IJV12

Implementation of the European Energy Performance of Buildings Directive (EPBD) introduced the first legal airtightness regulations into the 2008 Polish Building Codes. Unfortunately these provisions are currently not sufficiently precise or developed in relation to testing procedures to ensure appropriate airtightness. Generally there is a low level of awareness, experience and knowledge among architects, designers, investors, contractors and there are no certification requirements imposed for measurement companies.

Airtight construction lies at the heart of achieving high energy performance in dwellings. But how well does it apply in new construction? This paper presents results from airtightness measurements on 44 randomly selected, standard new built single family houses in Belgium and from 4 case studies including 78 additional measurements. The houses were randomly selected after completion, to assure that standard workmanship was used during construction.

As strategies for improving building envelope and HVAC equipment efficiencies are increasingly required to reduce building energy use, a greater percentage of energy loss will occur through building envelope leakage. Although the energy impacts of unintended infiltration on a building's energy use can be significant, current energy simulation software and design methods are generally not able to accurately account for envelope infiltration and the impacts of improved airtightness.

Although standards for single-zone air leakage tests are widely used, there are no existing standards for several multi-zone cases including: 1) testing air leakage between adjacent zones or 2) testing leakage to the outside from a single unit in a multi-zone building. While a range of test procedures have been used to determine inter-zone leakage using fan-pressurization, the accuracy of the methods can vary significantly. Using field measurements and simulations, we compared the uncertainty in the leakage between two adjacent zones for different measurement and calculation methods.

This paper describes two recent applications of aerosol sealing techniques in buildings for improving indoor air quality and reducing energy required for heating, cooling, and ventilation. One application applies a commercially-available duct sealing technology, which has typically been used in single-family applications, to large-building exhaust systems. The initial leakage rates, percent leakage sealed, and issues encountered are presented for several large buildings.

In 1998, NIST published a review of commercial and institutional building airtightness data that found significant levels of air leakage and debunked the "myth" of the airtight commercial building (Persily, 1998). Since then, NIST has expanded and maintained a database of whole building envelope leakage measurements of U.S. commercial and institutional buildings.

The Engineer Research and Development Center, Construction Engineering Research Laboratory (ERDC-CERL) recently developed design/construction strategies that improve the energy efficiency, reduce the potential for mould, and improve indoor air quality in newly constructed buildings and buildings undergoing major renovations. ERDC-CERL performed building envelope leakage tests on Army facilities to test their general integrity and the effect of increased airtightness on building energy consumption.

This paper presents results from whole building air leakage tests used to document the leakage reduction due to envelope sealing and assess the accuracy of contractor's estimates of the impact of their sealing. The measurements also compare the differences in envelope leakage reductions determined from depressurization versus pressurization tests and determine mechanical system leakage.

Concern over the airtightness of commercial buildings in North America goes back to the mid nineteen sixties, and with increasing concern in the mid-seventies, primarily due to the energy crisis, but also due to building performance, comfort and durability issues. The Model Canadian National Building Code was the first to adopt airtightness requirements for air barriers in 1985 and quantify it in 1995.

A full size simulation laboratory aircraft cabin comprising three rows of seats has been built. This represents the Airbus A320 and the China C919 aircraft. Experimental research on the attenuation rule of the individual air-conditioning isothermal jet flow from nozzles positioned above the seats was conducted. The results show that axial air velocity continuously decreases with increasing cross-sectional distance. For a distance x < 0.4 m, (the axis air velocity sharp attenuation area), the velocity of attenuation slows.