Reports measurements on air transport through homes made by a committee working a Dutch Standard on Heating Load Calculation similar to DIN 4701, but taking account of air infiltration losses through joints and cracks between glazing, window-frame and facade construction. Describes the measuring method applied. Tables air leakage coefficients c and flow exponents, n ,of a number of flats and single family houses. Also tables c and n values of cracks according to type of construction and material, use of weather strips and measuring institute.

Describes methods of measuring the three-dimensional flow field using a three-sensor hot-wire probe, with emphasis on the techniques developed by the author's group at the Pennsylvania State University. The hot-wire equations, data processing procedure, calibration techniques, and a discussion of various errors in the measurement are included. Some typical data acquired by thisprobe is also included.

In a modern residence with reduced air infiltration, a problem may arise if the fresh air requirement is left to natural leakage. The article discusses this problem, and describes techniques for measuring air leakage and typical results. The contaminants which define the need for ventilation are described and the case for controlled ventilation systems (and possibly heat recovery devices) is made. Areas for further research are recommended.

Discusses the use of a regenerative, air-to-air, rotary heat exchanger as part of a controlled ventilation system in a modern tightly built house. Describes analytical studies and the construction of a prototype. A four-month trial ina test-house indicated that the unit would be capable of recovering 5000 Kw/hof waste energy if operations were extended over the full heating system.

Discusses the provision of German Standard DIN 18017 regarding requirements for the ventilation of inner rooms such as bathrooms and kitchens. 

Characteristics of the ventilation in poultry buildings have been studied at the Hungarian Institute for Building Science. The pressure loss of the cross-building ventilation flow is determined for a section of a typical building and for two typical air inlet-outlet layouts. On the basis of velocity measurements the local hourly air change rates were determined in the cages and compared to the general air change rate in the building.

TNO Research Institute for Environmental Hygiene have developed a mathematical model (based on an electrical analogue model) for deciding on the best ventilation system (natural v. mechanical) for a building while it is still atthe design stage. This model has been applied to an auction complex situated at Bleiwijk to deduce the best ventilation system for the building. Conclusions are that a natural ventilation system can be realized by placing ventilating devices exclusively in the roof.

In dwellings and similar spaces with limited volume, dilution of indoor air contaminants may be insufficient. The concentration of contaminants in the inside air depends partly on the rate of emission into the room, partly on the ventilation and the concentration of impurities in the outside air. Sulphur dioxide, hydrocarbons, ozone and lead compounds occur in higher concentrations in the outside air, whereas nitrogen oxides, carbon monoxide, benzpyrene (from tobacco smoke), formaldehyde and dust have higher concentrations indoors.

Investigations in Denmark show that there are as many as 75 different compounds in indoor air in tight houses including toluene, xylene, and radon. The dust in homes contains a large number of allergically active ingredients, the most important being the dust mite, which occurs in bed clothes.< States that good air quality is therefore difficult to maintain with natural ventilation in new tight houses. If the hygienic demands of this decade increase the need for ventilation, mechanical ventilation seems to stand a good chance.

Shows that the leakage test in most buildings with mechanical ventilation may be performed with the ventilation system itself with only a slight reduction in the accuracy of the measurements. Using fans in the ventilation system, the pressure difference inside/outside may often reach a measurable value of 5-10 pa. If such a pressure difference is not obtained, the leakage exceeds allowable values and the building should be tightened. Before measuring, all of the supply air openings in outer core of the building should be closed and taped. All doors inside the apartment should be open.