Title 24 · California Energy Code
What hydronic control features (variable flow, reset, isolation) are required and how are they tested?
If your building has hydronic heating/chilled water, the California Energy Code requires variable‑flow pumping (except small systems), automatic isolation of individual chillers/boilers when more than one unit exists, and supply‑water reset for larger plants — and each feature must be demonstrated by the NA7/E805 acceptance tests (variable‑flow: modulation and pump/VFD response; reset: sensor calibration and ±2% tracking; isolation: valve leakage/closure under pump pressure).
Last reviewed: July 6, 2026
What the code requires — plain English
Buildings with hydronic heating and/or chilled‑water systems must be designed and accepted to use variable‑flow pumping where required, provide supply‑water temperature reset when required, and provide isolation of individual chillers/boilers when more than one is installed. The acceptance tests for these features are required before occupancy and are identified in § 120.5 with the specific test procedures in the Reference Nonresidential Appendix (NA7) and the Mechanical Code Appendix E test procedures. See § 120.5 and the hydronic measures in § 140.4(k) for the substantive requirements and test applicability.
The single most important rule: design hydronic systems to reduce unnecessary pump flow (variable flow), automatically reset supply temperatures when the system capacity exceeds thresholds, and install automatic isolation valves for each chiller or boiler when more than one unit is present — and demonstrate each by the listed acceptance tests before final occupancy.
Requirements in detail
Key defined terms and thresholds (first mentions are bolded)
- Variable‑flow system — a chilled‑ or hot‑water distribution system configured so pump flow varies as coils/valves modulate. § 140.4(k)1 requires variable flow capability to reduce flow rates to the larger of 50% of design flow or the equipment minimum flow (manufacturer requirement), with listed exceptions.
- Supply‑water temperature reset — automatic controls that change chilled or hot water supply setpoints as a function of building load or outdoor air when system size exceeds 500,000 Btu/hr (unless excluded). § 140.4(k)4 requires reset for qualifying systems.
- Isolation valve (chiller/boiler isolation) — automatic valve or arrangement that shuts off flow through a unit when that unit is shut off while allowing flow through other operating units. Required when more than one chiller or one boiler is served by the same plant (see § 140.4(k)2–3).
Decision‑relevant summary table
| Decision dimension | Required feature / value | Test / Acceptance form | Code Reference |
|---|---|---|---|
| System has ≥3 modulating control valves (or otherwise qualifies) | Variable‑flow pumps able to reduce flow to 50% of design or manufacturer minimum; pumps >5 hp require controls to limit motor demand to ≤ 30% of design wattage at 50% flow | Hydronic variable‑flow functional test (NA7.5.7 / Mechanical Appendix E: E805.10 / Form MECH‑10A) | § 140.4(k)1; test reference § 120.5 → NA7.5.7 |
| Total pump system power ≤1.5 hp OR ≤3 control valves | Variable‑flow requirement may be excepted | See exceptions in code | § 140.4(k)1 exceptions |
| Pumps serving variable‑flow system, motor > 5 hp | Variable speed drives or equivalent to meet motor demand ≤ 30% of design wattage at 50% flow; control as a function of differential pressure | Verified by variable flow acceptance test (E805.10) | § 140.4(k)6.A; test reference NA7.5.7 / E805.10 |
| Plant has >1 chiller | Chiller isolation — automatic shutoff of flow through a chiller when it is off while maintaining flow through other chillers | Valve leakage / isolation test (NA7.5.7 / Form MECH‑8A) | § 140.4(k)2; acceptance per § 120.5 → NA7.5.7 |
| Plant has >1 boiler | Boiler isolation — automatic shutoff of flow through a boiler when it is off while maintaining flow through operating boiler(s) | Valve leakage / isolation test (NA7.5.7 / Form MECH‑8A) | § 140.4(k)3; acceptance per § 120.5 → NA7.5.7 |
| System design capacity > 500,000 Btu/hr and NOT designed to use variable flow per §140.4(k)1 | Supply‑water temperature reset controls required (reset to building load or outdoor air) | Supply water reset functional test (NA7.5.8 / E805.9 / Form MECH‑9A) — sensors calibrated and supply within 2% of setpoint during test steps | § 140.4(k)4; test reference § 120.5 → NA7.5.8 |
Notes about sources: §120.5 lists the acceptance tests to be performed (NA7.5.7, NA7.5.8, NA7.5.9) and the Mechanical Code Appendix E contains the detailed test steps (E805.10, E805.9, E805.8) referenced above.
How each feature is tested (high level)
- Variable‑flow control test (NA7.5.7 / E805.10): open control valves to near full flow (≥90% of design) and verify pump speed increases, pressure control behavior, and system stabilizes (usually within 5 minutes). Then modulate valves down to 50% of design flow or less (but not below pump minimum) and verify pump speed decreases, setpoints change appropriately, pressure within ±5% and system stabilizes. Sensor calibration and sensor location (near most remote heat exchanger) are checked.
- Supply‑water reset test (NA7.5.8 / E805.9): verify supply temperature sensors are calibrated; change reset variable to maximum and minimum, confirm setpoint and actual supply temperature track the setpoint and are within 2% of control setpoint; restore to automatic and verify operation. Documentation on calibration and pass/fail recorded on MECH‑9A.
