SECTION 140.4 – PRESCRIPTIVE REQUIREMENTS FOR SPACE CONDITIONING SYSTEMS

A building complies with this section by being designed with and having constructed and installed a space-conditioning system that meets the applicable prescriptive requirements of Subsections (a) through (q).

(a) Sizing, equipment selection, and type.



1. Sizing and equipment selection. Mechanical heating and mechanical cooling equipment serving healthcare facilities shall be sized to meet the design heating and cooling loads as calculated according to the Subsection (b). Mechanical heating and mechanical cooling equipment serving hotel/motel buildings and nonresidential buildings other than healthcare facilities shall be the smallest size, within the available options of the desired equipment line, necessary to meet the design heating and cooling loads of the building, as calculated according to Subsection (b).

Exception 1 to Section 140.4(a)1: Where it can be demonstrated to the satisfaction of the enforcing agency that oversizing will not increase building LSC.

Exception 2 to Section 140.4(a)1: Standby equipment with controls that allow the standby equipment to operate only when the primary equipment is not operating.

Exception 3 to Section 140.4(a)1: Multiple units of the same equipment type, such as multiple chillers and boilers, having combined capacities exceeding the design load, if they have controls, that sequence or otherwise optimally control the operation of each unit based on load.

2. Single zone space-conditioning system type. Single zone space-conditioning systems with direct expansion cooling with rated cooling capacity 240,000 Btu/hr or less serving the following spaces shall meet the applicable requirements in Items A-H, or shall meet the performance compliance requirements of Section 140.1.

A. Retail and grocery building spaces in Climate Zones 2 through 15. The space-conditioning system shall be a heat pump.

B. Retail and grocery building spaces in Climate Zones 1 and 16 with cooling capacity less than 65,000 Btu/hr. The space-conditioning system shall be an air conditioner with furnace.

 C. Retail and grocery building spaces in climate zones 1 and 16 with cooling capacity 65,000 Btu/hr or greater. The space-conditioning system shall be a dual-fuel heat pump.

 D. School building spaces. For Climate Zones 2 through 15, the space-conditioning system shall be a heat pump. For Climate Zones 1 and 16, the space-conditioning system shall be a dual-fuel heat pump.

E. Office, financial institution, and library building spaces in Climate Zones 1 through 15. The space-conditioning system shall be a heat pump.

F. Office, financial institution, and library building spaces in Climate Zone 16 with cooling capacity less than 65,000 Btu/hr. The space-conditioning system shall be an air conditioner with furnace.

G. Office, financial institution, and library building spaces in Climate Zone 16 with cooling capacity 65,000 Btu/hr or greater. The space-conditioning system shall be a dual-fuel heat pump.

H. Office spaces in warehouses. The space-conditioning system shall be a heat pump in all climate zones.

3. Multi-zone space-conditioning system types. Space-conditioning systems in office buildings and school buildings not covered by Section 140.4(a)2 shall meet the following requirements:

Exception 1 to Section 140.4(a)3: Buildings greater than 150,000 square feet or greater than 5 habitable stories.

Exception 2 to Section 140.4(a)3: School buildings in climate zones 6 and 7.

A. Space-conditioning systems shall comply with one of the following:

  i. The space-conditioning system shall be a variable refrigerant flow (VRF) heat pump system that incorporates refrigerant-loop heat recovery and a dedicated outdoor air system (DOAS) providing ventilation to all zones served by the space-conditioning system. Indoor fans shall meet the requirements of Section 140.4(a)3D. The DOAS shall comply with Section 140.4(a)3E.

  ii. The space-conditioning system shall be four-pipe fan coil (FPFC) terminal units with a DOAS providing ventilation to all zones served by the space-conditioning system. The FPFC hot water coils shall be supplied by an air-to-water heat pump (AWHP) space-heating hot water loop that complies with Section 140.4(a)3C. Indoor fans shall meet the requirements of Section 140.4(a)3D. The DOAS shall comply with Section 140.4(a)3E.

iii.  For office buildings in all climate zones and school buildings in climate zones 2, 4 and 8 through 16, the space conditioning system shall be a variable air volume (VAV) system that utilizes heating supplied through a hot water loop served by an AWHP that complies with Section 140.4(a)3C and the following:

1. For Office buildings: The portion of perimeter zone terminal unit heating capacity utilizing parallel fan-powered boxes complying with Section 140.4(a)3E shall be:

1.  100 percent in climate zones 1 through 6, and 16.

2.  25 percent in climate zones 7 through 15.

Ventilation systems in climate zones 1, 3, and 5 shall be equipped with a heat recovery system in compliance with Section 140.4(q). The maximum allowed fan power in climate zones 3 and 5 shall be 15 percent lower than specified by Section 140.4(c)1.

b. For school buildings:

All perimeter zone terminal units shall be parallel fan powered boxes complying with Section 140.4(a)3E. 

Ventilation systems in climate zones 2, 4, and 11 through 16 shall be equipped with a heat recovery system in compliance with Section 140.4(q). 

The maximum allowed fan power in climate zone 2 shall be 15 percent lower than specified by Section 140.4(c)1. 

The design leaving water temperature of the heating loop shall be no greater than 120°F in climate zone 2.

iv. The space conditioning system shall be a dual fan dual duct (DFDD) system with hot and cold decks each served by separate fan systems, and:

      

     a.  When required by Section 140.4(e), economizers shall be located on the cold deck,

     b.   The hot deck shall supply 100% return air, except outdoor air may be supplied as required to supplement the cold deck to maintain the design minimum outdoor air rate,

     c.   The hot deck heating source shall be a heat pump, and

     d. The DFDD and DFDD terminal unit control sequence shall comply with ASHRAE Guideline 36.

v. A space-conditioning system determined by the Executive Director to use no more energy than the systems specified in Section 140.4(a)3.

                

B. Reserved

C. AWHP space-heating hot water loop. AWHPs used to comply with the requirements of Section 140.4(a)3Aii, 140.4(a)3Aiii, or 140.4(a)3B, when used for space-heating hot water shall meet the following requirements:

1. The minimum efficiency requirements specified in Table 110.2-J,
2. If chilled water produced by an AWHP is used for space-cooling then the heat recovery system shall comply with Section 140.4(s),
3. Supplemental heating shall be provided by an electric resistance boiler with a capacity of not greater than 50 percent of the design space-heating hot water loop heating capacity.

D. Indoor fans. Indoor fans used to comply with the requirements of Section 140.4(a)3Ai, or 140.4(a)3Aii, shall have a maximum fan power of 0.35 W/cfm at design airflow, shall have not less than three speeds, and shall turn off when there is no demand for heating or cooling in the space. At 66 percent air flow the power draw shall be no more than 51 percent of the fan power at full fan speed, and at 33 percent air flow the power draw shall be no more than 12 percent of the fan power at full fan speed.

