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Ventilation of buildings and homes is a key issue both from comfort and energy aspects. However to determine the average ventilation air flow or the Air Change Rate (ACH) for a heating season by tests in case of natural ventilation, involve certain difficulties. Essential requirements when testing a physical phenomenon:

Over three million subsidised dwellings were built in Spain between 1940 and 1980. Most of these buildings are now obsolete and fail to comply with thermal comfort and ventilation standards. A building's existing energy performance, including its airtightness, should be determined prior to conducting low-energy refurbishment, for those factors, particularly the latter, impact thermal comfort, energy demand and indoor air quality (IAQ) fairly heavily.

ATTMA, the Air Tightness Testing & Measurement Association has introduced mandatory lodgement for all members, representing over 140 companies and over 350 test engineers across the UK. This presentation will give an oversight as to how we have made lodgement mandatory, the software we are using and finally some statistical analyses showing where the UK is at the moment with average Air Permeability (AP50) results.

A new low pressure ‘quasi-steady’ pulse technique for determining the airtightness of buildings has been developed further and compared with the standard blower-door technique for field-testing a range of typical UK homes. The reported low pressure air pulse unit (APU) has gone through several development stages related to optimizing the algorithm, pressure reference and system construction. The technique, which is compact, portable and easy to use, has been tested alongside the standard blower-door technique to measure the airtightness of a range of typical UK home types.

Since 2006, the French Energy Performance regulation, named RT, has been allowing two ways to justify building airtightness: either with a measurement or with the application of a quality management approach. The quality management approach certification is managed by the French Ministry in charge of construction, for which it set up a specific expert committee to assess quality management approaches. Since 2012, the justification has been compulsory for residential buildings. This obligation led to a more systematic use of certified quality management approaches.

The zero pressure compensation method has proven to be the best method to measure air flow rates accurately although it also has be shown that the accuracy depends on the type of air terminal device and how and where the pressure to be compensated is measured in the instrument. Although the principal of the zero pressure method implies universal applicability, in practice this does not seem to be case. This has lead us to develop the ‘extended’ zero pressure method

Mastering building airtightness is essential to meet the requirements of current and future building codes, not only for saving energy but also for ensuring moisture safety. Perfect airtightness is difficult to achieve: failures are often observed, due to bad design or poor workmanship. Some published investigations proved that leaking air mostly flows through porous material and thin air channels, due to material imperfections and construction tolerances.

Since 2000, the French EP-calculations have been considering thermal losses due to building envelope airtightness. The last two regulations (RT2000 and RT2005) had included a default value for airtightness and the possibility to use a better-than-default value with a mandatory justification of this value, especially for voluntary approaches such as the BBC-Effinergie label. In 2013, strengthening the airtightness has become a requirement of the current EP-regulation (RT2012).

In 2014 the first multi storey residential building planned and constructed to meet the Passivhaus Institute (Darmstadt) criteria was put in operation in Ljubljana, the capital of Slovenia. This massive-structure building is part of the FP7 EE-Highrise project, aiming to demonstrate nearly zero energy building (nZEB) technologies, an integrated design concept, and advanced systems for sustainable construction.

Nowadays, there is increasing construction of high-rise buildings. Stack effect is one of the airflow characteristics in this type of tall buildings. The upward buoyant airflows in vertical shafts of high-rise residential (HRR) buildings can become an important way of gaseous pollutant transport during cold seasons. In this paper the airflows and pollutant transport driven by stack effect in a typical HRR building in Shanghai was simulated by using a multi-zone model. Measured and recommended leakage data were employed, and the air tightness level was kept the same for all floors.