The Ventilation Standard HASS-102 of The Society of Heating, Air-conditioning andSanitary Engineere of Japan (SHASE Japan) was revised in November, 1997. The title of therevised standard is Ventilation Standard for Acceptable Indoor Air Quality. So far, the oldVentilation Standard, which was issued in 1939, had been used for a long time. The task forrevision was undertaken by the Sub-committee on Ventilation Effectiveness and Standard(chaired by Murakami) of SHASE Japan.

Today, the development of new technologies to improve building envelope performances ishighly encouraged and provides a clear challenge for designers and researchers. In thiscontext several typologies of active envelopes have become very popular. The paper startswith an overview of the history and the performances of active envelopes in the context ofurban design.

Ventilation of buildings in urban areas may result in high internal concentrations of traffic pollutants if air intakes are positioned where external concentrations are highest. This paper presents the results of a wind tunnel study into different wind-driven natural ventilation strategies for a building situated close to a busy road.

The aim has been to determine ventilation rates and risk of moisture damage in three modernschools with passive stack ventilation. The users are supposed to control the ventilation byusing the lantern windows and the outdoor air is assumed to enter through an undergroundduct. The paper presents results, analysis and conclusions from the performed measurementsand calculations.The ventilation rates are sometimes low and vary with the use of the windows in the facadeand the lantern. It is, however, always possible to arrive at a sufficient ventilation rate.

A dynamic simulation of the ventilation processes and the thermal behaviour of an office building is developed. This is used to investigate two aspects of night cooling with natural ventilation: the control strategies and the required ventilation open

Heat recovery in ventilation systems for office buildings in cold climates is necessary for tworeasons:1. To obtain acceptable indoor thermal comfort by preheating of fresh air,2. To reduce ventilation energy lossThis paper describes a pilot system built in the laboratory of the Norwegian Building ResearchInstitute, NBI, based upon the concept of an advanced fan assisted natural ventilation systemwith heat recovery. The concept was developed by NBI.

This paper identifies successful ways of applying natural ventilation to non domestic buildings locatedin urban areas. Whilst noise and contaminant pollution sources are a problem methods of avoiding theseemissions are discussed. A review of literature has established that pollution problems arise for buildingswhich are in close proximity to roads, railways, airports and local industries. Location of ventilation airinlets will affect the quality of indoor air, therefore it is essential that they are located in ways thatminimise the ingress of external pollutants.

Since the beginning of this decade, natural ventilation in office buildings has been receiving specific interest. There are two sorts of application. Natural ventilation can be a strategy for indoor air quality control. It can also be used as night ventilation during warm or hot periods. In this case the objective is to cool down the thermal mass and improve the thermal summer comfort. The EC JOULE NatVent project wanted to identify the barriers to the application of natural ventilation in office-type buildings in moderate and cold climates and to provide solutions.

The paper describes the results of a Pan-European survey carried out on identifying thebarriers that restrict the implementation of natural or simple fan-assisted ventilation systems inthe design of new office-type buildings and in the refurbishment of existing such buildings.

This paper gives an overview of the EC NatVent (TM) project on 'Overcoming Technical Barriers to Low Energy Natural Ventilation in Office Type Buildings in Moderate and Cold Climates' which has been carried out under the European Commission Joule Programme 1994-98. The project was targeted at countries with low winter and moderate summer temperatures where summer overheating from solar and internal gain can be significantly reduced by low-energy design and good natural ventilation.