Describes the technique employed, including the mathematical model as well as results from a validation test using an experimental chamber. The model assumes an exponential decay of the tracer gas concentration. The precision of the analytical procedure is estimated at better than 9%, while the error of the measured ventilation rate of the test chamber was 5%.

Studies the daily behaviour with respect to heating, use of windows and ventilation in newly built identical houses in Oosterhout, Netherlands. The houses have external walls of brick with cavity insulation, double-glazed windows and natural ventilation, with a gas burner furnace in the loft for heating and hot water. 57 occupants were interviewed and 41 filled in hourly log-books during 14 days recording people at home, thermostat setting, periods of open windows and trickle ventilators in the different rooms, use of radiator valves and position of doors inside the house.

Reports a case study dealing with the relation between ventilating and airing behaviour and the outside climate. Also the significance of other variables such as preferences with respect to the indoor climate are considered. Wind speed is found to correlate, but outside temperature (varying from -3 to +9 degrees C) does not correlate with the length of time the windows in the bedrooms and bathrooms are opened. Rainfall and sunshine also seem to have some influence. The main reasons for airing are that the bedrooms are too warm and not fresh.

Negative pressure inside a building may create adverse or dangerous conditions. Discusses when make-up air is necessary, how need is determined, and how much make-up, with examples.

Ventilation requirements for the reduction of humidity. Required air change rates for hygiene and moisture removal for various rooms are given. Air flow rates are calculated for natural ventilation with closed windows, hopper windows and controlled ventilation. Ventilation by window opening is discussed. Gives examples of the transfer of moisture within a building, and the main reasons for ventilation, with particular emphasis on moisture removal. Lists danger of condensation on various building elements, causes and remedies. Advises on ventilation measures.

Discusses how air flow in a building is affected by the position of the ventilation openings in the outside wall. Treats factors determining selection of controlled ventilation system and provides examples of systems available: small air vents, mechanical ventilation with acoustic and thermal insulation, ventilation with heat recovery, etc. Discusses an optimal solution with air quality control.

It is necessary to design the ventilation system to avoid excess humidity in the apartments. Discusses the sources of moisture release in rooms, properties of air temperatures in relation to moisture absorption, condensation in bedrooms in particular, and moisture damage to building fabric. Advises on ventilation measures to control humidity.

Ventilation efficiency was measured with freon gas in 3 large industrial buildings under normal working conditions. Size of building varied from 3000 to 10000 m2 and room height from 5-19 m. The ventilation systems were of 3 types: 1. Overhead fresh air supply network with conventional air inlets, 2. Fresh air supply direct to occupied zones by a low impulse system, and 3. Overhead fresh air supply distributed by the Dirivent system. Describes techniques of tracer gas measurements. Illustrates some results in graphs.

Reviews current knowledge about the sources of a number of indoor pollutants and their concentrations: tobacco smoke, NO2, CO, radon, formaldehyde, SO2, CO2, O3, asbestos, mineral fibres, organics and allergens. Lists the adverse health effects from exposure to each of the pollutants. Finds instrumentation for measuring exposure acceptable, but monitoring and knowledge of distribution of sources and concentrations inadequate or marginal. Knowledge of exposure-effects relationship is inadequate, especially with regard to delayed effects of chronic exposures.

A general multi-chamber model is presented and explored from the viewpoint of air quality studies. The model involves the following key concepts: purging flow rate and age distribution of both air and contaminants. From the physical and mathematical properties of the model, are deduced estimates of themagnitude of, and the relations between, the key concepts. The practical use of the model is illustrated.