Exhaust Fan Outside Noise

I just bought an 8" exhaust fan, but i'm trying to figure out where to put it based on noise. I know there are a lot of factors, but typically, do exhaust fans sound as loud outside as they do inside?

Typically no.

But if you are exhausting directly outside expect to hear the exhaust air.


If you're asking will the fan be heard running in a bedroom from outside your house then the chances are low that it will be audible.




J

So, i'm going to be running an 8" maxfan out of a roof exhaust, but what you're saying is, the fan noise won't be audible at the point of exhaust, but the air noise will be? That'd be acceptable, but damn this fan is louder than I expected...I just don't want any neighbors to complain.

Yeah that sucks...you can buy a muffler if its in your budget. Also, a fan controller would help if you don't need the fan running at full load.

My other consideration was to exhaust through the wall, but right at ground level. I think that'd reduce the noise quite a bit. I could be wrong? I'd still be able to duct the intake point at the ceiling, so that i'm still exhausting all the hot air. Thoughts?

i vent from room to room so i am able to hear the fan noise directly

i have a 275watt fan which is powerful, it came in a metal box but it was still noisy
so i put it inside another box with some insulation, now it is nice and quiet

when the fan was only in the metal box it came in, the noise was loud enough that i was unable to hear any noise at all coming from the air rushing into the carbon filter
now i am able to hear the small amount of noise at the carbon filter

in contrast the outlet sounds very loud, this is not a problem for me at all as it is vented to a spare room
if it was vented outside, it would sound like a central heating system, the noise is very deep like a gushing sound reminds me of an airplane in the distance LOL
it would be noticed , personally i do not think the noise is suspicious folk would assume it is from a heating system or boiler

the best way to keep noise down is to use much larger fans on a speed or voltage controller
fans with large blades 12 inch or more can spin much slower to remove the same amount of air, this makes much less noise to begin with

you can also buy or make a silencer for the outlet or you can put another carbon filter on the outlet, but you will need a more powerful fan
if you are going to put any resistance on the outlet to reduce noise as it will reduce the performance of the fan

peace

TYVM for the input, Skunk. I ended up installing the fan without a muffler and without a carbon filter(for now) and its hardly noticeable outside even at its loudest. I guess i had no idea what to expect since it was the first time with an inline fan.

So, for anyone who had been curious, my inline fan sounded like 10 hairdryers running at the same time when i ran it without ducting, but after setting it up in the ducting, it quieted down a bit and its not even that loud outside at all. Nothing near what i expected.

Here's a pic of my exhaust after i set it all up. 8" Maxfan, 675cfm running to a roof vent

hi there mate. i have the solution to this problem. i have the same fan witch are great by the way. i had the same problem.

im not quite sure were about you are. but can fan do silences for that fan as you can see. here is a link. hope this helps
http://glandorehydro.com/Can-Silencers.html

Make a silencer if its buggin ya.