E. DOAS. DOAS used to comply with the requirements of Section 140.4(a)3Ai, or 140.4(a)3Aii, shall comply with Section 140.4(p), be equipped with a heat recovery system in compliance with Section 140.4(q), and have a maximum fan power of 0.77 W/cfm at design airflow. DOAS units that provide active heating or cooling  shall meet one of the following requirements:

                                   

i.   For hydronic heating or cooling:

      a.   DOAS heating coils shall be hydronic heating coils utilizing the AWHP space-heating hot water loop.

      b.   DOAS cooling coils shall be hydronic cooling coils utilizing space-cooling chilled water loop.

ii.  Other heating or cooling shall be provided by a heat pump. Electric resistance heating shall not be used.

(b) Calculations. In making equipment sizing calculations under Subsection (a), all of the following rules shall apply:

1. Heating and cooling loads. Heating and cooling system design loads shall be determined in accordance with the procedures described in Subsection A or B below:



 A. For systems serving hotel/motel buildings, and nonresidential buildings other than healthcare facilities, the method in the 2017 ASHRAE Handbook, Fundamentals shall be used, or as specified in a method approved by the Commission.

B. For system serving healthcare facilities the method in the California Mechanical Code shall be used.

2. Indoor design conditions. Indoor design temperature and humidity conditions for comfort applications shall be determined in accordance with Subsection A or B below:

A. For systems serving hotel/motel buildings, and nonresidential buildings other than healthcare facilities, ASHRAE Standard 55 or the 2017 ASHRAE Handbook, Fundamentals Volume, except that winter humidification and summer dehumidification shall not be required.

B. For system serving healthcare facilities the method in the California Mechanical Code shall be used.

3. Outdoor design conditions. Outdoor design conditions shall be selected in accordance with Subsection A or B below:

 A. For systems serving hotel/motel buildings, and nonresidential buildings other than healthcare facilities the design conditions shall meet the following:
i. Outdoor design conditions shall be selected from Reference Joint Appendix JA2 shall be used, which is based on data from the ASHRAE Climatic Data for Region X or the ASHRAE Handbook, Fundamentals Volume. 

      ii. Heating design temperatures shall be no lower than the 99.0 percent Heating Dry Bulb or the Heating Winter Median of Extremes values.

      iii. Cooling design temperatures shall be no greater than the 0.5 percent Cooling Dry Bulb and Mean Coincident Wet Bulb values.

B. For system serving healthcare facilities the method in Section 320.0 of the California Mechanical Code shall be used.

4. Ventilation. Outdoor air ventilation loads shall be calculated using the ventilation rates required in Section 120.1(c)3.

5. Envelope. Envelope heating and cooling loads shall be calculated using envelope characteristics, including square footage, thermal conductance, Solar Heat Gain Coefficient or shading coefficient, and air leakage, consistent with the proposed design.

6. Lighting. Lighting heating and cooling loads shall be based on actual design lighting levels or power densities as specified in Section 140.6.

7. People. Occupant density shall be based on the expected occupancy of the building and shall be the same as determined under Section 120.1(c)3A, if used. Sensible and latent heat gains shall be as listed in the 2017 ASHRAE Handbook, Fundamentals, Chapter 18.

8. Process loads. Loads caused by a process shall be based upon actual information on the intended use of the building.

9. Miscellaneous equipment. Equipment loads other than process loads shall be calculated using design data compiled from one or more of the following sources:

A. Actual information based on the intended use of the building; or

B. Published data from manufacturer's technical publications or from technical societies, such as the ASHRAE Handbook, Applications Volume; or

C. Other data based on the designer's experience of expected loads and occupancy patterns.

10. Internal heat gains. Internal heat gains may be ignored for heating load calculations.

11. Safety factor. Calculated design loads based on 140.4(b)1 through 10 may be increased by up to 10 percent to account for unexpected loads or changes in space usage.

12. Other loads. Loads such as warm-up or cool-down shall be calculated from principles based on the thermal capacity of the building and its contents, the degree of setback, and desired recovery time; or may be assumed to be no more than 30 percent for heating and 10 percent for cooling of the steady-state design loads. In addition, the steady-state load may include a safety factor in accordance with Section 140.4(b)11.

(c) Fan systems. Each fan system moving air into, out of or between conditioned spaces or circulating air for the purpose of conditioning air within a space shall meet the requirements of Items 1, 2 and 3 below. 



1. Fan power budget. For each fan system that includes at least one fan or fan array with fan electrical input power ≥ 1 kW, fan system electrical input power (Fan kW_{design,system}) determined per Section 140.4(c)1(B) at the fan system design airflow shall not exceed Fan kW_budget as calculated per Section 140.4(c)1(A).

A. Calculation of Fan Power Budget (Fan kW_budget). For each fan system:

i. Determine the fan system airflow and choose the appropriate table(s) for fan power allowance. 

a. For single-cabinet fan systems, use the fan system airflow and the power allowances in both Table 140.4-A and Table 140.4-B.

b. For supply-only fan systems, use the fan system airflow and power allowances in Table 140.4-A.

c. For relief fan systems, use the design relief airflow and the power allowances in Table 140.4-B.

d. For exhaust, return and transfer fan systems, use the fan system airflow and the power allowances in Table 140.4-B.

e. For complex fan systems, separately calculate the fan power allowance for the supply and return/exhaust systems and sum them. For the supply airflow, use supply airflow at the fan system design conditions, and the power allowances in Table 140.4-A. For the return exhaust airflow, use return /exhaust airflow at the fan system design conditions, and the power allowances in Table 140.4-B.

ii. For each fan system determine the components included in the fan system and sum the fan power allowances of those components. All fan systems shall include the system base allowance. If, for a given component, only a portion of the fan system airflow passes through the component, calculate the fan power allowance for that component per Equation 140.4-A:

EQUATION 140.4-A FAN POWER ALLOWANCE

Where

FPA_adj        =         The corrected fan power allowance for the component in w/cfm

Q_comp          =         The airflow through component in cfm

Q_sys             =         The fan system airflow in cfm

FPA_comp     =         The fan power allowance of the component from Table 140.4A or Table 140.4B

iii. Multiply the fan system airflow by the sum of the fan power allowances for the fan system.

iv. Divide by 1000 to convert to Fan kW_budget.

v. For building sites at elevations greater than 3,000 feet, multiply Fan kW_budget by the correction factor in Table 140.4-C.

B. Determining fan system electrical input power (Fan kW_{design,system}). Fan kW_{design,system} is the sum of Fan kWdesign for each fan or fan array included in the fan system with Fan kW_design ≥ 1 kW. If variable speed drives are used, their efficiency losses shall be included. Fan input power shall be calculated with two times the clean filter pressure drop, which is the mean of the clean filter pressure drop and design final filter pressure drop. The Fan kW_design for each fan or fan array shall be determined using one of the following methods. There is no requirement to use the same method for all fans in a fan system:

i. Use the default Fan kW_design in Table 140.4-D for one or more of the fans. This method cannot be used for complex fan systems.

ii. Use the Fan kW_design at fan system design conditions provided by the manufacturer of the fan, fan array, or equipment that includes the fan or fan array calculated per a test procedure included in USDOE 10 CFR Part 430, USDOE 10 CFR Part 431, ANSI/AMCA Standard 208-2018, ANSI/AMCA 
Standard 210-2016, AHRI Standard 430-2020, AHRI Standard 440-2019, or ISO 5801-2017.

iii. Use the Fan kW_design provided by the manufacturer, calculated at fan system design conditions per one of the methods listed in Section 5.3 of ANSI/AMCA 208-2018.

iv. Determine the Fan kW_design by using the maximum electrical input power provided on the motor nameplate.

