English

Natural ventilation rates in bedrooms at night have been measured in retrofitted apartments. The measurements indicate clearly that air quality in bedrooms may be unacceptable in dwellings with an energy-efficient minimal ventilation rate. The air supply rates may be as low as 1 l/s/person in themedian case of bedroom size, ventilation rate and two occupants. The carbon dioxide concentration will reach a level of 4000-4500 ppm in the morning depending on the length of sleeping time in a closed room.

The performance of whole-house mechanical ventilation systems was explored in an full-scale indoor test house (volume 176 m³ ) . A range of parameters were monitored: * The pressure distribution * The inflow of outdoor air to each room, the mean age of air in each room and the air-exchange effectiveness * The spread of a 'contaminant' released respectively in the kitchen and in the bedroom. The tests were undertaken both with the internal doors closed and with the internal doors open. Both mechanical extract system and balanced (combined) systems were tested.

Several infiltration models treat the complexity of air flows in multizone buildings, but most of them are written as research tools and are not generally available or user-friendly. Professional engineers and architects are in need of a simplified multizone infiltration model. This paper describes the first step in Lawrence Berkeley Laboratory's development of a multizone infiltration model for calculating the air flow distribution of a building without using any iteration procedure.

Ventilation can be advantageous as opposed to adventitious and, with careful building design, can eliminate the need for air conditioning in summer. This paper discusses the general principles of design for ventilation, inparticular the removal of excess heat, and presents two examples of buildings designed to eliminate air conditioning. One is a deep plan office block, the other an exhibition hall. In both cases ventilation models featured strongly in the design.

A Compact Equipment for Survey of Air Renewal (CESAR) was developed at the Ecole Polytechnique Federale de Lausanne in Switzerland. Controlled by a microcomputer, this apparatus uses tracer gas methods ( decay, continuous flow or constant concentration). Up to ten different locations in inhabited rooms can be monitored simultaneously over extended periods of time, using mainly the "constant concentration" technique. Several air renewal surveys were carried out on different inhabited buildings.

The increasing awareness that indoor air quality aspects may restrict energy conservation by infiltration and ventilation measures has led to extensive investigations of different ventilation strategies. Aiming at a reduction o f energy consumption air infiltration and ventilation rates have t o be minimized. But in order to maintain healthy, safe and comfortable conditions for the inhabitants and to avoid damages to the building fabric the outdoor a i r supply should not remain under minimum ventilation rates.

It is often stated that advanced ventilation or air conditioning is expensive or energy-wasting. There are, however, several examples of highly energy-efficient air conditioning systems in industrial, commercial and public buildings. Energy-efficiency can be achieved by - optimizing air flows or demand-controlled ventilation - avoiding simultaneous heating and cooling (except if "free") - advanced automatic control system - good operation and maintenance The performance of ventilation and air-conditioning depends on several factors in the building process.

A passive ventilation system has been installed in four new houses: it comprises simple ducts which lead up from the kitchen and bathroom to outside near the house ridge and utilise the wind and the temperature difference between inside and outside (the stack effect) as driving forces. During occupation the system provided a consistent background ventilation rate: the flows dropped only when it was warm and calm outside (when other ventilation measures might be taken by the occupier); when it was very cold and windy outside the system did not over extract but appeared to self-throttle.

Describes air sealing of existing homes by sealants, weatherstripping, air-vapour barriers, and other techniques. Discusses principles of air exchange, moisture movement, air sealing, control of indoor air quality, and combustion air. Identifies procedures for assessing air sealing measures in individual houses. Describes materials for air sealing and their applications.

Experimental measurements have been conducted on eight houses in the Ottawa area to study the changes induced in house performance when loose-fill insulation is installed in walls. The report presents details on the induced changes in furnace performance, house airtightness, temperatures, humidity levels and position of the neutral pressure plane. ECAP (Enhanced Conservation Assistance Program) auditing procedures were applied to the houses, and the predicted fuel consumptions showed a considerable disagreement with actual values.