*Minimum* Duct Length for ERV Intake?

I’m installing a Panasonic Whispercomfort ERV in a bedroom wall stud cavity, furred out to 7″ D. The runs are simple — 4″ vertical flex followed by a *rigid* 90… I’m installing a Panasonic Whispercomfort ERV in a bedroom wall stud cavity, furred out to 7″ D. The runs are simple — 4″ vertical flex followed by a *rigid* 90…Read MoreGreenBuildingAdvisor