Table 140.4-A Supply Fan Power Allowances (watts/ cfm)

Airflow	Multi-Zone VAV Systems  ≤ 5,000 cfm1	Multi-Zone VAV Systems > 5,000 and ≤ 10,000 cfm1	Multi-Zone VAV Systems > 10,000 cfm1	All Other Fan Systems ≤ 5,000 cfm	All Other Fan Systems > 5,000 and ≤ 10,000 cfm	All Other Fan Systems  > 10,000 cfm
Supply System Base Allowance for AHU serving spaces ≤ 6 floors away.	0.395	0.453	0.413	0.232	0.256	0.236
Supply system base allowance for AHU serving spaces > 6 floors away	0.508	0.548	0.501	0.349	0.356	0.325
MERV 13 to MERV 16 Filter upstream of thermal conditioning equipment (two times the clean filter pressure drop)2	0.136	0.114	0.105	0.139	0.120	0.107
MERV 13 to MERV 16 Final filter downstream of thermal conditioning equipment. (two times the clean filter pressure drop)2	0.225	0.188	0.176	0.231	0.197	0.177
Filtration allowance for > MERV 16 or HEPA Filter (two times the clean filter pressure drop) 2	0.335	0.280	0.265	0.342	0.292	0.264
Central Hydronic heating coil allowance	0.046	0.048	0.052	0.046	0.050	0.054
Electric heat allowance	0.046	0.038	0.035	0.046	0.040	0.036
Gas heat allowance	0.069	0.057	0.070	0.058	0.060	0.072
Hydronic/DX cooling coil or heat pump coil (wet) allowance3	0.135	0.114	0.105	0.139	0.120	0.107
Solid or liquid Desiccant system allowance	0.157	0.132	0.123	0.163	0.139	0.124
Reheat Coil for Dehumidification Allowance	0.045	0.038	0.035	0.046	0.040	0.036
Allowance for Evaporative humidifier/cooler in series with a cooling coil. Value shown is allowed watts/cfm per 1.0 Inches of water gauge (in.w.g.)  Determine pressure loss (in.w.g.) at 400 fpm or maximum velocity allowed by the manufacturer, whichever is less. [Calculation required, see note 4]	0.224	0.188	0.176	0.231	0.197	0.177

CONTINUED: Table 140.4-A – Supply Fan Power Allowances (watts/ cfm)

Airflow	Multi-Zone VAV Systems  ≤ 5,000 cfm1	Multi-Zone VAV Systems > 5,000 and ≤ 10,000 cfm1	Multi-Zone VAV Systems > 10,000 cfm1	All Other Fan Systems ≤ 5,000 cfm		All Other Fan Systems > 5,000 and ≤ 10,000 cfm	All Other Fan Systems  > 10,000 cfm
Allowance for 100% Outdoor air system5.	0.000	0.000	0.000		0.070	0.100	0.107
Energy recovery allowance for 0.50 ≤ ERR <0.55 6	0.135	0.114	0.105		0.139	0.120	0.107
Energy recovery allowance for 0.55 ≤ ERR <0.60 6	0.160	0.134	0.124		0.165	0.141	0.126
Energy recovery allowance for 0.60 ≤ ERR <0.65 6	0.184	0.155	0.144		0.190	0.163	0.146
Energy recovery allowance for 0.65 ≤ ERR <0.70 6	0.208	0.175	0.163		0.215	0.184	0.165
Energy recovery allowance for 0.70 ≤ ERR <0.75 6	0.232	0.196	0.183		0.240	0.205	0.184
Energy recovery allowance for 0.75 ≤ ERR <0.80 6	0.257	0.216	0.202		0.264	0.226	0.203
Energy recovery allowance for ERR ≥ 0.80 6	0.281	0.236	0.222		0.289	0.247	0.222
Coil Runaround Loop	0.135	0.114	0.105		0.139	0.120	0.107
Allowance for Gas phase filtration. Value shown is allowed w/cfm per 1.0 in. wg air pressure drop. [Calculation required, see note 4]	0.224	0.188	0.176		0.231	0.197	0.177
Economizer Return Damper	0.045	0.038	0.035		0.046	0.040	0.036
Air blender allowance	0.045	0.038	0.035		0.046	0.040	0.036
Sound attenuation section [fans serving spaces with design background noise goals below NC35]	0.034	0.029	0.026		0.035	0.030	0.027
Deduction for systems that feed a terminal unit with a fan with electrical input power < 1kW	-0.100	-0.100	-0.100		-0.100	-0.100	-0.100
Low-turndown single-zone VAV fan systems meeting the requirements in note 7.	0.000	0.000	0.000		0.070	0.100	0.089

Footnotes to Table 140.4-A
1. See Section 100.1 for the definition of FAN SYSTEM, MULTI-ZONE VARIABLE AIR VOLUME (VAV) .
2. Filter fan power allowance can only be counted once per fan system, except fan systems in healthcare facilities, which can claim one of the MERV 13 to 16 filter allowances and the HEPA filter allowance if both are included in the fan system.
3. Healthcare facilities can claim this fan power allowance twice per fan system where coil design leaving air temperature is less than 44 ⁰F.
4. Power allowance requires further calculation by multiplying the actual inches of water gauge (in.w.g.) of the device/ component by the watts/ cfm in Table 140.4-A.
5. The 100% outdoor air system must serve 3 or more HVAC zones and airflow during non-economizer operating periods must not exceed 135% of minimum requirements in Section 120.1(c)(3).
6. Enthalpy Recovery Ratio (ERR) calculated per ANSI/ASHRAE 84-2020.
7. A low-turndown single-zone VAV fan system must be capable of and configured to reduce airflow to 50 percent of design airflow and use no more than 30 percent of the design wattage at that airflow. No more than 10 percent of the design load served by the equipment shall have fixed loads.

