ISES SWC 2011: Notification of Acceptance and Paper Instructions

Dear Dr. Filetóth, On behalf of the ISES Solar World Congress 2011 Scientific Committee, we are pleased to inform you that your abstract with the ID 28730, titled:

• Quick Building Energy Analyses for Architects at the Early Design Stage has been accepted as an oral presentation. The reviewer and topic chair comments can be found at the end of this mail. Please consider the comments during the preparation of you paper. Every paper will be granted one discount, which can be used during your conference registration. The discount code for your paper is as follows: B5AB519. Please note that this discount can only be used once. Following the initial review of your abstract we are inviting you to submit a full paper (max. 12 pages) for inclusion in the ISES Solar World Congress 2011 proceedings. The proceedings are an important part of the conference and we expect each presentation to be accompanied by a full paper. The proceedings will be published online in the Download Area of the conference website as well as on a CD available in the ISES book shop. Please find the template for the preparation of your manuscript in the document: “ISES SWC_Paper_Instructions.doc ”. Follow the instructions carefully and prepare your paper using this template only! Manuscripts have to comply with typical quality standards for scientific publications and English language. Purely commercial or otherwise inadequate contributions will be rejected. The paper upload will open on May 23, 2011. The manuscript must be uploaded to www.swc2011.org as a .pdf document by August 15, 2011! Papers which do not meet the requirements or which are not uploaded in time cannot be considered for the ISES SWC 2011 proceedings. Please note that you have to accept a copyright agreement during the paper upload. For submission, please visit http://cms.swc2011.org/paper. If you have any questions or concerns, please do not hesitate to contact info@swc2011.org. We look forward to seeing you at the conference! Best regards Klaus Vajen (Congress Chair) and the ISES SWC 2011 Organizing Team No comments from reviewers

Quick Building Energy Analyses for Architects at the Early Design Stage Levente I. Filetoth PhD

Budapest University of Technology and Economics, Faculty of Architecture,

Department of Building Energetics and Services, Budapest (Hungary)

1. It’s time to go green

“In 2005, for the first time in human history, more people will live in urban areas than in rural areas. This transformation has already had a huge impact on the planet's resources, as well as an impact on our perspective of nature and the environment. No prior human experience offers a guide on how to feed, house and sustain so many people in so many cities. This generation must be committed to the task of bringing urban areas into balance with the natural environment."1

The design, construction, and the maintenance of buildings have a tremendous impact on our environment and our natural resources. Buildings use one-third of all the energy consumed in the U.S., and two-thirds of all electricity. By the year 2011, over 40 million buildings are expected to be constructed. And buildings are also a major source of air pollution that contributes greatly to climate change. "Typical" buildings consume more of our resources than necessary and generate a large amount of waste. Sustainable architecture is the practice of designing, constructing and maintaining buildings in a way that their environmental impact is minimized. Designing for sustainability helps preserve the environment and improve quality of life.

Fig. 1: Environmental impact: natural resources are exploited, 40% of global raw materials is consumed by buildings

“We must make the rescue of the environment the central organizing principle for civilization.”2 Governments and Authorities have long realized the importance of sustainable design and gradually founded organizations and created standards for developing high-performance, sustainable buildings. Green Building Council is a national sustainable design organization in the U.S. that developed the voluntary LEED (Leadership in Energy and Environmental Design) Green Building Rating System®. LEED emphasizes state-of-the-art strategies for sustainable site development, water conservation, energy efficiency, materials selection and indoor quality of environment. Currently all new U.S. federal buildings must achieve a LEED “Silver" certification.

Fig. 2: Governments and authorities have long realized the importance of sustainable design

‘‘Going green’’ has been a popular trend in the real estate industry in recent years. This is reflected in the dramatic increase in the number of green buildings worldwide. As of September 2009, there were over 3,800 LEED certified commercial projects worldwide, increasing from about 400 in 2005. The number of properties that had registered with the U.S. Green Building Council (USGBC) had increased from approximately 3,300 to more than 25,600 during the same period of time. “Environmental responsibility is the future of real-estate - the choice is not whether, but when.”3

1 United Nations Environment publication for World Environment Day, 2005 2 United States Department of the Interior 3 Douglas Durst, President, The Durst Organization, Inc.

