For that study, computer simulations and calculations of outdoor airflow rates and indoor air quality were made in parallel with site measurements in two Shanga office buildings equipped with typical Variable Air Volume systems.In addition to those site measurements, electrical consumption was recorded. Simulations and calculations of the electrical consumption and energy cost were performed.The site recorded data and the simulations results have been then compared and analyzed.
This paper is the presentation of the development and application of an IAQ audit methodology applied in tertiary institutional buildings in the tropics. For that study, a staff room and a typical lecture theatre have been selected.The IAQ audit consisted in monitoring thermal comfort parameters. In parallel the staff and students have answered a questionnaire to give a subjective assessment of the indoor air quality.The IAQ results will be then used to develop an IAQ database for institutional buildings in Singapore.
Due to its simplicity in installation and maintenance on the one hand, and to its potential to conserve energy on the other hand, the refrigerant modulating air-conditioning system has become very popular. This paper presents the results of an IAQ energy audit of two buildings in Singapore that use that kind of system. The results are compared to those obtained from conventional air-conditioning systems.
The objective of the European project AIRLESS was to develop strategies, principles and protocols to improve and control the performance of HVAC systems and their components to be incorporated in codes and guidelines.This paper is a sum-up fo the first-phase of the AIRLESS project : definition of air pollution caused by HVAC systems, investigation to prevent this pollution and definition of strategies to keep away that pollution.
This paper gives the description of a four-factor simulation design and a statistical procedure for analyzing material VOC time sensitivities with regard to the following parameter variations : VOC diffusion coefficient, VOC partition coefficient, material thickness, surface air velocity, along with their interaction effects.
The efficiency of an air diffusion system consists of two factors. The first is the ability of the system to remove heat and contaminants out of the ventilated room. This is most often characterized using temperature removal and contaminant removal efficiency. The second, seldom considered, factor is the uniformity of the temperature and contaminant distribution within the ventilated space. This factor describes how much the maximum contaminant concentration or minimum temperature differs from the average value.
The contaminant removal efficiency and the uniformity of contaminant concentration in the occupied zone of a room were studied in scale model with the following varying parameters : occupied zone obstruction level, air distribution system, air change rate, cooling load, contaminant sources distribution.
Results show that obstruction level, air distribution system, air change rate and cooling load have a small influence on contaminant removal efficiency and uniformity of contaminant concentration.
There is a variety of different methods consulting engineers use to design room system, room air diffusion, such as assumption of perfect mixing, design methods employing the empirical relations determined through research, air jet theory and computational fluid dynamics (CFD) codes. The most common design methods based on air jet theory allows only for the prediction of extreme values of air velocities and air temperatures in the occupied zone.
Dryness is still one of the major complaints concerning indoor air quality in office buildings and respective nonindustrial environments. Dampness in buildings in terms of excess amounts of water in the solid parts, and the harmful consequences have been discussed vigorously in recent years. Indoor air humidity, which means water vapour in the indoor air, has been given less attention.
The nesting of a new zonal model within a multizone model has allowed an increased resolution in the prediction of local air flow velocities, temperature and concentration distributions between rooms and within rooms.
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