Hot-water distribution, recirculation and demand controls

Grounded in the retrieved California Energy Code — click a citation to read the verbatim passage:

• § 501.2.2 High relevance — show source text

  Exception: Vertical supports, and horizontal and vertical anchors shall be installed on the pipe inside the pipe insulation.

  L 501.2.2 Building Cavities. Building cavities used for hot water supply and return piping shall be large enough to accommodate the combined diameter of the pipe plus the insulation, plus any other objects in the cavity that the piping must cross. L 501.3 Recirculation Systems. Recirculation systems shall comply with Section L 501.3.1 and Section L 501.3.2.

  L 501.3.1 For Low-Rise Residential Buildings. Circulating hot water systems shall be arranged so that the circulating pump(s) are capable of being turned off (automatically or manually) where the hot water system is not in operation. [ASHRAE 90.2-2007:7.2] L 501.3.2 For Pumps Between Boilers and Stor- age Tanks. Where used to maintain storage tank water temperature, recirculating pumps shall be equipped with controls limiting operation to a period from the start of the heating cycle to a maximum of 5 minutes after the end of the heating cycle. [ASHRAE 90.1:7.4.4.4] L 501.4 Recirculation Pump Controls. Pump controls shall include on-demand activation or time clocks combined with temperature sensing. Time clock controls for pumps shall not let the pump operate more than 15 minutes every hour. Temperature sensors shall stop circulation where the temperature set point is reached and shall be located on the circulation loop at or near the last fixture. The pump, pump controls, and temperature sensors shall be accessible. Pump operation shall be limited to the building’s hours of operation. L 501.4.1 Hot Water On-Demand Pumping Sys- tems. Hot water on-demand pumping systems manually actuated or automatically activated hot water pumping systems shall comply with IAPMO PS 115. L 501.5 Temperature Maintenance Controls. Systems designed to maintain usage temperatures in hot-water pipes, such as recirculating hot water systems or heat trace, shall be equipped with automatic time switches or other controls that are capable of being set to switch off the usage temperature maintenance system during extended periods where hot water is not required. [ASHRAE 90.1:7.4.4.2] L 501.6 System Balancing. Systems with multiple recirculation zones shall be balanced to distribute hot water uniformly, or they shall be operated with a pump for each zone. The circulation pump controls shall comply with the provisions of Section L 501.4.

  L 501.7 Flow Balancing Valves. Flow balancing valves shall be a factory preset automatic flow control valve, a flow regulating valve, or a balancing valve with memory stop.

  L 501.8 Air Elimination. Provision shall be made for the elimination of air from the return system. L 501.9 Gravity or Thermosyphon Systems. Gravity or thermosyphon systems are prohibited.

  L 502.0 Service Hot Water – Low-Rise Residential Buildings. L 502.1 General. The service water heating system for single-family houses, multi-family structures of three stories or fewer above grade, and modular houses shall comply with Section L 502.2 through Section L 502.7.3. The service water heating system of all other buildings shall comply with Section L 503.0.

• § 501.4.1 High relevance — show source text

  L 501.4.1 Hot Water On-Demand Pumping Sys- tems. Hot water on-demand pumping systems manually actuated or automatically activated hot water pumping systems shall comply with IAPMO PS 115. L 501.5 Temperature Maintenance Controls. Systems designed to maintain usage temperatures in hot-water pipes, such as recirculating hot water systems or heat trace, shall be equipped with automatic time switches or other controls that are capable of being set to switch off the usage temperature maintenance system during extended periods where hot water is not required. [ASHRAE 90.1:7.4.4.2] L 501.6 System Balancing. Systems with multiple recirculation zones shall be balanced to distribute hot water uniformly, or they shall be operated with a pump for each zone. The circulation pump controls shall comply with the provisions of Section L 501.4.

  L 501.7 Flow Balancing Valves. Flow balancing valves shall be a factory preset automatic flow control valve, a flow regulating valve, or a balancing valve with memory stop.

  L 501.8 Air Elimination. Provision shall be made for the elimination of air from the return system. L 501.9 Gravity or Thermosyphon Systems. Gravity or thermosyphon systems are prohibited.

