Cover Story

Green Features of PolyU's New Data Centre


High energy costs and spiking energy consumption rates are usually associated with traditional data centres. In early 2011, the Information Technology Services Office (ITS) of PolyU completed an audit on energy performance of the University Data Centre on the main campus and identified areas for improvement. ITS then adopted various green features in its development of a new Data Centre at Block Z to replace the Secondary Computer Room on the main campus.

What are the green features?

The new Data Centre at Block Z came into full operation starting from mid October 2013. It has an area of approximately 150 m2 storing the servers and a separate area of about 30 m2 serving as the electricity switch board room. It was designed by specialist consultant adopting cutting edge technologies in energy saving. Two important areas of energy saving lie in the air distribution arrangement and the efficiency of the computer room air conditioning (CRAC).

A traditional data centre usually allows the hot exhaust air from IT equipment mixes with cold air as the hot air makes its way back to the computer room air conditioning (CRAC) unit return vents. Energy is wasted when cold air is forced across long distances (as shown in Figure 1). Moreover, oversized power and cooling components reduce the data centre efficiency.

Two recent technology breakthroughs, i.e. the hot and cold aisle containment systems, have helped to remedy this situation. Both systems allow row-based cooling and separation of hot and cold air streams, brings the cooling source in very close proximity to the load to minimize energy loss. The technology currently employed in our new Data Centre is the cold-aisle containment system (CACS). Server racks with perforated front and rear doors are arranged in cold-and-hot aisle and constructed with two closed cold-aisle containments. These containments are built with end doors, ceiling panels, floor grommets and rack blanking panels to separate cold and hot air streams. Cold air delivered from CRAC outlets beneath raised floor flows across perforated floor grilles at the cold aisles inside the containments, reaches server intakes, picks up servers dissipated heat and exhausts at the rear of the racks into the hot aisle. Overhead data cables and power cable trunks beneath raised floor are built along hot aisles to ensure smooth and efficient air path for cooling. Hot air then returns to CRAC inlets. Figure 2 illustrates the air flow pattern of CACS.

This containment and rack arrangement offers at least the following benefits over traditional design:

  • The cooling system can be set to a higher temperature (thereby saving energy) but still supply the load with safe operating temperatures.
  • Better overall physical infrastructure utilization enables rightsizing, which, in turn, results in equipment running at higher efficiency.

Measures to increase the cooling and power efficiency

To further increase the cooling efficiency of the system, the fan speed of the CRAC can be adjusted to match with specific heat load. A grid of temperature sensors together with CFD (Computational Fluid Dynamics) suggests optimal CRAC temperature set point. Moreover, a feature of installed DCIM (Data Centre Infrastructure Management) advising the placement of new server installation to balance heat load inside the data centre can prevent the occurrence of "hot spot". In case "hot spot" inevitably occurs, instead of tuning down the temperature set point of CRAC, temperature sensor controlled fan grille will act accordingly to deliver more cold air to the particular high heat dissipation server. A damper of this special grille further channels air flow to the thermal source.

In addition, KVM/IP console system supports remote console operation to minimize personnel access to the data centre and thereby minimizes heat load to the areas. To achieve better heat insulation, glass windows are blocked to reduce solar thermal effect. Insulated floor void also reduces heat loss through the floor slab.

Besides, the following new features are also included to increase the power efficiency:

  • Unity power factor (PF=1) UPS (Uninterruptable Power Supply) improves power efficiency.
  • DCIM analyzes and recommends server power connection/ re-connection (upon obtaining detailed information from UPS) to optimize phase balancing and thus achieves energy saving.
  • Night-mode CCTV system allows "light-out" data centre operation.

Other Green Features initiated by ITS

Apart from the green infrastructure of the new Central Data Centre at Block Z, the existing Main Computer Centre at Core P will also undergo modifications to improve the running efficiency and to save energy. Moreover, ITS provides cloud services, server virtualization and collocation services which can save energy, space as well as energy cost. Exercises on virtualization and collocation of servers had already been carried out in several departments at PolyU. Besides, Managed Print Services (MPS) are also under trial in ITS and some other departments. This program minimizes the number of printers in the office that may save energy and papers. ITS endeavours to support campus sustainability by making use of current green technologies.