- Isolation / valve leakage test (NA7.5.7 / NA7.5.9 / E805.8 / MECH‑8A): verify piping/valve arrangements per design, then perform valve leakage test to ensure automatic isolation valves fully shut off flow for the unit taken out of service and do not allow leakage that would defeat isolation; also verify valves are sized/actuated to resist pump pressure and that automatic interlocks function. The valve leakage procedure and acceptance form are the mechanism for documenting conformance.
Exceptions & special cases
- Systems with no more than three control valves are excepted from the variable‑flow requirement in § 140.4(k)1. Also systems with total pump power ≤ 1.5 hp are excepted.
- Heating hot‑water systems and condenser water systems serving only water‑cooled chillers have specific exceptions or different provisions in some mechanical appendices; always check the exception language (see Appendix A6 / Mechanical notes).
- Systems that already meet the variable‑flow energy reduction criteria are excepted from supply‑water reset requirement in § 140.4(k)4 (i.e., if variable flow reduces pumping energy as required, reset is not additionally required).
- The Code treats chillers piped in series for increased ΔT as one chiller for isolation requirements; do not count them as multiple chillers for the isolation rule.
If you need the specific NA7.5.7 / NA7.5.8 / NA7.5.9 text blocks: § 120.5 explicitly references those NA7 test procedures for acceptance; the detailed step‑by‑step functional tests are included in the Mechanical Code Appendix E (E805.8, E805.9, E805.10) and the NA7 forms. The search results show the Mechanical Code test procedures (E805.x) but the full NA7 text pages were not returned verbatim in the provided files; the functional steps quoted above are taken from the Mechanical Appendix E procedures that correspond to NA7 tests.
Common mistakes
- Assuming the Appendix E / ASHRAE numbers replace the Code text — always cite the California Code sections (§ 140.4(k) and § 120.5) as the controlling requirements; Appendix E provides the test procedure language that the acceptance tests follow.
- Confusing the design flow turndown values: some Appendix/ASHRAE tables show 25% turndown in other contexts (Appendix E/ASHRAE provisions), but the California code's §140.4(k)1 sets the variable‑flow requirement as reduction to 50% of design flow or manufacturer minimum (see exceptions). Always use the California section for compliance.
- Not calibrating sensors or documenting calibration. Acceptance tests require sensor calibration certificates or field calibration documentation (supply‑water sensor calibration required for reset tests). Failing to provide calibration evidence is a common cause of rejection.
- Forgetting to test valve leakage/isolation under the actual pump pressure and piping arrangement; valves must be shown to shut off flow to the offline chiller/boiler while other units remain in service.
Worked example — concrete scenario with numbers
Scenario: A commercial building has a hot‑water plant with two boilers and pumps with combined motor power of 10 hp. The hydronic distribution has 4 modulating control valves (one per major zone); the plant capacity is 600,000 Btu/hr.
Is variable flow required?
- Yes. There are >3 control valves, and pump power is >1.5 hp, so § 140.4(k)1 requires variable‑flow capability and the ability to reduce flow to the larger of 50% of design or manufacturer minimum. The pumps for motors >5 hp must be controllable so motor demand is ≤ 30% of design wattage at 50% flow.
Is supply‑water reset required?
- Not required as a separate measure if the system uses variable flow to reduce pumping energy per § 140.4(k)4 exception. Because variable flow is required and provided, the supply‑water reset control is excepted. If the design opted not to implement variable flow, reset would be required because the plant capacity (600,000 Btu/hr) exceeds 500,000 Btu/hr.
Are isolation valves required?
- Yes. There are two boilers, so § 140.4(k)3 requires provisions to automatically shut off flow through any boiler when that boiler is off while maintaining flow through the other operating boiler. This must be demonstrated at acceptance (valve leakage/isolation test).
What tests will be performed at acceptance?
- Variable‑flow acceptance (NA7.5.7 / E805.10): Steps include exercising valves to ~90% design flow and verifying pump speed increases; reducing to 50% flow and verifying pump speed decreases and pressures are within ±5% of setpoint; sensors calibrated and system stabilizes within 5 minutes.
- Valve isolation/valve leakage (NA7.5.7 / MECH‑8A): Verify valve arrangement, operate the isolation for one boiler and show no substantial leakage and that other boilers continue to operate.
Related provisions
- § 120.5 — Required nonresidential mechanical system acceptance; references NA7 tests including hydronic tests.
- § 140.4(k) — Hydronic system measures (variable flow, isolation, reset, VFD requirements).
- NA7.5.7 / NA7.5.8 / NA7.5.9 — Acceptance test references for hydronic variable flow, supply‑water reset, related tests (referenced from §120.5).
- Mechanical Code Appendix E: E805.10 (hydronic variable flow), E805.9 (supply water reset test), E805.8 (valve leakage/isolation) — provide the step‑by‑step functional tests used to satisfy the NA7 acceptance tests.
Code references
Grounded in the retrieved California Energy Code — click a citation to read the verbatim passage:
§ 140.4 High relevance — show source text
Exception 4 to Section 140.4(i): In buildings with more than three chillers, only three chillers are required to meet the Path B efficiencies.
(j) Limitation of air-cooled chillers. Chilled water plants shall not have more than 300 tons provided by air-cooled chillers.
Exception 1 to Section 140.4(j): Where the water quality at the building site fails to meet manufacturer’s specifications for the use of water-cooled chillers.
Exception 2 to Section 140.4(j): Chillers that are used to charge a thermal energy storage system with a design temperature of less than 40°F (4°C).
