English

Describes what could be the requirements of a European standard (not yet numbered) prepared by Technical Committee 156 (Working Group 7) of CEN (European Standardization Committee) about the calculation of energy requirements for buildings with room conditioning systems.

A CFD code has been used to design and optimize the ventilation system of a building dedicated to auto-racing (120 000 persons, 45 cars). The constraints are the dimensions of the building, the heat and pollutants due to cars, their high speed and the size of granstands. The article shows the interest of airflow modeling to study the complex ventilation system of such a building.

Three measuring techniques have been compared for evaluation of the surface duct level in ventilation ducts : vacuum test, gravimetric tape method, optical tape method. Measurements have been operated in 13 recent buildings in Helsinki using the three methods. The vacuum test gives similar values to the gravimetric tape method when air ducts show no residual oil from their manufacturing (average values 1.1 and 1.2 g/m2). With residual oil, vacuum test gives higher dust levels than gravimetric tape method. The optical tape method is the most easy to use on site.

Relationships between research about indoor and outdoor air quality are reviewed. The author mentions that outdoor air pollution has attached greater regulatory interest, although people spend more time indoors. The contribution of exposure to indoor pollutants is now more recognized but this increased consideration has little effect on regulations. Nevertheless, the author considers that indoor air quality researchers and public health officials have a lot to learn from the outdoor air quality experience, in fields such as exposure, dosimetry, health effects and risks, mixed exposures.

The coupled thermal/airflow simulation software CONTAM97R was used to evaluate the performance of a naturally ventilated office building recently build in Entschede (The Netherlands), for which detailed measurements results within the Natvent project had already been published.

This study is a part of the Finnish contribution to the HYBVENT project (Annex 35 of IEA). Two 'hybrid' ventilation concepts designed for northern climates were evaluated for a 4300 m2 office building in Helsinki : one of them is low pressure mechanical exhaust with CO2-controlled air inlets ; the other uses mechanical air supply through coils and two parallel exhaust circuit with and without fan and heat recovery. They were compared with conventional systems in Finland (mechanical supply and exhaust with constant or variable air volume).

Experiments and calculations were operated to determine air flow distribution in a test room (9.9 m2) naturally ventilated through adjustable louvers overlooking outside. Air enters at the bottom (opening surgace 0.07 m2) and is exhausted at the top of the room (opening surface 0.12 m2). Air pressure and velocities across the opening allow to estimate wind pressure coefficients. Results show in particular the influence of wind on the internal air flow. Good agreement was found between measurements and calculations.

A two-dimensional particle image velocimetry (PIV) technique was used to measure velocity and turbulence of air flow around a heated manikin in a large room (volume about 80 m3). Measurements were operated in four horizontal and ten vertical planes. The article describes the PIV system and the type of results which were obtained.

Experimental results on the thermal conditions around a ventilated chair (with air supply openings in its base) are provided. They concern air velocities, temperatures and thermal comfort for a seated person. Results are commented compared to those obtained in a room with displacement ventilation with wall-mounted diffuser.

A thermal manikin with 16 independently heated sections has been used for measurements of thermal comfort with mixing and displacement ventilation. The thermal comfort is expressed at the location of the manikin as an equivalent homogeneous temperature (EHT).
Results lead to indications about the connection between EHT and the percentage of dissatisfied due to the vertical temperature gradient and draft rating.