Activities and Development on Campus

Consultation on PolyU's new policies on campus sustainability

Having a mission to foster sustainable development, PolyU is committed to building a green campus. Relevant policies have also been formulated recently by the Campus Sustainability Committee (CSC). These policies cover six areas including campus sustainability, energy conservation, water usage, waste management, green procurement and campus development. The initial policy consultation was conducted from 27 November to 31 December 2013 to solicit views from all PolyU stakeholders including staff and students. They were welcome to send their opinions to CSC by emails. Besides, an open forum was organized at Senate Room of Li Ka Shing Tower on 19 December 2013 to facilitate exchange of ideas. Participants actively shared their views on ways to improve the environmental performance of PolyU. As a sequel to the open forum and consultation, CSC is studying all comments collected and will consolidate the final version of policies in due course.

PolyU students were awarded at Upcycling Design Competition

On 9 November 2013, the Construction Industry Council and Zero Carbon Building (ZCB) announced the winners of the ZCB‟s "Upcycling Design Competition" and their award-winning designs at the award ceremony. The panel of judges selected seven pieces of home decorations and furniture as outstanding designs created by 14 students divided into teams. Mr. Lo Chun Yuen and Ms. Lam Choi Ching, students from PolyU, won the Merit Prize for their "LighTable", which is a coffee table with a lighting function. It is made from aged and unwanted materials, including abandoned wood pieces, used advertising banners and wine cases. With the dynamic light from the table through the graphics on banners, different people would have different views from different perspectives. By turning waste into treasure, innovative upcycling products helps to raise awareness on environmental protection and to promote a low-carbon lifestyle.

PolyU seeks to enhance the role of travel trade in reducing tourism's carbon footprint

Travel agents and tour operators in Hong Kong are one of the key providers of tourism information. They can play an active role in contribution to carbon emission and global climate change issue by providing relevant advice and shaping tourists' travel behaviour.

A study carried out the School of Hotel and Tourism (SHTM) found that though senior management and owners of travel agencies are aware of tourism's contribution to carbon emissions, the limited provision of carbon efficient products is hindering their frontline staff from promoting low carbon tourism to their clients. The study also found that frontline travel trade staff are equally concerned about the environmental issues, but many of them felt they are not well equipped and qualified to make knowledgeable suggestions for their clients. Besides, a digitized education toolkit was developed with topics and findings introduced in the training workshops, as well as tactics and strategies offered. It will contribute to a more sustainable development of the travel trade industry not only in Hong Kong but also worldwide.

InnoAsia 2013 and "Tech Forum on Eco-city EcoMobility"

The Hong Kong Science and Technology Parks Corporation organized "InnoAsia 2013" with the Theme "Towards a Smart Green City Agenda" on 4-7 December 2013, a four-day event consisting of a main conference, a chairmen‟s forum, 6 tech forums and investment workshop, at the Hong Kong Convention & Exhibition Centre. The event focused on energy optimization, renewable resources, carbon footprints reduction, green architecture, advanced robotics, healthcare and transportation system.

As one of the co-organizers, PolyU organized a half day "Tech Forum on Eco-city EcoMobility" on 6 December 2013, which brought together leading experts in the field of electrical engineering to share their valuable knowledge and experience on how smart technologies help to provide sustainable modernizations to our society and make our environment cleaner, greener and safer. PolyU offered 30 complimentary tickets to our staff and students to the Tech Forum.

Work-life Balance Weeks at PolyU

Human Resources Office organized "Work-life Balance Weeks" on 15-25 October 2013 with a variety of campaigns, workshops and activities to advocate the work-life balance for staff. A concert was also held at the end of the weeks. These activities aimed at reminding staff members of staying healthy while fulfilling one's work duties.

