Notes field evidence of increased condensation in houses with reduced ventilation and increased thermal insulation installed to conserve energy. Treats the possible long term effects. Gives advice on taking into account the whole package of heating and ventilation of the property when energy conservation measures are being contemplated.

Notes increasing concern with the quality of indoor air, allied with the desire to conserve energy by minimising ventilation rates. Examines on the basis of a literature search the sources of indoor air pollution and the characteristics of the pollutants. Pays particular attention to tobacco smoke and its deleterious effects on health. Discusses minimum ventilation rates for rooms in which people smoke. Points out that ventilation alone cannot ensure that the strictest criteria for room air quality are met with smoking.

Discusses the requirements of air supply installations in high-occupancy spaces. Describes the characteristics of different systems of air diffusion, illustrates them and their operation in diagrams and photographs and demonstrates the nature of the room air flows created by them. Lists and discusses the advantages and drawbacks of air introduction from chairs and desks, from pivoting nozzles in walls of galleries and from ceiling or floor diffusers.

Uses a model to estimate the incremental risk of lung cancer associated with increased radon concentrations in indoor air resulting from decreased air infiltration caused by increased air tightness of dwellings. Gives results for selected changes in the air exchange rate. Discusses findings.

The share of ventilation in the energy demand in Finnish building stock is about 50 per cent. An essential part of the ventilation heat losses is uncontrolled due to air infiltration, which only partly serves the demand of ventilation. The aim of improving the airtightness of windows and other leakpoints is to prevent the infiltration. But then, if the supply air intake is not mechanical, certain risks of insufficient ventilation occur. In thereport, the interconnection between the building envelope and ventilation system is studied.

A multi-cell calculation model was developed for calculation of the interconnections between airtightness, air change rates, pressure conditions and energy consumption. The flow equation used in the model is quadratic, which can be used as well for a single leakage path as for a whole building envelope. For energy calculation the area of wind directions is divided into12 sectors (each 30 degrees) plus one sector for calm wind conditions. The mean values of wind speed and outside temperature applied to each wind sector are calculated from weather data of several years period.

In these instructions for measuring the airtightness and air change rates in buildings, the principles of measurement methodics, the need for measurements and choosing the correct method for different purposes, are presented. Details of measuring are described for the most common methods: the pressure test, the collector chamber method for measuring local leakages, and the tracer gas methods. In addition, other methods and auxiliary measurements are presented.

Factors responsible for the heat needs of particular objects and principles of their correct determination for ensuring an appropriate microclimate of rooms are presented in the paper.

Commercial buildings require mechanical ventilating systems, the specifications for which are included in the building codes. These codes specify the amount of outdoor air to be supplied per person for designed occupancy conditions. Many buildings such as retail establishments operate much of the time at occupancy loads well below the design. Thus, they are generally over ventilated and waste energy when operated according to the codes. A control system based on measurement of the carbon dioxide generated by the occupants was tested in a small bank in Pasco, Washington.

Summary of an APCA International Speciality Conference. Contains information on some relatively unfamiliar trace gases and fungi, as well as on the better known indoor air pollutants. Studies range from those on human health tothose concentrating on pollutant emissions to those addressing building ventilation. Papers also cover sick building syndrome and pollutant and ventilation surveys.