Disputation i byggteknik: Uniben Tettey

Titel: Primary Energy Use of Residential Buildings – Implications of materials, modelling and design approaches
Ämne: Byggteknik
Fakultet: Fakulteten för teknik
Datum: Onsdagen den 15 mars 2017 kl 13.00
Plats: Sal M1083 (Södrasalen), hus M, Växjö
Opponent: Professor Jan-Olof Dalenbäck, Chalmers
Betygsnämnd: Professor Anne Grete Hestnes, Norges teknisk-naturvitenskapelige universitet, Trondheim, Norge
Professor Folke Björk, KTH, Stockholm
Professor Jesper Arfvidsson, Lunds universitet
Ordförande: Professor Ann-Charlotte Larsson, Institutionen för byggd miljö och energiteknik, Linnéuniversitetet
Handledare: Professor Leif Gustavsson, Institutionen för byggd miljö och energiteknik, Linnéuniversitetet
Examinator: Dr Krushna Mahapatra, Institutionen för byggd miljö och energiteknik, Linnéuniversitetet
Spikning: Onsdagen den 22 februari 2017 kl 10.00 på Universitetsbiblioteket i Växjö

Abstract

The building sector is a major user of primary energy and large emitter of greenhouse gas emissions. The construction, operation and disposal of buildings are associated with various energy- and material-related sustainability challenges. Climate change may affect buildings in diverse ways, including their thermal performance, indoor environment and deterioration of building components. Thus, buildings can play a crucial role in the transition to a sustainable society. Different strategies, including improved energy efficiency, substitution of carbon intensive materials and fuels, efficient energy supply can be employed for this purpose. In this thesis, implications of different insulation materials, modelling and design strategies on primary energy use of residential buildings are studied using a system analysis methodology with a life cycle perspective. The analyses focus on production primary energy and CO2 emission implications of different insulation materials in optimising building envelope components. Uncertainties related to modelling input parameters and assumptions and how they influence energy balance calculations of buildings as well as energy savings of different energy efficiency measures are also studied. Further, various design strategies and measures are analysed to optimise the operation and production energy use of buildings as well as their interaction with different energy supply systems under current and future climate scenarios.

The results show that application of extra insulation to building envelope components reduces operating primary energy use but also leads to increased primary energy and CO2 emissions from insulation material production. Input data and assumptions for building energy balance simulations vary widely in the Swedish context giving significant differences in calculated energy demand. Among the considered parameters, indoor air temperature, internal heat gains and efficiency of ventilation heat recovery have significant impacts on simulated building energy performance as well as on energy efficiency measures. Significant reductions are achieved in operation final and primary energy demands while overheating is avoided or greatly reduced when different design strategies and measures are implemented. Overall, the results suggest that significant primary energy reductions are achievable under climate change, if new buildings are designed with appropriate strategies.