Thermal Performance Assessment of Curtain Walls of Fully Operational Buildings Using Infrared Thermography and Unmanned Aerial Vehicles

Abstract

Architecture’s race skyward has brought with it a variety of functional innovations, one such being glass curtain wall systems. During such building’s operating life, failures of insulation systems create areas of reduced resistance to heat transfer, or thermal bridges. These failures enable energy flows that trigger unanticipated temperature changes and increased energy consumption and ultimately, damage the façade structure and cause problems to occupants. Discussion includes design and test method for rapidly identifying thermal bridges in façade systems, with minimum or no-disturbance of occupants. Research focus is set in determining if the damages are just local failures or if they are related to a poor systematic construction assembly. A non-traditional approach is adopted to survey an entire fully operational building using infrared thermography and an Unmanned Aerial Vehicle (UAV). The system is comprised of a non-contact infrared camera mounted on and operated from the UAV. It enables the registration of the emissivity of the façade materials and calculation of the thermal radiation and equivalent factors to estimate localized temperatures. The registration process yields thermal imaging results of the actual state whose temperature will be analyzed quantitatively using graphs and compared with the ASHRAE standards, retrieving the perfect state using THERM software. After evaluation of the results a statistical analysis will be performed, to inform the Architecture, Engineering, and Construction (AEC) community about the areas of most common failures for existing structures. It is expected that the results will also identify improvements for construction methods by projecting better and more efficient processes.