💨 NFPA 54 Section 9.3 (1 Sq In / 1,000 BTU Outdoor Air, Motorized Damper Sizing)

Gas Boiler Combustion Air Calculator

Size combustion air intake louvers, motorized dampers, and engineered mechanical supply fans for commercial gas boiler and water heater mechanical rooms under NFPA 54 Section 9.3 & IFGC: calculate mandatory net free opening area (1.0 sq in per 1,000 BTU/hr for two direct outdoor openings / 1.0 sq in per 4,000 BTU/hr for single opening), and mechanical HVAC margins.

1. Project & Operating Inputs

Total Mechanical Room Gas Input (MBH e.g. 6,000 MBH Boiler Plant)

Louver Free Area Percentage (% e.g. 50.0% Aluminum Screen Louver)

Customer Bid Price for Supplied & Wired Motorized Louver Package ($)

Ruskin Motorized Intake Damper, End-Switch Interlock, Electrician Labor ($)

2. Financial Breakdown & Yield

NFPA 54 COMBUSTION AIR LOUVERS

Turnkey Combustion Air Package Profit

Boiler Room Mechanical Contractor Margin

0.0%

Gross Revenue / Bill

Total Project CapEx

Operating / Material Cost