White Paper
“Breaking the Code, Rev 1”
Compliance Requirements for California Title 24-2013 for Cooling Towers,
Closed Circuit Coolers and Evaporative Condensers
The California Energy Commission released the final version of Title 24-2013 last Fall, and early this year
changed the effective date of the standard from January 1, 2014 to July 1, 2014. Equipment selected for the
State of California will need to meet the new Title 24, Part 6 requirements beginning July 1, 2014. Relevant
requirements include:







Increased efficiency requirements for Open, Axial Fan Cooling Towers.
Revised flow turn down requirements for Cooling Towers.
NEW-Mandatory efficiency requirements for Closed Circuit Cooling Towers.
NEW-Mandatory requirements to minimize the use of potable water in evaporative cooled equipment.
NEW-Updated Evaporator motor requirements.
NEW-Mandatory efficiency requirements for evaporative condensers used on Refrigerated
Warehouses.
The allowance of air-cooled condensers for ammonia systems.
This white paper highlights the Title 24 code sections that apply to EVAPCO product lines. The code section
is in grey and the action required to be in compliance is in blue. Download the final version of Title 24, Part 6
with the link below, the file is titled:
http://www.energy.ca.gov/2012publications/CEC-400-2012-004/CEC-400-2012-004-CMF-REV2.pdf
This white paper will cover the applicable code sections of Title 24 including:
Chapter 2
Chapter 3
Chapter 5
Appendices
110.2 Mandatory Requirements for Space-Conditioning Equipment
120.5 Required Non-Residential Mechanical System Acceptance Tests
120.6 Mandatory Requirements for Covered Processes Including
Refrigerated Warehouses and Commercial Refrigeration.
140.0 Performance and Prescriptive Compliance Approach
140.1 Performance Approach: Energy Budgets
140.2 Prescriptive Approach
140.4 Prescriptive Requirements for Space Conditioning Systems
140.9 Prescriptive Requirements for Covered Processes
Definitions
Acceptance Test and Requirements
1
Pages 2-4
Page 5
Pages 6-10
Page 11
Page 11
Page 12
Page 12-15
Page 16
Page 17
Page 18-22
Chapter 2 Section 110.2-Mandatory Requirements for Space-Conditioning Equipment (a) to (e)
NOTE: Sections (b) Controls for Heat Pumps with Supplementary Electric Resistance Heaters through (d) Gas- and Oil-Fired
Furnace Standby Loss Controls do not apply.
Action Required to be in Compliance with Table 110.2-G
● EVAPCO equipment shall meet the new efficiency levels for Open Cooling Towers and for Closed Circuit Cooling
Towers. The minimum efficiencies are specified in Table 110.2-G as shown below. Confirm with EVAPCO that the
equipment selection is in compliance with the below efficiency requirements including equipment options.
2
Chapter 2 Section 110.2-Mandatory Requirements for Space-Conditioning Equipment (a) to (e)
NOTE: Sections (b) Controls for Heat Pumps with Supplementary Electric Resistance Heaters through (d) Gas- and Oil-Fired
Furnace Standby Loss Controls do not apply.
This mandatory requirement in Section 110.2 (e), implements water efficiency practices that apply only to
cooling towers and coolers with capacities 150 tons and above. The options listed below must be provided
with the equipment, either by EVAPCO or the Mechanical Contractor.
Actions Required to be in Compliance with Section (e):
1) Conductivity or Flow Based Controls- Towers and coolers must be provided with conductivity
controllers to maintain maximum cycles of concentration1. This requirement can be met by providing
EVAPCO conductivity controllers either as an accessory or with an approved EVAPCO Water
Treatment System. NOTE: Pulse~Pure® and Smart Shield are standard with conductivity
controllers that maintain the proper maximum cycles of concentration.