TABLE 140.4-B – EXHAUST, RETURN, RELIEF, TRANSFER FAN POWER ALLOWANCES (WATTS/ CFM)

Airflow	Multi-Zone VAV Systems1 ≤ 5,000 cfm	Multi-Zone VAV Systems1 > 5,000 and ≤ 10,000 cfm	Multi-Zone VAV Systems1 > 10,000 cfm	All Other Fan Systems ≤ 5,000 cfm	All Other Fan Systems > 5,000 and ≤ 10,000 cfm	All Other Fan Systems > 10,000 cfm
Exhaust System Base Allowance	0.221	0.246	0.236	0.186	0.184	0.190
Filter (any MERV value)2	0.046	0.041	0.036	0.046	0.041	0.035
Energy Recovery Allowance For 0.50 ≤ ERR <0.55 3	0.139	0.120	0.107	0.139	0.123	0.109
Energy Recovery Allowance For 0.55 ≤ ERR <0.60 3	0.165	0.142	0.126	0.165	0.144	0.128
Energy Recovery Allowance For 0.60 ≤ ERR <0.65 3	0.190	0.163	0.146	0.191	0.166	0.148
Energy Recovery Allowance For 0.65 ≤ ERR <0.70 3	0.215	0.184	0.165	0.216	0.188	0.167
Energy Recovery Allowance For 0.70 ≤ ERR <0.75 3	0.240	0.206	0.184	0.241	0.209	0.186
Energy Recovery Allowance For 0.75 ≤ ERR <0.80 3	0.265	0.227	0.203	0.266	0.231	0.205
Energy Recovery Allowance For ERR ≥ 0.80 3	0.289	0.248	0.222	0.291	0.252	0.225
Coil Runaround Loop	0.139	0.120	0.107	0.139	0.123	0.109
Return or exhaust systems required by code or accreditation standards to be fully ducted, or systems required to maintain air pressure differentials between adjacent rooms	0.116	0.100	0.089	0.116	0.102	0.091
Return and/or exhaust airflow control devices required for space pressurization control	0.116	0.100	0.089	0.116	0.102	0.091

 

 

 CONTINUED: TABLE 140.4-B – EXHAUST, RETURN, RELIEF, TRANSFER FAN POWER ALLOWANCES (WATTS/ CFM)

Airflow	Multi-Zone VAV Systems1 ≤ 5,000 cfm	Multi-Zone VAV Systems1 > 5,000 and ≤ 10,000 cfm	Multi-Zone VAV Systems1 > 10,000 cfm	All Other Fan Systems ≤ 5,000 cfm	All Other Fan Systems > 5,000 and ≤ 10,000 cfm	All Other Fan Systems > 10,000 cfm
Laboratory and vivarium exhaust systems in high-rise buildings for vertical duct exceeding 75 ft. Value shown is allowed w/cfm per 0.25 in. wg for each 100 feet exceeding 75 feet. [Calculation required, see note 4]	0.058	0.051	0.045	0.058	0.052	0.046
Biosafety cabinet. Value shown is allowed w/cfm per 1.0 in. wg air pressure drop. [Calculation required, see note 4]	0.231	0.198	0.177	0.232	0.202	0.179
Exhaust filters, scrubbers, or other exhaust treatment required by code or standard. Value shown is allowed w/cfm per 1.0 in. wg air pressure drop. [Calculation required, see note 4]	0.231	0.198	0.177	0.232	0.202	0.179
Healthcare facility allowance5	0.231	0.198	0.177	0.232	0.202	0.179
Sound attenuation section [Fans serving spaces with design background noise goals below NC35.]	0.035	0.030	0.027	0.035	0.031	0.028

Footnotes to Table 140.4-B 

1.     See FAN SYSTEM, MULTI-ZONE VARIABLE AIR VOLUME (VAV) in definitions for Multizone to be classified as a Multi-Zone VAV System.

2.     Filter pressure loss can only be counted once per fan system. 

3.     Enthalpy Recovery Ratio (ERR) calculated per ANSI/ASHRAE 84-2020.

4.     Power allowance requires further calculation, multiplying the actual pressure drop (in. wg.) of the device/component by the watts/cfm in the Table 140.4-B.

5.     This allowance can only be taken for healthcare facilities.

 

TABLE 140.4-C AIR DENSITY CORRECTION FACTORS

Altitude (ft)	Correction Factor
<3,000	1.000
≥3,000 and <4,000	0.896
≥4,000 and <5,000	0.864
≥5,000 and <6,000	0.832
≥6,000	0.801

TABLE 140.4-D DEFAULT VALUES FOR FAN KWDESIGN BASED ON MOTOR NAMEPLATE HP

Motor Nameplate HP	Default Fan kWdesign with variable speed drive (Fan kWdesign)	Default Fan kWdesign without variable speed drive(Fan kWdesign)
<1	0.96	0.89
≥1 and <1.5	1.38	1.29
≥1.5 and <2	1.84	1.72
≥2 and <3	2.73	2.57
≥3 and <5	4.38	4.17
≥5 and <7.5	6.43	6.15
≥7.5 and <10	8.46	8.13
≥10 and <15	12.47	12.03
≥15 and <20	16.55	16.04
≥20 and <25	20.58	19.92
≥25 and <30	24.59	23.77
≥30 and <40	32.74	31.70
≥40 and <50	40.71	39.46
≥50 and <60	48.50	47.10
≥60 and <75	60.45	58.87
≥75 and ≤100	80.40	78.17

Footnotes to TABLE 140.4-D:
1. This table cannot be used for Motor Nameplate Horsepower values greater than 100.
2. This table is to be used only with motors with a service factor ≤1.15. If the service factor is not provided, this table may not be used.

2. Variable air volume (VAV) systems.

A. Static pressure sensor location. Static pressure sensors used to control variable air volume fans shall be placed in a position such that the controller set point is no greater than one-third the total design fan static pressure, except for systems with zone reset control complying with Section 140.4(c)2B. If this results in the sensor being located downstream of any major duct split, multiple sensors shall be installed in each major branch with fan capacity controlled to satisfy the sensor furthest below its setpoint; and

B. Setpoint reset. For systems with direct digital control of individual zone boxes reporting to the central control panel.

i.    Static pressure setpoints shall be reset based on the zone requiring the most pressure.

ii.    Control sequences of operation for static pressure setpoint reset shall be in accordance with ASHRAE Guideline 36.

3. Fractional HVAC motors for fans. HVAC motors for fans that are less than 1 hp and 1/12 hp or greater shall be electronically-commutated motors or shall have a minimum motor efficiency of 70 percent when rated in accordance with NEMA Standard MG 1-2006 at full load rating conditions. These motors shall also have the means to adjust motor speed for either balancing or remote control. Belt-driven fans may use sheave adjustments for airflow balancing in lieu of a varying motor speed.

Exception 1 to Section 140.4(c)3: Motors in fan-coils and terminal units that operate only when providing heating to the space served.

Exception 2 to Section 140.4(c)3: Motors in space conditioning equipment certified under Section 110.1 or 110.2.

