English

Ventilative cooling (VC) is a way to cool or to prevent overheating in a building by means of ventilation rates higher than hygienic ventilation rates. To this end, natural (such as windows, vents, louvers) as well mechanical (extract or supply fans) ventilation devices can be used.

There is a growing concern about the effects of indoor air particulate pollution, in relation to human health. The removal of indoor air pollution at its source is extremely difficult. Fine particles are continuously generated in outdoor air mainly by combustion processes. Coarse particles are constantly generated by activities indoors. There is a need for simple technology that can reduce these types of pollutants, which can work in conjunction with standard heating, ventilation and air conditioning (HVAC) systems.

The Proceedings of the 35th AIVC Conference "Ventilation and airtightness in transforming the building stock to high performance", held in Poznań, Poland, 24-25 September 2014.

The Presentations at the 35th AIVC Conference "Ventilation and airtightness in transforming the building stock to high performance", held in Poznań, Poland, 24-25 September 2014.

This session will discuss the major changes of the ventilation standards supporting the implementation of the Energy Performance of Buildings Directive recast. It is foreseen that some of these standards will serve as basis of future ISO standards as well.

Numerous tests are being performed throughout Europe. While most are or appear to be successful others have high calculated uncertainty values and others don’t correlate well when repeated by the same tester with the same equipment or where someone else does the repeated test. Some feel that equipment calibration is the key to consistent results but in most cases that it could be one of the smallest causes for lack of repeatability. We will take a look at how much different factors affect results and how to get the best results. 

For over a decade now, the OQAI — Observatoire de la qualité de l’air intérieur [French observatory for indoor air quality] — has been leading research into indoor air quality and occupant comfort in living spaces: housing, schools, offices, leisure spaces.

We have analysed the steady wind model error based on a simplified building model with one leak on the windward side and one on the leeward side of the building. Our model gives an analytical expression of this error that depends on the leakage distribution and pressure coefficients. Using a test pressure of 50 Pa in this model, standard measurement protocol constraints contain the steady wind model error within about 3% and 11% with wind speeds below 6 m s-1 and 10 m s-1, respectively. At 10 Pa, the error is in the range of 35% and 60% at 6 m s-1 and 10 m s-1, respectively.

The characterization of power-law coefficients of the airflow through ventilation system components and ductwork or building leaks should include corrections on the airflow rate measurement because of two phenomena: a) the temperature and pressure conditions at the flow measurement device may not be the same as those seen by the test object; b) the temperature and pressure conditions experienced by the object may differ from reference conditions. This paper gives the analytical expression of these corrections depending on the air viscosity, air density and flow exponent.

Adequate ventilation is necessary to maintain thermal comfort and remove indoor air pollutant concentrations (Crump et al., 2005). Indoor pollutant concentrations vary considerably depending on occupants’ behaviour patterns, building characteristics and meteorological parameters and seasonal effects. Experimental measurements are time consuming and expensive to carry out, while computational models are regarded as a valid complement.