One of the first things I did when I bought my house about 11 years ago was replace the bath fan with a Panasonic WhisperFit. Recently, I had a blower door test done and it’s clear several years of tightening up the house means I’m (way) overdue for some mechanical ventilation. I’ve decided to go exhaust-only with about 30CFM average. What I’d like to do is install a WhisperGreen, but it doesn’t appear any of those fit with my 6″ ceiling joists? My best option seems to be the latest version of the whisperfit (or keep my current older model).

Any suggestions as to the best fan that would fit in that space? Ideally with the ability to do about 80cfm for showers? I plan on using the Airetrak 1-A to run it at low speed 100% of the time and then full speed when selected by occupant for showers, etc. Or, a duty cycle to approximate an average of 30cfm.

Thanks!