(d) Space-conditioning zone controls. Each space-conditioning zone shall have controls designed in accordance with 1 or 2: 



1. Each space-conditioning zone shall have controls that prevent: 

A. Reheating; and 

B. Recooling; and

C. Simultaneous provisions of heating and cooling to the same zone, such as mixing or simultaneous supply of air that has been previously mechanically heated and air that has been previously cooled either by cooling equipment or by economizer systems; or

2. Zones served by variable air-volume systems that are designed and controlled to reduce, to a minimum, the volume of reheated, recooled, or mixed air are allowed only if the controls meet all of the following requirements:

A. For each zone with direct digital controls (DDC):

i. The volume of primary air that is reheated, recooled or mixed air supply shall not exceed the larger of:

a. 50 percent of the peak primary airflow; or

b. The design zone outdoor airflow rate as specified by Section 120.1(c)3.

ii. The volume of primary air in the deadband shall not exceed the design zone outdoor airflow rate as specified by Section 120.1(c)3.

iii. The first stage of heating consists of modulating the zone supply air temperature setpoint up to a maximum setpoint no higher than 95ºF while the airflow is maintained at the deadband flow rate.

iv. The second stage of heating consists of modulating the airflow rate from the deadband flow rate up to the heating maximum flow rate.

         

v. Control sequences of operation for reheat zones shall be in accordance with ASHRAE Guideline 36.

B. For each zone without DDC, the volume of primary air that is reheated, re-cooled, or mixed air supply shall not exceed the larger of the following:

i. 30 percent of the peak primary airflow; or

ii. The design zone outdoor airflow rate as specified by Section 120.1(c)3.

(e) Economizers.



1. Each cooling air handler that has a design total mechanical cooling capacity over 33,000 Btu/hr or chilled- water cooling systems without a fan or that use induced airflow that has a cooling capacity greater than the systems listed in Table 140.4-C, shall include either: 

A. An air economizer capable of modulating outside-air and return-air dampers to supply 100 percent of the design supply air quantity as outside-air; or 

B. A water economizer capable of providing 100 percent of the expected system cooling load, at outside air temperatures of 50°F dry-bulb and 45°F wet-bulb and below.

​​​​​TABLE 140.4-E CHILLED WATER SYSTEM COOLING CAPACITY

Climate Zones	Building Water-Cooled Chilled Water System	Air-Cooled Chilled Water Systems or District Chilled Water Systems
15	≥ 960,000 Btu/h (280 kW)	≥ 1,250,000 Btu/h (365 kW)
1-14	≥720,000 Btu/h (210 kW)	≥940,000 Btu/h (275 kW)
16	≥1,320,000 Btu/h (385 kW)	≥1,720,000 Bu/h (505 kW)

TABLE 140.4-F ECONOMIZER TRADE-OFF TABLE FOR COOLING SYSTEMS

Climate Zone	Efficiency Improvement a
1	70%
2	65%
3	65%
4	65%
5	70%
6	30%
7	30%
8	30%
9	30%
10	30%
11	30%
12	30%
13	30%
14	30%
15	30%
16	70%

^a If a unit is rated with an annualized or part-load metric, then to eliminate the required economizer, only the applicable minimum cooling efficiency of the unit must be increased by the percentage shown. If the unit is only rated with a full load metric, like EER or COP cooling, then that metric must be increased by the percentage shown. To determine the efficiency required to eliminate the economizer, when the unit equipment efficiency is rated with an energy-input divided by work-output metric, the metric shall first be converted to COP prior to multiplying by the efficiency improvement percentage and then converted back to the rated metric.

2. If an economizer is required by Section 140.4(e)1, and an air economizer is used to meet the requirement, then it shall be:

A. Designed and equipped with controls so that economizer operation does not increase the building heating energy use during normal operation; and

Exception to Section 140.4(e)2A: Systems that provide 75 percent of the annual energy used for mechanical heating from site-recovered energy or a site-solar energy source.

B. Capable of providing partial cooling even when additional mechanical cooling is required to meet the remainder of the cooling load.

C.  Designed and equipped with a device type and high limit shut off complying with Table 140.4-G.

D. If controlled by a DDC system, configured with control sequences of operation in accordance with ASHRAE Guideline 36.

TABLE 140.4-G AIR ECONOMIZER HIGH LIMIT SHUT OFF CONTROL REQUIREMENTS

Device Typea	Climate Zones	Required High Limit (Economizer Off When): Equationb	Description
Fixed Dry Bulb	1, 3, 5, 11-16	TOA > 75°F	Outdoor air temperature exceeds 75°F
Fixed Dry Bulb	2, 4, 10	TOA > 73°F	Outdoor air temperature exceeds 73°F
Fixed Dry Bulb	6, 8, 9	TOA > 71°F	Outdoor air temperature exceeds 71°F
Fixed Dry Bulb	7	TOA > 69°F	Outdoor air temperature exceeds 69°F
Differential Dry Bulb	1, 3, 5, 11-16	TOA > TRA	Outdoor air temperature exceeds return air temperature
Differential Dry Bulb	2, 4, 10	TOA > TRA-2°F	Outdoor air temperature exceeds return air temperature minus 2°F
Differential Dry Bulb	6, 8, 9	TOA > TRA-4°F	Outdoor air temperature exceeds return air temperature minus 4°F
Differential Dry Bulb	7	TOA > TRA-6°F	Outdoor air temperature exceeds return air temperature minus 6°F
Fixed Enthalpyc + Fixed Drybulb	All	hOA > 28 Btu/lbd or TOA > 75°F	Outdoor air enthalpy exceeds 28 Btu/lb of dry air; or Outdoor air temperature exceeds 75°F

^a Only the high limit control devices listed are allowed to be used and at the setpoints listed. Others such as Dew Point, Fixed Enthalpy, Electronic Enthalpy, and Differential Enthalpy Controls, may not be used in any Climate Zone for compliance with Section 140.4(e)1 unless approval for use is provided by the Energy Commission Executive Director. 

^b Devices with selectable (rather than adjustable) setpoints shall be capable of being set to within 2°F and 2 Btu/lb of the setpoint listed. 

^c At altitudes substantially different than sea level, the Fixed Enthalpy limit value shall be set to the enthalpy value at 75°F and 50% relative humidity. As an example, at approximately 6,000 foot elevation, the fixed enthalpy limit is approximately 30.7 Btu/lb.

E. The air economizer and all air dampers shall have the following features:

i. Warranty. 5-year manufacturer warranty of economizer assembly.

ii. Damper reliability testing. Suppliers of economizers shall certify that the economizer assembly, including but not limited to outdoor air damper, return air damper, drive linkage and actuator, have been tested and are able to open and close against the rated airflow and pressure of the system for 60,000 damper opening and closing cycles.

iii. Damper leakage. Economizer outdoor air and return air dampers shall have a maximum leakage rate of 10 cfm/sf at 250 Pascals (1.0 in. of water) when tested in accordance with AMCA Standard 500-D. The economizer outside air and return air damper leakage rates shall be certified to the Energy Commission in accordance with Section 110.0.

iv. Adjustable setpoint. If the high-limit control is fixed dry-bulb or fixed enthalpy + fixed dry-bulb, then the control shall have an adjustable setpoint.

v. Sensor accuracy. Outdoor air, return air, mixed air, and supply air sensors shall be calibrated within the following accuracies.

