English

Experiences of the past years showed that it is possible to achieve a considerably better air flow rate in large buildings than it is targeted by the regulation of energy saving. The cause is not that the quality of air tight levels is considerably better in large buildings than in single-family houses. These buildings rather have a bigger internal volume (reference volume) compared with a relatively small surface (envelope surface) through which air change takes place.

There are currently at least 6 national and European standards in Germany, which describe the assessment of infiltration- and exfiltration-volume flows subject to building air tightness. The results of window ventilation and balanced ventilation systems are identical for some standards; they partly distinguish themselves in height. The dependence on building leakage in buildings with a surplus of inlet or outlet air, e.g. of exhaust fans, has a principally different process for some algorithms than for other algorithms.

The airtight version of a building envelope has been accepted as a structural engineering challenge in by construction workers in Germany. At the same time, the interest in energy efficient buildings by investing clients has increased considerably.Whether the energy efficiency intended by the client has been reached or not will not be perceived by the client. The greater is the interest in respective quality checks. The examination of the air tightness of a building envelope for this purpose is of prior, but also of excessive importance.

The basic statistics of airtightness test results collected since 2002 in the Czech Republic arepresented. The test results are compared with the limit values according to national standard CSN 730540-2. An overview of airtightness related requirements stipulated in this standard is introduced inshort with an emphasis on the overall airtightness of building envelope. New preliminary standardsfocused on the assessment and classification of low-energy and passive houses are presented. The aim of these documents is explained.

When two adjacent residential buildings in Ludwigshafen were fully renovated in 2005/2006, energyefficiency was a focal point from the very beginning. One of the two buildings was so completelyrenovated using Passive House components that it now nearly meets the Passive House Standard for new buildings. The air-tightness of n50 = 0.46 h-1 is excellent. Measurements confirm that therenovation was a complete success. Not only has energy consumption come down to a very low level, but air quality is markedly good, as is resistance to moisture damage.

In this work the air leakage database of French single family dwellings, available at the CETE de Lyon (Centre d’Études Techniques de L’Équipement), has been analysed. This database accounts for 251 blower-door measurements of single family dwellings, made after 1983 as a result of several campaigns carried out across France to quantify the performance of French dwellings in terms of envelope airtightness and the existing directives.

The airtightness of office buildings influences energy use and thermal comfort. A leaky office buildingis likely to have a high use of energy and thermal discomfort. Except for a study carried out in theUSA, the knowledge of real airtightness levels of buildings and their impact on the energy use is verylow,. Therefore two different methods of airtightness testing were applied to an entire Swedish officebuilding. The first method involves using the ventilation system of the building and the second one touse a number of blower doors.

Air tightness of the building envelope contains important initial data for hygrothermal design and energy calculation. This study presents and analyses field measurements of air tightness of randomly selected Estonian apartment buildings (in total 136 apartments). Buildings were selected with different external walls: lightweight frame, concrete large-elements, monolithic concrete, lightweight largeelements, brick, and small building blocks (AAC, LECA, concrete) external walls.

Two studies have recently been performed to evaluate the current form of the Delta-Q test for duct leakage. In the first study 19 new homes in Wisconsin, USA were tested, and in the other 14 existing homes in Central Illinois, USA were measured. A primary goal was to determine whether the Delta-Q test was sufficiently reliable to use in production programs such as weatherization and home energy ratings, which currently use primarily the pressure pan or duct pressurization tests, respectively.

As we increase energy requirements on ventilation, it is essential to assess the real performance of these systems on site, both for energy savings and IAQ aspects.Applied on two new buildings located in Paris and near Lyon (France), "Performance" project has given the opportunity to check the feasibility of applying quality approach while building to improve performance and to measure precisely, during 2 years, in a large set of dwellings (29) the efficiency of the French standard ventilation system for new buildings (humidity controlled single exhaust mechanical ventilation).With numerous