The new proposal for ventilation requirements in the National Building Code of Finland is on public review. The structure of the proposal is different from the existing ventilation code. Minimum requirements for acceptable indoor climate will be given to a wider extent than before, eg new requirements for indoor air temperature and purity are proposed. Also the quality of outdoor air should be taken into account in design of ventilation. Health aspects are also considered, based on today's international knowledge of indoor air quality and human health.
Good indoor air quality and thermal comfort and good energy-efficiency can be achieved simultaneously only if the amount of ventilation can be demand-controlled. Two approaches are discussed in the article: CO2- control and use of so-called air quality sensors. The first experiments have been promising but further development of equipment is still needed, in order to improve the reliability and economy of demand-controlled ventilation.
Ventilation systems perform a number of tasks. They must remove contamination/pollution, they act as heat/cold transporters and they must create a satisfactory room climate without causing draughts. States that users must be aware of the limitations of ventilation systems and that ventilation systems are not able to carry out all tasks completely satisfactorily. Compares the efficiencies of displacement and mixing systems and gives guide values for temperature differences between room air and supply air for office and industrial applications.
There is no patent solution. Discusses duties of ventilation system: to create a satisfactory indoor climate in a cost-effective manner while considering the demands of three intimately associated factors - well-being, health, working efficiency, risk. Notes the various criteria to be complied with to provide satisfactory ventilation: thermal requirements, air quality requirements, noise/safety, flexibility and economy.
Gives a history of the development of air conditioning, and displacement ventilation in particular. Discusses the constant problem of working environments - contamination, and the 'side effects' of economy measures resulting from the 1974 oil crisis. Refers to collaboration between HVAC engineers and the health authorities. Recommends the use of displacement ventilation because of its improvement in air quality. Considers the problems caused by the use of floor coverings and filled carpets in particular.
Discusses two main methods of fan-assisted air supply to a room - mixing ventilation and displacement ventilation. Gives a detailed account of the effects which furniture and the opening of doors have on a room and discussses factors such as vertical temperature variations, air velocity at floor level. Illustrates these effects in diagram form. Notes difficulty in translating older comfort criteria for use in displacement ventilation.
Reports on research project to improve installation techniques using currently available building materials when making penetrations for services in sealing layers. States how careful installation and the use of proper materials and planning can ensure that Swedish Building Standards can be complied with. Notes small cost required to achieve improved sealing and recommends that sealing layers should not be penetrated where this can be avoided. Illustrates various service penetrations.
A large number of multifamily buildings have mechanical exhaust air ventilation. The control of such systems' function is often inadequate and adjustment is rarely carried out. One reason for this is the lack of simple methods for determining system performance and air change rates. The report describes a simple method and simple equipment for determining performance in terms of an installation's capacity curve or 'fan installation' curve. Defines terminology and measurement principle. Illustrates equipment and arrangement for measurements.
An important function of the Air Infiltration Centre, Bracknell, Berkshire, Great Britain, is to keep research organizations informed of on-going research into air infiltration if buildings. To fulfil this need, the Centre regularly undertakes aworldwide survey of current research. In this report, theresults of the Centre's most recent survey, completed in 1983, are used to provide a background to present European airtightness and air infiltration measurement practices. A wide range of research activities are summarized involving the use of both pressurization and tracer gas techniques.
Measurements on the rate of air exchange in residential buildings have been carried out by the Swedish Institute for Building Research since 1970. The results of an analysis of these measurements are presented in this paper for about 500 buildings not having mechanical ventilation. The studied buildings include one- and two-storey, detached, single- family houses, row houses, and multifamily residential buildings built between 1900 and 1982 and of various design. In some cases, the buildings have been retrofitted by improving the insulation of the attic or the exterior walls.