Mathematical models for predicting indoor pollutant levels are being developed and compared with measured concentration in three residential dwellings - a relatively new townhouse constructed according to rigid energy-conservation guidelines,
Since 1970 measurements of air change rate have been carried out in about one thousand buildings by the Swedish Institute for Building Research (SIB). In this paper we present results from these measurements. The studied buildings are of various design and have ventilation systems of different types, natural as well as mechanical. The buildings include single family houses, row houses, and multi family residential buildings, erected between 1900 and 1982. The measurements have then been carried out using tracer gas (decay) techniques to determine the rate of air exchange.
In 1981 Norwegian building regulations introduced quantitative requirements to air leakages in different types of buildings. The requirements were formed as maximum allowed air changes per hour at 50 Pa pressure difference according to the pressurization method. To evaluate the consequences of these new requirementsimposed to Norwegian building industry a model proposed by the Nordic Committee for Building Regulations (NKB) was used. The average air leakages of residential buildings , built before the new requirements,are known through a research project performed i n 1979.
This paper deals with the concept of energy efficient houses as integrated systems. Quantitative analysis is used to show that evenly distributed insulation is more effective than excessive insulation applied to only one element of a house and that ventilation rates are a critical factor in determining the magnitude of energy loss. For a new approach to be adopted on a large scale, it is suggested that a means to implement Planned Change is required. Various models to bring about this change are discussed with an indication of the final recipe used for a demonstration project.
Describes airing habits based on observation of windows of 50000 rooms in terraced housing and blocks of flats. Compares the results with observations in other countries. Derives an expression giving the fraction of indoor-outdoor temperature difference. Calculates from this information the average energy losses in Sweden due to airing.
Explores the various roles that mathematical models can play in the design of energy efficient ventilation systems. Uses an example (an existing terraced house) to illustrate how models may be used to investigate the energy implications and air distribution patterns of a range of mechanical andnatural ventilation options. Identifies key parameters needed for accurate results, and compares predicted infiltration rates with actual measurements taken in the house. Concludes that models of proven validity are an invaluable aid in ventilation design studies.
Two series of pressurisation and ventilation measurements have been made in a low-energy house. One of the objectives of the work was to assess the extent to which the ventilation pattern of the house could be improved by modifying its leakage distribution. The first series of measurements was interpreted to understand the ventilation pattern and to make recommendations for the modifications. The second series was used to find out the effects of the modifications.
Outlines a method for measuring the air leakage through the surface exteriors of an apartment, by adjusting the pressure of the adjoining apartments to that of the test apartment, so that no air leakage occurs through adjoining walls.
Describes the use of SF6 tracer gas measurement techniques employed in airtightness and ventilation research at Princeton in terraced housing. Notes use of measurement results for constructing models describing the total adventitious ventilation in a house. Refers also to similar techniques used in research at Berkeley in single family dwellings.
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