The inclination to “go green” has not been lost on Building owners either. In addition to the marketing potential of green buildings there is a clear financial benefit. According to the report commissioned by the Sustainable Building Task Force, which represents over 40 California governmental agencies, a building that incorporates "green" features costs on average 2% more to build, but over the 20-year life of the building those same features pay back the investment more than 10 times over. The report found that building green is most cost-effective when architects and contractors integrate green features into the design as far in advance as possible.

2. Sustainable design and building energy standards

“Intelligent use of energy must be regarded as a fundamental element in formulating the energy objectives of the European Union.”4

As leaders of the design process, architects have a major affect on building sustainability. Green design can lead to a better environment, increased productivity and a reduction in maintenance costs. Following this green trend, building owners also understand the ecological importance of green buildings, their marketing potential and, no less importantly, the financial benefits. As a result, the demand for green-oriented design is growing significantly and sustainability knowledge and experience is already a competitive advantage.

Fig. 3: Econia Business Park - ecological office building, C&J Architects - Helsinki, Finland

Sustainable design is the method that enables architects to streamline their projects and make them more environmentally-friendly. Each LEED-rated project is investigated and rated according to these principles: sustainable sites, water efficiency, energy and atmosphere, materials and resources, indoor environment, innovation in design, regional priority. Low-energy solutions are rewarded the most points in LEED, which indicates that energy is the most important topic of sustainable design.

Building energy standards can be classified as either stationary or dynamic. Presently, several regional and global calculation methods coexist worldwide. The most popular single-zone stationary method is EN 13790, which has been adopted by numerous European national standards and the Passivhaus Institute, as well. It is based on a simplified algorithm that can easily be used in Excel spreadsheets or even manually. Its localized versions are capable of producing accurate results, but only within a narrow range of climate conditions.

Fig. 4: Regional versus global building energy standards

Dynamic multi-zone analysis, on the other hand, is a global energy calculation solution. It is based on a complex physical model that enables virtual reality simulation of the buildings’ energy balance. The most advanced energy standards that describe such methodology are ANSI, ASHRAE 90.1, 189.1, and DIN V

4 Bendt Bendtsen, European Union Presidency, Minister for Economic and Business Affairs, DK

18599 with EnEv 2009. The first two have been adopted by the World Green Building Council, while the third is used in Germany.

Building energy regulations define the performance criteria that the projects must fulfill in order to obtain a building permit. As is the case with most such regulations, these threshold values are bound to get more and more stringent with time. The European Union Directive 2010, 31, for example, requires all newly built residential buildings to be at nearly zero energy level, by 2020.

"The Green Buildings concept is no longer earth-berm houses and grass roofs, but an intelligent business decision."5

3. Building energy information modeling

"We were determined to create a new, livable and efficient home. Being able to model your design, site, environment and green strategies all within a single BIM (Building Information Model) made attaining this goal much easier."6

Building energy calculations and energy-based design decisions are becoming a mission-critical part of architectural design. Providing correct information about the energy performance of their building, which – obviously - can become a rather complex task in the event of large-scale developments as shown on the illustrations.

Fig. 5: Architectural design phases and the corresponding building energy analyses method required

The truth of sustainable design is that approximately 80% of the design decisions that influence a building's energy performance are made by the architect in the early design phase; the remaining 20% are made by engineers at the later phases of design. Therefore, it is critical for architects to be able to utilize quick and reliable energy performance evaluation workflows at the earliest stage of the building design process, regardless the software tool they are using.

The architectural software applications evolved from plain, “2D” tools to intelligent, 3D solutions, capable handling the entire, “virtual model” of the design. Building Information Models (BIM) represent not only the 3D geometry of the elements but it can also contain additional “meta-data”: thermal-, acoustic- and visual characteristics of the materials and surfaces as well as the price- and other manufacturing specific information of the applied structures. It is crucially important to seamlessly integrate BIM technology with sustainable design and provide analysis tools for new constructions and also for refurbishment design projects.

Architects should not leave the BIM environment to access and determine the energy characteristics of their initial design. At the early design stage the design concept may greatly be modified in a short period of time: design professionals simply can’t afford – due to time and financial reasons – to heavily involve energy consultants at this design stage. According to the present practice energy experts typically receives the nearly finalized design documentation at a later design stage only, when conceptual design changes can not be performed any more. Architects must be able to bring design decisions based on the energy characteristics of

5 Brian Malarkey, AIA, LEED-accredited, Kirksey Architects, U.S. 6 Carol Richard, Richard Wittschiebe Hand (RWH) Architects, WI, USA on Wisconsin's first LEED Platinum Home

their initial design quickly and efficiently, without involving energy consultants.

