Energy efficient operation of variable speed fans in Variable Air Volume (VAV) systems ishighly dependent on both the type of duct design as well as the type of control strategy thathas been implemented in association with the volume flow demand profiles of each individualzone in the building. The quantification of energy savings due to duct design and the effects offan control have generally been poorly understood, even with very simplistic types of controlstrategies, e.g. static pressure P + I control which have often been employed.

This paper investigates the pollutant distribution patterns in a ‘negative pressure’ isolation room by means of objective measurement and CFD modelling. The isolation room has two air supply diffusers and two extract grilles mounted in the ceiling. Numero

There are many schoolchildren who have a minor chemical sensitivity and cannot go toschool just because of the activities taken place such as arts & craft, waxing the floor or justopening the textbook. The solution for those children to go school is to protect them fromthose chemicals. However a renovation to make the whole classroom into a chemical freeroom is not a realistic solution for just one child not just because of its cost but also the effectto the other schoolchildren going in and out from chemical free room because of the risk ofrebound.

The term air conditioning not only prescribes comfort temperature and the relative humidity,but also the quality of air inside the room. Indoor air quality (IAQ) has become a concomitantof air conditioning. The pollutants generated inside the room affect the quality of air inside theroom. The major pollutants considered are CO2, sulfur dioxide, toluene, etc. Monitoring andcontrolling of all the pollutants is cumbersome. CO2 is considered as the surrogate index ofpollutants. Appendix D of the ASHRAE standards 62-1999 recommends a ventilation rate of15 cfm per person.

The impact of airflow interaction on inhaled air quality and transport of contaminants betweenoccupants was studied in regard to pollution from floor covering, human bioeffluents andexhaled air, with combinations of two personalized ventilation systems (PV) with mixing anddisplacement ventilation. In total, 80 l/s of clean air supplied at 20C was distributed betweenthe ventilation systems at different combinations of personalized airflow rate. Two breathingthermal manikins were used to simulate occupants in a full-scale test room.

Various air cleaning technologies and products are commercially available to remove VOCsfrom indoor environment. By conducting full-scale chamber tests, this paper compares theremoval characteristics for VOCs between three commercial portable room air cleaners,representing three major types of technology: sorption filtration, ultraviolet-photo-catalyticoxidation (UV-PCO) and ozone oxidation.

The paper presents part of the outcomes from the project set up by the Polish Committee forScientific Research and devoted to development of the recommended control strategies forDemand Controlled Ventilation (DCV) systems in Poland. The performance of both differentCO2-based occupancy detection algorithms for online demand controlled ventilation systemsand different methods of digital filtration of signals have been studied.

The survey concerned three swimming pools using a similar type of basic water treatment, buthaving different structures and ventilation systems. The survey included measuring air currentvelocities above the pools and studying the microbiological and physico-chemical quality ofthe pool water. In addition, microbes were determined from the indoor air, structures andventilation systems, and airborne particles and volatile organic compounds from the indoor airsamples. The total particle concentration of the indoor air and their size distribution variedbetween the swimming pools.

Air supply diffusers used in air-conditioning systems can be classified as ceiling diffusers,side-wall diffusers, floor diffusers, jet nozzles and low velocity displacement diffusers. Fixedor adjustable slats are usually used to control airflow directions. Recently, swirling vanes areused in floor diffusers to create a swirling out-flow jet, so that more rapid mixing withambient air can be achieved.

In 2003, the World Health Organization received reports of ‘Severe Acute Respiratory Syndrome (SARS)’ in various parts of the World. Until 13 June 2003, there were 1755 people affected by atypical pneumonia in Hong Kong. While the mechanisms of the SARS a