Exception 3 to Section 140.4(j): Systems serving healthcare facilities.
(k) Hydronic system measures.
- Hydronic variable flow systems. HVAC chilled and hot water pumping shall be designed for variable fluid flow and shall be capable of reducing pump flow rates to no more than the larger of: a) 50 percent or less of the design flow rate; or b) the minimum flow required by the equipment manufacturer for the proper operation of equipment served by the system.
Exception 1 to Section 140.4(k)1: Systems that include no more than three control valves.
Exception 2 to Section 140.4(k)1: Systems having a total pump system power less than or equal to 1.5 hp. 2. Chiller isolation. When a chilled water system includes more than one chiller, provisions shall be made so that flow through any chiller is automatically shut off when that chiller is shut off while still maintaining flow through other operating chiller(s). Chillers that are piped in series for the purpose of increased temperature differential shall be considered as one chiller.
- Boiler isolation. When a hot water plant includes more than one boiler, provisions shall be made so that flow through any boiler is automatically shut off when that boiler is shut off while still maintaining flow through other operating boiler(s).
- Chilled and hot water temperature reset controls. Systems with a design capacity exceeding 500,000 Btu/hr supplying chilled or heated water shall include controls that automatically reset supply water temperatures as a function of representative building loads or outside air temperature.
Exception 1 to Section 140.4(k)4: Hydronic systems that use variable flow to reduce pumping energy in accordance with 140.4(k)1.
Exception 2 to Section 140.4(k)4: Systems serving healthcare facilities. 5. Water-cooled air conditioner and hydronic heat pump systems. Water circulation systems serving water-cooled air conditioners, hydronic heat pumps, or both that have total pump system power exceeding 5 hp shall have flow controls that meet the requirements of Section 140.4(k)6. Each such air conditioner or heat pump shall have a two-position automatic valve interlocked to shut off water flow when the compressor is off.
- Variable flow controls.
A. Variable speed drives. Individual pumps serving variable flow systems and having a motor horsepower exceeding 5 hp shall have controls or devices (such as variable speed control) that will result in pump motor demand of no more than 30 percent of design wattage at 50 percent of design water flow. The pumps shall be controlled as a function of required differential pressure. B. Pressure sensor location and setpoint. i. For systems without direct digital control of individual coils reporting to the central control panel, differential pressure shall be measured at the most remote heat exchanger or the heat exchanger requiring the greatest differential pressure. ii.
§ 160.3 High relevance — show source text
(d) Mechanical acceptance testing.
- Common areas. Before an occupancy permit is granted, the following systems and equipment serving multifamily common areas shall be certified as meeting the Acceptance Requirements for Code Compliance, as specified by Reference Nonresidential Appendix NA7. These systems and equipment shall also comply with the applicable requirements of Section
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160.3(d)3. A Certificate of Acceptance shall be submitted to the enforcement agency that certifies that the equipment and systems meet the acceptance requirements: A. Outdoor air ventilation systems shall be tested in accordance with NA7.5.1. B. Constant volume, single zone air conditioning and heat pump unit controls shall be tested in accordance with NA7.5.2. C. Duct systems shall be tested in accordance with NA7.5.3 where either: a. They are new duct systems; or b. They are part of an altered system. D. Air economizers, DOAS, HRV or ERV systems shall be tested in accordance with NA7.5.4. Exception to Section 160.3(d)1D: Air economizers installed by the HVAC system manufacturer and certified to the Commission as being factory calibrated and tested are not required to comply with the Functional Testing section of the Air Economizer Controls acceptance test as described in NA7.5.4.2. E. Demand control ventilation systems required by Section 160.2(c)3 shall be tested in accordance with NA7.5.5. F. Supply fan variable flow controls shall be tested in accordance with NA7.5.6. G. Hydronic system variable flow controls shall be tested in accordance with NA7.5.7 and NA7.5.9. H. Boilers or chillers that require isolation controls as specified by Section 170.2(c)4Iii or 170.2(c)4Iiii shall be tested in accordance with NA7.5.7.
I. Hydronic systems with supply water temperature reset controls shall be tested in accordance with NA7.5.8.
J. Automatic demand shed controls shall be tested in accordance with NA7.5.10.
K. Fault detection and diagnostics (FDD) for packaged direct expansion units shall be tested in accordance with NA7.5.11. L. Automatic fault detection and diagnostics (FDD) for air handling units and zone terminal units shall be tested in accordance with NA7.5.12.
M. Distributed energy storage DX AC systems shall be tested in accordance with NA7.5.13. N. Thermal energy storage (TES) systems shall be tested in accordance with NA7.5.14. O. Supply air temperature reset controls shall be tested in accordance with NA7.5.15. P. Water-cooled chillers served by cooling towers with condenser water reset controls shall be tested in accordance with NA7.5.16.
Q. When an energy management control system is installed, it shall functionally meet all of the applicable requirements of Part 6.
§ 805.7.1.1 High relevance — show source text
E 805.7.1.1 Construction Inspection. Prior to functional testing, verify and document the following:
(1) Supply fan controls modulate to increase capacity.
(2) Supply fan maintains discharge static pressure within plus or minus 10 percent of the current operating set point.
(3) Supply fan controls stabilize within a 5 minute period.
