Duct Furnaces and Heaters
NYC Mechanical Code § MC 911
in effectSection MC 911: Duct Furnaces and Heaters
911.1 General.
Duct furnaces and heaters shall be installed in accordance with the manufacturer's instructions. Electric furnaces and duct heaters shall comply with UL 1995 or UL 1996, as applicable. Unvented fuel-fired duct furnaces are prohibited.
911.2 Access panels.
Ducts connected to duct furnaces shall have removable access panels on both the upstream and downstream sides of the furnace.
911.3 Location of draft hood and controls.
The controls, combustion air inlets and draft hoods for duct furnaces shall be located outside of the ducts. The draft hood shall be located in the same enclosure from which combustion air is taken.
911.4 Circulating air.
Where a duct furnace is installed so that supply ducts convey air to areas outside the space containing the furnace, the return air shall also be conveyed by a duct(s) sealed to the furnace casing and terminating outside the space containing the furnace. The duct furnace shall be installed on the positive pressure side of the circulating air blower.
911.5 Duct Temperature.
The outlet duct temperature of duct furnaces shall not be greater than 250°F (121.1°C).
Source: City of New York, Charter, Administrative Code and Rules (American Legal Publishing XML export, codelibrary.amlegal.com)URL: https://codelibrary.amlegal.com/codes/newyorkcity/latest/NYCadmin/0-0-0-195269Fetched: 10/24/2026