English

Notes initial airtightness requirements in SBN 1980 and discusses various forms of ventilation. Discusses how tightness testing can reveal location and magnitude of leaks. Gives theoretical method of calculating air leakage flow and relates this to practical measurement. Considers different alternatives such as pressurising the building and combining tightness testing with thermography. Discusses 1980 building regulations and what buildings ought to be tested. Lists critical points of a building and measures which can contribute to good airtightness.

Notes job losses in prefabricated timber housing industry in Sweden and Hjaltevad's endeavours to produce a large series popular house with low-energy characteristics. House is on one and a half floors and has an occupied area of 150 sq.m. Heating economy is strongest sales argument with estimated annual consumption of 8000 Kwh. Low energy consumption results from electric boiler and heat pump. The heat pump assumes a mechanical exhaust air system and heat extracted is added to hot water system. Notes strict control of tightness before external cladding is nailed in position.

Examines the possibilities of achieving energy-efficient ventilation systems in naturally ventilated homes (which include the use of intermittent extract fans in individual rooms). Discusses factors affecting energy efficiency. Treats general design requirements for mechanical and natural ventilation systems. Discusses the characteristics of natural ventilation systems, including leakage, weather and window opening. Compares natural and mechanical systems. Provides suggestions for natural ventilation design.

Gives an account of the results of research into ventilation and radiation in buildings, including one-family dwellings and blocks of flats. Investigation includes recording the air change rate, the radon levels, the radium emanation rate and gamma radiation. The object of the investigation is to obtain background material for continued research into limit values for radon and radium emanation levels in dwellings.

Examines the fundamental building heat loss calculations. Points out some anomalies in the traditional view of room thermal behaviour. Treats equations governing room heat loss taking account of the temperature of the walls and the environmental temperature. Justifies the use of the environmental temperature rather then the air temperature. Examines the heat loss due to ventilation. Discusses the use of the temperature ratio.

Notes the high heat loss in Canadian houses due to air leakage and condensation problems caused by uncontrolled moisture movement into the exterior wall structure. Recommends the installation of an air-vapour barrier to form a completely sealed envelope around the house structure except at doors, windows, vents and other obstacles. The recommended thickness for the polyethylene sheet of the air vapour barrier is 6mm, which is continually sealed at all joints. Details the recommended installation procedures for realising an air-vapour barrier.

Uses "Track Etch" detectors to measure nearly 40000 time-averaged radon concentrations in Canadian, Swedish and US homes. In some areas indoor exposure rates exceed 20 pci/l in as many as 15% of homes surveyed. Such levels may lead to an increased lung cancer risk. The "Track Etch" detectors are based upon a plastic nuclear track detector which undergoes permanent radiation damage when struck by an alpha particle. These small detectors are very convenient to use in occupied homes and buildings.

Discusses common sources of indoor air pollution in buildings and the specific pollutants emitted by each source, including combustion emissions, formaldehyde and other organic substances and radon. Also covers potential health effects and possible control techniques, including dilution by natural or mechanical ventilation.

Assesses the impact of energy conservation retrofits on the indoor air quality of residential buildings, through a field monitoring project in which air leakage, air exchange rates and indoor air pollutants are measured before and after retrofit. Uses a mobile laboratory to make detailed on-site measurements of air exchange rates and concentrations of pollutants in 2 houses, and measures effective leakage area in 7 other houses. Impact on indoor air quality of the energy conserving retrofits seem to be minimal.

Gives a method of calculating the rate at which air enters a building, and how long it takes to reach a steady state, given the area of the door, the volume of the building and the air change rate caused by infiltration when the door is shut. Resulting heat losses are unacceptably high, but not as high as claimed by manufacturers of door closing devices.