English

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.

The term of “Active House” recently developed, addressing houses that target a balanced optimization of indoor environmental quality, energy performance and environmental performance. According to the idea of not only being energy efficient and eco-friendly, Active Houses equally focus on indoor environmental qualities, in particular daylight and air. With their tendency towards intensive sun penetration, natural ventilative systems and generally intensive connections to the exterior, Active Houses challenge the balance of technical and individual indoor climate control.

The article presents the results of our research, which was realized under a cooperation project between the University of Pécs, Hungary and the University of Osijek, Croatia. The aim was to gather 50 Pa ACH, air tightness and spontaneous ACH information of residential houses by the Croatian and Hungarian border. The budget of the project allowed approximately 50 tests for each university; these summarized results are presented together with correlations found between the results.  

A project at the Energie- und Umweltzentrum (e.u.[z].) Springe looked into strategies how insulation and sealing components can be installed in existing constructions to improve the best airtightness.

This study investigates the influence of outlet location on conventional, turbulent-mixing operating-room (OR) ventilation performance. This was done by numerical simulation using computational fluid dynamics. Multiple configurations of OR outlets, both at floor and ceiling level, were examined, and the results were compared. OR ventilation-system performance in each case was examined by conducting a tracer-recovery test. Two common anesthetic gases, halothane (C2HBrClF3) and desflurane (C3H2F6O), were used to perform the test.