Hydronic systems, boilers, and pump energy controls

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

• § 140.4 High relevance — show source text

  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.

  6. 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 140.4(k)6: Heating hot water systems.

  Exception 2 to Section 140.4(k)6: Condenser water systems serving only water-cooled chillers.

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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.

• § 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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  MULTIFAMILY BUILDINGS—PERFORMANCE AND PRESCRIPTIVE COMPLIANCE APPROACHES

  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.

• § 207.2.4 Medium relevance — show source text

  A6.207.2.4 Hydronic system measures.

  A6.207.2.4.1 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.

  Exceptions:

  1. Systems that include no more than three control valves.
  2. Systems having a total pump system power less than or equal to 1 [1] / 2 HP.

  A6.207.2.4.2 Chiller isolation. When a chilled water plant 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.

  A6.207.2.4.3 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).

  A6.207.2.4.4 Chilled and hot water temperature reset controls. Chilled and hot water systems with a design capacity exceeding 500,000 Btu/hr supplying chilled or heated water (or both) shall include controls that automatically reset supply water temperatures as a function of representative building loads or outside air temperature.

  Exception: Hydronic systems that use variable flow to reduce pumping energy in accordance with Section A6.207.2.4.1.

  A6.207.2.4.5 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 A6.207.2.4.6. Each air conditioner or heat pump shall have a two-position automatic valve interlocked to shut off water flow when the compressor is off.

  A6.207.2.4.6 Variable flow controls.

  A6.207.2.4.6.1 Variable speed drives. Individual pumps serving variable flow systems and having a motor horsepower exceeding 5 hp shall have controls and/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.

  A6.207.2.4.6.2 Pressure sensor location and setpoint.

  1. For systems without direct digital control of individual coils reporting to the central control panel, differential pressure shall be measured at or near the most remote heat exchanger or the heat exchanger requiring the greatest differential pressure.
  2. For systems with direct digital control of individual coils with central control panel, the static pressure set point shall be reset based on the valve requiring the most pressure and the set- point shall be no less than 80 percent open. The pressure sensor(s) may be mounted anywhere.

  Exceptions:

  1. Heating hot water systems.
  2. Condenser water systems serving only water-cooled chillers.
• § 170.2 Medium relevance — show source text

  • 40 percent of the design chiller cooling capacity. Exception 3 to Section 170.2(c)4G: Chillers used to charge thermal energy storage systems where the charging temperature is < 40°F. Exception 4 to Section 170.2(c)4G: In buildings with more than three chillers, only three chillers are required to meet the Path B efficiencies.

  H. Limitation of air-cooled chillers. Chilled water plants shall not have more than 300 tons provided by air-cooled chillers.

  Exception 1 to Section 170.2(c)4H: 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 170.2(c)4H: Chillers that are used to charge a thermal energy storage system with a design temperature of less than 40°F (4°C). I. Hydronic system measures . i. 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 170.2(c)4I: Systems that include no more than three control valves. Exception 2 to Section 170.2(c)4I: Systems having a total pump system power less than or equal to 1.5 hp. ii. 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.

  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.

• § 207.2.4.1. Medium relevance — show source text

  Exception: Hydronic systems that use variable flow to reduce pumping energy in accordance with Section A6.207.2.4.1.

  A6.207.2.4.5 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 A6.207.2.4.6. Each air conditioner or heat pump shall have a two-position automatic valve interlocked to shut off water flow when the compressor is off.

  A6.207.2.4.6 Variable flow controls.

  A6.207.2.4.6.1 Variable speed drives. Individual pumps serving variable flow systems and having a motor horsepower exceeding 5 hp shall have controls and/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.

  A6.207.2.4.6.2 Pressure sensor location and setpoint.

  1. For systems without direct digital control of individual coils reporting to the central control panel, differential pressure shall be measured at or near the most remote heat exchanger or the heat exchanger requiring the greatest differential pressure.
  2. For systems with direct digital control of individual coils with central control panel, the static pressure set point shall be reset based on the valve requiring the most pressure and the set- point shall be no less than 80 percent open. The pressure sensor(s) may be mounted anywhere.

