Earlier editions: 2022 2019

311.1 Source — 2025 California Mechanical Code

California Mechanical Code (Title 24, Part 4) · 2025 edition · updated 2026-09-25 · California

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Italicized text is a California amendment to the model code, as printed in the official publication.

Cite as: 2025 California Mechanical Code (Title 24, Part 4) § 311.1 · Effective January 1, 2026 · Official source: Building Standards Commission

A heating or cooling air system shall be provided with return air, outside air, or both. A heating or cooling air system regulated by this code and designed to replace required ventilation shall be arranged to discharge into a conditioned space not less than the amount of outside air specified in Chapter 4.

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▸Contents — California Mechanical Code (Title 24, Part 4)

California Mechanical Code (Title 24, Part 4)

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