Determination of thermal insulation properties of buildings and structures’ external envelope using infrared thermal imaging

The primary thrust of this study is to quantify the thermal properties of the various components in the building structural and insulation envelope; to that end the heat flux through the structural envelope must be quantified. If one assumes zero mass flow through the envelope then all heat lost from the building is in the form of radiation and a combined convection/conduction at the external surfaces.

This study identifies methods of quantification of heat flux through building thermal envelope components in terms of conductive, convective and radiative heat transfer. Each type of heat flux is considered in sufficient depth to allow quantification and development of models to be used in a database with a graphical user interface.

The author quantifies the radiative and convection/conduction heat loss at the building
external surface and then calculates the conductive heat flux through the building
structural envelope. With a knowledge of inner and outer temperatures and the quantified heat flux the author develops a model to calculate the thermal resistance, thermal conductivity and, with the surface area, the U-values.

The model developed is used in a MS-Access database to record parameters necessary to calculate U and R values for each building component. Local area environmental parameters are then used with the calculated U-value to predict annual energy loss through the building envelope in terms of kilowatt hours and in financial terms.

The study finishes with a thorough evaluation of a large commercial building with recommendations for improvement of insulation in accordance with this study and legislative requirements.