E 805.7.1.2 Functional Testing. The functional testing shall be in accordance with the following steps:
Step 1: Simulate demand for design airflow. Verify and document the following:
(1) Supply fan controls modulate to increase capacity.
(2) Supply fan maintains discharge static pressure within plus or minus 10 percent of the current operating set point. (3) Supply fan controls stabilize within a 5 minute period. Step 2: Simulate demand for minimum airflow. Verify and document the following: (1) Supply fan controls modulate to decrease capacity. (2) Current operating setpoint has decreased (for systems with DDC to the zone level). (3) Supply fan maintains discharge static pressure within plus or minus 10 percent of the current operating setpoint. (4) Supply fan controls stabilize within a 5 minute period. Step 3: Restore system to correct operating conditions.
E 805.7.2 Acceptance Criteria. Supply fan variable flow controls acceptance criteria shall be as follows: (1) Static pressure sensor(s) is factory calibrated (with calibration certificate) or field calibrated. (2) For systems without DDC controls to the zone level, the pressure sensor setpoint is less than one-third of the supply fan design static pressure.
(3) For systems with DDC controls with VAV boxes reporting to the central control panel, the pressure setpoint is reset by zone demand (box damper position or a trim and respond algorithm).
At full flow:
(1) Supply fan maintains discharge static pressure within plus or minus 10 percent of the current operating control static pressure setpoint. (2) Supply fan controls stabilizes within a 5 minute period. (3) At minimum flow (not less than 30 percent of total design flow). (4) Supply fan controls modulate to decrease capacity. (5) Current operating setpoint has decreased (for systems with DDC to the zone level). (6) Supply fan maintains discharge static pressure within plus or minus 10 percent of the current operating setpoint. E 805.8 Valve Leakage (Form MECH-8A). The purpose of this test is to ensure that control valves serving variable flow systems are designed to withstand the pump pressure over the full range of operation. Valves with insufficient actuators will lift under certain conditions causing water to leak through and loss of control. This test applies to the variable flow systems, chilled and hot-water variable flow systems, chiller isolation valves, boiler isolation valves, and watercooled air conditioner and hydronic heat pump systems.
E 805.8.1 Test Procedure. The procedure for performing a functional test for valve leakage shall be in accordance with Section E 805.8.1.1 and Section E
805.8.1.2.
E 805.8.1.1 Construction Inspection. Prior to functional testing, verify and document the valve and piping arrangements were installed in accordance with the design drawings. E 805.8.1.2 Functional Testing. The functional testing shall be in accordance with the following steps:
§ 90.1 High relevance — show source text
[ASHRAE 90.1:6.5.4.1]
2025 CALIFORNIA MECHANICAL CODE 439
), Copyright © 2025 IAPMO, and may not be used for any other purpose or distributed to any other persons or parties.
APPENDIX E
TABLE E 503.5.7.2
PUMP FLOW CONTROL REQUIREMENTS
[ASHRAE 90.1: TABLE 6.5.4.2]
BOILER SYSTEM DESIGN INPUT, Btu/h MINIMUM TURNDOWN RATIO
≥1 000 000 and≤5 000 0003 to 1
>5 000 000 and≤10 000 0004 to 1
>10 000 0005 to 1 »
TABLE E 503.5.7
BOILER TURNDOWN
[ASHRAE 90.1: TABLE 6.5.4.1]
For SI units: 1000 British thermal units per hour = 0.293 kW
E 503.5.7.2 Hydronic Variable Flow Systems. Chilled- and hot-water distribution systems that include three or more control valves designed to modulate or step open and close as a function of load shall be designed for variable fluid flow and shall be capable of and configured to reduce pump flow rates to not more than the larger of 25 percent of the design flow rate or the minimum flow required by the heating/cooling equipment manufacturer for the proper operation of equipment. Individual or parallel pumps serving variable-flow heating-water or chilledwater systems, where the nameplate horsepower of the motor or combined parallel motors is not less than the power shown in Table E 503.5.7.2, shall have controls or devices that will result in pump motor demand of not more than 30 percent of design wattage at 50 percent of design water flow. The controls or devices shall be controlled as a function of desired flow or to
maintain a minimum required differential pressure. Differential pressure shall be measured at or near the most remote heat exchanger or the heat exchanger requiring the greatest differential pressure. The differential pressure setpoint shall not exceed 110 percent of that required to achieve design flow through the heat exchanger. Where differential pressure control is used to comply with this section, and DDC systems are used, the setpoint shall be reset downward based on valve positions until one valve is nearly wide open.
Exceptions:
(1) Differential pressure set-point reset is not required where valve position is used to comply with Section E 503.5.7.4.
(2) Variable-pump flow control is not required on heating-water pumps where more than 50 percent of annual heat is generated by an electric boiler.
(3) Variable flow is not required for primary pumps in a primary/secondary system.
(4) Variable flow is not required for a coil pump provided for freeze protection.
