Advances in infection control practices include improved operating room environment (airflow velocity, turbulence level, temperature, and relative humidity). Operating theatres are complex spaces. CFD modelling is a powerful tool to enhance the knowledge of the air characteristics. The 3DHVAC program was used to predict the performance of HVAC system design in operating theatres of a 1200-beds Egyptian modern teaching hospital.

This paper deals with experiments made to test the performance of a personalised ventilation system (PVS). 30 human subjects have participated to the experiment in an office with 6 work stations equipped with a PVS supplying outdoor air.The perception of air quality and the thermal sensation for each participant has been reportedduring their exposure to combinations of 3 levels of personalized air temperature, 4 airflow rates and 3 levels of room air temperature.

30 human subjects participated in a 3 h 45 min. experiment, that took place in an office with mixing ventilation and personalised ventilation systems (PVS).Each person could choose the position of the personal air terminal device, the direction of the air supplied and the flow rate (up to 15 l/s.person).The subjects were exposed to 4 following experimental conditions : PVS supplying outdoor air at 20C, then 23C ; PVS supplying re-circulated room air ; mixing ventilation, without PVS.Results allow to know how the PVS were used by participants (choice of position and flow rate).

For workers sharing the same office, there is normally a need for slightly different temperatures to fit their own optimal thermal comfort. In a laboratory experiment with thermal manikin, local radiant heaters have been placed behind office chair , providing heat at their backs, shoulders and necks .
The heat loss from the whole body or from specific body segments was measured during the experiment. The system proved efficiency for keeping the heat balance of the body and reducing the sensation of draught.

This work deals with the characterization of the thermal performance of a LHS (Local Heating System) tested on 18 persons (9 males and 9 females) working in a real free-running office with mean room temperatures varying from 16C to 18C. Local heating systems investigated consist in a combination of two radiant panels and a foot heater. During the measuring tests, the metabolic rate, the tympanic and local skin temperatures were monitored.

Concerning thermal comfort (number one complaint in most offices), the range of occupants needs is very wide. An individual control ventilation system based on VAV (varying air velocity) and integrated into desk was installed in a bank in 20 work areas. The article describes several possible arrangements of this system and mentions air temperatures and flow rates to achieve individual thermal comfort as determined from a preliminary study with a mannequin in laboratory.

At first, this paper deals with the history of indoor environment and ventilation , with the evidence that a good IAQ is essential for public health. An inadequate ventilation plays a major role on the global burden of allergies, airways infections. The more complex the HVAC system is, the more liable it is to fail (if improper maintenance) sothe non-industrial indoor environment is the most important environment from a human health perspective.

This paper deals with the CFD (Computational Fluid Dynamics) method used for the analysis of the micro-climate surrounding the human body. The airflow characteristics of inhalation and exhalation are analysed under both steady and unsteady breathing conditions. The various examples given in this report make clear that CFD is a very effective and powerful tool for analysis and design of healthy indoor environments.

Numerical modelling of convective air movements inside a heated room was built, using a coupling of a zonal model and integral analysis. The model describes the heat transfer between air and walls, between different air layers inside the room, between air in the room and cold air jet from ventilation air supply, and between air and heat emitter. Experiments were conducted in a testing chamber with floor heating or heating by a hot water radiator, with steps in hot water and ventilation flow rates. Validation results are satisfying.

The study in 5 European countries has shown that indoor air quality was noted depending on the country first and on the perceived thermal comfort. Moderate humidity is perceived better while temperature in comfort zone less influence indoor air quality. When it is too hot or too humid, indoor air quality is badly perceived. CO2 levels have few relationship with perceived indoor air quality.