  Exceptions:

  1. Heating hot water systems.
  2. Condenser water systems serving only water-cooled chillers.

  A6.207.2.4.7 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: 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.

  A6.207.2.5 Air distribution system duct leakage sealing. All duct systems shall be sealed to a leakage rate not to exceed 6 percent of the fan flow if the duct system:

  A6.207.2.5.1 Is connected to a constant volume, single zone, air conditioners, heat pumps or furnaces; and

  A6.207.2.5.2 Serves less than 5,000 square feet of floor area; and

  A6.207.2.5.3 Has more than 25 percent duct surface area located in one or more of the following spaces:

  1. Outdoors; or

  2. In a space directly under a roof where the U -factor of the roof is greater than the U -factor of the ceiling; or Exception: Where the roof meets the requirements of Section 143(a)1C of Title 24, Part 6.

  3. In a space directly under a roof with fixed vents or openings to the outside or unconditioned spaces; or

  4. In an unconditioned crawlspace; or

  5. In other unconditioned spaces.

• § 1102.3 Medium relevance — show source text

  Chapter 10 Boilers and Pressure Vessels. Chapter 10 regulates the construction, installation, operation, repair, and alteration of boilers and pressure vessels. The safety provisions within this chapter address controls and limit devices for automatic boilers, methods of determining expansion tank capacities, discharge piping, relief valves, shutoff valves, gas-pressure and combustion regulators, and inspections and tests. Potable water heaters are free from the requirements of Chapter 10 as they are within the scope of the Uniform Plumbing Code (UPC).

  Pressure vessels store large amounts of energy and must comply with ASME Boiler and Pressure Vessel Code (BPVC) Section VIII.1. The stored energy must be contained to prevent disastrous failures. Boilers must comply with ASME BPVC Section I, ASME BPVC Section IV, or NFPA 85. Installing a safety relief valve and expansion tank prevents pressures in the tank from exceeding the design threshold.

  Chapter 11 Refrigeration. Chapter 11 regulates the design, installation, and construction requirements of refrigeration systems and the installation and construction of cooling towers. Refrigeration is a method used for achieving heat transfer to cool spaces. Refrigerants are the most common medium used to transfer the heat energy from the low-temperature level to the high-temperature level. Table

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  FORMAT OF THE UNIFORM MECHANICAL CODE

  1102.3 lists the most commonly used refrigerants and is labeled by a number. The concentration limits provided in Table 1102.3 are useful for the quantity of refrigerant required to cool a volume of space safely.

  A major milestone reached in the industry was the introduction of lower flammability refrigerants such as A2L and B2L. The industry’s concerns to address lower Global Warming Potential (GWP) refrigerants led to the development of these lower flammability refrigerants. Chapter 11 does not only include these lower flammability refrigerants in Table 1102.3, but it also contains specific A2L and B2L provisions to address the precautions necessary for the proper use of these products. In particular, high-probability systems using A2L refrigerants for human comfort applications are covered by provisions which include refrigerant concentration limits, mechanical ventilation, ignition sources, compressors and pressure vessels, and refrigerant sensors.

  In addition, Chapter 11 addresses other minimum requirements for refrigeration systems such as refrigeration machinery rooms (including ventilation), relief valves, and pressure vessels. Apart from refrigerants, the chapter also addresses minimum requirements for systems that use other mediums such as ammonia and brine systems. For ammonia systems, such systems are required to comply with IIAR 2, IIAR 3, IIAR/ANSI 4, IIAR 5, and IIAR 6.

  Chapter 12 Hydronics. Chapter 12 regulates hydronic systems that are part of heating, cooling, ventilation, and conditioning systems. Such piping systems include steam, hot water, radiant heating and cooling, chilled water, steam condensate, condenser water, ground source heat pump systems, snow and ice melt systems, ambient temperature loops, and district ambient temperature loops. Provisions within this chapter addressing ground source heat pumps and ambient temperature loops apply to the hydronic portions of the system. Geothermal energy systems, including ground source heat pumps and ambient temperature loops, are regulated by Chapter 17.

• § 805.10 Medium 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.

