Gives a brief review of recent indoor air quality research in the USA, including instrumentation, monitoring health effects and remedial action.

Briefly deals with Finnish research into formaldehyde concentrations in modern dwellings. Describes materials and methods used by the Institute of Occupational Health in Finland to measure formaldehyde concentrations in more than 100 dwellings. Ventilation rates have also been measured in 35 rooms in 20 dwellings, and 46% have been below the minimum acceptable value of 0.5 ach.Where the ventilation rate exceeded 0.5 ach only 9% of the measured HCHO concentrations exceeded the limit value for old houses.

States that the higher internal humidity and lower structural temperatures in UK timber frame houses, as compared to the US and central Europe increases the risk of interstitial condensation. Condensation risk has also increased in all countries because of energy conservation measures and changes in heating patterns, occupation density and moisture production. Gives recommendations for the prevention of interstitial condensation.

Reports on pressure tests carried out on the Kasarminkatu 24 building (a museum of architecture) in Helsinki. The fans in the building were used to measure airtightness of the building envelope, and the tightness of windows and doors was measured separately by the guarded box method. The tightness of the building envelope was good (2 ach at 50 Pa). 70% of total air leakage came through the wooden roof structure, and only 5-10% through the windowstructure. Three alternative mechanical ventilation systems were also studied in the same building to assess their impact on indoor climate.

Describes research work in Finland concerning air infiltration and ventilation in buildings from 1979. Types of ventilation system in finnish houses, flats and other buildings are discussed. Reports on a model developed to predict the correlation between various factors and air infiltration. Gives a summary of pressure test measurements carried out in a few hundred small houses, and presents proposals for recommended airtightness levels in new buildings. Describes warm air heating systems, heat recovery systems in flats, and maintenance problems with ventilation systems.

Discusses the problem of formaldehyde emissions from UF resins used in particle board in North America. Describes tests done by Forintek Canada Corp to monitor formaldehyde emission. One of the experiments involves a test chamber with a controlled air change rate and designed to imitate domestic conditions. Air samples are withdrawn from the chamber through impingers containing distilled water which is analyzed for formaldehyde content. Also describes the 'Dessicator' and 'Perforator' methods of measuring formaldehyde emission.

Looks at the separate requirements of ventilation and heat recovery. Discusses the energy cost of ventilation. Gives example calculations for four different situations to show how much saving an air-to-air heat exchanger can provide. Savings depend on ventilation rate, climate and energy price.

Presents results obtained in field studies of control and test houses provided with low cost retrofit infiltration controls. There are significant estimates of average energy savings during both heating and cooling seasons. However, the 95% confidence intervals for the heating season span the origin and theprobability that savings were actually observed is less than 85% for the heating season. The probability that actual savings were measured during the cooling season is >95%.

Describes trials undertaken by BRE and ECRC at Inverclyde to test small domestic electric dehumidifiers in council houses. Assesses 3 types of machine, selected to give a range of extraction rates from 1-4 kg per day. These were supplied free of charge and the running costs reimbursed. Shows that the equipment did lower the moisture levels in the houses satisfactorily. Preliminary analysis of results show that the early BRE model predicting moisture and ventilation interactions work well.

Energy is consumed in heating the air infiltrating into houses maintained at temperatures above ambient. By using climatic data tapes and a daily profile for indoor temperature of a house, it is possible to calculate factors, which in conjunction with a relationship between air change rate and wind speed enable the energy consumption due to infiltration to be calculated on amonthly basis. This has been done for Melbourne, Australia and the factors tabulated on a monthly, annual and heating season (April Nov) basis.