(5) Variable flow is not required for heat recovery coil runaround loops. [ASHRAE 90.1:6.5.4.2]
§ 170.2 High relevance — show source text
Chillers that are piped in series for the purpose of increased temperature differential shall be considered as one chiller.
iii. Boiler isolation. When a hot water plant includes more than one boiler, provisions shall be made so that flow through any boiler is automatically shut off when that boiler is shut off while still maintaining flow through other operating boiler(s). iv. Chilled and hot water temperature reset controls. Systems with a design capacity exceeding 500,000 Btu/hr supplying chilled or heated water shall include controls that automatically reset supply water temperatures as a function of representative building loads or outside air temperature. Exception to Section 170.2(c)4Iiv: Hydronic systems that use variable flow to reduce pumping energy in accordance with Section 170.2(c)4Ii.
v. Water-cooled air conditioner and hydronic heat pump systems. Water circulation systems serving watercooled air conditioners, hydronic heat pumps or both, that have total pump system power exceeding 5 hp, shall have flow controls that meet the requirements of Section 170.2(c)4Ivi. Each such air conditioner or heat pump shall have a two-position automatic valve interlocked to shut off water flow when the compressor is off.
vi. Variable flow controls.
a. Variable speed drives. Individual pumps serving variable flow systems and having a motor horsepower exceeding 5 hp shall have controls or devices (such as variable speed control) that will result in pump motor demand of no more than 30 percent of design wattage at 50 percent of design water flow. The pumps shall be controlled as a function of required differential pressure. b. Pressure sensor location and setpoint. I. For systems without direct digital control of individual coils reporting to the central control panel, differential pressure shall be measured at the most remote heat exchanger or the heat exchanger requiring the greatest differential pressure. II. For systems with direct digital control of individual coils with a central control panel, the static pressure setpoint shall be reset based on the valve requiring the most pressure, and the setpoint shall be no less than 80 percent open. Pressure sensors may be mounted anywhere. Exception 1 to Section 170.2(c)4Ivi: Heating hot water systems. Exception 2 to Section 170.2(c)4Ivi: Condenser water systems serving only water-cooled chillers. vii. 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 deadband of at least 20°F between initiation of heat rejection and heat addition by the central devices.
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Exception to Section 170.2(c)4Ivii: 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, deadbands of less than 20°F shall be allowed .
J. Reserved.
K. **Fan control.
§ 805.9.1 High relevance — show source text
This requirement applies to chilled and hot water systems that are not designed for variable flow, and that have a design capacity greater than or equal to 500 000 Btu/h (147 kW).
E 805.9.1 Test Procedure. The procedure for performing a functional test for supply water temperature reset controls shall be in accordance with Section E
805.9.1.1 and Section E 805.9.1.2.
E 805.9.1.1 Construction Inspection. Prior to functional testing, verify and document the supply water temperature sensors shall be either factory or field calibrated.
E 805.9.1.2 Functional Testing. The functional testing shall be in accordance with the following steps:
Step 1: Change reset control variable to its maximum value. Verify and document the following:
(1) Chilled or hot water temperature setpoint is reset to appropriate value.
(2) Actual supply temperature changes to meet setpoint.
(3) Verify that supply temperature is within 2 percent of the control setpoint.
Step 2: Change reset control variable to its minimum value. Verify and document the following:
(1) Chilled or hot water temperature setpoint is reset to appropriate value.
(2) Actual supply temperature changes to meet setpoint.
(3) Verify that supply temperature is within 2 percent of the control setpoint.
Step 3: Restore reset control variable to automatic control. Verify and document the following:
(1) Chilled or hot water temperature setpoint is reset to appropriate value.
(2) Actual supply temperature changes to meet setpoint.
(3) Verify that supply temperature is within 2 percent of the control setpoint.
E 805.9.2 Acceptance Criteria. The supply water temperature sensors are either factory calibrated (with calibration certificates) or field-calibrated. Sensor performance shall comply with the specifications. The supply water reset is operational.
E 805.10 Hydronic System Variable Flow Controls (Form MECH-10A). The purpose of this test is to ensure that hydronic variable flow chilled water and water-loop heat pump systems with circulating pumps larger than 5 hp (3.7 kW) vary system flow rate by modulating pump speed using a variable frequency drive (VFD) or equivalent. As the loads within the building fluctuate, control valves modulate the amount of water passing through each coil and add or remove the desired amount of energy from the air stream to satisfy the load. In the case of water-loop heat pumps, each two-way control valve associated with a heat pump will be closed where that unit is not operating. As each control valve modulates, the pump variable frequency drive (VFD) responds accordingly to meet system water flow requirements. This is not required on heating hot water systems with variable flow designs or for condensing water serving water cooled chillers. E 805.10.1 Test Procedure. The procedure for performing a functional test for hydronic system variable flow controls shall be in accordance with Section E
805.10.1.1 and Section E 805.10.1.2.
E 805.10.1.1 Construction Inspection. Prior to functional testing, verify and document the pressure sensors are either factory or field calibrated. E 805.10.1.2 Functional Testing. The functional testing shall comply with the following steps:
Step 1: Open control valves to increase water flow to not less than 90 percent design flow. Verify and document the following:
§ 5.1. High relevance — show source text
(a) Before an occupancy permit is granted, the following equipment and systems shall be certified as meeting the Acceptance Requirements for Code Compliance, as specified by the Reference Nonresidential Appendix NA7. A Certificate of Acceptance shall be submitted to the enforcement agency that certifies that the equipment and systems meet the acceptance requirements:
Outdoor air ventilation systems shall be tested in accordance with NA7.5.1.
Constant volume, single zone unitary air conditioning and heat pump unit controls shall be tested in accordance with NA7.5.2.
Duct systems that are subject to testing under Section 120.4(g)1, Section 141.0(b)2Di or Section 141.0(b)2Dii shall be tested in accordance with NA7.5.3.
