Heating Help

Inconspicuous HRV/ERV ceiling inlets/outlets

What's everyone using for small diameter (3", 4") ceiling duct terminations, such as what might be used for a HRV or ERV? Can't find anything that would be low profile and require a minimal cutout...

diffusers

I've seem everything from conventional louver-type diffusers to the round outlets for hi-velocity systems used.  The only thing I would recommend is that the outlets be mounted so they don't discharge directly onto anyone.  ER/HRV units are only about 80% efficient, and can discharge cold air on days when it is very cold outside.  Insulation of the ductwork is vital.

Thanks!

The diffusers seem to run on the large side of things. I like the high velocity outlets but they're $pendy. Oh, well...