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Thermal comfort variables were measured in Singapore mechanically ventilated classrooms. In parallel the cccupants filled questionnaires on their perception of the indoor climate. The results showed that ASHRAE Standard 55 was not applicable in free-running buildings in the tropics. The study showed that generally cool thermal sensations were more readily accepted by the classroom occupants than warm thermal sensations.

Variable Air Volume system use VAV boxes that serve open areas for five or more occupants, each zone is controlled with a single space temperature sensor. But VAV zone control strategies remained the same for the last years, so the designers have to consider that system : it provides a high quality environment for occupants, it permits the use of a smaller air-distribution system that is low cost and does not compromise building comfort or operating efficiency.

A contaminated supply air system may have an adverse effect on indoor air quality. The aim of that study was to evaluate the effectiveness of different protective actions in achieving a clean supply air duct system on the one hand and to find out the location in the ductwork where most of the duct is accumulated. Measurements were made and presented in tables.
It appears that dust accumulation can be partly avoided by ducts protection during the whole of the construction transportation and storage phases and that no ducts with residual oil on the inner surface should be used.

In air-based systems, ducts deliver heat and cool air to conditioned spaces. Taking extra time to properly seal ducts during the installation along with repairing and patching leaks in HVAC duct systems will save cooling, heating and fan energy. With aerosol-sealing technology higher performance ducts in new and existing buildings potentially exist.

Air quality in conditioned spaces can be improved even in humid locations, in Florida. A field experiment in a Florida school confirmed that the use of a dual-path air-distribution system with low temperature air can maintain lower and more comfortable humidity levels.
Furthermore, that system coupled with a thermal energy storage (TES) keeps energy use as low as possible, and makes costs savings.

In this article the author gives some guidelines and techniques to conduct IAQ investigations at low cost for school staff with small budgets : first he advises occupant interviews, followed by a physical survey of the premices. An IAQ toolkit at low cost can be prepared for a first level type of investigation.
Then a monitor data analysis can be made with the measurements of temperature, relative humidity and CO2.
Finally an hypothesis can be developed even with little background and small budget.
But particular problems may require an experienced consultant.

An effective and successful O&M (operation and maintenance) program for schools begins at the very start of the project and not at its facility completion : key design issues must be covered during planning and design phases. The owner must be identified and listened to, the understanding of how the O&M staff works, what its capabilities and technology skill level are, will help in designing the right facility within the capability of available resources.

This paper is a report on humidity control in schools mainly located in hot and humid climates : according to the US Department of Energy's investigation, most of them, use packaged cooling equipments that are not able to manage space humidity effectively when delivering a high percentage of outdoor air. Those schools don't respect the requirements of the ANSI/ASHRAE standard 62-1999.
By using the dedicated outdoor system (DOAS) approach, ventilation effectiveness and humidity control can be improved and meet the recommendations of the ASHRAE 62-1999 standard.

A heat and mass transfer model of a walking clothed human has been developed in that study. That model predicts the transient thermal responses of the human and clothing giving temperatures, and latent heat losses. A mathematical model was developed for the simulation of the dynamic thermal behavior of clothing and its interaction with the system of human thermoregulation under walking conditions.

A heatlhy environment at work has become a real preoccupation. It began first in offices but now it exists in industry which was reluctant up to now in spending money for it, because the output responsibles were not convinced that such an investment could bring an output gain. A loss of productivity can depend on the ambiant temperature for example.