• Codes
  • Features

    Features Overview

    Go to features
    Reference

    Reference.

    A reliable and up-to-date source of codes.
    Research

    Research.

    Rapidly and efficiently calculate project parameters.
    Collaboration

    Collaboration.

    Get everyone on the same page and streamline code research.
    Workflows
    Architects General Contractor Building Official & Plans Examiner Inspectors Owner Subcontractors Code Consultants
  • Pricing
  • Login
  • Sign Up
Sign Up
Login
  • Code Library
  • Features
  • Pricing
  • About
  • Careers
  • Help
  • Contact
  • Terms
  • Privacy
Sign Up
Upgrade to Premium
Code calculators: Code Calculators automatically generates a detailed list of requirements.
REFERENCE
Amendment Styling
Industry-leading search
Suggested code sections
Code diagrams
RESEARCH
Code calculators
Filter by topic
Code compare
Code sheet exports
COLLABORATION
Team projects
Bookmarks
Comments
START 2 WEEK FREE TRIAL
Have an account? Sign in
// CODE SNIPPET

701.4 Indoor Combustion Air

California Mechanical Code 2019 > 7 Combustion Air > 701.0 General > 701.4 Indoor Combustion Air
JUMP TO FULL CODE CHAPTER
The required volume of indoor air shall be determined in accordance with the method in Section 701.4.1 or Section 701.4.2, except that where the air infiltration rate is known to be less than 0.40 ACH (air change per hour), the method in Section 701.4.2 shall be used. The total required volume shall be the sum of the required volume calculated for appliances located within the space. Rooms communicating directly with the space in which the appliances are installed through openings not furnished with doors, and through combustion air openings sized and located in accordance with Section 701.5, are considered a part of the required volume. [NFPA 54:9.3.2]

701.4.1 Standard Method

The required volume shall be not less than 50 cubic feet per 1000 British thermal units per hour (Btu/h) (4.83 m3/kW). [NFPA 54:9.3.2.1]

701.4.2 Known Air Infiltration Rate Method

Where the air infiltration rate of a structure is known, the minimum required volume shall be determined as follows [NFPA 54:9.3.2.2]:
  1. For appliances other than fan-assisted, calculate using the following Equation 701.4.2(1). [NFPA 54:9.3.2.2(1)]
  2. For fan-assisted appliances, calculate using the following Equation 701.4.2(2). [NFPA 54: 9.3.2.2(2)]
  3. For purposes of these calculations, an infiltration rate greater than 0.60 ACH shall not be used in the equations in Section 701.4.2(1) and Section 701.4.2(2). [NFPA 54:9. 3.2.2(3)]
Required Volume other ≥ (21 ft3/ACH) x (Iother/1000 Btu/h) [Equation 701.4.2(1)]

Required Volume fan ≥ (15 ft3/ACH) x (Ifan/1000 Btu/h) [Equation 701.4.2(2)]

Where:
I other = All appliances other than fan-assisted input (Btu/h)
I fan = Fan-assisted appliance input (Btu/h)
ACH = Air change per hour (percent of volume of space exchanged per hour, expressed as a decimal)
For SI units: 1 cubic foot = 0.0283 m3, 1000 British thermal units per hour = 0.293 kW

Related Code Sections


506.2 Water Heaters, Indoor Combustion Air
The required volume of indoor air shall be determined in accordance with Section 506.2.1 or Section 506.2.2, except that where the air infiltration ...
California Plumbing Code 2016 > 5 Water Heaters > 506.0 Air for Combustion and Ventilation > 506.2 Indoor Combustion Air
506.2 Water Heaters, Indoor Combustion Air
The required volume of indoor air shall be determined in accordance with the method in Section 506.2.1 or Section 506.2.2, except that where the air ...
California Plumbing Code 2019 > 5 Water Heaters > 506.0 Air for Combustion and Ventilation > 506.2 Indoor Combustion Air
701.4 Combustion Air, Indoor Combustion Air
The required volume of indoor air shall be determined in accordance with the method in Section 701.4.1 or Section 701.4.2, except that where the air ...
California Mechanical Code 2016 > 7 Combustion Air > 701.0 General > 701.4 Indoor Combustion Air
701.4 Combustion Air, Indoor Combustion Air
The required volume of indoor air shall be determined in accordance with the method in Section 701.4.1 or Section 701.4.2, except that where the air ...
California Mechanical Code 2019 > 7 Combustion Air > 701.0 General > 701.4 Indoor Combustion Air
Help Contact Us Privacy Terms
Code Compare
Code Compare
Highlight differences between any two building codes.
Code Calculators
Code Calculators
Code calculators automatically generate a detailed list of requirements.
Code diagrams
Code diagrams
Unpack the code through illustrations and descriptions.
Search
Search
Don't miss relevant code. Quickly locate sections across your jurisdiction.
Code sheet exports
Code sheet exports
Generate a code sheet that integrates with your drawing set.
Shared projects
Shared projects
Projects provide a dedicated space to collaborate on code research.
UpCodes Premium
Leverage the most sophisticated code compliance platform.
TRY FREE FOR TWO WEEKS VISIT PRICING
UpCodes Premium
Leverage the full code compliance platform.
START 2 WEEK FREE TRIAL LEARN MORE