Abstract
This paper presents a case study of a single-family house, where the effect of using thermal energy storage integrated in the floor is evaluated regarding GHG-emissions during the life cycle. The house has a lightweight wood frame construction, is well insulated, and fulfils the Norwegian energy regulations from 2010. Different floor configurations have been studied, both regarding energy demand and emissions. Floors with PCM panels have been compared with a reference case without thermal energy storage integrated in the floor, and have also been compared with concrete and wood as replacement for the PCM panels. The effect of changing the thickness of the PCM, concrete and wood has also been investigated (5 mm, 25 mm and 50 mm), as well as the effect of changing the emission factor of the energy supply to the building. The simulations have been carried out with three different climates: Oslo in Norway, Prague in the Czech Republic and Rome in Italy. The conclusions are:
• PCM gives the highest energy savings, compared with concrete and wood, but have also significantly higher GHG-emissions related to production of the materials. Due to this, the total GHG-emissions is very dependant on the emission factor for the energy supply to the building.
• When the emission factor of the energy supply is 0.050 kg CO2 eq/kWh, the PCM causes increased GHG-emissions at 25 mm and 50 mm thickness. The wood and the concrete give only small reductions in emissions at all thicknesses.
• When the energy supply to the building is 0.500 kg CO2 eq/kWh, the PCM causes the highest reduction in GHG-emissions at 5 mm and 25 mm thickness, and concrete causes the highest reduction at 50 mm thickness.
• The reduction in energy demand and emissions is slightly higher in Prague than in Oslo, but significantly higher in the hot climate in Rome.
• PCM gives the highest energy savings, compared with concrete and wood, but have also significantly higher GHG-emissions related to production of the materials. Due to this, the total GHG-emissions is very dependant on the emission factor for the energy supply to the building.
• When the emission factor of the energy supply is 0.050 kg CO2 eq/kWh, the PCM causes increased GHG-emissions at 25 mm and 50 mm thickness. The wood and the concrete give only small reductions in emissions at all thicknesses.
• When the energy supply to the building is 0.500 kg CO2 eq/kWh, the PCM causes the highest reduction in GHG-emissions at 5 mm and 25 mm thickness, and concrete causes the highest reduction at 50 mm thickness.
• The reduction in energy demand and emissions is slightly higher in Prague than in Oslo, but significantly higher in the hot climate in Rome.