English

A computational study had been carried out on hot and cold air interaction across the door of an urban transport vehicle. The studies show that within 20 s after the door is opened all cool air beside the door of the vehicle would flow out when the amb

The efficiency of a kitchen ventilation system is usually determined by its ability in heat and effluent removal. The main part of a ventilation system is the hood, with its face (or capture) velocity. Heat generation associated with the cooking process is the main factor that affects the thermal comfort. The heat removal capability is studied under different capture velocities so as to determine the minimum requirement for efficient removal of heat and effluent.

A systematic analysis of recently constructed dwellings in the Flemish Region has been undertaken within the SENVVIV-project (1995-1998). In total 200 dwellings have been examined in detail. The study involved various aspects: energy related building

Filters used for general ventilation are mass produced and tested by type at rated airflow rate in order to determine the evolution of the pressure drop and the efficiencies during an artificial and shortened clogging process. For filters of better quality it is necessary to evaluate the efficiency concerning fine dust: the traditional atmospheric dust spot efficiency method is now being substituted with an innovative method which allows one to determine the fractional efficiency versus the particle diameter within a 0.2 divided by 3 um range.

Infiltration has traditionally been assumed to affect the energy load of a building by an amount equal to the product of the infiltration flow rate and the enthalpy difference between inside and outside. Results from detailed computational fluid dynamics simulations of five wall geometries over a range of infiltration rates show that heat transfer between the infiltrating air and walls can be substantial, reducing the impact of infiltration.

Simulations have been performed to investigate the performance of intelligent algorithms for control of indoor air quality through natural ventilation strategies whilst simultaneously meeting the requirements of thermal and visual comfort. The proposed control algorithms are founded on the knowledge base of the building physics and support the control of natural ventilation through control of the window opening, whilst simultaneously controlling the lighting, heating and cooling systems of the building.

Similar to supply air jets in mixing ventilation this paper describes a comprehensive flow model for displacement ventilation derived from the integrated Navier-Stokes differential equations for boundary layers. A new test method for low velocity diffusers in displacement ventilation is developed based on this new flow model. Contrary to jet flow, it is shown that the only independent variable in the new model is the buoyancy flux.

The air leakages can have a large impact on heating needs and thermal comfort in industrial buildings. This is sometimes poorly taken into account, both due to the lack of theoretical approach and knowledge of air tightness.

The air distribution effects of floor mounted swirl diffusers are investigated and described inthis paper. Results are based on a case study of an office typical of those in urban commercialenvironments. The effects of the swirl applied to the supply air as well as temperaturedifferentials between supply and room air are explored. The investigation is restricted tosituations where cooling is required.The results of the work, which is undertaken by way of CFD analysis, are presented in termsof appropriate ventilation effectiveness parameters.

The design of natural, including passive, ventilation systems assumes one of two genericforms: the nasty design problem where the designer seeks to size ventilation openings givenclimatic conditions and thermal comfort criteria or the nice design problem where the designerseeks to size ventilation openings given climatic conditions, indoor temperature distributions,and specified airflow rates - presumably determined from separate thermal or air qualityconsiderations.