Evapco Conductivity Controller-Standard with Pulse-Pure® or Smart Shield Water Treatment Systems (also sold separately)
3
Chapter 2 Section 110.2-Mandatory Requirements for Space-Conditioning Equipment (a) to (e)
NOTE: Sections (b) Controls for Heat Pumps with Supplementary Electric Resistance Heaters through (d) Gas- and Oil-Fired
Furnace Standby Loss Controls do not apply.
(e) Continued
2) Documentation of Maximum Cycles of Concentration: The local make-up water must be analyzed
and documented. Maximum cycles of concentration must be calculated and then posted with the local
authority. According to the code, cycles must be determined annually based on local water
conditions.
This section of Title 24 requires an LSI of 2.5 or less-LSI or Langelier Saturation Index2 is a measure
of the scaling tendency of the water.
NOTE: LSI is not the only water chemistry parameter utilized to determine optimum operating
conditions. EVAPCO uses a variety of calculators to determine the correct cycles of concentration
for the type of unit and its materials of construction.
3) A flowmeter is required on the make-up line. Contact EVAPCO regarding recommendation and
supply of flow meters. An example is shown below:
4) Overflow alarms are required in the event the make-up valve becomes stuck in the open position.
In order to trigger the alarm, an overflow sensor will need to be located in the appropriate location
in the cold water sump. EVAPCO meets this requirement by providing the 5-probe Electric Water
Level Control assembly with a new unit. The high probe can be connected to this alarm provided by
others.
5) Drift eliminators- EVAPCO meets the drift efficiency requirement with a 0.001% drift rate on all
cooling towers, closed circuit coolers and evaporative condensers.
Drift rate confirmed through testing in accordance with CTI’s ATC-140 Isokinetic Drift Measurement Test Code for Water Cooling Towers.
4
Chapter 3: Nonresidential, High-Rise Residential, Hotel/Motel Occupancies, And Covered Processes—
Mandatory Requirements
Note: Sections 120.1-120.4 and 120.7-120.9 do not apply to EVAPCO equipment and are not listed.
Section 120.5-Required Nonresidential Mechanical System Acceptance- This section covers
equipment and systems to be tested by the commissioning agent. Only Items 14 and 16 will apply to EVAPCO
equipment. Test procedures can be found in the “Referenced Appendices” document CEC‐400‐2012‐005‐CMF
available through the link posted on page 1.
Actions required to be in Compliance:
14. Commissioning agent to follow required test procedures for Thermal Storage Systems shown in Appendix 1.
16. Follow required test procedures for water cooled chillers in Appendix 11.
5
Chapter 3: Nonresidential, High-Rise Residential, Hotel/Motel Occupancies, And Covered
Processes—Mandatory Requirements
Section 120.6 Mandatory Requirements for Covered Processes-Refrigerated Warehouses
Note: Subsections 1-2 of Section 120.6 Mandatory Requirements for Refrigerated Warehouses do not
apply to EVAPCO equipment.
Actions required to be in Compliance with Subsection 3:
3. A. For single-phase voltages, Title 24 now allows the option of a 70 percent efficient motor in addition to
an electronically commutated motor. Contact EVAPCO for selection and pricing.
B. The previous version required variable speed on all applications, new language has been added in this
section to clarify the requirement with three (3) new exceptions.
C. A new exception has been added for single compressors that are not variable speed, requires fan
controls to reduce airflow as specified.
6
Chapter 3: Nonresidential, High-Rise Residential, Hotel/Motel Occupancies, And Covered
Processes—Mandatory Requirements
Section 120.6 Mandatory Requirements for Covered Processes-Refrigerated Warehouses
Actions required to be in Compliance:
4. A. No change from the 2008 version of the code regarding design conditions, cooling towers and fluid coolers were
added, and there is a new exception to this requirement if the application is for quick chilling or freezing.
B. Not applicable unless selecting an eco-ATC condenser for mostly dry operation in this application.
C. Cooling towers and fluid coolers were added to this variable speed fan requirement.
D. Not applicable unless selecting an eco-ATC condenser for mostly dry operation in this application.
E. New code language regarding condensing temperature reset based on ambient wetbulb temperatures or other
control strategies approved by Executive Director.
