CoolHeatOutIn Quantifying the impact of temperature-reducing measures in outdoor spaces on indoor cooling and heating energy requirements

Markus Koschenz 

University of Lucerne 

Abstract

The impacts of climate change can be minimized by planting vegetation such as trees and greening, designing buildings to take advantage of cold air currents and shading, and selecting optimal colors and materials for exterior surfaces. Since Switzerland has distinct summer and winter seasons, these solutions must be balanced to reduce cooling energy demand during hot periods without significantly increasing heating energy demand due to a lack of passive heat gains. As part of the project, various outdoor space simulations are being conducted for different architectural types and outdoor space concepts using the QKM software. QKM is a software solution developed by HSLU for the early planning phase. It is characterized by high computational speed, thereby enabling variant studies and annual simulations. These simulations of the outdoor environment form the basis for subsequent thermal building simulations using IDA-ICE. The simulations quantify the influence of the outdoor environment on the indoor cooling and heating energy demand of a reference building. Initial project results show that the cooling energy demand significantly exceeds standard values due to rising outdoor temperatures and the influence of the heat island effect. There is also a clear dependence on local shading of buildings by trees. It also becomes clear that open tilt windows provide only minimal benefit at night, whereas fully open windows can significantly reduce cooling energy demand. The presentation shows the results and provides a brief overview of QKM.

Bio

Markus Koschenz holds degrees in heating, ventilation, and air conditioning engineering and business engineering. He worked for fourteen years at the Swiss Federal Laboratories for Materials Testing and Research (EMPA) in the field of energy and building technology, focusing on building simulation, the development of concepts for thermally active building elements, and the implementation of the 2000-watt society in buildings. During his fourteen years at the construction company Implenia, he managed the HVAC department and the general contracting division for large-scale projects. Since mid-2020, he has been a professor at the Lucerne University of Applied Sciences and Arts (HSLU). His research focuses on the development of solutions to mitigate climate change in building and energy technology, as well as on the digitalization of the planning process with a focus on automated planning and simulation.