1. Drybulb and wetbulb temperatures accurate to ±2°F over the range of 40°F to 80°F;

2. Enthalpy accurate to ±3 Btu/lb over the range of 20 Btu/lb to 36 Btu/lb;

3. Relative humidity (RH) accurate to ±5 percent over the range of 20 percent to 80 percent RH;

vi. Sensor calibration data. Data used for control of the economizer shall be plotted on a sensor performance curve.

vii. Sensor high limit control. Sensors used for the high limit control shall be located to prevent false readings, including but not limited to being properly shielded from direct sunlight.

viii. Relief air system. Relief air systems shall be capable of providing 100 percent outside air without over-pressurizing the building.

  F. The space-conditioning system shall include the following:

   i. Unit controls shall have mechanical capacity controls interlocked with economizer controls such that the economizer is at 100 percent open position when mechanical cooling is on and does not begin to close until the leaving air temperature is less than 45^oF.

  ii. Direct Expansion (DX) units greater than 65,000 Btu/hr that control the capacity of the mechanical cooling directly based on occupied space temperature shall have a minimum of two stages of mechanical cooling capacity.

iii. DX units not within the scope of Section 140.4(e)2Fii shall comply with the requirements in Table 140.4-H and have controls that do not false load the mechanical cooling system by limiting or disabling the economizer or by any other means except at the lowest stage of mechanical cooling capacity.

TABLE 140.4-H DIRECT EXPANSION (DX) UNIT REQUIREMENTS FOR COOLING STAGES AND COMPRESSOR DISPLACEMENT

COOLING CAPACITY	MINIMUM NUMBER OF MECHANICAL COOLING STAGES	MINIMUM COMPRESSOR DISPLACEMENT
≥ 65,000 Btu/h and < 240,000 Btu/h	3 stages	≤ 35% full load
≥ 240,000 Btu/h	4 stages	≤ 25% full load

3. Systems that include a water economizer to meet Section 140.4(e)1 shall include the following:

A. Maximum pressure drop. Precooling coils and water-to-water heat exchangers used as part of a water economizer shall either have a waterside pressure drop of less than 15 feet of water, or a secondary loop shall be installed so that the coil or heat exchanger pressure drop is not contributing to pressure drop when the system is in the normal cooling (non-economizer) mode.

B. Economizer systems shall be integrated with the mechanical cooling system so that they are capable of providing partial cooling even when additional mechanical cooling is required to meet the remainder of the cooling load. Controls shall not false load the mechanical cooling system by limiting or disabling the economizer or by any other means, such as hot gas bypass, except at the lowest stage of mechanical cooling.

(f) Supply air temperature reset controls. Space-conditioning systems supplying heated or cooled air to multiple zones shall include controls that automatically reset supply-air temperatures. Air distribution systems serving zones that are likely to have constant loads shall be designed for the air flows resulting from the fully reset supply air temperature. Supply air temperature reset controls shall be:



1. In response to representative building loads or to outdoor air temperature; and
2. At least 25 percent of the difference between the design supply-air temperature and the design room air temperature.
3. Configured with control sequences of operation in accordance with ASHRAE Guideline 36.

Exception 1 to Section 140.4(f): Systems that meet the requirements of Section 140.4(d)1, without using Exception 1 to that section.

Exception 2 to Section 140.4(f): Where supply-air temperature reset would increase overall building energy use.

Exception 3 to Section 140.4(f): Systems supplying zones in which specific humidity levels are required to satisfy process loads. Computer rooms or other spaces with only IT equipment may not use this exception.

Exception 4 to Section 140.4(f): Systems serving healthcare facilities.

(g) Electric resistance heating. Electric resistance heating systems shall not be used for space heating.



Exception 1 to Section 140.4(g): Where an electric-resistance heating system supplements a heating system in which at least 60 percent of the annual energy requirement is supplied by site-solar or recovered energy. 

Exception 2 to Section 140.4(g): Where an electric-resistance heating system supplements a heat pump heating system, and the heating capacity of the heat pump is more than 75 percent of the design heating load calculated in accordance with Section 140.4(a) at the design outdoor temperature specified in Section 140.4(b)4.

Exception 3 to Section 140.4(g): Where the total capacity of all electric-resistance heating systems serving the entire building is less than 10 percent of the total design output capacity of all heating equipment serving the entire building.

Exception 4 to Section 140.4(g): Where the total capacity of all electric-resistance heating systems serving the entire building, excluding those allowed under Exception 2, is no more than 3 kW.

Exception 5 to Section 140.4(g): Where an electric resistance heating system serves an entire building that is not a hotel/motel building; and has a conditioned floor area no greater than 5,000 square feet; and has no mechanical cooling; and is in an area where natural gas is not currently available.

Exception 6 to Section 140.4(g): Heating systems serving as emergency backup to gas heating equipment.

Exception 7 to Section 140.4(g): Supplemental electric resistance heating systems complying with Section 140.4(a)3C.

(h) Heat rejection systems. Heat rejection equipment used in comfort cooling systems, such as air-cooled condensers, open cooling towers, closed-circuit cooling towers and evaporative condensers shall include the following:



1. Fan speed control. Each fan powered by a motor of 7.5 hp (5.6 kW) or larger shall have the capability to operate that fan at two thirds of full speed or less and shall have controls that automatically change the fan speed to control the leaving fluid temperature or condensing temperature or pressure of the heat rejection device.

Exception 1 to Section 140.4(h)1: Heat rejection devices included as an integral part of the equipment listed in Tables 110.2-A through Table 110.2-N.

Exception 2 to Section 140.4(h)1: Condenser fans serving multiple refrigerant circuits.

Exception 3 to Section 140.4(h)1: Condenser fans serving flooded condensers.

Exception 4 to Section 140.4(h)1: Up to one third of the fans on a condenser or tower with multiple fans where the lead fans comply with the speed control requirement.

2. 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:

A. The flow that is produced by the smallest pump, or

B. 50 percent of the design flow for the cell.

3. 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.

Exception 1 to Section 140.4(h)3: Cooling towers that are ducted (inlet or discharge) or have an external sound trap that requires external static pressure capability.

Exception 2 to Section 140.4(h)3: Cooling towers that meet the energy efficiency requirement for propeller fan towers in Section 110.2, Table 110.2-F.

4. Multiple cell heat rejection equipment. Multiple cell heat rejection equipment with variable speed fan drives shall:

A. Operate the maximum number of fans allowed that comply with the manufacturer’s requirements for all system components, and

B. Control all operating fans to the same speed. Minimum fan speed shall comply with the minimum allowable speed of the fan drive as specified by the manufacturer’s recommendation. Staging of fans is allowed once the fans are at their minimum operating speed.

5. Cooling tower efficiency. Axial fan, open-circuit cooling towers serving condenser water loops for chilled water plants with a total of 900 gpm or greater, shall have a minimum rated efficiency based on Table 140.4-H-2 when rated in accordance  with the conditions as listed in Table 110.2-F.