  L 502.0 Service Hot Water – Low-Rise Residential Buildings. L 502.1 General. The service water heating system for single-family houses, multi-family structures of three stories or fewer above grade, and modular houses shall comply with Section L 502.2 through Section L 502.7.3. The service water heating system of all other buildings shall comply with Section L 503.0.

  L 502.2 Water Heaters and Storage Tanks. Residentialtype water heaters, pool heaters, and unfired water heater storage tanks shall comply with the minimum performance requirements specified by federal law. Unfired storage water heating equipment shall have a heat loss through the tank surface area of less than 6.5 British thermal units per square foot hour [Btu/(ft [2] - h)] (20.5 W/m [2] ).

  [ASHRAE 90.2-2007:7.1] L 502.3 Recirculation Systems. Recirculation systems shall comply with the provisions of Section L 501.3. L 502.4 Central Water Heating Equipment. Service water heating equipment (central systems) that do not fall under the requirements for residential-type service water heating equipment addressed in Section L 502.2 shall comply with the applicable requirements for service water-heating equipment found in Section L 503.0. [ASHRAE 90.2-2007:7.3] L 502.5 Insulation. Insulation for hot water and return piping shall comply with the provisions of Section L 501.2. L 502.6 Hard Water. Where water has hardness equal to or exceeding 9 grains per gallon (gr/gal) (154 mg/L) measured as total calcium carbonate equivalents, the water supply line to water heating equipment in new one- and two-family dwellings shall be roughed-in to allow for the installation of water treatment equipment. L 502.7 Maximum Volume and Length of Hot Water. The maximum volume of water contained in a hot water

  branch shall be in accordance with Section L 502.7.1. The maximum length per volume of piping shall comply with Section L 502.7.2.

• § 170.1. High relevance — show source text

  000|≥10,000|≥5,000|≥5,000|≥2,000|≥2,000|≥2,000|≥2,000|≥2,000| |≥60% and <70%|≥2,000|≥2,000|≥6,000|≥6,000|≥6,000|NR|NR|≥18,000|≥9,000|≥4,000|≥4,000|≥2,000|≥2,000|≥2,000|≥2,000|≥2,000| |≥70% and <80%|≥2,000|≥2,000|≥6,000|≥5,000|≥5,000|NR|NR|≥15,000|≥8,000|≥3,000|≥3,000|≥2,000|≥2,000|≥2,000|≥2,000|≥2,000| |≥80%|≥2,000|≥2,000|≥6,000|≥5,000|≥5,000|NR|NR|≥12,000|≥7,000|≥3,000|≥3,000|≥2,000|≥2,000|≥2,000|≥2,000|≥2,000|

  256 2025 CALIFORNIA ENERGY CODE

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  MULTIFAMILY BUILDINGS—PERFORMANCE AND PRESCRIPTIVE COMPLIANCE APPROACHES

  (d) Domestic hot water systems. Water-heating systems shall meet the applicable requirements of 1 or 2 below:

  1. Individual systems. For systems serving individual dwelling units, the water-heating system shall meet the requirement of either A or B, or shall meet the performance compliance requirements of Section 170.1. For recirculation distribution systems serving individual dwelling units, only demand recirculation systems with manual on/off control as specified in the Reference Appendix RA4.4.9 shall be used. A. A single 240 volt heat pump water heater. In addition, meet the following: i. A compact hot water distribution system as specified in Reference Appendix RA4.4.6 in Climate Zones 1 and 16; and

  ii. A drain water heat recovery system that is field verified as specified in the Reference Appendix RA3.6.9 in Climate Zone 16.

  B. A single heat pump water heater that meets the requirements of NEEA Advanced Water Heater Specification Tier 3 or higher. In addition, for Climate Zone 16, a drain water heat recovery system that is field verified as specified in Reference Appendix RA3.6.9. Exception 1 to Section 170.2(d)1: Multifamily buildings four habitable stories or greater may install a gas or propane instantaneous water heater with an input of 200,000 Btu per hour or less and no storage tank. Exception 2 to Section 170.2(d)1: A 120V HPWH may be installed in place of a 240V HPWH for new dwelling units with one bedroom or less.

