There are two types of air movement in the shell of a building - movement along the insulation as in cavity walls and movement through the insulation. Generally the heat losses due to the faults in the inner lining of the vapour barrier and the consequential air movement through the shell are much bigger then losses due to faults in the insulation - they cannot be compensated for by using tighter wind protection.
Describes the results obtained and the problems encountered in the sealing and testing of 15 homes in Ottawa Ontario, for the Ontarion Ministry of Municipal Affairs and Housing. Gives a data summary for the 15 homes, outlining house characteristics, reductions in air leakage, materials and time needed. Finds that the average air leakage reduction is 38.7%, and the average time taken to perform the sealing and testing is 31 hrs. Covers:
Uses a similitude approach to develop predictive graphs for the ventilation rate due to the stack or chimney effect. Uses a half scale model of an open side wall structure with a continuous and restricted open ridge, and finds that:< 1. Ventilation rate is approximately proportional to ridge outlet width< 2. Outlet Reynolds number response ie ventilation rate to changes in Grashof number is a function of the ratio between building height and ridge width.
Looks at the requirements for computer model validation, especially in regard to predicting energy usage in buildings. Discusses the IEA project for comparing and validating several computer programs in this context. Describes the Glasgow commercial building monitoring project, which includes detailed measurement of temperature and air flow rates to provide data for model validation. States what type of data is needed for validation.
Lists three factors causing a high radon and radon daughter concentration in Swedish dwellings:< 1. By energy-saving measures the ventilation rate has become low.< 2. 10% of existing houses are built of light-weight concrete with a high proportion of radium.< 3. Large regions have high radium content in the ground.< Describes a method for detecting high radon daughter levels by measuring gamma radiation from the outside.
Shows that recent investigation has revealed harmful pollutants in greater concentrations in energy-conserving buildings then in the surrounding outdoor air. Some of the pollutants found include particulate matter, carbon monoxide, formaldehyde, nitrogen dioxide and radioactive radon. In the use of some construction materials, measures intended to reduce energy consumption may contribute to the buildup of indoor air pollution. Reviews characteristics of indoor pollutants and major methods of control.
Analyses an infiltration heat loss calculation in accordance with Standard CSN 06 0210, with regard to the minimum air exchange rate (0.3 ach/hr). Concludes that aeration through windows should be graded for buildings which are differently located in the landscape and thus differently exposed to the wind effect.
Describes sources of radon in buildings. Summarizes data on observed indoor radon concentrations in houses in New York, Salzburg Austria, and Florida. LBL studies in energy efficient buildings in Maryland, Minnesota, and New Mexico show that tight houses have higher radon concentrations then conventional houses. The data reported is based on "grab samples" taken on mild days (low wind and small indoor and outdoor temperature differences) with all doors and windows closed, resulting in a "worst case" estimate.
Describes the extent of the problem of condensation in roof spaces of well-insulated dwellings, discusses the mechanisms resulting in condensation, and evaluates possible solutions. Factors considered in condensation occurrence include air movement to the roof space, and roof space ventilation rates. Control measures discussed include direct extract ventilation to the kitchen and bathroom to control water vapour, and the provision of adequate roof ventilation according to British Standard BS 5250.
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