# Return-Air Ducted through the ceiling ### Issue Image: ![[Pasted image 20241219144332.png]] ## Issue Description: - in Apartments, return air is frequently ducted back to the Air conditioning units via the ceiling plenum. - This is a valid strategy where the ceiling is an air tight concrete ceiling. - If the ceiling is a leaky metal roof, this won't work as the air conditioner will suck in air from external spaces! - possible solutions included ducting the return air directly from the living space. ## Actions to Prevent this Issue: - [ ] The Mechanical engineer shall check the return air pathways for all AC units are not prone to sucking air from the wrong space. ## Source