Automated Generation of an Energy Simulation Model for an Existing Building from UAV Imagery

Abstract

An approach to automatically generate a dynamic energy simulation model in Modelica for a single existing building is presented. It aims at collecting data about the status quo in the preparation of energy retrofits with low effort and costs. The proposed method starts from a polygon model of the outer building envelope obtained from photogrammetrically generated point clouds. The open-source tools TEASER and AixLib are used for data enrichment and model generation. A case study was conducted on a single-family house. The resulting model can accurately reproduce the internal air temperatures during synthetical heating up and cooling down. Modelled and measured whole building heat transfer coefficients (HTC) agree within a 12% range. A sensitivity analysis emphasises the importance of accurate window characterisations and justifies the use of a very simplified interior geometry. Uncertainties arising from the use of archetype U-values are estimated by comparing different typologies, with best- and worst-case estimates showing differences in pre-retrofit heat demand of about ±20% to the average; however, as the assumptions made are permitted by some national standards, the method is already close to practical applicability and opens up a path to quickly estimate possible financial and energy savings after refurbishment.

Development of Multi-objective Optimization model integrating Construction Time, Cost, Quality and Risk using Ant Colony Algorithm

“…In addition to that, Correlation analysis is to be done to nd the interrelationship among the Time, Cost, Quality, and Risk components. Also, Different studies have done sensitivity analyses [33,34] concerning objective weight and population size. Here, Sensitivity analysis is mainly done to nd the impact of deviations from the TCQR on optimal solutions.…”

Integration of Heat Flow through Borders between Adjacent Zones in AixLib's Reduced-Order Model

“…Previous efforts to include interzonal heat transfer into the TEASER/AixLib tool chain were made in connection with measurements at an exemplary single-family building (Gorzalka et al 2021) 3 and 4 for an explanation of the variables and indices. core RC model.…”

“…Option 3 seemed most promising as a consequence. In our implementation, we keep the thermal network (shown for three elements in Figure 3) and add a possibility to connect multiple thermal zones, in this regard following the vectorization idea presented by Gorzalka et al (2021). Each zone border element is modelled as part of the RC model of the zone with the lower index through the Multizone model (see Figure 2) to avoid double modelling.…”

Field Work’s Optimization for the Digital Capture of Large University Campuses, Combining Various Techniques of Massive Point Capture

“…The modeling phase in NEST requires a prior graphic survey of the current state [13]. Depending on the reason for using the model, it will require a sufficient degree of precision to accurately determine the geometric configuration of buildings and their surroundings [14].…”

“…TLS data has the highest point density and can be used to specify data for those urban elements at individual level [46][47][48]. Some publications claim that TLS sometimes has poor mobility and occlusion issues that make The modeling phase in NEST requires a prior graphic survey of the current state [13]. Depending on the reason for using the model, it will require a sufficient degree of precision to accurately determine the geometric configuration of buildings and their surroundings [14].…”