Air economizers, DOAS, HRV or ERV systems shall be tested in accordance with NA7.5.4. Exception 1 to Section 120.5(a)4: Air economizers installed by the HVAC system manufacturer and certified to the Commission as being factory calibrated and tested are not required to comply with the Functional Testing section of the air economizer controls acceptance test as described in NA7.5.4.2. Exception 2 to Section 120.5(a)4: The DOAS, HRV, or ERV unit that does not meet the exhaust air heat recovery ratio as specified in Section 140.4(q)1 or does not include bypass or control to disable energy recovery as specified in Section 140.4(q)2.
Demand control ventilation systems required by Section 120.1(c)3 shall be tested in accordance with NA7.5.5.
Supply fan variable flow controls shall be tested in accordance with NA7.5.6.
Hydronic system variable flow controls shall be tested in accordance with NA7.5.7 and NA7.5.9.
Boiler or chillers that require isolation controls as specified by Section 140.4(k)2 or 140.4(k)3 shall be tested in accordance with NA7.5.7.
Hydronic systems with supply water temperature reset controls shall be tested in accordance with NA7.5.8.
Automatic demand shed controls shall be tested in accordance with NA7.5.10.
Fault Detection and Diagnostics (FDD) for Packaged Direct-Expansion Units shall be tested in accordance with NA7.5.11.
Automatic fault detection and diagnostics (FDD) for air handling units and zone terminal units shall be tested in accordance with NA7.5.12.
Distributed Energy Storage DX AC Systems shall be tested in accordance with NA7.5.13.
Thermal Energy Storage (TES) Systems shall be tested in accordance with NA7.5.14.
Supply air temperature reset controls shall be tested in accordance with NA7.5.15.
Water-cooled chillers served by cooling towers with condenser water reset controls shall be tested in accordance with NA7.5.16.
When an energy management control system is installed, it shall functionally meet all of the applicable requirements of Part 6.
Occupant sensing zone controls shall be tested in accordance with NA7.5.17.
Conductivity controls and overflow alarms for open and closed-circuit cooling towers shall be tested according to NA7.5.18.
§ 5.6. High relevance — show source text
Supply fan variable flow controls shall be tested in accordance with NA7.5.6.
Hydronic system variable flow controls shall be tested in accordance with NA7.5.7 and NA7.5.9.
Boiler or chillers that require isolation controls as specified by Section 140.4(k)2 or 140.4(k)3 shall be tested in accordance with NA7.5.7.
Hydronic systems with supply water temperature reset controls shall be tested in accordance with NA7.5.8.
Automatic demand shed controls shall be tested in accordance with NA7.5.10.
Fault Detection and Diagnostics (FDD) for Packaged Direct-Expansion Units shall be tested in accordance with NA7.5.11.
Automatic fault detection and diagnostics (FDD) for air handling units and zone terminal units shall be tested in accordance with NA7.5.12.
Distributed Energy Storage DX AC Systems shall be tested in accordance with NA7.5.13.
Thermal Energy Storage (TES) Systems shall be tested in accordance with NA7.5.14.
Supply air temperature reset controls shall be tested in accordance with NA7.5.15.
Water-cooled chillers served by cooling towers with condenser water reset controls shall be tested in accordance with NA7.5.16.
When an energy management control system is installed, it shall functionally meet all of the applicable requirements of Part 6.
Occupant sensing zone controls shall be tested in accordance with NA7.5.17.
Conductivity controls and overflow alarms for open and closed-circuit cooling towers shall be tested according to NA7.5.18.
(b) When certification is required by Title 24, Part 1, Section 10-103.2, the acceptance testing specified by Section 120.5(a) shall be performed by a certified mechanical acceptance test technician (CMATT). If the CMATT is operating as an employee, the CMATT shall
2025 CALIFORNIA ENERGY CODE 79
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NONRESIDENTIAL, HOTEL/MOTEL OCCUPANCIES, AND COVERED PROCESSES—MANDATORY REQUIREMENTS
be employed by a certified mechanical acceptance test employer. The CMATT shall disclose on the certificate of acceptance a valid CMATT certification identification number issued by an approved acceptance test technician certification provider. The CMATT shall complete all certificate of acceptance documentation in accordance with the applicable requirements in Section 10-103(a)4.
Note: Authority cited: Sections 25213, 25218, 25218.5, 25402 and 25402.1, Public Resources Code. Reference: Sections 25007, 25008, 25218.5, 25310, 25402(a)-(b), 25402.1, 25402.4, 25402.5, 25402.8 and 25943, Public Resources Code .
SECTION 120.6—MANDATORY REQUIREMENTS FOR COVERED PROCESSES
Nonresidential and hotel/motel buildings shall comply with the applicable requirements of Sections 120.6(a) through 120.6(k), and the applicable requirements of Sections 110.2(a) and 120.3.
(a) Mandatory requirements for refrigerated warehouses.
§ 8.6 High relevance — show source text
Actuation stations shall be wired in paral-_ lel to achieve redundancy and arranged so that fire damage to one station will not disable the ESD system (N). 3. Communications or control circuits to synchronize simultaneous closure of the shore isolation valves (SIVs) with the shut- down of loading pumps (N). 4. A manual reset to restore the ESD system to an operational state after each initiation (N). 5. An alarm to indicate failure of the primary power source (N). 6. A secondary (emergency) power source (N). 7. Periodic testing of the system (N/E). 8. Fire proofing of motors and control-cables that are installed in areas classified as Class I, Group D, Division 1 or 2 per the California Electrical Code [8.6]. Fire proofing shall, at a minimum, comply with the recommendations in Section 6 of API RP 2218 [8.7] (N).