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  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.

• § 140.4 Medium 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.

  1. 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.

  3. 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).
  4. 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.

  6. 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.

• § 207.1 Medium relevance — show source text

  Exceptions:

  1. Heat rejection devices included as an integral part of the equipment listed in Tables A6.207.1-A through A6.207.1-E.
  2. Condenser fans serving multiple refrigerant circuits.
  3. Condenser fans serving flooded condensers.
  4. Up to [1] / 3 of the fans on a condenser or tower with multiple fans where the lead fans comply with the speed control requirement.

  A6.207.2.3.3 Tower flow turndown. Open cooling towers configured with multiple condenser water pumps shall be designed so that all cells can be run in parallel with the larger of:

  1. The flow that’s produced by the smallest pump or
  2. 33 percent of the design flow for the cell.

  A6.207.2.3.4 Limitation on centrifugal fan cooling towers. Open cooling towers with a combined rated capacity of 900 gpm and greater at 95°F condenser water return, 85°F condenser water supply and 75°F outdoor wet-bulb temperature shall use propeller fans and shall not use centrifugal fans.

  Exceptions:

  1. Cooling towers that are ducted (inlet or discharge) or have an external sound trap that requires external static pressure capability.
  2. Cooling towers that meet the energy efficiency requirement for propeller fan towers in Section A6.207.1, Table A6.207.1-G.

  APPENDIX A6.1-18 2025 CALIFORNIA GREEN BUILDING STANDARDS CODE

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  APPENDIX A6.1 — VOLUNTARY STANDARDS FOR HEALTH FACILITIES [OSHPD 1, 2 & 4]

  A6.207.2.4 Hydronic system measures.

  A6.207.2.4.1 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.

  Exceptions:

  1. Systems that include no more than three control valves.
  2. Systems having a total pump system power less than or equal to 1 [1] / 2 HP.

  A6.207.2.4.2 Chiller isolation. When a chilled water plant 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.

  A6.207.2.4.3 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).

  A6.207.2.4.4 Chilled and hot water temperature reset controls. Chilled and hot water systems with a design capacity exceeding 500,000 Btu/hr supplying chilled or heated water (or both) shall include controls that automatically reset supply water temperatures as a function of representative building loads or outside air temperature.

  Exception: Hydronic systems that use variable flow to reduce pumping energy in accordance with Section A6.207.2.4.1.

• § 803.2.1.3 Medium relevance — show source text

  The responsible person shall perform the field testing and verification work, and where this is the case, the responsible person shall complete and sign both the field technician’s signature block and the responsible person’s signature block on the certificate of acceptance form. The responsible person assumes responsibility for the acceptance testing work performed by the field technician agent or employee. E 803.2.1.3 Certificate of Acceptance. The certificate of acceptance shall be submitted to the Authority Having Jurisdiction in order to receive the final certificate of occupancy. The Authority Having Jurisdiction shall not release a final certificate of occupancy unless the submitted certificate of acceptance demonstrates that the specified systems and equipment have been shown to be performing in accordance with the applicable acceptance requirements. The Authority Having Jurisdiction has the authority to require the field technician and responsible person to demonstrate competence, to its satisfaction. Certificate of acceptance forms are located in Section E 806.0.

  E 804.0 Commissioning Tests. E 804.1 General. Functional tests shall be performed on new equipment and systems installed in either new construction or retrofit applications in accordance with this section. The appropriate certificate of acceptance form along with each specific test shall be completed and submitted to the Authority Having Jurisdiction before a final occupancy permit can be granted.

  E 804.2 Tests. Functional testing shall be performed on the devices and systems listed in this section. The functional test results are documented using the applicable certificate of acceptance forms shown in parenthesis and located in Section E 806.0. The functional tests shall be performed in accordance with Section E 805.0 using the following forms:

  (1) Minimum ventilation controls for constant and variable air volume systems (Form MECH-2A).

  (2) Zone temperature and scheduling controls for constant volume, single-zone, unitary air conditioner and heat pump systems (Form MECH-3A).

  (3) Duct leakage on a subset of small single-zone systems depending on the ductwork location (Form MECH-4A).

