house

Three different investigations of radon in Swedish dwellings are presented - a nationwide study conducted primarily to determine the collective dose to the Swedish population from exposure to radon and radon daughter, a supplementary study of newly built detached houses in order to find out whether theregulations in the Building Code prescribes acceptable radon levels in new houses built on normal ground, and measurements made by the local authorities in order to find houses with levels of radon daughters above the norm.

To develop effective monitoring and control programs for indoor radon it is important to understand the causes of the broad range of concentrations that have been observed. Measurements of indoor radon concentration and air-exchange rate in dwellings in several countries indicate that this variability arises largely from differences among structures in the rate of radon entry.

Treats a research study by the Danish Building Research Institute to develop a comprehensive set of design details for the use of bricks in a highly insulated cavity wall and building methods that could easily be followed by contractors. Illustrates photographically and describes the detached house which resulted from the project. Illustrates structural details diagrammatically. The energy consumption of the house is less than a quarter of older houses of similar size. Explains the design details to avoid thermalbridges and the application of modular coordination.

Compares in tables international requirements for housing regarding ventilation requirements of the entire dwelling, plus kitchen, bathrooms and W.C.s, living rooms and bedrooms. Discusses them. Examines the efficiency of ventilation openings and the requirements made on them. Discusses air flow through a house and the effect of wind forces. Notes how effective pressure difference is affected by the distribution of joints and air leaks.

The problem of indoor air pollution has many facets, ranging from excess humidity, mould and insects over emissions from gas boilers to high levels of various chemicals in tight buildings. The common denominator of all these problems is the existence of several sources of pollution inside a volume of relatively low dissipative capacity. Where the resulting concentration from a single substance exceeds an already established hygienic standard regulatory measures are straightforward. Assessing the risk of several substances being present at the same time is still difficult.

The problem of radon emission in buildings first came to light at the end of the 1970s, when a report by the Swedish National Institute of Radiation Protection revealed high radon daughter concentrations in some houses. Temporary limits on permitted concentrations in different types of dwellings were imposed in Sweden. They were related to the age of dwellings, due to the known historical use of alum shale in lightweight concrete.

Notes that moisture problems could arise with improvements to thermal insulation of buildings. In addition indoor radon levels could rise. Considers the choice of heating system. Compares total costs of alternative systems. Treats the effects of increased insulation on internal environments. Identifies moisture sources. Stresses this should be regarded as only a limited guideline and that there is a need to ascertain the heat and mass transfer behaviours of building materials, particularly those that affect prediction of the transient behaviour.

Notes that the Department of the Environment is considering the implications of imposing limits for the maximum annual dose of radiation to which occupants of existing and new homes should be exposed, as recommended by the Royal Commission on Environmental Pollution in its report of 1984. Describes radon's properties and origins in buildings, where levels are at least ten times higher than outdoors. The occupants of some homes, chiefly on granitic soils, receive up to 100 times the national average dose from radon. Explains the units used when discussing radon.

Examines the most important sources of indoor air pollution in dwellings. These include pollutants introduced with the outside air, pollutants generated by human activity, emissions from building materials, furnishings, cleaning and polishing materials and disinfectants. Notes the importance of keeping formaldehyde and carbon dioxide down to safe levels. Discusses the consequences for the minimum room air change rate.

The U.S. EPA initiated an indoor air monitoring program in 1982, concentrating on commercial or public-access buildings (homes for the elderly, schools, and office buildings). Several buildings from each category are sampled over 2-3 day peri