leakage

Wind pressure and thermal forces are driving forces for pressure difference on the building envelope. In European and German standards infiltration is calculated using wind speed, temperature difference and wind pressure coefficients result-ing from upstream and downstream flow on the building envelope. This long term measurements shall present measured pressure differences on the building envelope in comparison to those calculations.

Wind pressure and thermal forces are driving forces for pressure difference on the building envelope. In European and German standards infiltration is calculated using wind speed, temperature difference and wind pressure coefficients resulting from upstream and downstream flow on the building envelope. This long term measurements shall present measured pressure differences on the building envelope in comparison to those calculations

Against the background of increased global demands for energy efficiency, property owners should raise the standards of ductwork systems for ventilation, heating and air conditioning. This would not only save energy, but also mean lower installation costs, shorter assembly times and better air quality thanks to less leakage. The importance of energy-efficient buildings will increase in the future, not only due to rising electricity prices, but also due to increased environmental awareness.

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.  

We have developed a simple model to estimate ductwork leakage and heat conduction losses in steady-state conditions for a balanced ventilation system. Implemented in a spreadsheet, it allows us to calculate their impact on heat recovery efficiency consistently with EN 15241 without the need for a dynamic simulation tool. One case study shows that the global heat recovery of a balanced ventilation system with a nominal heat recovery of 80% can be reduced to less than 50% if the ductwork leakage and thermal resistance are poor.

Accidental releases occurring in industrial platforms or during transportation of hazardous materials can entail the dispersion of toxic gas clouds. In case of such an event, the best protection strategy for people is to identify a shelter in a nearby building and stay in this room until the toxic cloud has finally been swept off.

The 2012 French thermal regulation will include a minimum requirement for residential buildings envelope airtightness, with two options to justify its treatment: a) measurement at commissioning or b) adoption of an approved quality management approach. This paper describes the qualification process for air-tightness measurement authorized technicians when their results are to be used in the EP-calculation method. Our analyses underline the importance of the qualification process to ensure homogeneous measurement practice among technicians.

Origins of toxic gas clouds may be diverse, including accidental releases due to industry or to hazardous materials transportation, or biological or chemical attacks. A protection to such a phenomenon consists in taking advantage of the protection offered by buildings against airborne pollutants. In this event, people can shelter in a building and wait until the toxic plume has gone.

The feasibility of good air-tightness in new buildings can be determined based on the obtained air tightness classes as defined in EN 12237. In this paper a model is described which allows to calculate the energy loss caused by leak losses in ventilation systems based on the air tightness class and the feasibility of realising a good air-tightness.

Tracer gas measurements are an unparalleled means of measuring air recirculation, leakage, and air flow rates in air handling systems [1-5]. However, such measurements are subject to significant measurement uncertainty in field conditions. A common problem is imperfect mixing of tracer gas.