  2. **Central systems.
• § 170.1. High relevance — show source text

  MULTIFAMILY BUILDINGS—PERFORMANCE AND PRESCRIPTIVE COMPLIANCE APPROACHES

  (d) Domestic hot water systems. Water-heating systems shall meet the applicable requirements of 1 or 2 below:

  1. Individual systems. For systems serving individual dwelling units, the water-heating system shall meet the requirement of either A or B, or shall meet the performance compliance requirements of Section 170.1. For recirculation distribution systems serving individual dwelling units, only demand recirculation systems with manual on/off control as specified in the Reference Appendix RA4.4.9 shall be used. A. A single 240 volt heat pump water heater. In addition, meet the following: i. A compact hot water distribution system as specified in Reference Appendix RA4.4.6 in Climate Zones 1 and 16; and

  ii. A drain water heat recovery system that is field verified as specified in the Reference Appendix RA3.6.9 in Climate Zone 16.

  B. A single heat pump water heater that meets the requirements of NEEA Advanced Water Heater Specification Tier 3 or higher. In addition, for Climate Zone 16, a drain water heat recovery system that is field verified as specified in Reference Appendix RA3.6.9. Exception 1 to Section 170.2(d)1: Multifamily buildings four habitable stories or greater may install a gas or propane instantaneous water heater with an input of 200,000 Btu per hour or less and no storage tank. Exception 2 to Section 170.2(d)1: A 120V HPWH may be installed in place of a 240V HPWH for new dwelling units with one bedroom or less.

  2. Central systems. For systems serving multiple dwelling units, the water-heating system shall meet the applicable requirement of A through F, or shall meet the performance compliance requirements of Section 170.1: A. For heat pump water-heating systems serving multiple dwelling units, the water-heating system shall be installed according to the manufacturer’s design and installation guidelines and meet the following requirements, or meet the requirements of NEEA Advanced Water Heater Specification for commercial heat pump water heater Tier 2 or higher: i. The primary heat pump water heater shall be a single-pass heat pump water heater. ii. The hot water return from the recirculation loop shall connect to a recirculation loop tank and shall not directly connect to the primary heat pump water heater inlet or the primary thermal storage tanks. iii. The fuel source for the recirculation loop tank shall be electricity. iv. The primary storage tank temperature setpoint shall be at least 135°F. v. The recirculation loop tank temperature setpoint shall be at least 10°F lower than the primary thermal storage tank temperature setpoint. vi. The minimum heat pump water heater compressor cut-off temperature shall be equal to or lower than 40°F ambient air temperature. vii. Design documentation shall be provided in accordance with JA14.4. B. For gas or propane systems serving multiple dwelling units, the water-heating system that includes the following components shall be installed: i. For Climate Zones 1 through 9, 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 are allowed to meet this requirement with an input capacity-weighted average of at least 90 percent.
• § 303.1 High relevance — show source text

  2025 CALIFORNIA GREEN BUILDING STANDARDS CODE APPENDIX A4-11

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  APPENDIX A4-12 2025 CALIFORNIA GREEN BUILDING STANDARDS CODE

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  A4 RESIDENTIAL VOLUNTARY MEASURES

  DIVISION A4.3 – WATER EFFICIENCY AND CONSERVATION

  SECTION A4.301—GENERAL (RESERVED)

  SECTION A4.302—DEFINITIONS (RESERVED)

  SECTION A4.303—INDOOR WATER USE

  A4.303.1 Kitchen faucets. The maximum flow rate of kitchen faucets shall not exceed 1.5 gallons per minute at 60 psi. Kitchen faucets may temporarily increase the flow above the maximum rate, but not to exceed 2.2 gallons per minute at 60 psi, and must default to a maximum flow rate of 1.5 gallons per minute at 60 psi.

  Note: Where complying faucets are unavailable, aerators or other means may be used to achieve reduction.

  A4.303.2 Alternate water sources for nonpotable applications. Alternate nonpotable water sources are used for indoor potable water reduction. Alternate nonpotable water sources shall be installed in accordance with the California Plumbing Code.

  A4.303.3 Appliances. Install at least one qualified ENERGY STAR dishwasher or clothes washer.

  Note: See Section A5.303.3 for nonresidential dishwashers and clothes washers.

