I have a question for the Fire Alarm Gurus / NICET certification holders. I am currently on a project where there are quite a few Duct detectors indicated on ducts where there is no way to install the housing at the locations prescribed by the manufacturer's installation instructions. There is just not enough duct. I have heard muttering and statements that in this situation, as close to meeting the criteria as possible will suffice. I am not able to make this determination from NFPA 72, nor am I an expert on airflow. this issue was brought up to me by the mechanical contractor asking how to proceed. Surely this cannot be the only time that this issue has come up on a project. Does anyone have any input on how this situation has been successfully remedied?