  (4) Air economizer controls for economizers that are not factory installed and tested (Form MECH-5A).

  (5) Demand-controlled ventilation control systems (Form MECH-6A).

  (6) Supply fan variable flow controls (Form MECH-7A).

  (7) Valve leakage for hydronic variable flow systems and isolation valves on chillers and boilers in plants with more than one chiller or boiler being served by the same primary pumps through a common header (Form MECH8A).

  (8) Supply water temperature reset control strategies programmed into the building automation system for water systems (e.g., chilled, hot, or condenser water) (Form MECH-9A).

  (9) Hydronic variable flow controls on a water system where the pumps are controlled by variable frequency drives (e.g., chilled and hot water systems; water-loop heat pump systems) (Form MECH-10A).

  (10)Automatic demand shed control (Form MECH-11A).

  (11)Fault detection and diagnostic for DX units (Form MECH-12A).

  (12)Automatic fault detection and diagnostic systems (AFDD) (Form MECH-13A).

  (13)Distributed energy storage DEC/DX AC systems (Form MECH-14A).

  (14)Thermal energy storage (TES) systems (Form MECH15A). E 804.3 Acceptance Process. The functional testing process shall comply with Section E 804.3.1 through Section E 804.3.4.

• § 160.3 Medium relevance — show source text

  (d) Mechanical acceptance testing.

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

  MULTIFAMILY BUILDINGS—MANDATORY REQUIREMENTS

  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.

• § 503.5.11.3. Medium relevance — show source text

  APPENDIX E

  point up to a maximum setpoint while the airflow is maintained at the dead band flow

  rate.

  (d) The second stage of heating consists of modulating the airflow rate from the dead band flow rate up to the heating maximum flow rate.

  (3) Laboratory exhaust systems that comply with Section E 503.5.11.3.

  (4) Zones where at least 75 percent of the energy for reheating or for providing warm air in mixing systems is provided from site-recovered energy (including condenser heat) or on-site renewable energy. [ASHRAE 90.1:6.5.2.1]

  E 503.5.5.1 Supply Air Temperature Reheat Limit. Where reheating is permitted in accordance with this appendix, zones that have both supply and return or exhaust air openings more than 6 feet (1829 mm) above the floor shall not supply heating air more than 20°F (11°C) above the space temperature setpoint.

  Exceptions:

  (1) Laboratory exhaust systems in accordance with Section E 503.5.11.3.

  (2) During preoccupancy building warm-up and setback. [ASHRAE 90.1:6.5.2.1.1]

  E 503.5.5.2 Hydronic System Controls. The heating of fluids in hydronic systems that have been previously mechanically cooled and the cooling of fluids that have been previously mechanically heated shall be limited in accordance with Section

  E 503.5.5.2.1 through Section E 503.5.5.2.3.

  [ASHRAE 90.1:6.5.2.2]

  E 503.5.5.2.1 Three-Pipe System. Hydronic systems that use a common return system for both hot water and chilled water shall not be used. [ASHRAE 90.1:6.5.2.2.1]

  E 503.5.5.2.2 Two-Pipe Changeover Sys- tem. Systems that use a common distribution system to supply both heated and chilled water are acceptable where in accordance with the following:

  (1) The system is designed to allow a dead band between changeover from one mode to the other of not less than 15°F (8°C) outdoor air temperature.

  (2) The system is designed to operate and is provided with controls that will allow operation in one mode for not less than 4 hours before changing over to the other mode.

  (3) Reset controls are provided that allow heating and cooling supply temperatures at the changeover point to be not more than 30°F (17°C) apart. [ASHRAE 90.1:6.5.2.2.2]

  E 503.5.5.2.3 Hydronic (Water Loop) Heat Pump Systems. Hydronic heat pumps connected to a common heat pump water loop with central devices for heat rejection (e.g., cooling tower) and heat addition (e.g., boiler) shall have the following:

  (1) Controls that are capable of and configured to provide a heat pump water supply temperature dead band of at least 20°F (11°C) between initiation of heat rejection and heat addition by the central devices (e.g., tower and boiler).