As part of the National Environment Agency’s (NEA) on-going efforts to improve energy efficiency in Singapore industry, water-cooled chilled water systems in industrial facilities [1] must conform to minimum energy efficiency requirements from 1 December 2020 onwards.
Scope of Minimum Energy Efficiency Standards (MEES)
- The Minimum Energy Efficiency Standards (MEES) will cover electrically-driven, water-cooled chilled water systems in industrial facilities that:
a) has a total installed capacity(1) of 1055 kW (300 RT) or more; and
b) produces chilled water at a temperature of 3°C or higher
Chillers solely utilising brine or glycol and air-cooled chillers that form part of the water-cooled chilled water system will be exempted.
- The MEES will be applied to a water-cooled chilled water system, comprising, among others, chillers, chilled water pumps, condenser water pumps and cooling towers that uses chilled water as the medium to transfer heat.
- An industrial facility refers to:
a) any single-user facility that has a business activity attributable to any of the following industry sectors:
i) manufacturing and manufacturing-related services;
ii) supply of electricity, gas, steam, compressed air and chilled water for air-conditioning; and
iii) water supply and sewage and waste management
b) any multi-user facility that is sited on URA Masterplan B1 or B2 zone.
Compliance Timeline
- New Industrial Facilities: Water-cooled chilled water systems in a new industrial facility that requires Planning Permission (PP) clearance or equivalent on or after 1 December 2020 must conform to MEES within 3 months of:
a) one year after the TOP is issued for a new single-user industrial facility.; and
b) three years after TOP or when 80 per cent of occupancy is reached, whichever is earlier, for a new multi-user industrial facility
- Existing Industrial Facilities: Water-cooled chilled water systems installed in existing industrial facilities must conform to MEES by the following deadlines:
Type of industrial facility | Compliance Deadline |
Industrial facilities regulated under the ECA | By 1 December 2025 |
All other industrial facilities | By 1 December 2029 |
Detailed Requirement
Operating system performance
- Chilled water systems in industrial facilities may be used for space or process cooling. In process cooling, a wide range of chilled water supply temperatures may be used. As temperature has a direct effect on the performance of a chiller, and thus the performance of a chilled water system, the performance standards vary for chilled water systems that operate at different chilled water supply temperatures.
- The table below displays the MEES for different chilled water supply temperatures.
Chilled water supply temperature (˚C)(2) | 3 | 4 | 5 | 6 | 7 | 8 | 9 | ≥10 |
MEES in kWe/kWc(3) (kW/RT(4) | 0.203 (0.71) | 0.200 (0.70) | 0.197 (0.69) | 0.194 (0.68) | 0.191 (0.67) | 0.188 (0.66) | 0.185 (0.65) | Energy performance for chilled water supply temperature ≥10°C to be improved from 0.185 kWe/kWc at 9°C by 0.003 kWe/kWc for every 1°C increase in chilled water supply temperature |
Measurement & Verification System
To show that operating chilled water system performances meet MEES, permanent measurement and verification (M&V) systems must be installed. A M&V system should be linked to a monitoring system such as a building automation system (BAS) or a standalone energy management system (EMS). The monitoring system should be capable of:
- displaying and trend logging performance parameters; and
- generating a report, consisting of annual aggregated data in a standard reporting format.(This requirement will be imposed at a later date)
Refer to the attached file on M&V requirements and guidelines for MEES.
First Report for New and Existing Industrial Facilities
- By the compliance deadline, a report must be submitted to NEA to show that:
a) operating chilled water system performance meets the MEES threshold; and
b) M&V system is accurate, which is demonstrated through a heat balance substantiating test5 where the heat balance is within 5% for 80% of the operating points during the assessment period.
- The report must be:
a) prepared and signed off by an Energy Efficiency Opportunities (EEO) Assessor with systems-specific experience in chilled water systems or a Professional Engineer in the branch of mechanical engineering, electrical engineering or chemical engineering; and
b) endorsed by the Chief Executive (or equivalent) of the company
Subsequent Reporting for Existing Industrial Facilities
After the approval of the First Report, key performance data of the chilled water system will have to be reported to NEA on a periodic basis to demonstrate that the operating system performance is maintained. Data should be aggregated in the monitoring system, downloaded in a standard reporting format and uploaded onto a NEA-designated online reporting portal. (This requirement will be imposed at a later date)
Review by NEA
Annually, NEA will review the annual average operating system performance and other key performance data of the chilled water system. NEA may also conduct on-site verification on the accuracy of the M&V system.
In the event that a company fails to comply with any of the requirements, the company may be required to take corrective actions to ensure compliance. Fines will be imposed for non-compliance.
The following information should be kept for a minimum of 5 years:
- First Report, annual reports and all information used in producing the reports eg raw data and calculations6
- Technical specifications of chilled water system components
- All input parameters and settings for the permanent instrumentations
- Instruments’ calibration certificates from accredited laboratories and/or their factory calibration certificates from manufacturers
- As-built schematic drawings of the chilled water system
Grants
Grants are available to support companies to upgrade their water-cooled chilled water systems before the mandatory requirements kick in. Industrial companies can email NEA_E2F@nea.gov.sg for more information.
(1) includes both operating and standby chillers
(2)To be rounded up to the nearest whole number.
(3) kWe/kWc = Total energy consumption of the chilled water system (kWhe) during the assessment period ÷ total cooling load produced by the system (kWhc) during the assessment period(4) kW/RT = Total energy consumption of the chilled water system (kWhe) during the assessment period ÷ total cooling load produced by the system (RTh) during the assessment period
(5)This indicator is the ratio of the difference between the heat input and the heat output, to the heat output of the chilled water system. Ideally, according to the law of conservation of energy, heat input to a system = heat output from a system. This indicator is used to determine the quality of the measurements i.e. the uncertainty, installation and position of the instruments.
(6) Information recorded and calculated in the BAS/EMS should be kept in the EMS for a minimum of 3 years