Computer-aided decision supporting tool for nearly Zero Energy Building renovation

Transcription

1 A global multidisciplinary network on housing research and learning Computer-aided decision supporting tool for nearly Zero Energy Building renovation Suzana Domjan, Ciril Arkar, Sašo Medved Faculty of Mechanical Engineering, Laboratory for Sustainable Technologies in Buildings, University of Ljubljana, Slovenia 23 rd September 2016, Manchester, UK Third International Conference Global dwelling

2 TOOL DEVELOPMENT BACKGROUND Final energy consumption, EU-28, 2014 (% of total) (source: Eurostat (online data code: nrg_100), 2016)

3 TOOL DEVELOPMENT BACKGROUND According to EPBD Recast (Directive 2010/31/EU) Member States shall ensure that: (9.1.a) by 31 December 2020, all new buildings are nearly zero energy buildings; and (9.1.b) after 31 December 2018, new buildings occupied and owned by public authorities are nearly zero-energy buildings. Nearly zero-energy building (nzeb) means a building that has (2.2): very high energy performance, nearly zero or very low amount of energy required should be covered to a very significant extent by energy from renewable sources, including energy from renewable sources produced on-site or nearby.

4 TOOL DEVELOPMENT BACKGROUND (9.2 & 9.3) Member States shall ensure detailed application in practice of the definition of nearly zero-energy buildings, reflecting their national, regional or local conditions, and including a numerical indicator of primary energy use expressed in kwh/m 2 per year. Primary energy factors used for the determination of the primary energy use may be based on national or regional yearly average values and may take into account relevant European standards. Building type Single family building Multi family building Nonresidential building Max. primary energy use (kwh/m 2 a) New building Major reconstruction Min. share of RES (%) RER (REHVA definition) Indicators for nzeb (Slovenia) (source: nzeb AP, 2014) Status of nzeb definition for new buildings, as of April 2015 (source: BPIE, 2015)

5 TOOL DEVELOPMENT BACKGROUND Directive 2009/125/EC (recast) establishing a framework for the setting of ecodesign requirements for energy-related products points out: (3) Energy-related products account for a large proportion of the consumption of natural resources and energy in the Community. (4) Many energy-related products have a significant potential for being improved in order to reduce environmental impacts and to achieve energy savings through better design which also leads to economic savings for businesses and end-users. In addition to products which use, generate, transfer, or measure energy, certain energy-related products, including products used in construction such as windows, insulation materials, or some water-using products such as shower heads or taps could also contribute to significant energy savings during use. (7) Action should be taken during the design phase of energy-related products, since it appears that the pollution caused during a product s life cycle is determined at that stage, and most of the costs involved are committed then.

6 TOOL DEVELOPMENT BACKGROUND According to Commission Delegated Regulation (EU) No 244/2012 supplementing EPBD on the energy performance (2): It is the responsibility of Member States to set minimum energy performance requirements for buildings and building elements. The requirements must be set with a view to achieving cost-optimal levels. National minimum energy performance requirements should not be more than 15 % lower than the outcome of the cost-optimal results of the calculation taken as the national benchmark. The cost-optimal level shall lie within the range of performance levels where the cost-benefit analysis over the lifecycle is positive. specific costs in a life-cycle ( /m 2 ) % Q' p (kwh/m a)

7 TOOL DEVELOPMENT BACKGROUND (source: DGNB, 2015) energy environment cost TOOL

8 TOOL DEVELOPMENT BACKGROUND (source: DGNB, 2015) energy environment cost TOOL E tool BEPT LCAT

9 TOOL Building energy performance tool Building envelope LCI LCIA LCCA list of LCA materials in database; reference quantity: 1 m 3 or 1 m 2 list of LCA windows/ doors ; reference quantity: 1 m 2 BEPT Energy carriers LCI LCIA LCCA data in database added for all energy carriers reference quantity: 1 kwh/a of final energy Appliances and systems LCI, LCIA, LCCA heating system reference quantity: heat generator power solar heating system reference quantity: solar collectors area, heat exchanger volume PV system reference quantity: PV panels area

10 TOOL

11 TOOL Automatic start of LCAT and data transfer Designer input Building energy performance tool Life cycle assessment tool BEPT LCAT - E tool Building envelope LCI LCIA LCCA list of LCA materials in database; reference quantity: 1 m 3 or 1 m 2 list of LCA windows/ doors ; reference quantity: 1 m 2 Energy carriers LCI LCIA LCCA data in database added for all energy carriers reference quantity: 1 kwh/a of final energy Appliances and systems LCI, LCIA, LCCA heating system reference quantity: heat generator power solar heating system reference quantity: solar collectors area, heat exchanger volume PV system reference quantity: PV panels area Existing building New building Reference project (RP) Present project (PP) LCEA - RP LCEA - PP LCIA Desired energy class Selection of assessment method LCCA Economic parameters Report LCA period

12 METHODS ENERGY ASSESSMENT (LCEA) Two time intervals are common for energy performance calculations: Monthly methods can be performed with simple tools taking into account average monthly data of ambient and indoor temperatures and solar radiation. Hourly methods can be performed using sophisticated computer tools that analyze quasi-unsteady heat transfer in building elements and dynamic thermal response of the building and use hourly meteorological data and hourly profiles of operation, occupancy and internal heat gains building use.

