Discusses the tracer dilution method for measuring air change rates. The technique entails introducing small amounts of tracer gas into a building and measuring the rate of change in tracer concentration. Describes the method and compares different tracer gases. Outline ways of obtaining an estimate of the air infiltration from experimental data. An appendix discusses the errors in the procedure.

Four two-storey four-bedroom test houses were built in 1974 near Columbus, Ohio and have been instrumented and monitored by Ohio State University. All four houses are unoccupied. Air infiltration rates were measured in all four houses using sulphur hexafluoride as a tracer gas and two of the houses were pressure tested for air leakage. Discusses results and the correlation between infiltration, inside-outside temperature difference and wind velocity. Compares tracer gas results with pressurization tests.

Reviews the state of the art in the measurement of ventilation and air infiltration. Considers tracer gas techniques and discusses some of the tracer gases used as well as some of the potential sources of error. Also discusses fan pressurization-evacuation procedures for measuring building tightness and compares fan and tracer measurements. Discusses the ASHRAE crack method.

Discusses flow of air between two rooms through an open door. Considers 6 cases with and without mechanical ventilation and with a temperature difference between the two rooms. Gives examples of the calculation of air flow. Recommends that for hospitals where the transfer of bacteria should be avoided, doors should be kept shut as much as possible and that it is not economically justifiable to choose such a high ventilation rate that no undesirable back flow occurs with the doors open.

An earlier paper gave the flow to be expected through an open door from theoretical considerations. Describes model tests designed to check these theoretical predictions. The model used was 6.3% of full size and water was used instead of air for the flow medium. Concludes there is reasonably good agreement between model and theory.

Gives a brief guide to the computer program ZSTEP, which is a program for simultaneous calculation of the thermal performance of up to ten zones in a building. Outlines the structure and operation of the program and describes the type of input needed and the output produced. Discusses applications of the program and planned developments. An appendix gives data preparation sheets.

Reports a study carried out to assess whether homeowners occupying more highly insulated houses have actually realised fuel savings over those realised by comparable homeowners in less heavily insulated houses. Describes method of the survey which included air leakage tests.

It has been shown by Bankvall that forced convection reduces the efficiency of thermal insulation considerably. The reductions can become drastic if the inner skin is not airtight. The leakage around a switch or junction box issufficient. The material in the windproofing skin must be sufficiently impermeable. If complicated joints are to be avoided it must retain its dimensions in varying humidity. If the inner skin is not tight caulking or taping the joints in a plasterboard skin halves the leakage.

Reports measurements of air leakage rates in the four energy-conservation research houses using the fan pressurization method. One of the houses is standard for the area and the other three houses have added insulation and vapour barriers. One house has a heat pump and one an air-to-air solar heating system. Air infiltration rates were measured in two of the houses using CO2 as a tracer gas. Discusses results and compares tracer gas with pressurization tests.

A market review of inlet/exhaust ventilation with heat recovery in single family houses. Traces recent developments in new house production. Tabulates review on several criteria including manufacturer, type, flow rate, frost protection, position of heat exchanger, type approval. Review covers over 40,000 units installed.