Indoor air quality and energy issues of refrigerant modulating air-conditioning systems in the tropics

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.

A field study of thermal comfort in outdoor and semi-outdoor environments in subtropical Sydney Australia

Many indoor models have been developed to describe thermal indoor discomfort, but are they relevant to outdoor or semi-outdoor environments ? They have not been yet critically validated . So, the thermal comfort of more than one thousand subjects living in outdoor and semi-outdoor locations in subtropical Sydney has been investigated by a questionnaire on the one hand and measured with micro-meteorological instruments.

Why, when and how do HVAC-systems pollute the indoor environment and what to do about it ? The European AIRLESS project

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.

Thermal comfort study of an air-conditioned lecture theatre in the tropics

Objective measurement, CFD modelling and subjective assessment have been used in that study to evaluate the thermal comfort of an air-conditoned lecture theatre in the tropics. The simulated parameters are temperature, airflow rate and relative humidity.The parameters were found in the limits of the comfort standard. Occupants' vote show that they were uncomfotable and dissatisfied.

L'ambiomètre : un outil de mesure du confort d'ambiance dans les bureaux (The Ambiometer : a sensor for the ambient comfort in offices)

The ambiometer is a tool that allows both the recording of physical parameters of comfort and sensations of the occupant.The method developed is based on field investigations of four components of comfort : thermal, acoustic, visual and olfactory components : the experiment comfort parameters are recorded with the Ambiometer and the occupant gives his own feeling on each comfort parameter and on overall comfort.A database including those physical and perceptive parameters of comfort has been made, information was collected from about sixty offices.

Standard 62's Multiple spaces equation : for design not control

The intent of this paper is to show that using Equation 6-1 from ASHRAE standard 62 based on occupancy is a non sense if used as a control algorithm in so far as up to now no sensors can physically count each individual in the space. Equation 6-1 describes how to calculate the amount of outdoor air required from an air-handling unit serving multiple spaces for system design purposes.

Classification for the room air conditioning strategies

This paper introduces a new strategy approach for the room air conditioning including classification and terminology. The aim of the classification is not to value one strategy over another (piston, stratification, zoning and mixing strategies are presented with their advantages and drawbacks, design criteria and applications) , it is up to the designer to select the most desirable strategy for each case. A clear classification of the ideal strategies will help the evaluation of the present room air distribution methods in different operating conditions.

Effects of temperature and humidification in the office environment

In this paper, the links between temperature and Sick Building Syndrome symptoms on the one hand and temperature and workers'perceptions of air dryness in environments with and without humidification on the other hand are evaluated .The average intensity of symptoms and perceptions of dry air relative to room temperature in humidified and non-humidified conditions are studied. The results are presented then analysed .

"Europart" Airborne particles in the indoor environment. European interdisciplinary review of scientific evidence on associations between exposure to particles in buildings and health effects.

The European interdisciplinary group of researchers have reviewed 70 papers and selected 8 studies for their final review. From most studies, no definite conclusions could have been drawn concerning the association between particles matter concentration and health outcomes.
So giving limit values or guidelines for particulate mass or number concentrations in non-industrial indoor environment is not an adequate scientific evidence.

Calculated and observed human thermal sensation in an extremely hot and dry climate

This paper presents a case study : under extremely hot and arid climate, the thermal perception of 36 students has been tested. For the calculations, energy balance models of Fanger and Gagge et al. were used. There was a discrepancy between the observed and calculated values during daytime under extremely hot conditions.

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