*NOTE: For Items A to E, consider control set points for condensing temperatures and their effect on oil cooling
requirements for compressors.
7
Chapter 3: Nonresidential, High-Rise Residential, Hotel/Motel Occupancies, And Covered
Processes—Mandatory Requirements
Section 120.6 (a) Mandatory Requirements for Covered Processes-Evaporators and Evaporative Condensers
[Subsection (4) continued from Page 7]
NEW for 2013! Evaporative Condenser Minimum Efficiency Requirements
NOTE: Mandatory Section Compliance for Evaporative Condensers:
NEW condenser minimum efficiency requirements for evaporative and air-cooled condensers
are required to meet the code for refrigerated warehouses only. Item F also addresses the
CEC method of calculating the efficiency used in Table 120.6-B4.
4. F.
G.
Not applicable, air cooled only.
Interpreting Table 120.6-B Fan Powered Condensers-Minimum Efficiency Requirements
● Outdoor Evaporative Cooled Condensers > 8,000 MBH
Evaporative condensers must meet the 350 Btuh/Watt efficiency at the stated rating conditions. The
“outdoor evaporative” condenser is an axial fan design.
Contact EVAPCO for selections that meet this efficiency requirement.
● Outdoor and Indoor Evaporative Cooled Condensers < 8,000 MBH
Evaporative condensers must meet the 160 Btuh/Watt efficiency requirement at the stated rating
condition. The “outdoor/indoor” evaporative condenser referenced can be axial or centrifugal fan.
Contact EVAPCO for selections that meet this efficiency requirement.
8
Chapter 3: Nonresidential, High-Rise Residential, Hotel/Motel Occupancies, And Covered
Processes—Mandatory Requirements
Section 120.6 (a) Mandatory Requirements for Covered Processes-Evaporators and Evaporative Condensers
6. Infiltration Barriers. Not applicable to EVAPCO equipment.
Compliance Requirements:
5. Compressors- Note compressor requirements may affect evaporative condenser selection.
7. Refrigeration System Acceptance Section Compliance.
A. Does not apply.
B. See Acceptance Requirements for evaporators and fan motors. (NA7.10.2) in Appendix III.
C. See Acceptance Requirements for evaporative condensers (NA7.10.3.1) in Appendix IV.
9
Chapter 3: Nonresidential, High-Rise Residential, Hotel/Motel Occupancies, And Covered
Processes—Mandatory Requirements
Section 120.6 (b) Mandatory Requirements for Commercial Refrigeration-Evaporators and Evaporative
Condensers
Section (b) Compliance for Evaporative Condensers, Fluid Coolers and Cooling Towers:
1. A. All condenser, tower and cooler fans must be variable speed drive, with all fans operating at the same speed.
B. Does not apply unless selecting an eco-ATC condenser for mostly dry operation in this application, in this case the
condensing temperature shall be reset according to dry bulb temperature.
C. Evaporative condensers shall use control logic to reset condensing temperature according to ambient wet bulb
temperature.
D. Minimum condensing set point shall be 70°F or less.
E. See Table 120.6-C efficiency requirements for condensers below at the specified rating condition:
NOTE: Section 120.6 (b) Exceptions for Evaporative Condensers
10
Chapter 5: Nonresidential, High-Rise Residential, And Hotel/Motel Occupancies—Performance And
Prescriptive Compliance Approaches For Achieving Energy Efficiency
Section 140.0-140.1-Performance and Prescriptive Compliance Approaches
Section 140.0 Compliance Requirements for Cooling Towers and Coolers :
(a) Comply with mandatory requirements as noted in pages 2-4 of this document.
(b) Comply with mandatory requirements as note in pages 5-10 of this document.
(c) Design shall select either the performance (Section 140.1) or prescriptive path (Section 140.2)
shown on page 12.
