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Chapter 5 — NONRESIDENTIAL AND HOTEL/MOTEL OCCUPANCIES—PERFORMANCE AND PRESCRIPTIVE COMPLIANCE APPROACHES FOR ACHIEVING ENERGY EFFICIENCY

Section 140.5 — PRESCRIPTIVE REQUIREMENTS FOR SERVICE WATER-HEATING SYSTEMS

2025 California Energy Code (Title 24, Part 6) · 2025 edition · updated 2026-07-25 · California

(a) Nonresidential occupancies. Service water-heating systems in nonresidential buildings shall meet the requirements of 1 or 2 below, or meet the performance compliance requirements of Section 140.1:

  1. School buildings less than 25,000 square feet and less than 4 stories in Climate Zones 2 through 15. A heat pump water-heating system that meets the applicable requirements of Sections 110.1, 110.3 and 120.3.

Exception to Section 140.5(a)1: A water-heating system serving an individual bathroom space may be an instantaneous electric water heater.

  1. All other occupancies. A service water-heating system that meets the applicable requirements of Sections 110.1, 110.3, 120.3 and 140.5(c).

(b) Hotel/motel occupancies. A service water-heating system installed in hotel/motel buildings shall meet the requirements of Section 170.2(d).

(c) High-capacity service water-heating systems . Gas service water-heating systems with a total installed gas water-heating input capacity of 1 MMBtu/h or greater shall have gas service water-heating equipment with a minimum thermal efficiency of 90 percent. Multiple units can meet this requirement if the water-heating input provided by equipment with thermal efficiencies above and below 90 percent averages out to an input capacity-weighted average of at least 90 percent.

Exception 1 to Section 140.5(c): If 25 percent of the annual service water-heating requirement is provided by site-solar energy or site-recovered energy.

Exception 2 to Section 140.5(c): Water heaters installed in individual dwelling units.

Exception 3 to Section 140.5(c): Individual gas water heaters with input capacity at or below 100,000 Btu/h shall not be included in the calculations of the total system input or total system efficiency.

Note: Authority: Sections 25213, 25218, 25218.5, 25402 and 25402.1, Public Resources Code. Reference: Sections 25007, 25008, 25218.5, 25310, 25402, 25402.1, 25402.4, 25402.8, and 25943, Public Resources Code.

on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

NONRESIDENTIAL AND HOTEL/MOTEL OCCUPANCIES—PERFORMANCE AND PRESCRIPTIVE

COMPLIANCE APPROACHES FOR ACHIEVING ENERGY EFFICIENCY

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Contents — 2025 California Energy Code (Title 24, Part 6)
2025 California Energy Code (Title 24, Part 6)
  1. Chapter 1 — ALL OCCUPANCIES—GENERAL PROVISIONS
  2. Chapter 2 — ALL OCCUPANCIES—MANDATORY REQUIREMENTS FOR THE MAN…
  3. Chapter 3 — NONRESIDENTIAL, HOTEL/MOTEL OCCUPANCIES, AND COVER…
  4. Chapter 4 — NONRESIDENTIAL AND HOTEL/MOTEL OCCUPANCIES—MANDATO…
  5. Chapter 5 — NONRESIDENTIAL AND HOTEL/MOTEL OCCUPANCIES—PERFORM…
  6. Chapter 6 — NONRESIDENTIAL AND HOTEL/MOTEL OCCUPANCIES—
  7. Chapter 7 — SINGLE-FAMILY RESIDENTIAL BUILDINGS—
  8. Chapter 8 — SINGLE-FAMILY RESIDENTIAL BUILDINGS—PERFORMANCE AN…
  9. Chapter 9 — SINGLE-FAMILY RESIDENTIAL BUILDINGS—ADDITIONS AND …
  10. Chapter 10 — MULTIFAMILY BUILDINGS—MANDATORY REQUIREMENTS
  11. Chapter 11 — MULTIFAMILY BUILDINGS—PERFORMANCE AND PRESCRIPTIV…
  12. Chapter 12 — MULTIFAMILY BUILDINGS—ADDITIONS, ALTERATIONS AND …

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