For shit’s n’ giggles, I just took sound level readings. Readings are taken with an app on my phone. While probably not relevant to anyone else in the world, they’ll give me a baseline to work with as I make changes.
Readings noted are LAF measurements. With the fan off, furnace off (it’s in the next room) the ambient sound level is about 28 dBA. With the fan running on low speed sound level is 58 dBA and at highest speed the reading is 64 - 65 dBA.
First order of business will be to get the intake of the fan dealt with, even if it’s only a chunk of screen. Safety first and all that. Plan is to box the fan in and get a filter happening somehow.
@Muleskinner - This fan is for light cooling only. Carbon scrubber is a project for another day and will use a separate multi-speed fan.