Problems of heat and mass transfer optimization in the plate cross-flow heat exchangers, usedin air conditioning systems for energy recovery from exhaust air, are discussed. The mainpeculiarity of the investigated unit is the possibility of realization of heat transfer withinexhaust air canals in the dry heat exchange conditions or in the conditions of coupled heatand mass transfer with occurrence of vapour condensation on the whole or on a part of theheat exchange surface of the matrix in the form of dew or frost.

In this paper, the very recent laboratory research results on personalized air supply (PAS)from three universities are critically reviewed. Based upon these experimental results, thepotential improvements on inhaled air quality versus indoor air quality are analysed in termsof reduced air pollutant levels in the inhaled air. Depending on the configuration of the PAStested, up to 80% reduction of pollutant levels in the inhaled air can be achieved at the sametotal ventilation rate of the present mixed ventilation methods.

Air-conditioning and ventilation systems, which help to maintain the indoor environment ofbuildings, account for more than half of the energy consumed in them. While it is necessary toimprove the energy efficiency of buildings due to economic and environmental reasons, it isimportant to do so without compromising their indoor environment. Various optimizingstrategies for air-conditioning and ventilation systems that help to improve energy efficiencywhile enhancing the quality of the indoor environment of buildings are described in this paper.

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.