Protecting IAQ through intake placement

An optimal placement of outside air intakes is important for a good IAQ protection. A proper intake placement can also reduce the need for filtration, and reduce re-entrainment of chemical emissions.

Assessment and description of humidity controlled system in french residential buildings

In France, ventilation in new residential buildings must be designed and dimensioned according to the Health regulation (Arrêté du 24 mars 1982) which is basically based on required extract air flow rates. Two points are to be noticed : 1) The extract flo

Comparison of diffuser model in numerical simulation for task air conditioning

This paper is concerned with the different methods to present inlet condition for computational fluid dynamics (CFD) simulation of task air conditioning (TAC). The boundary conditions at the supply opening have a strong influence on the flow in the room, and they are, therefore, very important. Usual methods are outlined. Comparison and analysis are then given. The terminal device of TAC is close to people and is relatively large compared to the dimension of the occupied zone. The occupied zone is in the forward flow zone, not return flow zone.

The HVAC system - Friend or foe in environmental disasters and bio-terrorist attacks ?

In this paper the author analyses the different weaknesses of the HVAC systems in case of air contamination by a deliberate pollution of the inducted air due to vandalism, terrorism or any other motives.To prevent that danger he gives some advice about HVAC installation :A safe air intake is necessary, but the intake grille for ventilation must be inaccessible from outside the building and its position at ground level unsuitable.Air dampers must have effective sealing and be closed in the event of a bioterrorist attack.Recirculation systems can be contamined too from a source within the bui

Experimental work on a linked, dynamic and ventilated, wall component

In conventional construction, the ventilation air enters a building through a combination of ‘desired’ pathways, via opened apertures, such as a window, vents, and ‘undesired’ pathways, via cracks such as around external openings, joints between building

Influences of fresh air supply locations on temperature distribution of fan filter unit (FFU) type unidirectional cleanrooms

In general, there are 3 locations used for the fresh air supply in a standard cleanroom : under the ceiling of supply air plenum, at the return air shaft, and under the raised floor. In this study, the influences of the three different fresh air supply locations on field velocity and temperature distributions of fan filter unit are investigated then compared. The airflow distribution is simulated by the standard k-e turbulence model. Results are presented and discussed..

Friction and contraction by ventilation openings with movable flaps

In this paper, after theoretical considerations, two ventilation openings are analysed : an opening with top-hinged flap and a wall inlet with central flap. The analysis shows that it is possible to split artificial resistance coefficients from literature into pure resistance and pure contraction coefficients .

Contribution à la qualification des systèmes de ventilation des bâtiments : intégration d'éléments perturbants

This thesis was based on numerous experiments operated in a full-size cell in order to study ventilation efficiency and thermal comfort associated with several positions of air inlet and outlet, taking into account different sources of disturbance (heating systems, occupants, etc.).

Airflow through large openings - a catchment problem ?

This paper reports some findings from IEA ECBCS Annex 35 about wind driven flow through building openings. Wind tunnel studies have been performed on simplified buildings, in order to know if pressure distributions on sealed buildings can be used to predict airflow through facade openings. A new parameter, the catchment area, is introduced by author.

In-situ testing of ventilation air intake louvers subjected to snow

Resistance of louvers to the penetration of snow is a main parameter in Nordic countries. The study presents an experiment on 10 louvers tested in situ. The snow has been collected in bag filters and pressure drop variation was the chosen criteria for ranking the louvers.