A European standard on calculation of the HVAC energy requirement of buildings with room conditioning systems

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.

Design of a ventilation system for an indoor auto-racing complex

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.

Thermal comfort for sedentary and moderate activity levels

Conditions of human thermal comfort was studied as function of the following parameters : dry bulb temperature (22.8 to 27.8 °C), relative humidity (20 to 65%), air velocity (0.15 and 0.25 m/s) and activity level (1 and 2.3 met) with a panel of 256 person

The field comparison of three measuring techniques for evaluation of the surface dust level in ventilation ducts

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.

Linkages between outdoor and indoor air quality issues : pollutants and research crossing the threshold

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.

Study on cross-ventilation with radiatonal panel cooling for hot and humid regions

A CFD code was used to study an office equipped with a radiant cooled ceiling and a wind-induced cross-ventilation system. Calculations covered several heights of the ceiling.

Modeling the performance of a naturally ventilated commercial building with a multizone coupled thermal/airflow simulation tool

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.

Performance simulations of hybrid ventilation systems in a five-story office building

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).

Air flow distribution for different wind pressure coefficient values in a naturally ventilated room

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.

CFD analysis on rising stream around a human body and its effect on inhalation air quality

CFD calculations were performed in a ventilated room of 5.7 m2, with an air supply near the floor and an air exhaust near the ceiling on the opposite wall. Air flow rate and inlet temperature are 14.3 l/s and 22C. Calculation results show for example that a standing or seated occupant inhales air coming from the aera close to the floor, which flows upwards due to metabolic heating. A new index (IECI) was used to characterize the effectiveness of contaminant inhalation. The higher values of IECI in the room indicate the zones which the inhaled air comes from.

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