3108F.3.2.1 Emergency shutdown (ESD) valves. ESD valves shall conform to the requirements in Section 3109F.5, as applicable, and the following: 1. Be located near the dock manifold connection or loading arm (N/E). 2. Have “Local” and “Remote” actuation capabilities (N).
3108F.3.2.2 Shore isolation valves (SIVs). Shore isolation valve(s) shall conform to the requirements in Section 3109F.5, as appli- cable, and the following: 1. Be located onshore for each cargo pipeline. All SIVs shall be clustered together, for easy access (N). 2. Be clearly identified together with associated pipeline (N/E). 3. Have adequate lighting (N/E). 4. Be provided with communications or control circuits to synchronize simultaneous closure of the ESD system with the shutdown of loading pumps (N).
31F-80 2025 CALIFORNIA BUILDING CODE
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MARINE OIL TERMINALS
5. Have a manual reset to restore the SIV system to an operational state after each shut down event (N). 6. Be provided with thermal expansion relief to accommodate expansion of the liquid when closed. Thermal relief piping shall be properly sized and routed around the SIV, into the downstream segment of the pipeline or into other contain- ment (N/E). 7. SIVs installed in pipelines carrying H C liquids, or at a MOT with a spill classification “Medium” or “High” (see Table 31F-1- 1), shall be equipped with “Local” and “Remote” actuation capabilities. Local control SIVs may be motorized and/or operated manually (N).
3108F.4 Automated fire detection system. An MOT shall have a permanently installed automated fire detection or sensing system (N).
Fire detection systems shall be tested and maintained per the manufacturer or the local enforcing agency requirements. Specifica- tions shall be retained. The latest testing and maintenance records shall be readily accessible to the Division (N/E).
§ 805.10 High relevance — show source text
E 805.10 Hydronic System Variable Flow Controls (Form MECH-10A). The purpose of this test is to ensure that hydronic variable flow chilled water and water-loop heat pump systems with circulating pumps larger than 5 hp (3.7 kW) vary system flow rate by modulating pump speed using a variable frequency drive (VFD) or equivalent. As the loads within the building fluctuate, control valves modulate the amount of water passing through each coil and add or remove the desired amount of energy from the air stream to satisfy the load. In the case of water-loop heat pumps, each two-way control valve associated with a heat pump will be closed where that unit is not operating. As each control valve modulates, the pump variable frequency drive (VFD) responds accordingly to meet system water flow requirements. This is not required on heating hot water systems with variable flow designs or for condensing water serving water cooled chillers. E 805.10.1 Test Procedure. The procedure for performing a functional test for hydronic system variable flow controls shall be in accordance with Section E
805.10.1.1 and Section E 805.10.1.2.
E 805.10.1.1 Construction Inspection. Prior to functional testing, verify and document the pressure sensors are either factory or field calibrated. E 805.10.1.2 Functional Testing. The functional testing shall comply with the following steps:
Step 1: Open control valves to increase water flow to not less than 90 percent design flow. Verify and document the following:
(1) Pump speed increases.
(2) System pressure is either within plus or minus 5 percent of current operating setpoint, or the pressure is below the setpoint, and the pumps are operating at 100 percent speed.
(3) System operation shall stabilize within 5 minutes after test procedures are initiated.
Step 2: Modulate control valves to reduce water flow to 50 percent of the design flow or less, but not lower than the pump minimum flow. Verify and document the following:
(1) Pump speed decrease.
(2) Current operating setpoint has decreased (for systems with DDC to the zone level).
(3) Current operating setpoint has not increased (for all other systems).
(4) System pressure is within 5 percent of current operating setpoint.
(5) System operation stabilizes within 5 minutes after test procedures are initiated.
2025 CALIFORNIA MECHANICAL CODE 487
), Copyright © 2025 IAPMO, and may not be used for any other purpose or distributed to any other persons or parties.
APPENDIX E
E 805.10.2 Acceptance Criteria. The differential pressure sensor is either factory calibrated (with calibration certificates) or field calibrated. The pressure sensor shall be located at or near the most remote HX or control valve. The setpoint system controls shall stabilize.
E 805.11 Automatic Demand Shed Control (Form MECH-11A). The purpose of this test is to ensure that the central demand shed sequences have been properly programmed into the DDC system.
E 805.11.1 Test Procedure. The procedure for performing a functional test for automatic demand shed controls shall be in accordance with Section E 805.11.1.1
and Section E 805.11.1.2.