Sustainability related talks, workshops and conference

During the period from October to December 2013, various sustainability-related talks, workshops and conference were held on the PolyU campus:

  • Seminar on Low Carbon Logistics: Good Practice and Guideline for SMEs (V)

    Date:11 October 2013
    Organizer:CY Tung International Centre for Maritime Studies (ICMS)
    Content:This workshop covered different topics of low carbon logistics, including:-
    • Partnership and Collaboration is the Only Way Forward
    • Green Logistics Management
  • PolyU Green Economy Luncheon

    Date:16 October 2013
    Speaker:Professor Cheng Siwei, Economist and former Vice Chairman of the Standing Committee of the National People's Congress of the People's Republic of China
    Organizer:Faculty of Business
    Content:Economist Professor Cheng Siwei gave a talk on the green economy at a luncheon from different angles – economic, environmental and social.
  • Seminar on Low Carbon Logistics: Good Practice and Guideline for SMEs (VI)

    Date:2 November 2013
    Organizer:CY Tung International Centre for Maritime Studies (ICMS)
    Content:This workshop covered different topics of low carbon logistics, including
    • Overview of current stages of Low Carbon Logistics
    • Powering SMEs the Energy Efficient Way
    • Low Carbon Management in Terminals
    • Low Carbon Logistics Policy in Pearl River Delta
  • Public Lecture of Distinguished Chinese Visiting Scholars Scheme - Sustainability : From Practice to Science

    Date:27 November 2013
    Speaker:Professor Niu Wenyuan, Member of the World Academy of Sciences and Chairman and Chief Scientist of the Sustainable Development Strategy Programme of China at the Chinese Academy of Sciences
    Organizer:Faculty of Business
    Content:Professor Niu shared his valuable knowledge and inspiring experience on sustainability development.
  • International Conference on Power Electronics Systems and Applications (PESA)

    Date:11-13 November 2013
    Organizer:The Hong Kong Polytechnic University
    Content:The three-day conference focused on the recent research and the industrial project of power electronics and related technology. Environmental protection and alternative energy was one of the topics of interest. The conference aimed to be a key international forum for the exchange and dissemination of technical information on power electronics among academics and practicing engineers in the field.
  • Seminar on Energy Shift in Wastewater Industry: From Mega-Consumer to Energy-Gain Enterprise

    Date:23 December 2013
    Speaker:Professor Shihwu Sung, Department of Civil, Construction and Environmental Engineering, Iowa State University, USA
    Organizer:Faculty of Construction and Environment
    Content:Professor Sung presented a paradigm-shifting strategy by which the energy-efficiency of wastewater treatment could be dramatically improved by advancing the roles of novel anaerobic and anoxic bio-based mechanisms in lieu of heavily relying on aerobic treatment

PolyU Micro Fund: innovate for a sustainable campus

PolyU Micro Fund Scheme, a knowledge transfer initiative launched in 2011, aims at cultivating innovative and entrepreneurial ambience within the PolyU community and nurturing socially responsible young entrepreneurs with the "Do Well Do Good" entrepreneurial spirit. The theme of Innovation Stream for this year is "Innovate for a Sustainable Campus". It is expected that the innovations will have a lasting contributions to make PolyU a sustainable campus. A series of green activities and workshops have been organized:

  • Campus Eco Tour

    Date:6 December 2013
    Content:This tour was guided by Mr. Joseph Chan, Campus Sustainability Manager of Health, Safety and Environment Office, to introduce the sustainable and environmental protection features on the PolyU main campus.

  • PolyU Tree Appreciation Tour

    Date:4 December 2013
    Content: This tour was guided by Mr. Ken KY So, Chief Executive of the Conservancy Association, to introduce various kinds of trees and shrubs on the PolyU main campus.

  • Upcycling Product Design Workshop

    Date:3 December 2013
    Content: This workshop showed DIY upcycling techniques for transforming waste materials, such as used plastic bottles, into the beautiful decoration.

