Evaluation of aerial thermography to discriminate loft insulation in residential housing

• Main Author: Allinson, David
• Published: University of Nottingham 2007
• Subjects: 693.832; TH 845 Architectural engineering
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.440279

This thesis examines the use of aerial thermography data to discriminate loft (attic) insulation levels in residential housing, with ventilated pitched roofs, in the UK. Quantitative techniques from the fields of remote sensing, GIS, building physics and atmospheric science were used to develop a methodology and analyse survey data flown over Nottingham in 2001. The quantitative techniques were applied to real survey data using the most up to date atmospheric propagation models. A new model of the heat loss through the ceiling, loft and roof was developed for this study, based on the most recent methods. The limitations of these techniques were explored. A complete methodology, valid for any future study, was defined. It was found that, measuring roof surface temperature from the thermal image was complicated by roof material properties, the intervening atmosphere and the surrounding topography. Relating roof surface temperature to insulation thickness was further complicated by loft space ventilation and the outside surface heat balance. The additional data, needed to quantify the results, produced inaccuracies caused by measurement error. Analysis of the uncertainties, by simulation, indicated that loft insulation level could not be discriminated by aerial thermography. This was confirmed by comparing the results, calculated from the survey data, with the actual insulation level for a number of houses in test areas of the city.