Public Consultation on the Introduction of Minimum Energy Efficiency Standards (MEES) for Water-cooled Chilled Water Systems in Industrial Facilities

National Environment Agency

National Environment Agency - Resource Conservation Department

Consultation Period: 31 Dec 2018 - 31 Jan 2019
Status: Closed
Detailed Description


The National Environment Agency (NEA) of Singapore is seeking feedback on the introduction of minimum energy efficiency standards (MEES) for water-cooled chilled water systems in industrial facilities1.  The consultation exercise will start on 31 Dec 2018 and end on 31 Jan 2019.


2 Singapore ratified the Paris Agreement and formalised our pledge to reduce our emissions intensity2 by 36% from 2005 levels by 2030, and to stabilise our greenhouse gas emissions with the aim of peaking around 2030. The industrial sector is expected to account for more than half of the projected emissions in 2030, and has the largest potential for emission reduction.

3 Analysis of data3 submitted by industrial companies regulated under the Energy Conservation Act (ECA) revealed that cooling systems accounted for about 16% of the 2016 electricity consumed by the companies and is one of the major electricity-consuming systems.

4 Among the different types of cooling system, water-cooled chilled water system is the most commonly used among industrial companies, particularly those with large cooling loads. Water-cooled systems have more component parts, and hence can achieve higher energy savings through system integration and optimisation vis-à-vis improving efficiency of individual component parts of the system.

5 Under the Building Control (Environmental Sustainability Measures for Existing Buildings) Regulation 2013, chilled water systems used in commercial buildings4 must meet the minimum energy efficiency standards under the Green Mark certification scheme (i.e. at “Certified” level). On the other hand, there are currently no minimum energy efficiency standards for chilled water systems used at industrial facilities, and more than 70% of these systems were reported3 to be performing at sub-optimal efficiency levels.

Rationale for Minimum Energy Efficiency Standards (MEES) for Water-cooled Chilled Water Systems in Industrial Facilities

6 The introduction of Minimum Energy Efficiency Standards (MEES) will help to phase out inefficient technologies from the Singapore market, and catalyse market transformation towards more efficient ones. Incorporating a more efficient system design in new constructions or during retrofits also help facility owners reap life-cycle cost savings through:

a) Lower capital costs from rightly-sized equipment;

b) Lower operating costs over the typical life-span of chilled water system of 15 years, due to lower energy use; and

c) Lower maintenance costs as equipment operate closer to their design requirements

This will in turn reduce the electricity consumption and carbon emissions of the industrial sector.

Scope of MEES

7 The proposed MEES requirements will cover any electrically-driven water-cooled chilled water system installed in an industrial facility that:

a) Has a total installed cooling capacity5 of 300 RT (~1 MW) or more; and

b) Produces chilled water at a temperature of 3°C or higher.

8 The chilled water system should consist of all components used in transferring heat from a heat source to the chilled water and removing heat from the chilled water, which include:

a) Chillers;

b) Chilled water pumps (both primary and secondary pumps);

c) Condenser water pumps; and

d) Cooling towers

Refer to Annex 1 for illustrated examples of the definition of chilled water systems.

Minimum Energy Efficiency Standards (MEES)

9 Unlike the chilled water systems in commercial buildings which are used mainly for space cooling, chilled water systems in industrial facilities are also used for process cooling. Depending on the application, a wide range of chilled water temperatures can be used for process cooling. As the temperature set-point has a direct effect6 on the chiller’s performance, it will be more appropriate to have a tiered-MEES that caters for different chilled water temperatures. For chilled water temperature of 7˚C, the MEES will be at 0.67 kW/RT7 and will be adjusted by 0.01 kW/RT for each 1˚C deviation from 7˚C of the chilled water temperature. Refer to the table below for the corresponding MEES levels for different chilled water temperatures ranging from 3 to 15˚C.

