English

Decision about the use of natural, mechanical or hybrid ventilation system in a building should be taken at the early stages of the building design. While for a mechanical system the decision may be taken on the grounds of purely deterministic procedures, the use of natural forces requires a different approach. Therefore, a simple tool is needed which, given a few important and readily known building parameters and information about the local outdoor climate, enables the designer to determine the most suitable ventilation system.

This paper analyses buoyancy-driven natural ventilation assisted or opposed by winds in a building with thermal stratification. Theoretical analysis shows that the ventilation flow is mainly characterised by two air change parameters, namely a buoyancy air change parameter and a wind change parameter, as well as the ventilation openings. It also shows how the clean zone height is affected by ventilation openings. Our new analysis also reveals that the hysteresis behaviour found when uniform temperature distribution is assumed also exists in buildings with thermal stratification.

As part of IEA Annex 35 "Hybrid Ventilation in New and Retrofitted Office Buildings" a number of pilot study buildings are monitored for demonstration of hybrid ventilation performance. The monitoring programmes investigates the performance regarding indoor air quality (IAQ), thermal comfort, control strategies and energy consumption. This paper presents detailed measurements from the Danish contribution. Detailed results from short-term measuring periods are presented.

This paper justifies the need for an integrated approach to building performance assessment and provides examples of the technical appraisals that may then be enabled. The contention is that the use of design tools which focus on a single domain will result in sub-optimum design solutions in terms of indoor air quality, occupant comfort, energy use and environmental impact.

The determination of building insulation levels is an indispensable part of low-energy residential building design. It is necessary to study the impacts of varying insulationlevels of outer walls and roof on room heating loads and cooling loads per square metre. Although diversity of researches on this subject have been carried out over the past years, simulation models have not been employed to evaluate the energy saving effect of different insulation levels all year, and the results were not quantitatively analysed.

This paper explores the problems about the layout of smoke emission for inside hallways of high-rise buildings and underground garages, the selection of smoke emission fans and fire proof valves for basement air feed systems. With the continuous development of urban construction in our country, high-rise buildings are greatly increased in the large and middle cities, the fireproof problems have been paid great attention by all parties concerned. Authors put forward some superficial views on the design of smoke management for high-rise buildings.

Indoor air humidity is an extremely important environmental parameter that can significantly affect the energy consumption of a building, its structure, the chemical emissions from building materials, as well as occupants' comfort and health. How to control indoor relative humidity has been the subject of much attention in the past decade. This paper expounds the passive and active control strategies, introduces a new control theory with a corresponding control scheme, and gives a simple simulation of a typical controlled room.

Energy consumption in building accounts for 30 percent of all the energy consumption of external envelope takes an important part. But in China, because of the insufficiency in thermal behaviour of building external envelope, indoor average heating temperature is low, while heating energy consumption per unit area is 2-3 times as much as that in developed countries under the same climate condition. In this paper, according to measurement and analysis on some kinds of walls, windows and roofs, the detail methods in energy saving of these structures are described.

Some guidelines for a method devoted to the evaluation of different physical characteristics of building facades, equipped with glazed surfaces, are proposed. New graphs are introduced for checking at the same time the behaviour of several technical-physical parameters of walls, in order to allow comparative analysis of different design configurations in terms of acoustics, lighting and heat transfer properties.

Aiming at the running property of hig-speed passenger cars, the paper discusses its indoor air quality's evaluation index and method for calculating outdoor ventilation rate. It studies the influence of the factors of outdoor air quality, outdoor ventilation rate, outdoor pressure fluctuating, drainage mode and fitment material to the indoor air quality and points out some improving measures for them.