dwellings

Over three million subsidised dwellings were built in Spain between 1940 and 1980. Most of these buildings are now obsolete and fail to comply with thermal comfort and ventilation standards. A building's existing energy performance, including its airtightness, should be determined prior to conducting low-energy refurbishment, for those factors, particularly the latter, impact thermal comfort, energy demand and indoor air quality (IAQ) fairly heavily.

One of the most commonly used strategies to reduce the heating demand in low energy buildings is reducing the leakage level of the building envelope. Dedicated ventilation systems are then installed to compensate for the reduced air change rate in an energy efficient way. Most occupants, however, operate their ventilation system at very low flow rates. Together with the emission of bio-effluents, linked to the presence of the occupants, moisture production related to household activities is one of the most important sources of indoor air pollution in dwellings.

New homes currently being built within the UK all incorporate some type of ventilation system, the majority of which are of the fixed mechanical fan type. These generally come in three generic designs known as single room background ventilators, continuous mechanical systems and continuous mechanical systems with heat recovery. Installation, inspection and commissioning of these systems is covered by Building Regulations, and there are training schemes in place which allow individuals to become Competent Persons to undertake these tasks.

Airtight construction lies at the heart of achieving high energy performance in dwellings. But how well does it apply in new construction? This paper presents results from airtightness measurements on 44 randomly selected, standard new built single family houses in Belgium and from 4 case studies including 78 additional measurements. The houses were randomly selected after completion, to assure that standard workmanship was used during construction.

Origins of toxic gas clouds may be diverse, including accidental releases due to industry or to hazardous materials transportation, or biological or chemical attacks. A protection to such a phenomenon consists in taking advantage of the protection offered by buildings against airborne pollutants. In this event, people can shelter in a building and wait until the toxic plume has gone.

Natural ventilation of buildings is a design strategy for the passive cooling of buildings that can be considerably efficient if properly undertaken. In Brazil, as in many other developing countries, spontaneous (self build) housing is often of poor quality. Also, each of these dwellings has a negative impact on the neighbouring ones and on the impact on the urban environment. In the city of Campinas, Brazil, with its hot-humid climate, adequate ventilation is essential for thermal comfort.

Radon surveys started in Estonia in 1989. The Department Building Physics at the Estonian BuildingResearch Institute measured radon levels in dwellings, in building materials produced in the country,and in the soil. The indoor radon concentrations in more than 400 houses were measured under grabsamplingtechniques using Lucas cells. The highest measured radon level was 6700 Bqm-3. The resultsof these measurements made during 1989-91 showed that the main source of indoor radon is the soilunderneath buildings.

CRR, the Regional Center for Radioactivity, is monitoring Veneto, a region in the north-east of Italy, to trace a map of areas with elevated indoor radon levels. This survey is based on analysis of territorial distribution of radon concentration in dwellings. Maps of potential risk are searched in the upper part of the region based on the indication of a previous survey. Percentage of dwellings exceeding reference levels are estimated on the base of log-normal data distribution. Normalizations to ground floor or average housing type are produced.

Field measurements of the indoor climate have been carried out in 128 lightweight timber-framedetached houses in Finland and in Estonia during the years 2002-2005. The temperature and relativehumidity were continuously measured in bedrooms, living rooms and outdoors for each house at 1-hourintervals over a 1-year period.

Portugal has technical recommendations and standards regarding ventilation rates in naturalventilation systems.