Ventilation systems and building technologies for a sustainable built environment

Transcription

1 Ventilation systems and building technologies for a sustainable built environment Ambrose Dodoo Växjö,

2 Research goal and interest To increase understanding of strategies for development of resourceefficient built environment with low environmental impacts Building energy systems modelling & simulation (Ventilation and Heating systems) Thermal comfort and indoor climate modelling Systems analysis of building Economic optimization of energy efficiency measures Lifecycle analysis of the built environment

3 Relative contributions of different sources to total primary energy supply of the world, EU-28 and Sweden 100% Solar, wind, geothermal & heat Biofuels and waste Oil Coal Hydro Nuclear Fossil gas Relative contributions of different fuels to total primary energy suply 75% 50% 25% 0% 87% 90% 82% 77% 65% 32% World EU-28 Sweden Non-Renewable Fossil fuel Data for the world and Sweden are from IEA (2013a; 2013b) & that for EU-28 is from BP (2012)

4 Design and analysis of ventilation systems Ventilation heat recovery (VHR) systems in buildings Versions of 4-storey building with mechanical exhaust ventilation VHR (FTX) system of 85% efficiency installed for building Dodoo et al. (2011). Primary energy implications of ventilation heat recovery in residential buildings. Energy and Buildings, 43(7),

5 Annual final operation energy use when using ventilation systems with and without VHR 180 Electricity for household & facility Electricity for ventilation Tap water heating Space heating 150 Final energy use (kwh/m 2 ) Conventional Conventional, VHR Passive Passive, VHR Dodoo et al. (2011).

6 Ventilation heat recovery systems in buildings Net annual primary energy savings 80 BST BIGCC Net primary energy savings (kwh/m 2 ) Conventional Passive Conventional Passive Conventional Passive Conventional Passive Electric resistance heating Heatpump District heating, 50% CHP District heating, 90% CHP Supply system: Biomass-based steam turbine (BST) or Biomass-based integrated gasification with combined cycle (BIGCC) Dodoo et al. (2011).

7 Design and analysis of ventilation systems Centralized, semi-centralised vs. decentralized ventilation systems Centralised system Analysed building in Ronneby Decentralised system Dodoo et al. (2017). Final energy savings and cost-effectiveness of deep energy renovation of a multi-storey building. Energy, 135,

8 Centralized vs. decentralized ventilation systems Designed in collaboration with InPro AB and IV produkt Decentralised system with 3 air handling units, one on each stairwell Centralized system with 1 air handling unit, on roof

9 Ventilation system with heat recovery Centralized vs. decentralised ventilation systems Energy performance & cost-effectiveness Space heating use (MWh/yr) Peak Heating load (kw) Final heat savings (MWh/yr) Increase electricity use (MWh/yr) Reference Total investment cost (k ) Centralised a /132.7 b /138.5 c Decentralised a /152.3 b /162.1 c a BAU scenario with 5% discount rate; b intermediate scenario with 3% discount rate; c sustainability scenario with 1% discount rate. Ventilation system with heat recovery NPV of total energy savings (k ) NPV of total energy savings (k ) / total investment cost (k ) BAU Intermediate Sustainability BAU Intermediate Sust Centralised Decentralised Dodoo et al. (2017).

10 Climate change implications for Swedish buildings Dodoo, A., Gustavsson, L. (2016). Energy use and overheating risk of Swedish multistorey residential buildings under different climate scenarios. Energy

11 Hourly indoor air temperature profiles in summer, (1 st June to 31 st August) without control strategies 34 Historical Recent RCP4.5_2050s RCP8.5_2050s Indoor air temperature ( o C) Hours Dodoo, A., Gustavsson, L. (2016)

12 Hours per year with and without control strategies with indoor air temperatures between o C and over 28 o C Temperature > 28 o C o C Temperature o C o C Annual operating hours No intervention Increased airing Shading Increased airing + Shading CIBSE guide: a building is overheated if indoor temperature exceeds 28 C in living areas or 26 C in bedrooms for more than 1% of the occupied time within a year Dodoo, A., Gustavsson, L. (2016).

13 Changed annual space heating and space cooling demands compared to historical data Changed space conditioning demand 150% 120% 90% 60% 30% 0% -30% Space heating Space cooling Recent RCP4.5_2050s RCP8.5_2050s Dodoo, A., Gustavsson, L. (2016)

14 Implementing of work at LNU Cooperations with surrounding society, e.g. Goda-hus, InPro AB IV produkt AB Conservator AB Wikells Byggberäkningar AB Växjö & Ronneby Kommuns Hållbart Byggande i Syd, Malmö

15 Doctoral candidate student Cooperations with Goda-hus on doctoral research Focus on nearly zero energy building Involves energy balance simulation, energy systems modelling, energy monitoring, analysis of energy profiles in existing buildings, and visualisation of energy use, production and supply in buildings

16 Analysis of ventilation systems Centralized, semi-centralised vs. decentralized ventilation systems Performances of mechanical ventilation retrofit solutions for Swedish multi-storey residential buildings Primary energy use Cost-effectiveness Indoor environment LCA of ventilation systems

17 Ventilation heat recovery systems in buildings Change in annual primary energy use for space heating and ventilation Change in primary energy use (kwh/m 2 ) Ventilation electricity, BST Space heating, BST Ventilation electricity, BIGCC Space heating, BIGCC Conventional Passive Conventional Passive Conventional Passive Conventional Passive Electric resistance heating Heat pump District heating, 50% CHP District heating, 90% CHP Supply system: Biomass-based steam turbine (BST) or Biomass-based integrated gasification with combined cycle (BIGCC) Dodoo et al. (2011).