Measured occupancy levels in Swedish offices

In order to accurately design and analyze demand controlled volume ventilation systems, theoccupancy level in the room must be known. The occupancy level corresponds to the length of time people occupy a room. Since there is a lack of data for occupancy levels in regards to offices, this study reports on measured occupancy levels for three cell offices in Sweden. The same occupancy sensors were used as those found on the ventilation systems. The results showed that the occupancy level for an office was as low as 11.2%.

Associations between classroom CO2 concentrations and student attendance in Washington and Idaho

This paper presents the results of a study that explored if higher indoor minus outdoor CO2 concentrations were associated with increased student absence. The results of multivariate analyses are presented.

Revised air-exchange efficiency considering occupant distribution in ventilated room

This article defines a new air-exchange efficiency that takes into account the occupancy in each zone.. Cases studies are then described and show that the new efficiency can better evaluate the ventilation effect of the room.

A numerical investigation of effects of a moving operator on airflow patterns in a cleanroom

In this paper, the variations of the airflow induced by a moving operator in a cleanroom installed with a curtain, are studied numerically. The effects of the moving operator and curtain on the airflow patterns are taken into account.

Dispersal of exhaled air in stratified surroundings - CFD studies -

CFD is used to simulate the effects of respiration in displacement ventilated rooms. It was done in a satisfactory manner.An extra simulation was carried out with "density-corrected" exhalation temperature, to see if the results are sensitive to variations of this parameter. This proved not to be the case. The choice of the flow rate is more important for the flow pattern.

Investigation of seat occupancy rate in office

This paper reports a large-scale investigation result on seat occupancy rate in a typical Japan office with 240 workers. The experiment lasted 3 months. The sensing device continuously recorded the seating status for about one week for each working person. From these results , a practical use situation of the personal air-conditioning system in the office could be predicted.

A simplified model for human induced convective air flows - Model predictions compared to experimental data.

This paper proposes a simple mathematical model for calculation of the convective air flow rate induced by humans. That model has been then compared to a more complex one and to experimental data with satisfactory results.

Influence of geometry of a a computer simulated person on contaminant distribution and personal exposure.

By means of CFD, the results of that study express a significant influence of Computer Simulated Person geometry on local flow pattern and on personal exposure to contaminants released from the floor surface.

Experimental study on a ductless air supply system using low temperature air

Experioments has been conducted with a ice thermal storage and a ceiling plenum. This ductless air supply system can be an alternative to the use of chilled water tubes. This system supplies air to the ceiling plenum chamber by mixing return air and low temperature air.

Theoretical study of pollutant mixing in rooms induced by occupancy

This study presents a model to predict the time required by a pollutant to disperse in a room, due to the effects of room occupancy (a moving person enhances the mixing of pollutants).