Section 140.1 Performance Approach Requirements :
Designer shall comply with (a) through (c) above in Section 140.1 Performance Path.
11
Chapter 5: Nonresidential, High-Rise Residential, And Hotel/Motel Occupancies—Performance And
Prescriptive Compliance Approaches For Achieving Energy Efficiency
Section 140.2 & 140.4-Performance and Prescriptive Compliance Approaches
NOTE: “Section 140.3 Prescriptive requirements for building envelopes” is omitted, does not apply to EVAPCO
EVAPCO must only comply with items (b) and (g) in Section 140.2 & applicable sections as noted in Section 140.4 :
Rule
Rule
Rule
Rules
1
2
3
4
Methodology-Does not directly apply to EVAPCO equipment.
Heating and cooling loads-Decisions on load will impact EVAPCO equipment selection.
Indoor Design Conditions-Decisions on load could impact EVAPCO equipment selection.
Outdoor design conditions. See below requirements for EVAPCO compliance.
Exception: 140.4(b)4: Evaporative cooling equipment selection shall be based on a 0.5 percent wet bulb for cooling
towers and coolers.
Rules 5 to 13 below reference building load calculations and will only impact EVAPCO equipment thermal capacity, not unit construction:
5-Ventilation, 6-Envelope, 7- Lighting, 8-People, 9-Process Loads, 10-Miscellaneous Equipment, 11- Internal Heat Gains, 12- Safety
Factor, 13- Other loads
12
Chapter 5: Nonresidential, High-Rise Residential, And Hotel/Motel Occupancies—Performance And
Prescriptive Compliance Approaches For Achieving Energy Efficiency
Continuation of Section140.4-Performance and Prescriptive Compliance Approaches (c through g)
c) Power consumption of fans- Does not apply to EVAPCO, only applies to air handler/VAV fans.
d) Space conditioning zone controls- Does not apply to EVAPCO, controls air handler/VAV fans.
Section 140.4-Performance and Prescriptive Compliance Approaches
Section 140.4(e)1. B. Compliance Requirements for Cooling Towers and Coolers :
EVAPCO equipment selected must meet the design conditions for free cooling as stated in this code requirement and
efficiency must meet or exceed requirements in Table 140.4-A.
f) Supply Air Reset Temperature Controls-Does not apply to EVAPCO equipment.
g) Electric Resistance Heating-Does not apply to EVAPCO equipment.
13
Chapter 5: Nonresidential, High-Rise Residential, And Hotel/Motel Occupancies—Performance and
Prescriptive Compliance Approaches For Achieving Energy Efficiency
Continuation of Section140.4-Performance and Prescriptive Compliance Approaches-(h)
Section 140.4-Performance and Prescriptive Compliance Approaches
Section 140.4 (h) Compliance Requirements for Cooling Towers, Coolers and Evaporative Condensers:
(h) 1. Scope of this section applies to all EVAPCO equipment used in comfort cooling applications.
2. Fan speed control: All fan motors 7.5 hp and greater shall be capable of operating at 2/3 fan speed or less (variable
speed drive), and have controls to maintain leaving water temperature or condensing set points. Note exceptions 1
to 4 above in this requirement.
3. NOTE: The code has changed from the 2008 requirement of 33% condenser flow turn down. NEW CODE:
Open cooling towers shall be designed to accommodate lower condenser water flow of 50% of the design flow as the
minimum.
4. Centrifugal fan cooling tower limitation: Only open, axial fan cooling towers 900 gpm and greater shall be used
for the design conditions stated. Follow the two exceptions for those cases that require ducting, sound attenuation
and centrifugal cooling towers that meet axial fan efficiencies in Section 110.2, Table 110.2-G.
5. A&B: For multiple cell equipment, operate fans at the same speed, staging of fans can be utilized once each fan has
reached its minimum speed.
