Low impact energy saving strategies for individual heating systems in a modern residential building: A case study in Rome

The goal of this paper is to evaluate the advantages achieved through the adoption of low impact energy saving strategies for an independent natural gas fired boiler heating system in a recently built residential building in Rome. For this purpose, an existing apartment was selected as a case study and dynamically simulated in TRNSYS with which the model was validated. Low impact retrofit solutions and heating system management were considered as possible solutions to achieve energy savings. The chosen retrofit solutions consist of envelope elements replacements and building automation controls improvement while heating system management depends on occupants' behavior. Overall, 36 scenarios were considered, starting from the combination of 3 comfort temperature set-points, 2 insulation levels for transparent components, 2 types of zone comfort set-point control with 3 dead-band temperatures. Each case is evaluated in terms of energy results and economic results. The simulation results provide energy savings up to 44% when windows are replaced lowering their transmittance nearby 32%. The choice of a proportional control for zone temperature set-point compared to a simple on-off control guarantee energy saving up to 39% when temperature set-point is low (19 degrees C) and controls dead-band is 0.5 degrees C. The effect of different temperature control dead-bands is higher when proportional controls are adopted (up to 40% passing from 2 to 0.5 degrees C dead-band for 19 degrees C set-point). Energy consumption reductions up to 63% are achieved if the indoor temperature set-point is lowered 2 degrees C, underlining the importance of occupants' behavior. At last, an analysis on socio-economic impacts was performed, based on the results of a previous study focused on the externality costs due to pollutants emissions. (C) 2019 Elsevier Ltd. All rights reserved.