Chilled water temperature (˚C)8 3 4 5 6 7 8 9 10 11 12 13 14 15
MEES Level (kW/RT) 0.71 0.70 0.69 0.68 0.67 0.66 0.65 0.64 0.63 0.62 0.61 0.59 0.58

Compliance Deadlines

New Industrial Facilities

10 Owner of a new industrial facility who:

a) Applies for Planning Permission (PP) clearance on or after the effective date of MEES, which is proposed to be from 4Q 2020 onwards, and 

b) Intends to install a water-cooled chilled water system in the new facility, 

must ensure that the operating chilled water system efficiency9 meets the MEES one (1) year after the temporary occupation permit (TOP) has been issued. Refer to Annex 2 for an illustration of the compliance milestones for a new industrial facility.

Existing Industrial Facilities

11 Owner of an existing industrial facility installed with a chilled water system must ensure that the operating system efficiency meet the MEES by the following compliance deadlines:

Type of industrial facility Compliance Deadline
Industrial facilities registered under the ECA By 2025
All other industrial facilities By 2029

Measurement & Verification System

12 To show that the operating chilled water system efficiency meets the relevant MEES level, a permanent measurement and verification (M&V) system must be installed. The M&V system should be linked to a centralised monitoring system such as a building automation system (BAS) or a standalone energy monitoring system (EMS). The centralised monitoring system must also have the capability to transfer data automatically for subsequent reporting to NEA. Refer to Annex 3 for the detailed requirements of the M&V system.

Reporting Requirements

First Report for New and Existing Industrial Facilities

13 By the compliance deadline, a report (“First Report”) must be submitted to NEA to show that: 

a) Operating chilled water system efficiency meet the relevant MEES; and

b) M&V system is accurate, which is demonstrated through a heat balance substantiating test10 where the heat balance is within 5% for 80% of the operating points during the assessment period.

14 The First Report must be:

a) Prepared and signed off by an Energy Efficiency Opportunities (EEO) Assessor or a Professional Engineer; and

b) Endorsed by the Chief Executive (or the top management office holder with similar responsibilities) of the company.

Subsequent Reporting for Existing Industrial Facilities

15 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 efficiency is maintained. These data should be aggregated in the centralised monitoring system and transmitted automatically to NEA online portal, at least once a month. The online portal will monitor the chilled water system performance and alert the owner of any deviation so that timely interventions can be taken to rectify inefficiencies and reduce energy wastages.

Review by NEA

16 Annually, NEA will review the annual average operating system efficiency 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, corrective actions will have to be taken by the company.

Public Consultation

17 This proposal is released for the purpose of consultation.  All comments received during the consultation exercise will be reviewed thoroughly and may be incorporated into the final measure.  Interested parties can submit their feedback to  The consultation exercise will end on 31 Jan 2019.

18 To ensure that the consultation is productive and focused, respondents are requested to observe these guidelines when providing their feedback:

a) Identify yourself as well as the organisation you represent (if any) so that we may follow up with you to clarify any issues, if necessary

b) Be clear and concise in your comments

c) Focus your comments on the proposal to introduce MEES for chilled water systems and how it can be improved

d) As far as possible, substantiate your points with illustrations, examples, data or alternative suggestions.

1 In this paper, an industrial facility refers to any site used for a business activity that is attributable to one 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;
iii. Water supply and sewage and waste management.
2 Emissions intensity refers to greenhouse gas emissions per dollar of GDP, measured in CO2-equivalent per $.
3 Based on the reports submitted by companies regulated under the ECA in 2017 for their energy use in 2016.
4 The Building Control (Environment Sustainability Measures for Existing Buildings) Regulations will apply to all buildings with centralised cooling systems and gross floor area greater than 5,000 m2 when installing or replacing the building cooling system. The regulation does not cover industrial buildings, railway premises, port/airport services and facilities, religious buildings, data centres, utility buildings and any residential buildings (excluding serviced apartments).
5 Includes both operating and standby chillers
6 According to major chiller suppliers, the chiller efficiency can differ by 2-5% for each 1˚C deviation in chilled water supply temperature.
7 kW/RT = Electrical power input to the chilled water system in kW ÷ Cooling load produced by the chilled water system in RT
8 To be rounded up to the nearest whole number.
9 Operating chilled water system efficiency = Total power consumption of the chilled water system (kWh) during the assessment period ÷ total cooling load produced by the system (RTh) during the assessment period
10 This indicator is the ratio of the difference between the heat input and the heat output, to the heat output of the central chilled water system. Ideally, according to the conservation law 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.