  A4.303.4 Nonwater urinals and waterless toilets. Nonwater urinals or composting toilets are installed.

  Where approved, nonwater urinals with drain cleansing action (formerly hybrid urinals), as defined in Chapter 2, shall be considered nonwater urinals.

  A4.303.5 Hot water recirculation systems. One- and two-family dwellings shall be equipped with a demand hot water recirculation system, as defined in Chapter 2. The demand hot water recirculation system shall be installed in accordance with the California Plumbing Code, California Energy Code and the manufacturer’s installation instructions.

  SECTION A4.304—OUTDOOR WATER USE

  A4.304.1 Rainwater catchment systems. An approved rainwater catchment system is designed and installed to use rainwater generated by at least 65 percent of the available roof area. Rainwater catchment systems shall be designed and installed in accordance with the California Plumbing Code.

  A4.304.2 Potable water elimination. When landscaping is provided and as allowed by local ordinance, a water efficient landscape irrigation design that eliminates the use of potable water beyond the initial requirements for plant installation and establishment shall be provided. Methods used to accomplish the requirements of this section shall comply with the requirements of the California Building Standards Code and shall include, but not be limited to, the following:

  1. Use of captured rainwater.
  2. Use of recycled water.
  3. Water treated for irrigation purposes and conveyed by a water district or public entity.
  4. Use of graywater.
  5. Use of drought tolerant plants.

  A4.304.3 Landscape water meters. For new water service connections, landscaped irrigated areas less than 5,000 square feet shall be provided with separate submeters or metering devices for outdoor potable water use.

• § 180.2 High relevance — show source text

  Existing duct systems constructed, insulated or sealed with asbestos are not required to comply with the requirements of Subsection 180.2(b)2Biiib.

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  MULTIFAMILY BUILDINGS—ADDITIONS, ALTERATIONS AND REPAIRS TO EXISTING MULTIFAMILY BUILDINGS

  3. Hot water systems . Altered or replacement water-heating systems or components serving individual dwelling units shall meet the applicable requirements below: A. Pipe insulation. For newly installed piping and existing accessible piping, the insulation requirements of Section 160.4(e) shall be met. B. Distribution system. For recirculation distribution system serving individual dwelling units, only demand recirculation systems with manual on/off control as specified in Reference Appendix RA4.4.9 shall be installed. C. Water-heating system. The water-heating system shall meet one of the following: i. A natural gas or propane water-heating system; or ii. A single heat pump water heater. The storage tank shall not be located outdoors and shall be placed on an incompressible, rigid insulated surface with a minimum thermal resistance of R-10. The water heater shall be installed with a communication interface that either meets the requirements of Section 110.12(a) or has an ANSI/CTA-2045-B communication port; or iii. A single heat pump water heater that meets the requirements of NEEA Advanced Water Heater Specification Tier 3 or higher; or iv. If the existing water heater is an electric resistance water heater, a consumer electric water heater. v. A water-heating system determined by the Executive Director to use no more energy than the one specified in Sections 180.2(b)3Ci through iii above; or if no natural gas is connected to the existing water heater location, a water-heating system determined by the Executive Director to use no more energy than the one specified in Section 180.2(b)3Civ above.

  4. Lighting. A. Dwelling unit lighting. The altered lighting system shall meet the lighting requirements of Section 160.5(a). The altered luminaires shall meet the luminaire efficacy requirements of Section 160.5(a). Where existing screw base sockets are present in ceiling-recessed luminaires, removal of these sockets is not required, provided that new JA8 compliant trim kits or lamps designed for use with recessed downlights or luminaires are installed. B. Common use area—lighting, sign lighting, and electrical power distribution systems . i. Spaces with lighting systems installed for the first time shall meet the applicable requirements of Sections 110.9, 160.5(b)1, 160.5(b)2, 160.5(b)3, 160.5(b)4, 160.5(c), 160.5(e), 170.2(b), and 170.2(e)1 through 170.2(e)6. ii. When the requirements of Section 160.5(b)4D are triggered by the addition of skylights to an existing building and the lighting system is not recircuited, the daylighting control need not meet the multi-level requirements in Section 160.5(b)4D. iii. New internally and externally illuminated signs shall meet the requirements of Sections 110.9, 160.5(d) and 170.2(e)7. iv. Altered indoor lighting systems.

