b'method allows for a more reliableestimation of U-values, even incomplex building assemblies withsignificant insulation.THE INFRARED INDEX:A NEW METRIC FORHOLISTIC BUILDING PERFORMANCE ASSESSMENTIn addition to advancing U-value estimation, the researchers introduced the Infrared Index (IRI), a novel metric designed to provide a holistic assessment of building envelope performance. The IRI considers all sources of heat loss, including doors, windows and other thermal anomalies, and ranks building envelopes based on their overall thermalFIGURE 3RANKING OF THE WALL BASED ON IRI (HIGHER IRI efficiency (Figure 3). This rankingINDICATES POORER OVERALL THERMAL PERFORMANCE).system is particularly useful for large- as wind and temperature variations,To overcome these challenges, methods scale surveys, where quickly identifyingcan significantly affect the accuracy ofwere developed to stabilize the infrared the most energy-inefficient buildings isthermal readings. For instance, drone- cameras during flight. By using shields to essential for prioritizing retrofits. induced wind during flight can causeminimize the effects of wind and turbu-The IRI is based on the assumption oftemperature deviations, leading to lesslence, it was possible to significantly steady-state conditions, which allowsaccurate measurements compared toreduce the deviation between dynamic for consistent ranking across differentstationary IRT. and stationary measurements (Figure 4). environmental conditions. This makes the IRI a reliable tool for energy auditors, building managers and policymakers who need to assess the thermal perfor-mance of large numbers of buildings in a short period. By providing a more nuanced understanding of how various factors contribute to energy loss, the IRI enables more informed decision-making when it comes to retrofitting strategies, ensuring that interventions are both effective and cost-efficient.DYNAMIC INFRARED THERMOGRAPHY WITH UAVS: EXPANDING THE(A)SCOPE OF ENERGY AUDITSOne of the most promising advance-ments presented in the research is the integration of IRT with Unmanned Aerial Vehicles (UAVs). UAVs equipped with infrared cameras offer a new dimen-sion in building energy audits, allowing for rapid, large-scale thermal assessments that cover areas difficult or dangerous to access manually. This technology is particularly valuable for surveying tall buildings, complex structures and large industrial sites.However, the research also highlighted(B)several challenges associated withFIGURE 4DYNAMIC IRT MEASUREMENTS USING UAVS: (A) TEMPERATURE DATA ARE AFFECTEDdynamic IRT measurements usingBY DRONE-INDUCED WIND DURING THE FLIGHT. (B) THE SHIELD MINIMIZES THE EFFECTUAVs. Environmental conditions, suchOF SUDDEN TURBULENCE AROUND THE CAMERA DURING THE FLIGHT.FALL/WINTER 2024 15'