Indoor climate and user interaction on modern Swedish one family houses - results using a questionnaire.

Disadvantages and advantages with different heating and ventilation systems in modern housing have been discussed during many years in Sweden. The discussion has intensified for modem low energy houses, where the use of forced air heating has increased during the last fifteen years, mostly in one-family houses. In many articles and the general debate diverging opinions have been presented concerning the thermal comfort, the air quality, the ventilation and the energy use in modern one-family houses with forced air heating. All modern Swedish one-family houses are very well insulated, fairly airtight and are equipped with mechanical ventilation. The indoor climate (thermal comfort and ventilation), the energy use and the user interaction were examined using questionnaires in 236 houses built after 1988, 144 houses with exhaust fan ventilation and radiator heating and 92 houses with balanced ventilation and forced air heating. In 50 of the 236 houses measurements have been carried out, one-time tests of mechanical air flows, air tightness, status of heating system, indoor temperature, particles and long-term tests of outdoor air ventilation, humidity, carbon dioxide and indoor temperature during a winter month. This report presents and discusses the quality of the indoor climate and the user interaction in modern Swedish one-family houses. Improvements to future houses are proposed e.g. reduce sound from the outside in "exhaust" houses, reduce draught from outdoor air vents in "exhaust" houses, reduce sound from the ventilation system in "balanced" houses, make more readable operating and maintenance instructions for the heating and ventilating systems, provide better air temperature control of individual rooms, reduce the ventilation rate?, supply all outdoor air to the bedrooms? The investigated houses show appr. the same level of complaints concerning the indoor climate as in a study of the Swedish building stock i e there are no serious problems. There are some differences between houses with the two types of heating and ventilating systems.