• § 501.2 High relevance — show source text

  L 501.2 Insulation. Hot water supply and return piping shall be thermally insulated. The wall thickness of the insulation shall be equal to the nominal diameter of the pipe up to 2 inches (50 mm). The wall thickness shall be not less than 2 inches (51 mm) for nominal pipe diameters exceeding 2 inches (50 mm). The conductivity of the insulation [k-factor (Btu•in/(h•ft [2] - °F))], measured radially, shall not be more than 0.28 [Btu•in/(h•ft [2] - °F)] [0.04 W/(m•K)]. Hot water piping to be insulated shall be installed such that insulation is continuous. Pipe insulation shall be installed to within [1] ⁄ 4 of an inch (6.4 mm) of appliances, appurtenances, fixtures, structural members, or a wall where the pipe passes through to connect to a fixture within 24 inches (610 mm).

  2025 CALIFORNIA PLUMBING CODE 507

  ), Copyright © 2025 IAPMO, and may not be used for any other purpose or distributed to any other persons or parties.

  APPENDIX L

  Exceptions:

  (1) Where the hot water pipe is installed in a wall that is not of a width to accommodate the pipe and insulation, the insulation thickness shall be permitted to have the maximum thickness that the wall is capable of accommodating and not less than [1] ⁄ 2 of an inch (12.7 mm) thick.

  (2) Hot water supply piping exposed under sinks, lavatories, and similar fixtures.

  L 501.2.1 Pipe Supports. Pipe supports shall be installed on the outside of the pipe insulation.

  Exception: Vertical supports, and horizontal and vertical anchors shall be installed on the pipe inside the pipe insulation.

  L 501.2.2 Building Cavities. Building cavities used for hot water supply and return piping shall be large enough to accommodate the combined diameter of the pipe plus the insulation, plus any other objects in the cavity that the piping must cross. L 501.3 Recirculation Systems. Recirculation systems shall comply with Section L 501.3.1 and Section L 501.3.2.

  L 501.3.1 For Low-Rise Residential Buildings. Circulating hot water systems shall be arranged so that the circulating pump(s) are capable of being turned off (automatically or manually) where the hot water system is not in operation. [ASHRAE 90.2-2007:7.2] L 501.3.2 For Pumps Between Boilers and Stor- age Tanks. Where used to maintain storage tank water temperature, recirculating pumps shall be equipped with controls limiting operation to a period from the start of the heating cycle to a maximum of 5 minutes after the end of the heating cycle. [ASHRAE 90.1:7.4.4.4] L 501.4 Recirculation Pump Controls. Pump controls shall include on-demand activation or time clocks combined with temperature sensing. Time clock controls for pumps shall not let the pump operate more than 15 minutes every hour. Temperature sensors shall stop circulation where the temperature set point is reached and shall be located on the circulation loop at or near the last fixture. The pump, pump controls, and temperature sensors shall be accessible. Pump operation shall be limited to the building’s hours of operation.

• § 110.12 High relevance — show source text

  iii. Altered space-conditioning systems. When a space-conditioning system is altered by the installation or replacement of space-conditioning system equipment (including replacement of the air handler, outdoor condensing unit of a split system air conditioner or heat pump, or cooling or heating coil: a. For all altered units where the existing thermostat does not comply with the requirements for demand responsive controls specified in Section 110.12, the existing thermostat shall be replaced with a demand responsive thermostat that complies with Section 110.12. All newly installed space-conditioning systems requiring a thermostat shall be equipped with a demand responsive thermostat that complies with Section 110.12; and

  b. The duct system that is connected to the new or replaced space-conditioning system equipment shall be sealed, if the duct system meets the criteria of Section 120.4(g), as confirmed through acceptance testing, in accordance with the applicable procedures for duct sealing of altered existing duct systems as specified in Reference Nonresidential Appendix NA7.5.3, and conforming to the applicable leakage compliance criteria in Section 180.2(b)2Bii. Exception 1 to Section 180.2(b)2Biiib: duct sealing . Buildings altered so that the duct system no longer meets the criteria of Section 170.2(c)4Ji are not required to comply with Subsection 180.2(b)2Biiib. Exception 2 to Section 180.2(b)2Biiib: duct sealing . Duct systems that are documented to have been previously sealed as confirmed through acceptance testing in accordance with procedures in the Reference Nonresidential Appendix NA7.5.3 are not required to comply with Subsection 180.2(b)2Biiib. Exception 3 to Section 180.2(b)2Biiib: duct sealing . Existing duct systems constructed, insulated or sealed with asbestos are not required to comply with the requirements of Subsection 180.2(b)2Biiib.

