English

The role of ventilation in the housing stack is to provide fresh air and to dilute internally-generated pollutants in order to assure adequate indoor air quality. Providing this ventilation service requires energy either directly for moving the air or indirectly for conditioning the outdoor air for thermal comfort. Different kinds of ventilation systems have different energy requirements. Existing dwellings in the United States are ventilated primatiy through leaks in the building shell (i.e., infiltration) rather than by mechanical ventilation systems.

This paper reports results from the ventilation and air tightness measurements in Swedish dwellings as part of the 1992 Swedish Energy and Indoor Climate Survey (the ELIBstudy). The indoor climate in a random sample of 1200 single- and multi-family houses from the Swedish housing stock were investigated. Among different parameters the ventilation and the air-tightness of the houses were measured.

Ventilation codes for swimming pools are based on preventing condensation. To save energy, air recycle with dehumidification is common. This successfully controls moisttke, but does not remove airborne contaminants arising from evaporation of chemically treated pool water. This contamination may cause discomfort, irritation or even harm.

Cooling ceilings are more and more proposed, in order to eliminate excess heat in office buildings without consuming much energy in air transport. On the other hand, piston ventilation is proposed to efficiently eliminate contaminants. These two systems may however interact and experiments were planned to look at these interactions. Measurements of the age of air and air change efficiency were performed, together with more classical temperature and air velocity measurements, on various ventilation systems installed in the test chamber of Sulzer Infra, in Winterthur.

Ventilation of buildings is necessary, both to insure adequate indoor air quality and to protect the building itself against condensation and mould growth. On the other hand, ventilation rates must not lead to excessive energy consumption. French regulation doesn't appreciate directly the indoor air quality but fixes requirements for the value of exhaust stale air in service rooms ; furthermore heat losses related to cross ventilation due to wind effects are also taken into account.

The paper presents a criterion to assess the performance of mechanical exhaust hoods for dome stic kitchens and a procedure to experimentally test them; an analysis of the relevant parameters which affect their performance is made, the test results are shown, and finally these are compared with the results of a numerical fluid dynamic code. Experiments were performed using the tracer gas technique, and attention has been drawn rather on the hood efficiency in the removal of pollutants than on the IAQ in the test room.

Increases in the levels of thermal insulation required in the walls and roofs of houses in the U.K. in recent years have meant that heat losses through floors now assume greater significance, as a proportion of the total heat loss from a dwelling. To effect further reductions in the energy consumption of houses, the thermal performance of floors needs to be examined to assess the most cost effective insulation strategy.

The major objective of the IEA task XIII project is to design and construct low energy dwellings which should be technically and economically realistic in the period 2000-2010. The design criteria for the Belgian dwelling are the following: - low energy demand for heating purposes; - good thermal comfort conditions, as well in winter as in summer with attention to the problem of overheating; - very good airtightness (n50 <= 1 h^-1); - good indoor air quality conditions; - attractive design for majority of potential clients; - only use of realistic technical solutions.

This paper shows the extensive influence of humidity on comfort, cooling load and refrigeration capacity. Modern computer programs allow an effective consideration of humidity in systems.

The growing diffision of small power, gas-fired individual units for space heating and service hot water production, as well as concern about operational safety issues, has promoted greater attention to the understanding of ventilation mechanisms in the dwellings equipped with such units. Within a joint research project between Politecnico di Torino and Italgas, an experimental campaign has been conducted in order to investigate the influence of purpose-provided ventilation openings (sized according to the national UNI-CIG 7129-72 standard) on air changes and IAQ.