As-Is 3D Thermal Modeling for Existing Building Envelopes Using a Hybrid LIDAR System

Abstract

This paper introduces a hybrid method for rapidly measuring thermal data and three-dimensional (3D) geometries of buildings, allowing “virtual” representations of the energy and environmental performance of existing buildings. The 3D thermal models can be further used for many applications by building occupants, owners, and outside consultants to make retrofit decisions. Existing buildings represent the greatest opportunity to improve building energy efficiency and reduce environmental impacts. This research aims to help decision makers improve their buildings by providing reliable, visual information about their buildings’ energy performance using the developed hybrid light detection and ranging (LIDAR) system. The 3D thermal model described consists of point clouds of building geometry with thermal data on each point, including temperature values (°C) and thermal color generated on the basis of the temperature value. Window detection algorithms were developed in this study to create virtual thermal points on window glasses because a LIDAR system is unable to collect geometric data from transparent objects. The system’s technical feasibility has been successfully demonstrated through intensive lab and field experiments on residential and small commercial buildings.