Suggests use of an electron capture detector for the routine estimation of the SF6 content of a mixture of gases without preliminary chromatographic separation. Gives chromatogram illustrating method.

Increasing use is made of open front or cold confinement buildings for fattening beef cattle. Reports model study of an open front beef confinement building a) to evaluate the effects of ridge vent design on airflow characteristics and temperature and b) to determine prediction equations forthe relationship between wind velocity and outlet velocity. Reviews literature on the subject. Compares results with previous studies. Discusses relationships between outlet velocity, wind speed and temperature difference. Recommends open and baffled ridge vents.

Presents examples of the use of a generalized model of air infiltration, developed earlier, to estimate the air infiltration characteristics of two test homes using data for the structures, weather and furnace installation. One of these is a single-storey home with basement of wood- frame construction, equipped with an oil-fired central heating furnace.

Discusses the two methods for calculating air infiltration given in the ASHRAE handbook. These are the air change method, a gross estimate based on the number of windows and doors in each room, and the crack method based on measurements of flow through the cracks around windows and doors. Presents comparisons of tracer gas measurements with calculations by both air change and crack methods for test houses in California and Minnesota. Find agreement is adequate for sizing equipment but that the crack method underestimates infiltration at low wind velocity.

Describes computer program used for calculating heating and cooling loads on buildings. Discusses current state of heating and cooling load techniques and various unique features of NBSLD. Gives summary of various subroutines of NBSLD including an algorithm for calculating air infiltration Gives complete Fortran listing of NBSLD and data preparation forms.

Reports tests of the air leakage of 24 houses made using a fan to depressurize each house. Gives a table of results including indoor humidity, air-particulate levels, energy consumption and comfort conditions for each house. Comparison of test results with calculated values for air leakage suggests than doors and windows account for only a fraction of the total. Finds some correlation between indoor humidity, air-particulate levels and leakage.

Reports laboratory tests of sound transmission loss, thermal transmittance and rate of air leakage conducted on full-scale specimens of typical residential exterior wall constructions, either unbroken or penetrated by a door or window. A total of 109 acoustical tests and 48 thermal tests are reported. The resultant data are compared with literature data on similar constructions. Some correlation was found between sound transmission loss and air leakage.

Describes exterior walls of metal studs and gypsum board, used as infill walls in frame construction of industrial, commercial and high-rise residential buildings. Discusses problems of high thermal conductivity of such walls, and the application of a vapour barrier to reduce air leakage.

Describes a system which automatically operates a small gas chromatograph and measures parts per billion concentrations of sulphur hexafluoride in air. It samples air on a 10-minute cycle and records the response on a strip chart recorder. When SF6 in distributed in the air of a building, data is obtained from which air infiltration rates may be determined.

Presents further measurements of wind pressures on models of the experimental Aylesbury house of the Building Research Establishment (U.K.). following a previous paper in which mean pressure coefficients only were compared, this stud compares fluctuating pressures as well. In these tests, the upwind hedges of the full scale site were modelled, but found to cause little difference to the velocity profiles and to the measured pressures.