Heat demand profiles of energy conservation measures in buildings and their impact on a district heating system. (1st January 2016)

• Record Type: Journal Article
• Authors: Lundström, Lukas; Wallin, Fredrik
• Is Part Of: Applied energy. Volume 161(2016)
• Page Start: 290
• Page End: 299
• Publication Date: 2016-01-01
• Subjects: DH district heating -- DHS district heating system -- ECM energy conservation measure -- TMY typical meteorological year -- RMSE root mean square error -- HO heat only (boiler) -- CHP combined heat and power -- FGC flue gas condensing -- EAHP exhaust air heat pump -- HRV heat recovery ventilation -- ERV energy recovery ventilation -- HDD heating degree days -- PE(F) primary energy (factor); District heating -- Energy conservation -- Weather normalisation -- Typical meteorological year -- Building energy simulation -- Energy system assessment; Power (Mechanics) -- Periodicals; Energy conservation -- Periodicals; Energy conversion -- Periodicals; 621.042
• DOI: 10.1016/j.apenergy.2015.10.024
• Languages: English
• ISSNs: 0306-2619

Abstract

Graphical abstract: Highlights: Energy savings impact on an low CO2 emitting district heating system. Heat profiles of eight building energy conservation measures. Exhaust air heat pump, heat recovery ventilation, electricity savings etc. Heat load weather normalisation with segmented multivariable linear regression. Abstract: This study highlights the forthcoming problem with diminishing environmental benefits from heat demand reducing energy conservation measures (ECM) of buildings within district heating systems (DHS), as the supply side is becoming "greener" and more primary energy efficient. In this study heat demand profiles and annual electricity-to-heat factors of ECMs in buildings are computed and their impact on system efficiency and greenhouse gas emissions of a Swedish biomass fuelled and combined heat and power utilising DHS are assessed. A weather normalising method for the DHS heat load is developed, combining segmented multivariable linear regressions with typical meteorological year weather data to enable the DHS model and the buildings model to work under the same weather conditions. Improving the buildings' envelope insulation level and thereby levelling out the DHS heat load curve reduces greenhouse gas emissions and improves primary energy efficiency. Reducing household electricity use proves to be highly beneficial, partly because it increases heat demand, allowing for more cogeneration of electricity. However the other ECMs considered may cause increased greenhouse gas emissions, mainly because of their adverse impact on the cogeneration of electricity. If biomass fuels are considered as residuals, and thus assigned low primary energy factors, primary energy efficiency decreases when implementing ECMs that lower heat demand.