13 METHODS ENERGY ASSESSMENT (LCEA) Regardless which method is used, indicators are determinate in three steps that are in opposite direction comparing to actual energy flows. Energy efficiency indicators for buildings are calculated at three levels: energy needs for heating Q NH and cooling Q NC are compared to national defined maximum allowed values; the values are expressed as yearly specific needs per 1 m 2 of building conditioned area; Q NH Q NC heating, ventilation, hot water, cooling, airconditioning, lightning actual energy flow Q f, i computational energy flow determination of delivered energy Q f (energy supplied to the building through the last market agent); consumption of each energy carrier needed for operation of installed systems are calculated based on energy needs and properties of installed system components; knowing the type and amount of each energy carrier needed for building operation, primary energy needs Q p and CO 2 emissions are calculated as specific values calculated per 1 m 2 of building conditioned area. Q p CO 2

14 METHODS ENVIRONMENTAL ASSESSMENT (LCIA) For environmental assessment we decided to use Type III Life-cycle data declarations (ISO 14025, EN 15804). They present the environmental performance of a product to enable objective comparisons between products fulfilling the same function. EPDs are: based on independently verified life-cycle assessment (LCA) data, life-cycle inventory analysis (LCI) data, converted LCI data to reflect the life-cycle impact assessment (LCIA) of a product or information modules; developed using predetermined parameters; subject to the administration of a programme operator, such as a company or a group of companies, industrial sector or trade association, public authorities or agencies, or an independent scientific body or other organization. Example of Environmental Product Declaration (source: construction-environment.com)

15 METHODS ENVIRONMENTAL ASSESSMENT (LCIA) Environmental impact parameters: Global Warming Potential (GWP, kg eqco 2 ), Ozone Depletion Potential (ODP, kg eqcfc-11), Acidification Potential (AP, kg eqso 2 ), Eutrophication Potential (EP, kg eq(po 4 ) 3- ), Photochemical Ozone Creation Potential (POCP, kg eqc 2 H 4 ), Recycling (D) Abiotic Depletion Potential Elements (ADPE, kg eqsb), Abiotic Depletion Potential Fossil (ADPF, MJ). Raw materials (A1-A2) Database in E-tool at the time covers A1-A3 stages of life-cycle, but it can be expanded by user. End-of-life (C1-C4) Building liftime (B1-B7) Manufacturing (A3) Logistics (A4) Installation (A5) (source: thinkstep.com, 2016) Different approximation polynoms were used for different building elements. For example GWP for windows: GWP w = A w f g GWP g + A w 1 f g d f GWP f + GWP s kg eqco 2 glass frame spacer or ODP for heat generators or heat pumps: ODP = a 0 + a 1 P + a 2 P 2 nominal power kg eqcfc 11

16 METHODS COST ASSESSMENT (LCCA) Cost assessment of measures follows the Delegated Regulation (EU) No 244/2012, Annex I Cost-optimal methodology framework: C g τ = C I + j τ i=1 C a,i j R d i V f,τ (j) R d p = r 100 p where are: t calculation period C g (t) global cost (referred to starting year t = 0) over the calculation period C I initial investment costs for measure or set of measures j C a,i (j) annual cost during year i for measure or set of measures j V f,t (j) residual value of measure or set of measures j at the end of the calculation period (discounted to the starting year t = 0) R d (i) discount factor for year i based on discount rate r p number of years from the starting period r real discount rate

17 METHODS COST ASSESSMENT (LCCA) Similar approximation polynoms were used for different building elements as at environmental assessment. Example for windows: C I = b 0 + b 1 d w,h = b 0 + b 1 4 A w O w = b 0 + b 1 4 A w 1 f g A w d f + 4 d f EUR Price determination for windows with a wooden frame and a two-layer glazing, depending on the hydraulic diameter of the window or solar collector and heat storage: 2 C I = 1.25 b 1 A SC EUR C I = b 0 + b 1 V HS + b 2 V HS EUR

18 TOOL ENERGY ASSESSMENT (LCEA)

19 TOOL ENVIRONMENTAL ASSESSMENT (LCIA)

20 TOOL ENVIRONMENTAL ASSESSMENT (LCIA)

21 TOOL COST ASSESSMENT (LCCA)

22 STUDY CASE OPTIMIZATION OF MULTI-FAMILY BUILDING ENVELOPE REFURBISHMENT Reference project: building without thermal insulation and old wooden windows (U w = 3.0 W/m 2 K). Energy needed for heating: Q' NH = kwh/m 2 a District heating Conditioned area: 1,950 m 2 LCA period: 30 years Thermal insulation thickness optimization on the basis of the criteria of cost-effectiveness in the life-cycle (30 years for residential buildings). The optimum thickness of 25 cm was achieved at maximum cost saving in 30 years (52 EUR/m 2 in 30 years). Cost optimization of the windows replacement shows that windows with double glazing are more cost effective and provide the same reduction in specific primary energy needed for the building operation. Macroeconomic greenhouse gas emissions costs indicator also gives priority to this technology.

23 FUTURE In future we plan to expand E-tool with environmental indicators that are currently not commonly represented in Environmental Product Declarations, such as emissions of particular matter. We would also like to expand the software with database on services and maintenance that could be selected by user, when applicable. From research point of view we would like to integrate cost evaluation of the indoor environment quality in terms of health, productivity and well-being.

24 Thank you for your attention! If you would like more information about the content of this presentation please contact: or visit our web site This project is funded with support from the European Commission (Project number LLP ES-ERASMUS). This publication reflects the views only of the authors, and the Commission cannot be held responsible for any use which may be made of the information contained therein.