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.
Ambient temperature may influence both the emission and the perception of human odour. This paper studies how human odour is perceived at different temperatures.
A survey is given of the sitution in The Netherlands with regard to ventilation and infiltration. Starting from a point of generally very leaky and hardly insulated buildings now the necessity is felt on the one side to make standards for the airtightness to prevent energy wastes by too high infiltration rates and on the other hand to define minimum ventilation rates to secure safe and hygienic conditions in well insulated and airtight buildings. This minimum ventilation rate is based on contaminants, caused by the occupants themselves, the so-called unavoidable sources.
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.
As airtight houses become more popular across Canada, reduced ventilation rates may lead to poor air quality and high humidity problems in these dwellings. This paper reviews the needs for ventilation, ventilation methods and systems, and current codes and standards, particularly with respect to airtight and energy efficient houses. Current research in Canada is reviewed and considerations for a new ventilation standard are discussed.
This paper discusses the indoor formaldehyde levels in two groups of houses. With the exception of the heating and ventilation systems, the house construction, formaldehyde sources and occupancy were similar for the two groups, One group (A) used electric baseboard convective heaters for space heating and semi-ducted heat recovery ventilators (HRV) for supplying outdoor air and exhausting indoor air , The second group (B) had electric forced-air furnaces with a ducted air supply to every room, Outdoor air was drawn in via a connection to the return air ductwork.
The increasing awareness that indoor air quality aspects may restrict energy conservation by infiltration and ventilation measures has led to extensive investigations of different ventilation strategies. Aiming at a reduction o f energy consumption air infiltration and ventilation rates have t o be minimized. But in order to maintain healthy, safe and comfortable conditions for the inhabitants and to avoid damages to the building fabric the outdoor a i r supply should not remain under minimum ventilation rates.
It is often stated that advanced ventilation or air conditioning is expensive or energy-wasting. There are, however, several examples of highly energy-efficient air conditioning systems in industrial, commercial and public buildings. Energy-efficiency can be achieved by - optimizing air flows or demand-controlled ventilation - avoiding simultaneous heating and cooling (except if "free") - advanced automatic control system - good operation and maintenance The performance of ventilation and air-conditioning depends on several factors in the building process.
Energy conservation in dwellings has been realized mainly by tight windows and by improving heat insulation. Increasing damage to the building fabric by humidity and mould has been noticed. But there is no correlation between this damage and the improved insulation. Rather it is caused by too low ventilation rates. This paper deals with these problems in detail. Ventilation rates in the order of 0.5 to 0.8 per hour are assumed to be sufficient to avoid detrimental effects for the building and the inhabitants.
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