  • Social Entrepreneurship Lecture Series: Beyond Business as Usual - Systems and Sustainable Opportunities

    Date:3 December 2013
    Content: This seminar shared how firms were looking across their value chains for opportunity recalibrate their processes, products and people, reduce risk and increase opportunity, especially in the area of waste management and reduction.

Green activities at the Green Hall of the Homantin Halls

Green Hall of the Homantin Halls is dedicated to promoting sustainability. Residents of Green Hall have paid high attention to green lifestyle since the very beginning of the Hall establishment. In line with such mission, signature green programs are regularly organized for the residents. Recently, a candle making workshop was held in October 2013. Participants utilized recycled materials including used candles and empty milk boxes to make new candles with beautiful colors and shapes. During the past three months, the Green Hall also endeavored to promote several green activities including the Chinese Dolphin Campaign and Glass Bottles Recycling Program organized by other green parties, and encouraged hall residents to actively support these campaigns.

In November 2013, the Green Hall participated in the Green Living Contest held by Friends of the Earth (HK). Learning through this contest, the Green Hall is currently developing an online thrift store which will possibly be available in the coming semester.

Promotion of food saving by the Green Society

In Hong Kong, over 3,200 tonnes of food waste are generated every day. Such large amount of food waste ends up in the landfill, speeding up the saturation of our already limited landfill space and posing a severe burden on the local environment. Other than an environmental problem, the unequal distribution of food is also an issue.

In PolyU, we are producing nearly two tonnes of food waste each day, most of which comes from students‟ leftovers. In this regard, the Green Society formed a team named "Less Rice, please!" Flash Mob (「少飯,吾該!」快閃黨 ) to advocate food saving and reduction of food waste. Team members went to the canteens on the PolyU main campus and promoted the "less rice" lifestyle to our students and staff. As an incentive, individuals who finished all their foods without any leftovers would be awarded with coupons for drinks. So far, some 50 students successfully won the coupons.


Resources Conservation

The Used-item Collection Campaign

The PolyU Staff Association (PUSA) and the Community Recycling Coop, a subsidiary of Industrial Relations Institute (IRI), jointly organized the Used-item Collection Campaign again on campus from 20 to 21 November 2013. Staff from the Community Recycling Coop came to the PolyU main campus to collect usable secondhand items from our staff and students. A total of about 1,445 kg used items were collected. Collected items including clothes, shoes, bags, electrical appliances, housewares, stationery and books which were in good condition, were then sold to the needies in Sham Shui Po at very low prices. Similar campaigns have been organized since 2008. This meaningful event not only helps the disadvantaged, but also reminds us that it is a blessing for us to be able to give.

Campus-wide green action on food waste

Food waste accounts for about 40 percent of municipal solid waste disposed at landfills in Hong Kong note. As one of the Food Wise Partners of the HKSAR Food Wise Charter, PolyU is committed to reducing food waste and facilitating food waste recycling.

In this regard, PolyU has commissioned a food waste collection and recycling contractor, the Hong Kong Organic Waste Recycling Centre (HKOWRC), to collect food waste at all catering facilities on the main campus, HKCC Hung Hom Bay Campus, and Student Halls of Residence at Homantin starting from 2 December 2013.

The food waste collected by HKOWRC will be recycled mainly into composts and pig feeds. To facilitate the recycling process, our catering facilities have to exercise food waste source separation before final disposal of food waste into dedicated collection bins.

Moreover, Hotel ICON has joined the "Food Angel" program organized by Bo Charity Foundation since January 2013. You may also contribute to reducing food waste by simply adopting a thoughtful dining habit.

Note: Monitoring of Solid Waste in Hong Kong - Waste Statistics for 2011, Environmental Protection Department (EPD)

Bring Your Own (BYO) campaign

As revealed by the Environmental Protection Department note, about 100 tonnes of PET plastic bottles are disposed of at landfills every day. The plastic will then take at least hundreds of years to decompose. Minimizing the use of disposable plastic bottles and using one‟s reusable cups or bottles will certainly contribute to building a more sustainable and cleaner Hong Kong.

