I would like to know your opinion based on the regulations on the following.
Q1) Do I have to install the duct CO detector even though the CO detector is installed in the mechanical room?
Our contractor said, "We installed duct mounted CO detector in the bldg that has an existing warm air furnace installed, which distributes heat into the rooms via a supply fan and HVAC ducting. This duct CO detector meets the requirements of UFC 3-600-01 (para. 5-9.2) and NFPA 720 (para. 22.214.171.124.1(2)). Please note that the bldg has one zone for heat distribution, thus a duct mounted CO detector was provided for centralized monitoring of CO, and initiate the shutdown of the fan if the duct CO detector activates."
But as I understand it, only the CO detector is mentioned in the regulations. And I understand that 'HVAC zone' or 'Centrally located' means is indoor, not inside duct. Please tell me your opinion.
Q2) Do the duct CO detector and the CO detector have to be interconnected?
If so, can you tell me the regulation?