English

Compares the air change rates measured with SF6 and CO2 using the tracer gas decay technique and the fan extraction method over a wide variety of test chamber sizes and mixing systems. Shows that the conventional air handling orportable floor fans can provide adequate mixing for SF6 tracer gas decay measurements of infiltration. Warns that the mixing operation may become the dominant driving force of infiltration during calm climatic conditions. Finds that +-0.08 ach/h is a reasonable measure of experimental error at the 95%confidence level using SF6 as the tracer gas.

Briefly reviews sources and types of air contaminants common in tight houses. Covers four indoor pollutants - carbon-monoxide and nitrogen dioxide from gas stoves, particleboard plywood and urea-formaldehyde from insulation, and radon from various building materials.Suggests ways of lowering pollutant levels without compromising energy conservation considerations.

Proposes a simple equation derived using a more complex theoretical model for use in the prediction of the infiltration performances of houses over a range of meteorological conditions. Initial comparisons have been made with the results from field measurements in a range of typical modern UK house types.

Briefly reviews the study of wind flow around buildings. Shows that fundamental theoretical and experimental studies are beginning to produce simple descriptive and mathematical models of flows round buildings. These should enable designers to predict the general features of wind around a proposed building or group of buildings at an early stage in the design. Gives some examples of these models.

The results of a prediction method for calculating ventilation rates in a detached house are compared with experimental measurements described in aprevious paper. The method is capable of giving good agreement for a wide range of ventilation conditions. The need is demonstrated for further work in two important areas - the spatial distribution of background areas and the effect of turbulence.

Derives analytical expressions for the exchange of air across doorways or similar apertures, in terms of the temperature difference between the spaces on both sides of the opening and the net volume of air flowing through this as a result of unbalanced air supply or extract.

Describes work sponsored by the Electric Power Research Institute (EPRI) to investigate indoor air quality in 10 single-family houses and 2 office buildings in Boston. The point was to compare indoor and outdoor pollutant levels, and find reasons for the differences. Found particulate levels were higher indoors, and houses with gas facilities showed higher concentrations of carbon monoxide and nitrogen oxides.

A combination of a wind-tunnel investigation and a mathematical simulation technique conducted on models of two-storey parking garage situated beneath alarge block of buildings (consisting of houses, shopping centre and offices) shows that wind penetrating the partly open garage facades can provide sufficient ventilation. Studies the effects on ventilation of varying the open area of the facades and of fitting openings in the garage roofs. Measures the effect of such ventilation means on air quality close to buildings.

Numerically predicts air quality and thermal comfort in 2-dimensional ventilated air spaces of several geometries when conditions on the various room surfaces are taken to be either adiabatic or constant temperature. 

Reviews methods of energy conservation in factories. States that excessive infiltration is unlikely to be the cause of high energy consumption, but that the most significant loads imposed by infiltration probably occur through open loading bays. Suggests the installment of double door lobbies to overcome this. Says the ideal factory heating system would include mechanical ventilation, with outside air mixed with warm "roof level" air. Describes potential sources of energy wastage and ways of rectifying this situation.