Transfer duct instead of gaps under door - MVHR

[embra]

Planning ahead to ensure the right air circulation between rooms with our MVHR system. Our designer (Paul Heat Recovery) include this note in their install guide, along with specifying 10 mm gaps under doors between rooms where air transfer is required. 

 

Has anyone installed wall ducts as an alternative to this? Did you pay attention to "periscope" arrangement / noise attenuation? Can you share any examples or merchant where this kit is available?

 

I am interested to implement this where noise may be more of a concern such as er... the bathrooms.

 

[jack]

We did this. I left something like 40 mm of height between the doorframe and the wall frame, and lined it with a strip of something like this:

 

 

(The orange line is where the strip is cut - I cut it slightly narrower than the studwork.)

 

We aggressively chamferred the inner top edge of the door frame along the gap to maximise transfer.

 

I've never particularly noticed any sound transfer through these openings. Noise-wise, I can't see any reason why it would be any worse than a 10 mm, unlined gap under the door.

[JohnMo]

Just undercut the door, Uber simple, no cost, next to zero noise transfer.  Making something costly, complex for no good reason. Spend your money on good design so the noise transfer from the MVHR unit is minimised. Big ducts for low velocity, oversized MVHR unit for low running speed and decent plenum.