Jump to content

Source of "max 2.5m/s" rule of thumb?

Recommended Posts

I've seen it quoted on MVHR supplier sites and here, but where does it come from and why?


Is it draughts, or air moving faster than this is audible (in any diameter pipe)?

Link to comment
Share on other sites

How timely, I was talking to a man from an MVHR supplier and fitters yesterday at the Swindon show and he said he designed for 3.5 m.s-1 max.  But if it did go a bit over, then it was generally not a problem.

Link to comment
Share on other sites

Passivhaus trust say

Within a single dwelling the air speed in the primary ducts should not exceed 2~3 m/s and in the final runs to room valves the speed should be limited to 1~2 m/s.


So I assume for noise is one reason. But secondly to keep fan speed low. The higher the velocity the more the pressure drop, for a given flow rate, so the faster the fan has to run to compensate.

  • Like 2
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Create New...