Comparison of indoor and vehicle-borne thermography

Abstract

One of the tools traditionally used in assessments of the thermal status of buildings is the application of JR-techniques. This application has to a large extent been restricted to indoor inspections of attics, external walls and basements, or to roof inspections by means of aerial thermography, or to detection of air leaks by pressurisation of the building. These applications have, in general, been very successful.In this paper is presented an evaluation of a staged process where major building envelope anomalies have been detected by outdoor thermography, classified using indoor thermography, moisture meters and fiber optics techniques, and evaluated with regard to their impact on energy consumption and envelope performance.In the evaluation of this process, inspections of external walls using indoor thermography and vehicleborne outdoor thermography have been compared to one another regarding factors such as the number of suspected thermal anomalies detected, the accuracy in predicting real damages, the time required for the operation and the image analysis, factors limiting operational efficiency, and the ease of the operation. Also, the measured external surface temperatures have been compared to those predicted by an analytical calculation.It is concluded that vehicle-borne JR-inspections may provide a quick way of detecting building thermal anomalies. The prediction accuracy relative to indoor inspections to some extent depends on the building design. However, most major damages detected by indoor thermography can, under suitable operating conditions, be detected also from the outside. Thus, a process combining outdoor thermography to detect building anomalies and indoor thermography to survey selected details, in a cost-efficient way gives a rather complete picture of building damages and building thermal status.To make an efficient use of the thermographic data collected, the information should be stored in a data base containing also other data on the building, for example, data on building function,design and operation. The whole process of gathering data by IR-techniques should be integrated into already existing schemes for building management, operation and maintenance. INTRODUCTIONBuildings require continous control and maintenance. The service life of buildings may vary from 20 to 100 years depending on buildingfunction and design and on maintenance frequency. Cheap energy and lack of reliable, operational methOds has led to a reduction in the frequency and extent of maintenance. In some cases, the maintenance of buildings has never had a high priority due to lacking interest or lack of economic resourses. However, neglect of control and maintenance of buildings sooner or later leads to severe building damages, increasing energy cost and deteriorating building performance. 92 / SPIE Vol 1313 Thermosense XII (1990) Downloaded From: http://proceedings.spiedigitallibrary.org/ on 06/26/2016 Terms of Use: http://spiedigitallibrary.org/ss/TermsOfUse.aspx

<title>Thermography and complementary method: a tool for cost-effective measures in retrofitting buildings</title>

“…The aim of the study is that the results are to be implemented for use in the routines for the maintenance and management of buildings managed by the Swedish Department of Defence, as well as for other similar buildings (3). The aim of the study is that the results are to be implemented for use in the routines for the maintenance and management of buildings managed by the Swedish Department of Defence, as well as for other similar buildings (3).…”

“…3. One of the major applications is the assessment of the condition and performance of the building envelope with regard to 1.…”

“…The surveillance of basements must be done from the building interior (2). For external walls, the thermographic examination can be carried out from the inside or from the outside (3). If applied to a single building, it is often combined with a pressurization or depressurisation of the building interior to detect more easily paths of air infiltration or exfiltration.…”

<title>Infrared thermography as a diagnostic tool to indicate sick-house-syndrome: a case-study</title>

“…Several studies presented at Thermosense conferences confirms that thermography is a useful tool to detect and identify different damage situations and energy related conditions known as primary factors jeopardizing the envelope of the building, disturbing the building performance and function, and eventually gradually causing a poor indoor environment (Allen, 1991, Calantonio, 1992, Knehans et al, 1992, Ljungberg et al, 1990, Ljungberg, 1994. However, none of the earlier studies presented has been devoted entirely to the problems of the sick-house-syndrome.…”