|
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.
|