14
Chapter 5: Nonresidential, High-Rise Residential, And Hotel/Motel Occupancies—Performance And
Prescriptive Compliance Approaches For Achieving Energy Efficiency
Continuation of Section140.4-Performance and Prescriptive Compliance Approaches-(i) through (k)
(i) Minimum Chiller Efficiency-Does not apply to EVAPCO equipment.
Section 140.4(j) Compliance Requirements for Cooling Towers and Coolers :
j. Limitation of Air-Cooled Chillers. The capacity limit on air-cooled chillers increases to 300 tons.
Previously, the limit was 150 tons.
Exceptions:
1) Water Quality: This exception will rarely apply, most water can be treated to meet manufacturers
specifications allowing the use of more energy efficient evaporative cooled equipment.
2) Thermal Energy Storage: This exception is acceptable to EVAPCO for applications that use air cooled
chillers to charge ice thermal storage systems.
3) Minimum Air Cooled Chiller Efficiencies: This statement is open to interpretation by the California
Energy Commission, and will need to be reviewed on case by case basis.
Section 140.4(k) Compliance Requirements for Cooling Towers and Coolers:
k. Hydronic Variable Flow Systems: Open cooling towers can be turned down to 50% of design flow to
meet this requirement. NOTE: This only applies to chilled water systems with cooling towers. Coolers and
condensers do not have this capability of varying the speed on integral pumps for capacity control.
15
Chapter 5: Nonresidential, High-Rise Residential, And Hotel/Motel Occupancies—Performance And
Prescriptive Compliance Approaches For Achieving Energy Efficiency
Section 140.9 Prescriptive Requirements for Covered Processes
(Sections 140.5 through 140.8 Do Not Apply)
Section 140.9 Compliance Requirements for Cooling Towers and Coolers :
(a) Prescriptive Requirements for Computer Rooms.
1. Economizers.
A. Air side economizers do not apply to EVAPCO equipment.
B. Cooling towers or coolers shall meet the free cooling load at the stated outside air temperatures.
Under Subsection (a) the remaining subsections 2 through 6 do not apply to EVAPCO- 2-Reheat, 3Humidification,4-Power Consumption of Fans, 5-Fan Control, 6-Containment.
Section (b) Prescriptive requirements for Commercial Kitchens- and (c) Prescriptive Requirements for
Laboratory exhaust systems, do not apply to EVAPCO equipment.
16
Definitions
1) Cycles of Concentration (COCs): Cycles of Concentration are defined as the ratio of the makeup rate to the sum
of the blow down and drift rate. The COCs can also be monitored by calculating the ratio of the chloride ion, which is
highly soluble, in the system water to that in the makeup water. The number of COCs is dependent on the composition
of the makeup water, particularly minerals and their quantity contained in the makeup water supply. Provided courtesy of
ASHRAE Standard 191 definitions.
2) Langelier Saturation Index (LSI): LSI was developed years ago as a way of predicting how much protective scale
(Calcium Carbonate CaCO3) would be formed on water supply pipes. The LSI can also be used to predict the scaling
tendency of the local make-up water. However, LSI under cooling water conditions cannot be used entirely to predict
scale, because some Calcium Carbonate may drop out during operation . See Table 3 below with the indices for each type
of water chemistry.
4) Condenser Specific Efficiency is the full load condenser Total Heat of Rejection (THR) capacity at
standardized conditions divided by the fan input electric power (including but not limited to spray pump electric input
power for evaporative condensers) at 100 percent rated fan speed.
17
Appendix 1-Thermal Storage Acceptance Test NA7.5.14
18
Appendix 1I-Water cooled chillers with Cooling Towers Acceptance Test NA7.5.16
19
Appendix III-Acceptance Requirements for Evaporators NA7.10.2
20
Appendix IV- Acceptance Requirements for Evaporative Condensers NA7.10.3
21
Appendix IV- Acceptance Requirements for Evaporative Condensers NA7.10.3.1
22