English

Describes method for calculating the adventitious ventilation of a building using information from a pressurization test. The method requires a knowledge of the surface pressures on a building, calculated from wind speed and direction, the inside-outside temperature difference, and the distribution and characteristics of openings in the building shell. Applies formulae to threebuildings and finds a great dependence of infiltration on wind direction. Discusses the effect of wind and stack effect, separately and combined.

An automated air infiltration measurement system for large buildings isdescribed. The system consists of a micro-computer, electron capture gaschromatograph, a ten port sampling manifold, and five tracer gas injectionunits. The system controls the injection and sampling of tracer gas in amulti-zone building, calculates the air infiltration rates of each zone, andmeasures the on-time of events such as HVAC fan operation, exhaust fan operation,and door/window openings.

Discusses standards and guidelines used for calculating the heat demand over a heating season. Notes inadequacy of current methods, in particular the inadequate account taken of certain environmental conditions and of particular window constructions. Proposes improved sizing procedure to take into account heat loss due to infiltrating air. Discusses simplifying assumptions. Gives expressions for critical heat output and for the quantity of air infiltrating a room.

A simple method for generating values of the monthly mean wind speed from Caton's annual wind speed map has been developed. Gives details of method. Results have been checked against observation as far as the limited data tohand will allow. When derived wind speeds are inserted into the average day computer programs developed in the Department of Building Science at Sheffield University the predicted air temperatures agree reasonably closely with observed air temperatures. Concludes method is practicable for applications in building energy studies.

Presents code of practice which supersedes CP3:chapter 1(c):1950. Deals with ventilation of buildings for human occupation. Outlines main reasons for provision of ventilation and gives recommended quantitative air flowrates. Shows that these form the basis for air supply recommendations for different types of buildings, and rooms characterised by usage. Gives basis for choice between natural and mechanical ventilation. Provides guidance on design of natural ventilation systems. chapter headings are: General, General principles of ventilation, natural ventilation, appendices.

By-product gypsum, produced as a waste in the phosphate industry, could be used in bulk as a building material but it has a higher radium content than other building material. Reports an analysis of the dose rate that would result if gypsum were used for a two-storey, three-bedroom, centre terrace house. Discusses the dose from beta radiation, gamma radiation and radon gas,assuming one air change per hour.

Discusses condensation within dwellings. Treats conditions conducive to reducing risk of condensation, factors which control concentration of water vapour in the air in a building and temperature of building fabric. Distinguishes between those under control of occupier and those controlled by design of building fabric. Considers in particular effect of ventilation on dewpoint of the air in bedrooms and humidity and temperature conditions in a bedroom during the day. Provides several case histories which illustrate relationship between ventilation and condensation.

Proposes a method of linking pressurization measurements in buildings with infiltration rates. The method is based on a simple theoretical model. Gives details of whole house pressurization tests and tracer gas measurements of ventilation rate (using N2O) in fifteen houses. Gives details of the theoretical model and compares field measurements with model predictions. Finds good agreement and concludes model may be used to estimate air change rates using leakage data. Finds surface pressure coefficients for typical house shapes and notes a dearth of data of this type.

Describes the development of an anemometer for the measurement of rapidly fluctuating air flows. Describes the B.R.E. shielded hot wire anemometer. Discusses modifications made to this anemometer to improve its response by using different shields and moving sensor wires closer together. Outlines system for processing signals from the anemometer using a micro-computer. Gives results of performance tests. Gives simple applications of theinstrument.

Reports a systematic investigation of the wind pressure variations when test models of varying height are surrounded by uniform roughness arrays of various densities in a boundary layer wind tunnel. Describes the effect of the surrounding roughness in shielding the bluff model when the model height is less than the average roughness height and of the degree of exposure experienced by a model taller than the surrounding roughness. Discusses results and gives 24 graphs of pressure coefficients.