  2025 CALIFORNIA ENERGY CODE 279

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  MULTIFAMILY BUILDINGS—ADDITIONS, ALTERATIONS AND REPAIRS TO EXISTING MULTIFAMILY BUILDINGS

  3. Hot water systems . Altered or replacement water-heating systems or components serving individual dwelling units shall meet the applicable requirements below: A. Pipe insulation. For newly installed piping and existing accessible piping, the insulation requirements of Section 160.4(e) shall be met. B. Distribution system. For recirculation distribution system serving individual dwelling units, only demand recirculation systems with manual on/off control as specified in Reference Appendix RA4.4.9 shall be installed. C. Water-heating system. The water-heating system shall meet one of the following: i. A natural gas or propane water-heating system; or ii. A single heat pump water heater. The storage tank shall not be located outdoors and shall be placed on an incompressible, rigid insulated surface with a minimum thermal resistance of R-10. The water heater shall be installed with a communication interface that either meets the requirements of Section 110.12(a) or has an ANSI/CTA-2045-B communication port; or iii. A single heat pump water heater that meets the requirements of NEEA Advanced Water Heater Specification Tier 3 or higher; or iv. If the existing water heater is an electric resistance water heater, a consumer electric water heater.
• § 110.3 High relevance — show source text

  1. Outlet temperature controls. On systems that have a total capacity greater than 167,000 Btu/hr, outlets that require higher than service water temperatures as listed in the ASHRAE Handbook, Applications Volume, shall have separate remote heaters, heat exchangers or boosters to supply the outlet with the higher temperature. Exception to Section 110.3(c)1: Systems covered by California Plumbing Code Section 613.0 shall instead follow the requirements of that section.
  2. Controls for hot water distribution systems. Service hot water systems with circulating pumps or with electrical heat trace systems shall be capable of automatically turning off the system. Exception to Section 110.3(c)2: Systems serving healthcare facilities.
  3. Insulation. Unfired service water heater storage tanks and backup tanks for solar water-heating systems shall have: A. External insulation with an installed R -value of at least R-3.5; or

  B. Internal and external insulation with a combined R -value of at least R-16; or

  C. The heat loss of the tank surface based on an 80°F water-air temperature difference shall be less than 6.5 Btu per hour per square foot. 4. Water heating recirculation loops serving multiple dwelling units, high-rise residential, hotel/motel, and nonresiden- tial occupancies. A water heating recirculation loop is a type of hot water distribution system that reduces the time needed to deliver hot water to fixtures that are distant from the water heater, boiler or other water heating equipment. The recirculation loop is comprised of a supply portion, connected to branches that serve multiple dwelling units, guest rooms, or fixtures and a return portion that completes the loop back to the water heating equipment. A water heating recirculation loop shall meet the following requirements: A. Air release valve or vertical pump installation. An automatic air release valve shall be installed on the recirculation loop piping on the inlet side of the recirculation pump and no more than 4 feet from the pump. This valve shall be mounted on top of a vertical riser at least 12 inches in length and shall be accessible for replacement and repair. Alternatively, the pump shall be installed on a vertical section of the return line. B. Recirculation loop backflow prevention. A check valve or similar device shall be located between the recirculation pump and the water heating equipment to prevent water from flowing backwards though the recirculation loop. C. Equipment for pump priming. A hose bibb shall be installed between the pump and the water heating equipment. An isolation valve shall be installed between the hose bibb and the water heating equipment. This hose bibb is used for bleeding air out of the pump after pump replacement. D. Pump isolation valves. Isolation valves shall be installed on both sides of the pump. These valves may be part of the flange that attaches the pump to the pipe. One of the isolation valves may be the same isolation valve as in Item C. E. Cold water supply and recirculation loop connection to hot water storage tank. Storage water heaters and boilers shall be plumbed in accordance with the manufacturer’s specifications The cold water piping and the recirculation loop piping shall not be connected to the hot water storage tank drain port. F. Cold water supply backflow prevention. A check valve shall be installed on the cold water supply line between the hot water system and the next closest tee on the cold water supply line.

