Cover Story

The management of Indoor Air Quality (IAQ) on PolyU campus


Indoor air quality (IAQ) is a term referring to the air quality within and around buildings and structures, especially as it relates to the health and comfort of building occupants. Nowadays people spend more than 70% of their time at homes, in offices and other indoor environments. Since poor IAQ may lead to discomfort or even ill health, people are inclined to be more concerned about this issue.

PolyU is situated in a busy urban area next to the Hung Hom Cross Harbour Tunnel with very heavy traffic load. As a result, high levels of pollutants are likely to be present in our ambient air. Nevertheless, PolyU endeavors to maintain good IAQ in its buildings by means of facility design and maintenance procedures. This article summaries the management of IAQ on PolyU campus.

How is IAQ managed in PolyU?

As a well-designed and efficient ventilation system is the prerequisite for good IAQ, our Facilities Management Office (FMO) is committed to assuring good IAQ in our campus buildings via the following means:

  • Sophisticated design of the mechanical, ventilation and air conditioning (MVAC) system – The MVAC systems are carefully designed in PolyU to provide well-conditioned air to all buildings on campus. Basically, fresh air driven into the ventilation systems via fresh air intakes is passed through particulate filters for preliminary treatment. To ensure that sufficient fresh air is supplied to the premises, carbon dioxide-based demand controls of fresh air supply are also incorporated into the system.
  • Effective maintenance procedures – In order to maintain the operating efficiency of the ventilation systems, FMO carries out regular cleaning of the cooling coils and fins. All air filters are also cleaned or replaced regularly to ensure that the filters are not clogged with dusts. Moreover, FMO checks all automatic temperature controls on a regular basis to ensure that they are operating properly.

All the above-mentioned measures not only guarantee the normal operation of the ventilation systems and thus provide a good and comfortable indoor environment, but also enhance energy saving on campus.

In addition, FMO is responsible for handling IAQ problems such as identifying obvious sources and reasons for unacceptable IAQ, making recommendations and implementing remedial actions for further improving IAQ. Users of PolyU premises are welcome to approach the Help Desk of FMO at 2766-7777 for such service. For special IAQ issues (e.g. occurrence of unpleasant smells that are not directly related to the MVAC system), FMO collaborates with the Health, Safety & Environment Office (HSEO) in conducting the necessary investigations.

In-house IAQ Research Study Group

PolyU has its first IAQ Research Study Group back in 1999. The group was formed by members from the then Health and Safety Office, the then Estates Office, Department of Building Services Engineering and Department of Civil and Structural Engineering. The objectives of the study group were to :

  • report on the IAQ conditions based on a campus-wide survey with representative samples especially in critical areas with frequent complaints;
  • comment on the possible impact on health and comfort due to the IAQ conditions;
  • identify obvious causal factors on unacceptable IAQ; and
  • give recommendation on further work and detail study.

This study group contributed a lot to the establishment of IAQ management in PolyU till its function discontinued in 2009.

PolyU joined the IAQ Certification Scheme

To promote public awareness of the importance of IAQ, the Environmental Protection Department of the HKSAR Government has launched a voluntary IAQ Certification Scheme for Offices and Public Places since 2003. This scheme aims at recognizing good IAQ management practices and providing incentives for owners of premises/buildings or property management companies to attain the best level of IAQ.

There are two levels of IAQ objectives under this scheme, i.e. the Good Class and the Excellent Class. Buildings that participate in this scheme are assessed by competent examiners with respect to twelve IAQ parameters. They include the following thermal comfort factors and common indoor air pollutants:

  • Room temperature
  • Relative humidity
  • Air movement
  • Carbon dioxide
  • Carbon monoxide
  • Respirable suspended particulates
  • Nitrogen dioxide
  • Ozone
  • Formaldehyde
  • Total volatile organic compounds
  • Radon
  • Airborne bacteria

If the assessment results meet the certification requirements, the buildings may be certified as either Good or Excellent Class. Each certificate is valid for 12 months and can be renewed annually in the following four years through confirming the re-measured results of carbon dioxide and respirable suspended particulates are in compliance with the certification requirements.

PolyU first participated in this scheme in 2008 and all its classrooms and offices were certified to be of Good-Class IAQ. However, certification was not renewed due to financial constraints. In late 2010, a Certificate Issuing Body (CIP) was again appointed by PolyU for IAQ assessment. Assessment has just been completed and our application for certification is still under processing. Hopefully, offices and classrooms of PolyU will attain at least Good-Class IAQ certification.

Activities and Development on Campus

PolyU Engineering Summer Camp promotes green living

"Engineering Goes Green, Brings a Better Life" is the theme of this camp with about 300 secondary students from 13 secondary schools as participants. This camp was held by the Faculty of Engineering of PolyU from 5 to 7 July 2011. The students stayed in the Student Halls of Residence and enjoyed various programmes such as innovative projects, High Table Dinner and field visits to leading corporations in town. The projects taken up by students included wearable computing and robotics, environmentally friendly CD player, 3D object modelling and animation, electric motor, energy-saving light, logistics simulation and solar amphibious vehicle. The purpose of this camp is to promote students' learning of engineering knowledge and stimulate their imagination and creativity in order that they can gain better insights on their planning for future studies and careers.

PolyU supported the Hong Kong No Air Con Night 2011

The "Hong Kong No Air Con Night 2011" was held from 7:00 pm on 29 September 2011 to 7:00 am the next morning. PolyU supported this event by encouraging our staff and students to switch off air conditioners at home or in the Student Halls that night. At the Student Halls of Residence, about 200 students pledged to support this event heartily by signing their names on the poster displayed at the entrance of the Halls.

