The air change rate and the volume of heated air of the villa were measured by the constant concentration tracer gas method during a period of 11 days. The total volume of the villa is 1000 m3 and the heated volume 530 m3. It is built on six half-levels. The occupants continued their normal lifestyle during themeasurements. The Compact Equipment for Survey of Air Renewal (CESAR) was used with nitrous oxide as tracer gas at a concentration of 100 ppm. The mean global air change rate was 0.50/h.

The total air infiltration rates can be determined by the tracer gas decay method, but to measure the influence of inhabitants or convective exchanges between rooms, the constant concentration method is more suitable. In order tomeasure these effects, the Compact Equipment for Survey of Air Renewal (CESAR), developed at the LESO, was used to perform an air exchange analysis on data recorded at regular intervals in up to 10 locations simultaneously. Three tracer gas methods were implemented: decay, constant concentration and continuous flow.

Airtightness measurements were carried out in ten typical Dutch dwelling complexes. In each complex four homes were measured. The IMG calculation model was used to calculate expected ventilation for these dwellings. Results of a survey of 1500 occupants on use of ventilation are given. The ventilating behaviour in 610 homes was studied in greater detail. 210 of these had some form of mechanical ventilation. Ventilation requirements are given for individual rooms.

A Compact Equipment for Air Renewal Survey (CESAR) has been developed by the Ecole Polytechnique Federale de Lausanne. The device has been designed for simultaneous analysis of up to 10 different inhabited rooms over extended periods of time (days or weeks). The constant concentration tracer gastechnique was used for the first survey done in the South rooms of the LESO building. Mean outdoor to room flow rates of between 1 and 40 m3/h were found.The mean building to room air flow was found to be 5 m3/h for rooms with only one communicating door with the rest of the building.

Notes that the trend to airtight window constructions has upset the balance in buildings between moisture generation and its removal. Treats the factors which combine to determine whether a building will have moisture problems. Presents a procedure for the straightforward determination of the specific minimum air flow required in a particular building to prevent condensation on the inner surface of corners formed by two dimensional external walls. Determines the base air flow and the supplementary air flow for four models of representative apartments.

The bacterial content of the air and physical environment of two crated veal calf units were monitored over the growing period of 16 weeks. The rate of release of bacteria colony forming particles (BCFP) from the calves was rapid.

Discusses the established principles and rules of air hygiene for animal housing and areas in which guidelines have yet to be devised. The most common pollutants are ammonia, hydrogen sulphide, methane and carbon dioxide. Dust and aerial microbial flora also have to be considered. Ventilation criteria for pigs and poultry and for cattle, sheep and horses are discussed. The current threshold limiting values for noxious gases and inert dust which could be used in the design and operation of livestock buildings are based on studies of humans rather than farm animals.

The objectives of a ventilation system are to provide an aerial environment in which 1, animals' health and productivity can be maintained, 2, the stockman's comfort and health needs are satisfied, and 3, the building and equipment are protected from damage. Criteria for evaluating ventilation include: thecontrol of air temperature and air speed at animal height, the control of relative humidity and prevention of condensation, and the maintenance of tolerable concentrations of gases, dust, and airborne microorganisms.

Measured energy consumption figures are presented for a townhouse complex located in Regina, Saskatchewan. The complex consists of 8 two-storey wood frame structures incorporating low energy design principles and some passive solar features.