English

Laboratory experiments were performed to evaluate the effect of different CO2-based demand-controlled ventilation strategies (on/off, proportional, linear, PID) on energy consumption and indoor air quality, with various ventilation rates and occupancy profiles, and with one- or two-zones controls. Results show the capability of different strategies to maintain acceptable indoor CO2 level with the minimum outdoor air requirement.

A specially designed garment for direct physical measurement of both the convective and the radiative components of human heat loss was developped, using sensitive heat flux transducers housed in clothing pockets. Investigation with a human subject showed the advantages and the precautions to be taken using this equipment.

Ventilation airflow rates and internal air distribution were measured in four poultry slaughter plants (250 to 775 workers), equipped with negative pressure ventilation systems (exhaust flow rate from 7.1 to 27.4 m3/s - no air intakes - supply air entering through various openings). Results lead the authors to recommend the installation of diffusers for makeup air supply, changes in the organisation of rooms to avoid contamination of one by the other and regular maintenance and cleaning of ventilation components.

An audit of 20 hospital operating rooms was operated in Grece in order to collect information about the HVAC installations and the indoor physical parameters. Data were also collected from 560 medical personnel through a questionnaire about the assessment of the indoor conditions.

The risk of contaminant deposition (10 microns particles) on an operating room surgical site is evaluated for different ventilation systems - conventional, laminar, non-aspirating, displacement -, using airflow modeling and particle tracking methodologies. Results show that laminar flows are the most appropriate to avoid particles deposition.

The paper gives an explanation of the phenomenon of attachment of a cold air jet to a ceiling, based on a theoretical analysis. A formula to calculate the distance between the blowing slot and the point where the cold air jet will separate from ceiling is given. The results of calculations using this formula show good agreement with experimental data.

The market evolution of domestic exhaust air heat pumps since 1979 in Sweden is described. Some information is also given about the German market. Technologies of different exhaust air heat pumps systems are shown and results of several monitoring projects in Sweden are summarized : they show for houses built in the 1980's an electricity consumption of 90 to 130 kWh/m2/year (including domestic hot water and household electricity), depending on the thermal characteristics of the building envelope. The energy savings thanks to the exhaust air heat pump are about 30%.

The revision of Ashrae standard 62, Ventilation for Acceptable Indoor Air Quality, began in 1991. This article gives a summary of the changes that have been approved and describes the issues that remain to be resolved.

Describes the content of the European and International standard EN-ISO 13792 which allows the simplified calculation of the internal temperature in hot season of a room without mechanical cooling.

The article presents the scope and content of ISO 13790 standard which is intended to calculate the energy use for space heating of buildings. Information is given about the accuracy of the standard calculation method.