   

Table 140.4-H-2 - MINIMUM EFFICIENCY FOR PROPELLER OR AXIAL FAN OPEN-CIRCUIT COOLING TOWERS (GPM/hp)

CZ1	CZ2	CZ3	CZ4	CZ5	CZ6	CZ7	CZ8	CZ9	CZ10	CZ11	CZ12	CZ13	CZ14	CZ15	CZ16
42.1	70	60	70	70	80	80	80	80	80	60	70	80	60	80	42.1

(i) Minimum chiller efficiency. Chillers shall meet or exceed Path B from Table 110.2-D. 



Exception 1 to Section 140.4(i): Chillers with electrical service > 600V.

Exception 2 to Section 140.4(i): Chillers attached to a heat recovery system with a design heat recovery capacity > 40 percent of the design chiller cooling capacity.

Exception 3 to Section 140.4(i): Chillers used to charge thermal energy storage systems where the charging temperature is < 40 F.

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 Section 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.

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.

(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 2 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. 

2. All other systems, including but not limited to DX cooling systems and chilled water systems that control the space temperature by modulating the airflow to the space, shall have proportional fan control such that at 50 percent air flow the power draw is no more than 30 percent of the fan power at full fan speed.

3. Systems that include an air side economizer to meet Section 140.4(e)1 shall have a minimum of two speeds of fan control during economizer operation.

TABLE 140.4-I FAN CONTROL SYSTEMS

Cooling System Type	Fan Motor Size	Cooling Capacity
DX Cooling	Any	≥ 65,000 Btu/hr
Chilled Water and Evaporative	≥ 1/4 HP	Any

(n) Mechanical system shut-off. Any directly conditioned space with operable wall or roof openings to the outdoors shall be provided with interlock controls that disable or reset the temperature setpoint to 55°F for mechanical heating and disable or reset the temperature setpoint to 90°F for mechanical cooling to that space when any such opening is open for more than 5 minutes.



Exception 1 to Section 140.4(n): Interlocks are not required on doors with automatic closing devices.

Exception 2 to Section 140.4(n): Any space without a thermostatic control (thermostat or a space temperature sensor used to control heating or cooling to the space). 

Exception 3 to Section 140.4(n): Healthcare facilities. 

(o) Exhaust system transfer air. Conditioned supply air delivered to any space with mechanical exhaust shall not exceed the greater of:

     

1. The supply flow required to meet the space heating or cooling load; or
2. The ventilation rate required by the authority having jurisdiction, the facility Environmental Health and Safety Department, or by Section 120.1(c)3; or
3. The mechanical exhaust flow minus the available transfer air. Available transfer air shall be from another conditioned space or return air plenums on the same floor and same smoke or fire compartment, and that at their closest point are within 15 feet of each other. 

Exception 1 to Section 140.4(o): Biosafety level classified laboratories 3 or higher.

Exception 2 to Section 140.4(o): Vivarium spaces.

Exception 3 to Section 140.4(o): Spaces that are required by applicable codes and standards to be maintained at a positive pressure differential relative to adjacent spaces.

Exception 4 to Section 140.4(o): Spaces where the highest amount of transfer air that could be used for exhaust makeup may exceed the available transfer airflow rate and where the spaces have a required negative pressure relationship.

Exception 5 to Section 140.4(o): Healthcare facilities.

(p) Dedicated outdoor air systems (DOAS).



      HVAC systems that utilize a dedicated outdoor air system (DOAS) such as a DX-DOAS, HRV or ERV unit to condition, temper, or filter 100 percent outdoor air separate from local or central space-conditioning systems serving the same space shall meet the following criteria:

1. DOAS unit fan systems with input power less than 1 kW shall not exceed a total combined fan power of 1.0 W/cfm. DOAS with fan power greater than or equal to 1 kW shall meet the requirements of Section 140.4(c)
   
   Exception to Section 140.4(p)1: DOAS complying with Section 140.4(a)3E.
   
   
2. The DOAS supply air shall be delivered directly to the occupied space or at the outlet of any terminal heating or cooling coils and shall cycle off any zone heating and cooling equipment fans, circulation pumps, and terminal unit fans when there is no call for heating or cooling in the zone.
   
   Exception 1 to Section 140.4(p)2: Active chilled beam systems.
   
   Exception 2 to Section 140.4(p)2: Sensible-only cooling terminal units with pressure-independent variable-airflow regulating devices limiting the DOAS supply air to the greater of latent load or minimum ventilation requirements.
   
   Exception 3 to Section 140.4(p)2: Any configuration where a DOAS unit provides ventilation air to a downstream fan (a terminal box, air handling unit or other space-conditioning equipment) where the total system airflow can be reduced to ventilation minimum or the downstream fan power is no greater than 0.12 Watts per cfm when space temperatures are within the thermostat deadband (at low speed per manufacturer’s literature).
3. DOAS supply and exhaust fans shall have a minimum of three speeds to facilitate system balancing.
4. DOAS with mechanical cooling providing ventilation to multiple zones and operating in conjunction with zone heating and cooling systems shall not use heating or heat recovery to warm supply air above 60°F when representative building loads or outdoor air temperature indicates that the majority of zones require cooling.

(q) Exhaust air heat recovery.

Fan systems designed to operate to the criteria listed in Table 140.4-J or Table 140.4-K, or where required by Section 140.4(a)3, shall include an exhaust air heat recovery system that meets the following:

1.  A sensible energy recovery ratio of at least 60 percent or an enthalpy recovery ratio of at least 50 percent for both heating and cooling design conditions and a rating in accordance with AHRI 1060. 

Exception 1 to Section 140.4(q)1: Compliance is not required for sensible recovery ratio at heating design conditions for climate zone 15.

Exception 2 to Section 140.4(q)1: Compliance is not required for sensible recovery ratio at cooling design conditions for Climate Zone 1.

2. Energy recovery bypass or control to disable energy recovery and to directly economize with ventilation air based on outdoor air temperature limits specified in Table 140.4-G. For energy recovery systems where the transfer of energy cannot be stopped, bypass shall prevent the total airflow rate of either outdoor air or exhaust air through the energy recovery exchanger from exceeding 10 percent of the full design airflow rate.

Exception to Section 140.4(q)2: For DOAS units with the capability to shut off when a separate space-conditioning system serving the same space meets the economizer requirements in Section 140.4(e)1A.    

Exception 1 to Section 140.4(q): Systems meeting Section 140.9(c), Prescriptive requirements for laboratory and factory exhaust systems.

Exception 2 to Section 140.4(q): Systems serving spaces that are not cooled and that are heated to less than 60°F.

Exception 3 to Section 140.4(q): Where more than 60 percent of the outdoor air heating energy is provided from site-recovered energy in Climate Zone 16.    

Exception 4 to Section 140.4(q): Where the sum of the airflow rates exhausted and relieved within 20 feet of each other is less than 75 percent of the design outdoor airflow rate, excluding exhaust air that is either:

1.  used for another energy recovery system,

2.  not allowed by the California Mechanical Code (Title 24, Part 4) (CMC) for use in energy recovery systems with leakage potential, or

3. of Class 4 as specified in Section 120.1(g).