• § 613.4 High relevance — show source text

  613.4 Water storage tanks shall be fabricated of corrosion- resistant materials or lined with corrosion-resistant materials.

  613.5 Temperature control valves shall be provided to auto- matically regulate the temperature of hot water delivered to plumbing fixtures used by patients to a range of 105°F (41°C) minimum to 120°F (49°C) maximum. High temperature alarm set at 125°F (52°C) shall be provided. The audible/visual device for the high temperature alarm shall annunciate at a continuously occupied location.

  613.6 Hot-water distribution system serving patient care areas shall be under constant mechanical recirculation to provide continuous hot water at each hot water outlet. Hot water recir- culation piping shall return the recirculation loop back through the hot water source. Non-recirculated fixture branch piping shall not exceed 10 feet (3.05 meters) in length. Dead-end pip- ing (risers with no flow, branches with no fixture) shall not be installed. In renovation projects, dead-end piping shall be removed in the area of renovation. Empty risers, mains, and branches installed for future use shall be permitted.

  613.7 At fixtures where water exceeding 125°F (52°C) is acces- sible to patients or personnel, warning signs in letters at least 2 inches (51 mm) high shall be posted above the fixtures.

  613.8 Sectionalizing valves shall be provided as required by Section 606.8.

  2025 CALIFORNIA PLUMBING CODE 161

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  WATER SUPPLY AND DISTRIBUTION

  613.9 Hot water distribution shall include test ports and valved openings for flushing of portions of the system in accordance with the facilities water management program as defined in Appendix N.

  614.0 Dialysis Water-Distribution Systems. [OSHPD 1, 2, 3, 4 & 5]

  614.1 Dialysis water feedlines shall be CPVC (chlorinated polyvinyl chloride), PVC (polyvinyl chloride), glass, stainless steel, PEX, PVDF (polyvinylidene fluoride), or other material deemed acceptable by ANSI/AAMI/ISO 23500-2 and sized to provide a minimum velocity of 1.5 feet per second (0.46 m/s). The piping shall be a singleloop system with or without recir- culation. Branches to dialysis machines shall be [1] ∕ 4 inch (6.4 mm) inside dimension and take off from the bottom of the main feedline. Branch lines may be PFA (perfluoroalkoxy). 614.2 All piping for multistation or central dialysis units shall be rigid where possible. All piping and tubing shall be in a neat arrangement. The placement of piping or tubing on the floor is not permitted.

  614.3 All valves shall be located in accessible locations.

• § 140.4 Medium relevance — show source text

  2025 CALIFORNIA ENERGY CODE 125

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  NONRESIDENTIAL AND HOTEL/MOTEL OCCUPANCIES—PERFORMANCE AND PRESCRIPTIVE

  COMPLIANCE APPROACHES FOR ACHIEVING ENERGY EFFICIENCY

  7. Hydronic heat pump (WLHP) controls. Hydronic heat pumps connected to a common heat pump water loop with central devices for heat rejection and heat addition shall have controls that are capable of providing a heat pump water supply temperature dead band of at least 20°F between initiation of heat rejection and heat addition by the central devices.