§ 1.08 High relevance — show source text
30| |W10 × 45|100|1.08|2.07|2.90|3.64| |W10 × 45|110|1.16|2.18|3.04|3.80| |W10 × 45|120|1.23|2.29|3.18|3.96|
2025 CALIFORNIA BUILDING CODE 7-87
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FIRE AND SMOKE PROTECTION FEATURES
TABLE 722.5.1(5)—FIRE RESISTANCE OF CONCRETE MASONRY PROTECTED STEEL COLUMNS—continued Col2 Col3 Col4 Col5 Col6 COLUMN SIZE ** CONCRETE MASONRY**
DENSITY POUNDS
PER CUBIC FOOTMINIMUM REQUIRED EQUIVALENT THICKNESS FOR FIRE-RESISTANCE
RATING OF CONCRETE MASONRY PROTECTION ASSEMBLY,****Te (inches)MINIMUM REQUIRED EQUIVALENT THICKNESS FOR FIRE-RESISTANCE
RATING OF CONCRETE MASONRY PROTECTION ASSEMBLY,****Te (inches)MINIMUM REQUIRED EQUIVALENT THICKNESS FOR FIRE-RESISTANCE
RATING OF CONCRETE MASONRY PROTECTION ASSEMBLY,****Te (inches)MINIMUM REQUIRED EQUIVALENT THICKNESS FOR FIRE-RESISTANCE
RATING OF CONCRETE MASONRY PROTECTION ASSEMBLY,****Te (inches)COLUMN SIZE ** CONCRETE MASONRY**
DENSITY POUNDS
PER CUBIC FOOT** 1 hour** ** 2 hours** ** 3 hours** ** 4 hours** W10 × 33 80 1.06 2.00 2.79 3.49 W10 × 33 100 1.22 2.23 3.07 3.80 W10 × 33 110 1.30 2.34 3.20 3.96 W10 × 33 120 1.37 2.44 3.33 4.12 W8 × 40 80 0.94 1.85 2.63 3.33 W8 × 40 100 1.10 2.10 2.93 3.67 W8 × 40 110 1.18 2.21 3.07 3.83 W8 × 40 120 1.25 2.32 3.20 3.99 W8 × 31 80 1.06 2.00 2.78 3.49 W8 × 31 100 1.22 2.23 3.07 3.81 W8 × 31 110 1.29 2.33 3.20 3.97 W8 × 31 120 1.36 2.44 3.33 4.12 W8 × 24 80 1.14 2.09 2.89 3. § 160.2 High relevance — show source text
Nonresidential Appendix NA1 160.2(a), 160.3(c)2H, 180.1(a)2, 180.1(b)3, 180.2(b)2B NA2 141.0(b)2E, 160.2(a)1, 160.3(c)2H, 180.1(a)2, 180.1(b)3, 180.2(b)2B, 180.2(b)5 NA2.2.4.1.5 160.2(b)2B, 170.2(c)3B NA2.4 141.0(b)2Q NA2.4.7 141.0(b)2Q NA5 140.3(a)9 NA6 110.6(a)2, 110.6(a)3, 110.6(a)4, 120.6(a)7, 140.3(a)5, 150.1(c)3, 170.2(a)3A NA7 110.6(a)6, 120.5(a), 120.6(c)7, 120.6(b)6, 120.6(c)8, 120.6(e)6, 120.6(f)5, 120.6(g)2, 140.9(b)3, 140.9(c)4B, 160.3(d)1, 160.3(d)2 NA7.15 120.6(g) NA7.16 140.9(c)3 NA7.18.1 160.3(d)2 NA7.18.2 160.3(d)2 NA7.18.3 160.2(b)2C, 160.3(d)2 NA7.18.4 160.3(d)2, 170.2(c)3 NA7.5.3 120.4(g)1, 120.5(a)3, 141.0(b)2D, 160.3(d)1C NA7.5.4 120.5(a)4, 160.3(d)1D NA7.5.5 120.5(a)5, 160.3(d)1E NA7.6 130.4(a)7, 160.5(e)1 NA7.6.1 130.4(a)3, 160.5(e)1C NA7.6.2 120.6(h)2B, 120.6(h)6B, 130.4(a)4, 160.5(e)1D
NA7.6.3 110.12(c), 130.4(a)5, 160.5(e)1E NA7.6.5 130.4(a)8, 160.5(e)1H NA7.7.1 130.4(b)1, 160.5(e) NA7.8 130.4(a)6, 160.5(e)1 Nonresidential Building Occupancy Types Assembly Table 140.6-B Bank or Financial Institution 140.4(a), Table 140.6-B Grocery Store 120.2(e),130.1(c)4, Table 140.6-B Gymnasium Table 140.6-B Healthcare Facility 140.4(a), Table 140.6-B Industrial/Manufacturing Facility Table 140.6-B Library 130.1(c), 140.
Frequently asked questions
What triggers the need for hydronic variable‑flow design?
If the system has more than three control valves or otherwise meets the criteria in § 140.4(k)1, variable flow is required unless total pump power ≤ 1.5 hp or another exception applies.
If my plant is >500,000 Btu/hr but I provide variable flow, do I still need supply‑water reset?
No — § 140.4(k)4 explicitly excepts systems that use variable flow in accordance with §140.4(k)1 from the reset requirement.
Which test form documents valve isolation and leakage?
Valve leakage and isolation are documented with the valve leakage acceptance test (MECH‑8A / NA7.5.7 references in §120.5); the Mechanical Code Appendix E describes the valve leakage functional test steps.
How close must actual supply temperature be to the reset setpoint during testing?
Supply temperature must track the control setpoint and be within 2% of the setpoint during reset functional testing per the reset test procedure (E805.9 / MECH‑9A).
Where are the NA7 test procedures located?
§ 120.5 directs acceptance testing to Reference Nonresidential Appendix NA7 (NA7.5.x). The step‑by‑step test procedures appear in the Mechanical Code Appendix E (E805.x) which correspond to NA7 tests. The code and the Mechanical Appendix together are used to perform and document acceptance.
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