This is the second year that Green Sense organized this territory-wide energy-saving event in Hong Kong. More than 60,000 families, 208 schools and 174 enterprises joined this event by switching off their air conditioners for one night with an aim to reducing greenhouse gas emissions.

Resources Conservation

Contribution to promoting solar energy on the road

As reported earlier this year, Prof. Eric Cheng and his team from the Department of Electrical Engineering had won a Special Prize and Silver Medal for the Solar-powered Air-conditioning System at the 39th International Exhibition of Inventions of Geneva. This system harvests solar energy and supports a stand-alone electric air-conditioner installed on a vehicle which can be switched on when the vehicle engine is not running. It was first installed on the top of a truck for pilot testing last year.

With strong support from the industry, this green innovation is now applied to different types of vehicles including mini-bus, taxi, public light bus and truck. On 26 September 2011, the "Green Transport Powering Ceremony" was held on PolyU campus to mark this further use of solar energy on the road. Dr. Kitty Poon Kit (Under Secretary for the Environment), the Honourable Mrs. Miriam Lau Kin-yee (Legislative Councillor), Prof. Timothy W. Tong (PolyU President) and other guests from the stakeholders addressed the occasion and showed their support.

Trial use of new water flushing devices to save water

Buildings on campus are currently receiving fresh water for toilet flushing from the government. In order to reduce water consumption associated with the flushing of urinals, FMO has installed some water-free urinals in three men's toilets on campus for trial use since April this year. The performance of these urinals is being closely monitored. Moreover, FMO's suggestion on two other ways of water conservation has been taken in the new projects managed by the Campus Development Office (CDO). One is the use of dual-flush toilets to provide two different flush volumes. Water closet users can choose a greater flush volume for feces or a smaller volume for urine. The other is the provision of twin-tank system for flush water supply system in the new student hostel which will be receiving seawater for toilet flushing. When cleaning traditional single-compartment water tanks, water supply will be suspended for a few hours. Occupants may need to store potable water for temporary use or use potable water to flush toilets during the cleaning period. In the twin-tank system, the water tank is divided into two compartments. The system adopts an "alternately operating" approach in its operations. When one of the compartments is being cleaned, the other one is still in operation, ensuring continual water supply.

Besides, FMO is planning to further save water by suspending the automatic flushing of urinals late at night where use of urinals is not anticipated.

Modification of the chilled water system to save energy

In a chilled-water system, the air conditioner cools water down to about 4 to 7°C. The chilled water is distributed throughout the building in a piping system and connected to air-conditioning cooling units if necessary. Recently, FMO has installed differential pressure controllers with water balancing valves in chilled-water systems at certain buildings on campus to enable uniform distribution of chilled water supply to the user end. This arrangement minimizes waste of energy in certain areas with a lower demand for chilled water.

PolyU actively supports printer cartridge recycling

Printer cartridges, from laser printers, ink jet printers, or fax machines, can be recycled. However, only some of the proprietary suppliers have their schemes of collection and recycling.

To facilitate recycling of all printer cartridges, PolyU, in collaboration with the Greeners Action, has provided recycling bins on campus since April 2011. These bins are located at or near cores A, F, M, P, Q, R and Y. Any printer cartridges, including ink cartridges, can be deposited into the bins. The cartridges will be collected from time to time by the facilitator, and will either be refilled, if feasible, or dismantled to retrieve the recyclable materials. PolyU members actively support this scheme. About 240 cartridges had been collected up to the end of September 2011.

Pollution Control

New legislation on clinical waste disposal

The Waste Disposal (Clinical Waste)(General) Regulation (Cap. 354O, Laws of HKSAR) already came into effect on 1 August 2011. This new legislation requires that clinical wastes be properly segregated, packaged and stored by the waste producers before they are collected by licensed clinical waste collectors. To delineate the procedural requirements for clinical waste disposal on campus, PolyU has prepared a document entitled "Clinical Waste Management Plan" for our staffs' and students' reference. This document is retrievable from the homepages of the Facilities Management Office (FMO) and the Health, Safety & Environment Office (HSEO).

Implementation progress of the Motor Vehicle Idling (Fixed Penalty) Ordinance

According to the Motor Vehicle Idling (Fixed Penalty) Ordinance (Commencement) Notice (L.N. 134 of 2011) published in the Government of the HKSAR Gazette, the Motor Vehicle Idling (Fixed Penalty) Ordinance (Cap. 611, Laws of HKSAR) will be effective on 15 December 2011. This legislation requires drivers to switch off the engines while their vehicles are stationary in order to reduce air pollution at the road side. Except under certain exemption conditions, a driver who contravenes the legislation is liable to a fixed penalty of $320.

News and Tips

Green products for stationery

To enhance the protection of environment, our Finance Office (FO) arranges term contracts for the supply of green stationery and paper.

Examples of such green products include:

1. Ball-point pen refills (this removes the need to discard a whole pen when the pen has run out of ink);

2. Paper made from recycled materials (this reduces the use of virgin timber and conserves forest resources);

3. Rechargeable batteries and their chargers (this mitigates waste generation, in particular that of heavy metals; worn-out rechargeable batteries can be placed in recycle bins on campus).

PolyU members are encouraged to select these environmentally friendly products for their daily office operations.