally so it is hard to replicate. Thoughts, please, and Thanks

[Porcupinepuffer]

A lot of these have a fresh air damper. It may be open, or partially open causing that sound. Unless there's a breach somewhere around the unit that isn't sealed fully between the outside and inside, you shouldn't hear any wind noise.