Briefly outlines the approach used and the results obtained by computer modelling in estimating the magnitude of natural ventilation in irish housing. Concludes that in general air-change-rates in irish housing are excessive.
Give method for collecting and analysing sulphur hexafluoride used as a tracer gas. The gas is separated by gas chromatography from other components of moist air on columns of silica gel and activated carbon in series and is detected by electron-capture analysis in concentrations near 1 p.p.b. states that sensitivity can be enhanced at least 2000-fold by freeze-out concentration. States that SF6 backgrounds in air are undetectable except near leakage sources such as transformers.
Shows by comparison with simplified methods for dimensioning structural beams that the degree of tightness of a shell is not the arithmetic sum of the leakage of components. States that leakage occurs where there is a pressure difference caused by wind, temperature difference and fans. The amount of leakage depends on whether the air flow is laminar or turbulent. Gives equations for the calculation of leakage in buildings without ventilation, with natural ventilation, with mechanical evacuation and with both mechanical inlet and evacuation.
States that considerable research has been carried out in Sweden in an attempt to conserve energy. Results of measurements of air infiltration obtained with tracer gas do not correspond well with those obtained by a pressure method. Air leakage in frame houses has been higher than expected. States need for air-tight components and reviews the consequences of tighter houses.
Describes the two major methods of measuring air leakage in buildings; the tracer gas method and the pressure method. The three ways of using tracer gas are with decreasing gas concentration, constant gas concentration, and with constant gasrelease. In Sweden nitrous oxide is normally used. The results of the tracer gas method may depend on the weather at the time of measurement. The pressure method is fast and accurate, but only gives the total leakage through the building. Local differences can be detected by use of infrared photography.
States that the need for fresh air to dilute cigarette smoke is the dominant criterion for ventilation design. Reviews the literature of the subject and concludes that the three main health factors are carbon monoxide, acrolein and particulate matter. Finds very wide differences in sensitivity between people. compares IHVE guide of 1970 with the british standard draft code of practice CP3 concludes that cigarette smoke shouldbe treated as a contaminant and not linked with body odour dilution.
Reports measurements in seven groups of town house in Gavle, Sweden of concentrations of radon and daughter products. Gives results with the type of building materials, the ventilation systems and air-change rates measured using nitrous oxide as a tracer gas. Gives formula for the permitted limits of radionucleides in building materials. Discussed results and concludes that the concentration of radon does not differ significantly from single family to multi-family houses.
Presents some results not previously published of the full-scale loading project carried out at the post office tower, London. Autocorrelations and pressure spectra were determined for all the pressure transducers, and the variations of these around thestructure as well as vertically are discussed.
Proposes general method to identify contribution of resident-dependent effects to observed variability of energy consumption in similar houses. Method assumes that in addition to records of energy consumption over time, there is access to information about date of change of occupants. For data on TwinRivers, New Jersey, shows that the role of resident-dependent effects dominates the role of effects that depend on structural variations over which residents have no effective control.
Discusses fresh air requirements and tolerable levels of contamination from various sources within a space. Explains the calculation of dilution rates. States that in summer the rates required will generally be higher than those derived from theinformation given because of the need to reduce temperatures in non-air-conditioned buildings and gives method for calculation of ventilation rate required.
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