I’m installing a Fujitsu ceiling cassette unit, with the 3-way outlet configuration. The manual shows a min. 4″ clearance, but then makes a note about ensuring sufficient service access. There is plenty of access from above in the attic.

Do you read that as the 4″ clearance is required only to ensure access, or that 4″ clearance is required no matter what?

I’m in a tight spot between trusses which can’t be altered, and the otherwise ideal place to locate the unit leaves around 2.5″ or 3″ clearance to wall. Would you expect performance / comfort / airflow issues with this configuration?