  Exception to Section 140.4(k)7: Where a system loop temperature optimization controller is used to determine the most efficient operating temperature based on real-time conditions of demand and capacity, dead bands of less than 20°F shall be allowed. 8. High capacity space heating gas boiler systems. In Climate Zones 1 through 6, 9 through 14, and 16, gas hot water boiler systems for space heating with a total system input of at least 1 MMBtu/h but no more than 10 MMBtu/h shall meet all of the following requirements. A. Boiler system efficiency. Gas hot water boilers shall have a minimum thermal efficiency of 90 percent. Systems with multiple boilers can meet this requirement if the space-heating input provided by equipment with thermal efficiencies above and below 90 percent has an input capacity-weighted average thermal efficiency of at least 90 percent. For boilers federally regulated by combustion efficiency, the calculation for the input capacity-weighted average thermal efficiency shall use the combustion efficiency value. B. Hot water distribution design. The hot water distribution system shall be designed to comply with Items i and ii. i. Coils and other heat exchangers shall be selected so that at design conditions the hot water return temperature entering the boilers is 120°F or less. ii. Under all operating conditions, the water temperature entering the boiler is 120°F or less or the flow rate of supply hot water that recirculates directly into the return system, such as by three-way valves or minimum flow bypass controls, shall be no greater than 20 percent of the design flow of the operating boilers. Exception 1 to Section 140.4(k)8: Where 25 percent of the annual space heating requirement is provided by on-site renewable energy, site-recovered energy or heat recovery chillers. Exception 2 to Section 140.4(k)8: Space heating boilers installed in individual dwelling units. Exception 3 to Section 140.4(k)8: Where 50 percent or more of the design heating load is served using perimeter convective heating, radiant ceiling panels or both. Exception 4 to Section 140.4(k)8: Individual gas boilers with input capacity less than 300,000 Btu/h shall not be included in the calculations of the total system input or total system efficiency.

  (l) Reserved.

  (m) Fan control. Each cooling system listed in Table 140.4-I shall be designed to vary the indoor fan airflow as a function of load and shall comply with the following requirements:

  1. DX and chilled water cooling systems that control the capacity of the mechanical cooling directly based on occupied space temperature shall A. Have a minimum of two stages of fan control with no more than 66 percent speed when operating on stage 1; and B. Draw no more than 40 percent of the fan power at full fan speed, when operating at 66 percent speed.
• § 203.1.2 Medium relevance — show source text

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

  APPENDIX A4 — RESIDENTIAL VOLUNTARY MEASURES

  A4.203.1.2 Prerequisite options. In addition, a minimum of TWO of the efficiency measures specified in Sections A4.203.1.2.1 through A4.203.1.2.7 must be met.

  A4.203.1.2.1 Roof deck insulation, or ducts in conditioned space. Meet one of the three options for the location of ducts and air handlers as well as insulation R -values and installation of a radiant barrier as specified in Title 24, Part 6, Section 150.1(c)9A or B:

  1. Below roof deck insulation with a minimum R -value of 19; or,

  2. Continuous above deck insulation with a minimum R-8 and with an air space present between the roofing and the roof deck; or,

  3. All ducts and air handlers in conditioned space as specified in the Title 24, Part 6, Reference Appendix RA3.1.

  A4.203.1.2.2 High performance walls. Meet the climate zone dependent U -factor or insulation R -value for either 2x6 or 2x4 framing as specified in Title 24, Part 6, Section 150.1(c)1B: maximum U -factor of 0.048.

  A4.203.1.2.3 Compact hot water distribution system. Meet the requirements for installation of Compact Hot Water Distribution Systems specified in the Title 24, Part 6, Reference Appendix RA3.6.5.

  A4.203.1.2.4 Drain water heat recovery. Meet the requirements for installation of Drain Water Heat Recovery specified in Title 24, Part 6, Reference Appendix RA4.4.21.

  A4.203.1.2.5 High performance vertical fenestration. Meet the climate zone dependent U -factor and Solar Heat Gain Coefficient (SHGC) as rated in accordance with Title 24, Part 6, Section 110.6, and shall have a maximum U -factor of 0.21 in Climate Zones 1 − 16, maximum SHGC of 0.23 in Climate Zones 2, 4, and 6 − 14, and maximum SHGC of 0.20 in Climate Zone 15.

  Exception to A4.203.1.2.5: Fenestration in Climate Zones 1, 3, 5, and 16 is not required to comply with the maximum SHGC requirements.

  A4.203.1.2.6 Heat pump water heater demand management. For buildings with heat pump water heating, meet the requirements for installation of controls specified by Title 24, Part 6, Reference Appendix JA13.3.3.

  A4.203.1.2.7 Battery storage system controls. For buildings with battery storage systems, meet the requirements for installation of controls specified by Title 24, Part 6, Reference Appendix JA12 for either the Time-of-Use Control or Advanced Demand Flexibility Control option.