infiltration

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.

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.

Air quality in the office room areas, as well as their energy demands for heating and cooling are directly depended on the ventilation levels in those rooms. Specifically, high internal air quality requires high levels of ventilation and therefore high energy demands. On the other hand, high energy savings can be accomplished by full building impermeability, which means low to none ventilation and at the same time low air quality.

The importance of adventitious air leakage under normal operational conditions and its reduction in order to save energy is highlighted by the relvant building standards of many countries. This operational leakage is often inferred via the measurement of air permeability, a physical property of a building that indicates the resistance of its fabric to airflow. A building’s permeability is the measure of airflow rate through its envelope at a constant pressure differential of 50 Pascals.

This paper reports on the construction, experimental set up and infiltration characteristics of a purpose built full-scale experimental house. The building has been designed as an experimental platform for measuring the moisture removal effectiveness of active and passive ventilation systems with indoor and outdoor climate conditions seen in New Zealand.

When planning ventilation systems for energy efficient housing, an appropriate design of the overflow elements between rooms is important as it influences ventilation losses, indoor air quality and sound attenuation between rooms. Based on calculation results of the natural in- or exfiltration rates through the building envelope as a function of the overflow element’s flow resistance, this work proposes a maximal pressure drop of 2-3Pa for overflow elements in energy efficient buildings.

In 1998, Persily 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. Since that time, the U.S. National Institute of Standards and Technology (NIST) has maintained a database of measured airtightness levels of U.S. commercial building leakages, in part to support the development and technical evaluation of airtightness requirements for national and state codes, standards and programs.

Air leakage and other diagnostic measurements are being added to LBNL’s Residential Diagnostics Database (ResDB). We describe the sources of data that amount to more than 80,000 blower door measurements. We present summary statistics of selected parameters, such as floor area and year built. We compare the house characteristics of new additions to ResDB with prior data.

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.

Reduction of infiltration in the Equinox House, a residence under construction in Urbana Illinois, has been characterized through a series of blower tests as different joints and seams in the building were sealed. Equinox House is constructed with 30 cm thick SIPs (Structural Insulation Panels) wall and roof panels consisting of a Styrofoam core and oriented strand board sheathing on interior and exterior surfaces. Blower door tests were performed as each type of seam in the house was sealed.