The Campus Sustainability Committee (CSC) recently initiated the "Bring Your Own (BYO)" campaign. This is a campus-wide sustainability program to advocate the culture of "Bring You Own" to minimize the use of disposable containers and plastic bottles. No matter you are ordering foods, picking up takeout or planning to take away the leftovers, using your own reusable containers will be the most environmental-friendly lifestyle. Some restaurants and catering facilities on our campus even offer the BYO discounts if you bring your own containers or mugs to collect foods or drinks.

PolyU members are also encouraged to practise BYO by using the drinking fountains which can be found easily on the PolyU campus. Moreover, free drinking water can be obtained at all student canteens as well. For more details about this campaign, please visit

Note: Monitoring of Solid Waste in Hong Kong - Waste Statistics for 2011, Environmental Protection Department (EPD)

Pollution Control

The newly launched Air Quality Health Index

The Environmental Protection Department (EPD) launched a new air pollution information system, the Air Quality Health Index (AQHI) on 30 December 2013. It is hoped that the new system, which has replaced the Air Pollution Index (API), can convey the implications of air pollution on health more effectively.

The AQHI is a health risk-based index that estimates the short-term health risk caused by air pollution and provides more timely and useful air pollution information to the public. It is reported on a scale of 1 to 10 and 10+, and is grouped into five health risk categories, i.e. low, moderate, high, very high and serious. Affiliating with the index is different health advice for people with different degrees of susceptibility to air pollution.

The AQHI is calculated based on the cumulative health risk attributable to the three-hour moving average concentrations of four air pollutants including ozone, nitrogen dioxide, sulphur dioxide and particulate matter (PM2.5 and PM10). EPD also developed a dedicated AQHI mobile application, "HK AQHI", with features such as customized filters on AQHI information by district, risk categories and an alert system for smartphone users. For more information about the AQHI, please visit .


News and Tips

New facebook page on sustainability at PolyU

Further to the establishment of a website on campus sustainability, a new facebook page on this same subject was also launched in November 2013. This page can be accessed by searching for "PolyU Green Campus". It is a trend in making use of the social network to promote sustainability and environmental awareness. You may find the latest information about PolyU's green news, events, tips and gallery, etc. posted on this facebook page. Please visit this page and add your "like" at!

Hong Kong's first Zero Carbon Building

Buildings accounts for 60% of greenhouse gas emission in Hong Kong. It is obvious that built environment has to be more energy efficient and climate friendly. The Construction Industry Council, in collaboration with the Hong Kong SAR Government, had developed the Zero Carbon Building (ZCB) as a showcase to promote eco-building design and technologies to the construction industry locally and internationally, and to raise community awareness of low carbon living in Hong Kong.

ZCB is the first zero carbon building in Hong Kong. It covers a total area of 14,700 square meters of land, comprising a 3-storey Zero Carbon Building and a landscape area. It has indoor exhibition and education area, multi-purpose hall, eco-office, eco-home, eco-cafe, eco-plaza, outdoor exhibition area and an urban native woodland.

ZCB generates on-site renewable energy from photovoltaic panels and a tri-generation system using biofuel made of waste cooking oil and achieves zero net carbon emissions on an annual basis. Beyond the common definition of a "zero carbon building‟, ZCB exports surplus energy to offset embodied carbon of its construction process and major structural materials. By using the passive design approach, natural elements such as sunlight and wind are used to heat, cool, or light a building. Advantages are also taken of the building itself, including building orientation, window placement, skylight installation, insulation and building materials, windows and window shades. The energy efficient active systems, such as lighting and ventilation system, also save considerable amount of energy as compared to a similar building of the current standard design. The urban native woodland covers an area of about 2,000 square meters. It has 220 native trees of over 40 different species and diverse array of native shrubs and offers a pleasant natural aroma and fresh oxygen.

The general public is welcome to visit ZCB. For more information, please visit