Above-ground multi-level car parks in large shopping centres are highly amenable to hybrid ventilation applications, particularly those centres with retail shops at the lower levels and car parks at the higher levels. The higher level car parks allow the benefit of higher wind velocity and better dissipation of car exhaust emissions than at ground level; at the same time, larger perimeter wall opening area can be used without affecting the aesthetic feature of the building.

In this paper, a full-scale test house constructed in Tohoku University, Japan and some kinds of residential ventilation systems including hybrid ventilation within it is described firstly, and then the ventilation systems' performance is evaluated by field studies and numerical simulations.

Despite a great accumulation of empirical information on the passive performance of houses for either free-running or conditioned modes, very little work has been done on the thermal performance of buildings that can operate with a mixed-running strategy in warm-humid climates. Buildings with such design features would be able to balance the needs for comfort, privacy, energy efficiency during different periods of the year.

The aim of this paper is to identify the weak points in nowadays ventilation installations in Belgium and to discuss energy performance approach of buildings as a way to solve many of the ventilation related problems.

Three hybrid ventilation concepts are described: alternate use of natural and mechanical ventilation; fan assisted natural ventilation; stack and wind supported mechanical ventilation. The concepts described comprise some newly constructed rather advanced buildings but also some existing more traditional type buildings. All buildings with hybrid systems up till now are far from what might be the optimum solution. There is a knowledge gap especially on dimensioning and control of hybrid ventilation systems.

To investigate the possibility of indoor air quality (IAQ) control by hybrid energy saving ventilation with an air cleaner using the sorption effect of building materials, this paper describes the identification to estimate the parameters related to the sink effect of materials, the concept of the novel air cleaner, and the performance evaluation of IAQ control for a house installed with the hybrid ventilation system to remove chemical contaminants by computer simulation.

This paper points out that the operation and management of the system for indoor air quality (IAQ) is more important than the design of air conditioning system. It is a widespread practice that for the sake of saving energy and operating expense, many building owners change the system's installations and operating manners of fresh air system of air conditioning. Almost all the building owners neglect the maintenance and management of air conditioning system. Those behaviours lead to seriously poor IAQ.

A new method of transport process visualisation is suggested to analyse the fluid flow and heat transfer structures. A two-dimensional displacement ventilation flow model is comprehensively investigated. Results demonstrated that the streamline and heatline visualising means macroscopically exhibit the nature of momentum and heat transfer philosophy, providing a direct insight to see the IAQ.

Today there is an increasing focus on the importance of a proper ventilation system to obtain good working conditions in the term of air and thermal quality to ensure high productivity. Different ventilation principles are used, e.g., mixing ventilation and displacement ventilation. In order to ensure that the ventilation system meets the demands it is important to know which parameters that influence the performance of the system. In this work the mixing ventilation principle was investigated.

Radon is a kind of radioactive inert gas. It exists in the soil pore, the underground water and the air. Radon and radon daughters can damage the human body. After they are inhaled into the lungs, radon daughters decay, emit alpha particles, lead to internal irradiation and even cause lung cancer. Radon can accumulate indoors; the problems of indoor radon concentration have aroused a great deal of attention. In this paper, the characteristics, sources, and health effects of radon are discussed in detail.