Application Procedures

High-tier data centres may consider adopting water-cooled air-conditioning system, which is more energy efficient then air-cooled system, for data centre cooling purposes. In Hong Kong, the authority of approval for fresh water supply for cooling purpose for non-domestic buildings within designated areas under the Government's voluntary Fresh Water Cooling Towers (FWCT) Scheme for Air Conditioning Systems (the Scheme) administered by the Electrical and Mechanical Services Department (EMSD) falls under the Water Supplies Department (WSD). For data centre projects using fresh water cooling towers for water-cooled air conditioning systems, project developers should apply for participation in the Scheme to ensure the cooling towers meet the environmental and public health requirements. Besides, the participation will also facilitate WSD's consideration of approval for fresh water supply to the cooling towers.

The Scheme was launched by an inter-departmental working group, comprising EMSD, WSD, Buildings Department (BD) and various government departments. Specifically, EMSD, WSD and BD would provide relevant approvals of (i) cooling tower design and installation (in environmental and public health aspects), (ii) fresh water supply & plumbing works, and (iii) building works respectively. The Scheme applies to all non-domestic new and existing buildings within the designated areas (see Scheme Location Plans of Designated Areas ). Applications for buildings not within the designated areas will be considered on a case-by-case basis. Apart from the approvals from EMSD, WSD and BD, cooling towers should also comply with other relevant statutory requirements¹.

To facilitate application for joining the Scheme, EMSD has promulgated a thematic website, which contains details of the Scheme including a Scheme Brochure, an Application Process Chart, and the Code of Practice for Water-cooled Air- conditioning Systems (in 3 parts) for the design, installation, testing, commissioning, operation and maintenance of cooling towers, and other relevant references. There are also Guidance Notes (Guidance Notes on Code of Practice for Water-cooled Air Conditioning Systems) which facilitate satisfying the design requirements of the aforesaid code of practice.

1. Other statutory requirements involve areas of sewage services; water pollution, air pollution and noise control; nuisance control; and occupational safety and health, with which the installation and operation of cooling towers should also comply. Applicants should seek relevant professional advice from Authorised Persons, Registered Professional Engineers of building services and mechanical engineering disciplines, Licensed Plumbers and other competent professionals.

Project planning

As experience shared by industry, developers in contemplating a data centre project involving installation of fresh water cooling towers should note the following areas that will facilitate smooth proceeding of application and approval process with relevant departments:

• The application and approval process consists of multiple steps and some of them also have interdependency involving EMSD and WSD (please refer to the Application Flowchart). Therefore, adequate time allowance should be provided for the application and approval process in the project planning stage.
• Incomplete information submission (vis-à-vis as required in relevant practice notes, technical memos or guidelines) or non-compliance of the designs with relevant codes of practices/ordinances will cause extra time required for approval due to the need for change in designs, resubmissions and reassessments.
• Developers are advised to engage experienced professionals and contractors (including Authorised Persons, Registered Professional Engineers, Licensed Plumbers and other competent professionals) on relevant works to assure quality submissions to the departments.
• To identify suitable location for cooling towers, the project designer should make early reference to the aforesaid EMSD Guidance Notes to ensure meeting with design requirements of the code of practice.
• It would also be useful to conduct feasibility assessment at initial project stage (in aspects such as applicable designated area, and basic design requirements like separation distances from surrounding air openings) before engagement of designers/contractors for substantive designs and implementation work, so as to avoid undue delay or abortive work.
• Relatively large quantity of bleed-off water may be generated from cooling towers installed in data centres for discharge. To meet the general requirement of reuse of bleed-off for flushing as per the code of practice, design strategy to enable effective reduction, reuse and discharge of bleed-off water should be developed early during the design stage.

For more information on the Scheme, please refer to the EMSD website or make enquiry to EMSD via info@emsd.gov.hk.