Exception 5 to Section 140.4(q): Systems expected to operate less than 20 hours per week.

   

TABLE 140.4-J Energy Recovery Requirements BY Climate Zone and percent outdoor air at full design airflow (<8,000 hours / year)

% Outdoor Air at Full Design Airflow

CZ 1

CZ 2

CZ 3

CZ 4

CZ 5

CZ 6

CZ 7

CZ 8

CZ 9

CZ 10

CZ 11

CZ 12

CZ 13

CZ 14

CZ 15

CZ 16

≥10% and <20%

NR

NR

NR

NR

NR

NR

NR

NR

NR

NR

NR

NR

NR

NR

NR

NR

≥20% and <30%

≥15,000

≥20,000

NR

NR

NR

NR

NR

NR

NR

NR

≥18,500

≥18,500

≥18,500

≥18,500

≥18,500

≥18,500

≥30% and <40%

≥13,000

≥15,000

NR

NR

NR

NR

NR

NR

NR

NR

≥15,000

≥15,000

≥15,000

≥15,000

≥15,000

≥15,000

≥40% and <50%

≥10,000

≥12,000

NR

NR

NR

NR

NR

NR

NR

≥22,000

≥10,000

≥10,000

≥10,000

≥10,000

≥10,000

≥10,000

≥50% and <60%

≥9,000

≥10,000

NR

≥18,500

NR

NR

NR

NR

NR

≥17,000

≥8,000

≥8,000

≥8,000

≥8,000

≥8,000

≥8,000

≥60% and <70%

≥7,000

≥7,500

NR

≥16,500

NR

NR

NR

NR

≥20,000

≥15,000

≥7,000

≥7,000

≥7,000

≥7,000

≥7,000

≥7,000

≥70% and <80%

≥6,500

≥7,000

NR

≥15,000

NR

NR

NR

NR

≥17,000

≥14,000

≥5,000

≥5,000

≥5,000

≥5,000

≥5,000

≥5,000

≥80%

≥4,500

≥6,500

NR

≥14,000

NR

NR

NR

NR

≥15,000

≥13,000

≥2,000

≥2,000

≥2,000

≥2,000

≥2,000

≥2,000

NOTES to Table 140.4-J:
Flow rates in Table 140.4-J represent the design supply fan airflow rate in CFM.
For a DOAS unit providing outdoor air to another space-conditioning system, the full design supply fan airflow rate shall be the total airflow of only the DOAS unit.

TABLE 140.4-K Energy Recovery Requirements BY Climate Zone and percent outdoor air at full design airflow (≥8,000 hours / year)

% Outdoor Air at Full Design Airflow

CZ 1

CZ 2

CZ 3

CZ 4

CZ 5

CZ 6

CZ 7

CZ 8

CZ 9

CZ 10

CZ 11

CZ 12

CZ 13

CZ 14

CZ 15

CZ 16

≥10% and <20%

≥10,000

≥10,000

NR

NR

NR

NR

NR

NR

NR

≥40,000

≥40,000

≥20,000

≥10,000

≥10,000

≥10,000

≥10,000

≥20% and <30%

≥2,000

≥5,000

≥13,000

≥9,000

≥9,000

NR

NR

NR

NR

≥15,000

≥15,000

≥5,000

≥5,000

≥5,000

≥5,000

≥5,000

≥30% and <40%

≥2,000

≥3,000

≥10,000

≥6,500

≥6,500

NR

NR

NR

≥15,000

≥7,500

≥7,500

≥3,000

≥3,000

≥3,000

≥3,000

≥3,000

≥40% and <50%

≥2,000

≥2,000

≥8,000

≥6,000

≥6,000

NR

NR

NR

≥12,000

≥6,000

≥6,000

≥2,000

≥2,000

≥2,000

≥2,000

≥2,000

≥50% and <60%

≥2,000

≥2,000

≥7,000

≥6,000

≥6,000

NR

NR

≥20,000

≥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

(r) DDC Controller Logic Using ASHRAE Guideline 36.  HVAC systems with DDC controllers shall use controller logic originating from a programming library based on sequences of operation from ASHRAE Guideline 36 in accordance with the following:

1. Requirement applies to all controllers that are capable of being programmed in the field; and

2. Requirement applies to the entirety or all applicable portions of equipment control for configurations included in the programming library; and

3. The programming library shall be certified to the Energy Commission as meeting the requirements of Reference Joint Appendix JA18.

Exception to Section 140.4(r)3: Nonprogrammable (configurable-only) controllers for zone terminal units shall follow applicable ASHRAE Guideline 36 zone sequences referenced in Reference Joint Appendix JA18, Table 18.3-1, but are not subject to certification requirements.

Exception 1 to Section 140.4(r): Logic from the certified programming library modified to suit application-specific operation that are not included in ASHRAE Guideline 36 sequences.

Exception 2 to Section 140.4(r): Systems serving healthcare facilities.

(s) Mechanical Heat Recovery

1. Simultaneous Mechanical Heat Recovery

A. Simultaneous mechanical heat recovery is required for newly constructed buildings that meet either i or ii:

1. CHL + 0.1*CLL ≥ 200 tons and SWHCAP + HCAP ≥ 2200 kBtuh; or
2. CCAP ≥ 300 tons and SWHcap + 0.1*HCAP ≥ 700 kBtuh

Where:

CCAP = design capacity of all mechanical cooling systems.

CHL = coincident peak cooling load of all spaces with a design equipment power density > 5 watts/ft2 and a minimum outdoor airflow requirement < 0.5 cfm/ft2, i.e., high load spaces.

CLL = CCAP - CHL. If the design includes capacity for future cooling systems, then assume 20% of future systems serve high load spaces.

SWHCAP = design capacity of all service water heating (SWH) systems, excluding systems expected to operate less than 5 hours per week, such as instant-hot water systems for emergency eyewash stations.

HCAP = design capacity of all space heating systems.

B. The heat recovery system shall include a heat recovery chiller, or other means, capable of transferring the lesser of the following from spaces in cooling to spaces in heating and/or to the SWH system:

1. 25% of the peak heat rejection of the cooling system.
2. 25% of (SWHCAP + HCAP).

Exception 1 to Section 140.4(s)1: Laboratory buildings with exhaust air heat recovery systems meeting Section 140.9(c)6.

Exception 2 to Section 140.4(s)1: Buildings in Climate Zone 15 with SWHCAP < 600 kBtuh.

2. Heat recovery for service water heating. If the building is required to have simultaneous mechanical heat recovery by Section 140.4(s)1, and SWHCAP ≥ 500 kBtuh, then the heat recovery system shall also heat or preheat the service hot water. The heat recovery system shall have the capacity to transfer the smaller of:

1. 30% of the peak heat rejection of the cooling system; or
2. 30% of SWHCAP.

Exception to Section 140.4(s): Buildings with a computer room heat recovery system or wastewater heat recovery system capable of providing not less than 25% of SWHCAP + HCAP.