The Air Barrier Movement:
The air barrier is an important component of a building enclosure system that can improve HVAC system performance, increase occupant comfort, improve smoke/fire control, decrease damage to enclosure components from condensation, and maybe most importantly reduce energy consumption. The air barrier is defined by the Air Barrier Association of America (ABAA) [1] as an assembly to "control the unintended movement of air into and out of a building enclosure." By reducing the air infiltration and exfiltration through the exterior enclosure to almost negligible amounts, the air barrier reduces energy consumption by reducing the associated heating and cooling loads and allows the designers to downsize the HVAC system. The reduction in uncontrolled air movement through a building enclosure will also minimize the potential for interstitial condensation development within the envelope cavity by reducing the water vapor carried by airflow and its contact with surfaces below the dew point temperature. In heating climates, the focus is on interior moisture-laden air exfiltration, whereas in humid, cooling climates, the concern is reversed and focuses on exterior moisture-laden air infiltration into air-conditioned structures. Air barriers also improve occupant comfort through noise transmission reduction, along with odor and contaminant control.

This article was published in the September/October issue of TME Magazine.

The U.S. Army Corps of Engineers (USACE) has taken a leading role in requiring field performance testing to measure and verify the air tightness of building enclosures. Some state and federal governing agencies as well as model building codes and standards include building air sealing requirements. However, these requirements are non-quantitative, and air sealing results are not required to be verified by testing. As a result, the benefits of enclosure air tightness are likely not achieved.

ABSTRACT
This paper will review and discuss the determination of the emissivity of common construction materials to aid the investigator during infrared investigations/surveys of building envelope systems. Specifically, this paper will discuss the results of product testing of constructed wall assemblies. The wall assemblies are constructed to mimic the common materials encountered in building envelope surveys. They include materials such as hardboard lap siding, stone veneers (faux and natural), stucco, exterior insulation and finish systems (EIFS), trim accessories, vinyl frames, painted flashings, self-adhering flexible flashing membranes, oriented strand board (OSB), ethylene-propylene-diene monomer (EPDM roofing material), wood framing, and concrete. In order to provide a better analysis and determination of results with thermography measurements it is important to understand the relationships of the products emissivity on multi-surface, multi-material constructed assemblies. As well, the thermographer should understand the effects of the angle of inclination utilized when conducting thermographic surveys. This paper will deal with the determination of the values of emissivity of such common materials and the effect of the angle of view used at the time of the thermographic imaging. Additionally, it will discuss the effects of visible light on the heating of objects and, therefore, its implications when performing emissivity calculations in the presence of visible light such as sunlight. Multiple full-scale mock-ups of building wall assemblies will be constructed and a determination of parameters will be made from these full-scale assemblies. The results will be tabularized and provided for this paper.

ABSTRACT
Reported problems with recently constructed buildings exposed to severe climate led to a legal case regarding the performance of the heating systems and the buildings. The buildings were examined using visual methods, infrared imaging, blower door, and flow hood measurements, and modeled using CFD (computational fluid dynamics) software for both flow and heat transfer. Information from the measurements provided the data that allowed development of a comprehensive CFD model of the air and heat flows in the building, which gave a visual illustration of the air paths in the structure. These illustrative exhibits aided the writers in developing a method of presentation for the legal proceedings, as well as confirming the owner reported complaints of stratification in the units. The findings will be reviewed and the measurements and simulations compared in this paper.

Article written by Ronald D. Lucier, reprinted by FLIR Systems from November 2004 issue of Cleaning and Restoration - official publication of ASCR International.

C&R has reported extensively on the time, cost and benefits of using infrared (IR) thermography to inspect buildings in order to trace the source and scope of water damage, and thus potential mold. In addition, IR thermal imaging is extremely fast, noninvasive and provides evidentiary-quality, intuitively understandable data that have a much higher degree of accuracy and reliability than other moisture detection technologies.

ABSTRACT
This paper will review and discuss the benefits of infrared thermography as its technology applies to the investigations of various in-floor (interior) and concrete slab (interior and exterior) radiant heating systems, both electrical and fluid systems. The purpose of this paper is to outline the various applications of infrared thermography for investigation of the systems, as presented in a case study format. The technique illustrates how infrared can be utilized to determine such post-construction items as identification of system zones, failure or impeded heat loss analysis, sensor identification, leak analysis, and line system identifications for intrusive testing or slab coring.

Both resistance electrical and fluid radiant heat systems have become widely used in high-altitude and cold, mountainous regions such as Colorado. Initially, the objective of such systems was to reduce the need for manual methods of snow and ice removal from pedestrian or vehicular surfaces, but these systems have recently become fairly common forms of residential interior heating and temperature control in higher end homes. Manufacturer and design deficiencies, as well as installation defects, result in system malfunctions and non-performance issues. The cost of the failures is staggering, considering the cost to remove finish materials, determine the location of the problem, and then rebuild the system and replace the finish materials. Infrared thermography can help identify and aid in the development of positive solutions both in the post construction and pre-construction stages.

ABSTRACT
This paper outlines the use of infrared thermography in forensic and construction defect engineering in the mountainous State of Colorado. The building envelope case studies explored in this paper include the use of infrared thermography in the analysis and solution of problems including cold roof ventilation, ice damming, roof ice melt systems, in-floor radiant heat systems, exterior insulation and finish systems/stucco, stone veneer, plaza decks/balconies, flat roof and at-grade foundation clearance failure analysis and building envelope system performance.