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Displacement flow has been found to be the best flow principle for ventilation, with ventilating air being supplied to the occupied zone. The design procedure should, amongst other things, contain an analysis of contaminant source in order to design the ventilating system to create the most favourable flow pattern for the contaminants. This paper deals with design principles and problems related to displacement ventilating systems.

A short description of a second generation low-energy house built at Hjortekaer in 1984, with a calculated annual heat demand of 3500 kWh (excluding domestic hot water), is given. The house is superinsulated and very airtight. The roof and walls are insulated with 400 and 300 mm of high quality mineral wool respectively, with infinitesimal thermal bridges, and the floor is a slab-on-grade construction insulated with 200 mm polystyrene. Most of the windows are south facing and fitted with a new type of lightweight external insulating shutter.

Examines the design of two houses, built in 1982, which integrate an exhaust air heat pump and a warm air heating system into a very well insulated structure. Monitored during 1983-84, they consumed 50% less energy than a typical Swedish house. Apart from occasional (avoidable) high temperatures, the warm air heating system led to a comfortable indoor climate. The performance of the houses could be improved by installing energy conservation appliances. The house of the future should be tight, well-insulated and mechanically ventilated.

The air exchange rate and total heat loss were measured in 11 detached dwellings to find the relationship between measured and calculated transmission heat loss factors based on standard Norwegian calculation methods. For 9 houses the measurements were done under stable climatic conditions. Air change rate varied between 0.2 and 0.7 ach with an average value of 0.45 ach. These measurements, together with several others, confirm that the Norwegian Standard (NS3031) for calculation of the transmission heat losses is reasonably correct.

Much research work has been carried out on modelling ventilation air currents. The authors propose that the currents be divided into specific zones, the air parameters of each zone being determined by different conditions. The formula is then derived by the addition of an infinite number of elementary currents flowing from a multitude of point sources. From this, a general formula is proposed to calculate the velocity, temperature and admixture concentration along the whole flow of the current.

Body odour emitted by 16 occupants at three activity levels (1, 4 and 6 met) was evaluated by 30 male and female judges. The judges assessed, when entering the occupied room, the intensity and acceptability of the body odour. CO2 concentration and air change rate were measured. For the same CO2 concentration, the body odour intensity was of the same magnitude whether the occupants were sedentary or engaged in physical activity up to 6 met. But odour caused by physical activity was less acceptable than odour from sedentary occupants.

Reviews the possible indicators for monitoring the indoor air quality and controlling the outdoor air intake. The technical feasibility of the system is also discussed. At present CO2 seems to be the best and most reliable indicator for indoor air quality when occupancy load varies. In future, however, it is likely that measuring devices based on semiconductor technology and measuring devices for particles will be more reliable and inexpensive and so very suitable for controlling the air quality, because they can take into account both occupancy load and tobacco smoke.

The influence of air infiltration and window opening on the indoor air quality in Austrian residential buildings was investigated. During the heating season, air infiltration plays a major role in securing hygienic conditions of indoor air and acts as basic ventilation. Air tight windows in new or renovated buildings do not provide this basic ventilation and can give rise to poor indoor air quality unless acceptable fittings for permanent ventilation are provided. Window opening can not replace the effect of permanent ventilation but plays a role as comfort ventilation.

Identifies sources of gaseous, vaporous, particulate (inert and viable) and radioactive contaminants within nine functional categories of a hospital. Preliminary criteria for control purposes are recommended, and available methods of control are reviewed. It is concluded that control of gases, vapours and radionuclides may be as important to occupant well-being as control of viable particulates, and that air distribution patterns within and between rooms are as important to dilution and removal control as the quantity of air supplied to the rooms.

The participating countries of Annex IX "Minimum Ventilation Rates" study emission rates and time dependence for building materials and their dependence on various factors including human behaviour; indoor transfer and interactions; control and air treatment; modelling indoor pollution including economic and social factors; strategies for indoor air pollution control under the restraints of energy conservation. The results of this international programme will be pooled to produce recommendations for guidelines.