max silent duct velocity

[Lacustral]

If you have air going at 1430 feet/min in 8" diameter
sheet metal duct, will it make whistling or whooshing noises?
I don't think so from the info I've gotten so far, but what do you think?

thanks
Laura

 

[chilled]

I thin it will make more like a whootling / waddelling sound.

 

[mechanicaldude]

1430 feet per minute is standard velocity in a low pressure system. For an 8" round duct that is about 500 cfm of air.
This shouldn't generate any significant noise. If there is a whistling or whooshing noise or even a whootling or waddeling sound it might be because of the diffuser or a hole or leak in the sheet metal.

 

[ChrisConley]

For quiet duct applications our accoustical consultants like us to keep duct velocity under 600fpm.