“EcoDesigner” (developed by Graphisoft R&D, www.graphisoft.com) realizes such building energy information modeling tool focusing on the design workflow of architects. EcoDesigner’s calculation methodology incorporates dynamic simulation, which is the most up-to-date technology for building energy calculation. EcoDesigner is also fully integrated with ArchiCAD: GRAPHISOFT industry-leading BIM design and documentation software solution for architects.

"We were determined to create a new, livable and efficient home. Being able to model your design, site, environment and green strategies all within a single BIM model made attaining this goal much easier."7

4. One-click energy analyses for architects

“EcoDesigner” uses a straight-forward, simple calculation method that can be initiated with a single-click and the results are instantly displayed on the screen. EcoDesigner implements a three-step workflow to determine the energy characteristics of the project: model analysis, energy calculation and displaying the results.

Fig. 6: Three-step workflow to calculate the energy-characteristics of the design project: model analysis, evaluation, results

4.1. Model analysis The model analysis is performed – derived from the BIM model - in a fully automated manner. It does not require any interaction from the side of the architect. At the same time the “Model Review” palette enables manual optimization of the automatically generated building energy model.

Fig. 7: The “Model Review” palette enables manual review and optimization of building shell elements

Using this palette designers can review and modify the classification groups of the building shell elements generated automatically from the BIM project (roofs, walls, intermediate and basement floor slabs, interior structures). The eye icon can be used to show or hide a certain element group for better visual feedback and understanding of the project. Element groups in each of the above broad categories are displayed on screen in the colors indicated on the palette. The color-coded building energy model display - on the floor plan and in 3D. EcoDesigner automatically updates the building energy model if the architectural design changes,

7 Carol Richard, Richard Wittschiebe Hand (RWH) Architects, WI, U.S. on Wisconsin's first LEED Platinum Home

therefore the calculation results will always reflect the latest design stage.

Building shell elements – components of the building envelope - are automatically listed in groups with their default physical properties. All elements that are identical in terms of orientation, element type, fill and thickness are aggregated and listed as a single entry, with additional properties that are relevant for the energy evaluation: Area, Thickness, U-value, Surface and Infiltration. These values may be reviewed or changed with the help of the extensive built-in material database to assemble composites, and the U-value Calculator to control their heat transfer characteristics. It is also possible to set the heat transfer coefficient of multiple structure groups directly, using the U/R-value override function.

Fig. 8: Building shell elements are listed with their default physical properties

4.2. Thermal property assignment Every material as well as skin characteristics of composite structures are automatically derived from the central BIM project, however these material properties can also be changed manually, and the effect of such modification can be seen in the building energy analyses instantly. Thermal conductivity, density and heat capacity of the applied materials and skins can be reviewed and modified.

Fig. 9: U-value Calculator, Thermal Property Assigment and Material Catalog

The “Thermal Property Assignment” panel lists all the material types of the design project. Each listed material is shown with the relevant physics properties that are assigned to it. Here any value can be edited, either directly or by choosing defined values from the “Material Catalog” provided. Any change here will automatically be reflected in all project elements that include the edited material.

4.3. Openings, fenestration and shading EcoDesigner compiles the list of fenestration and external doors automatically for all of the openings on the

building shell, by orientation and opening type. For each orientation: the opening type’s total surface area; the shading device used; the ratio of the transparent glass surface area; the heat transmission coefficient; the total solar transmission ratio and the infiltration values are displayed.

Fig. 10: Openings, fenestration and shading characteristics

The “Openings Catalog” can be used to assign performance data to openings, moreover specific product properties can also be provided manually and then equip fenestration with fixed or mobile shading devices, in order to control solar gains.

4.4. Additional data input Besides the thermal characteristics of the building shell and openings - some project specific data has to be provided before starting the very first building energy calculation. The project north, grade level to project zero, wind protection and surrounding surfaces settings define basic site characteristics and the building's situation on the site, while façade shadings determine shadows on the building's elevations.

Fig. 11: Project location and function related additional data input

Location-specific weather data - ASHRAE standard-compliant IWEC air temperature, relative humidity, wind speed, and solar radiance data for default cities are included in the program's built-in database. If a custom location is entered using geographical coordinates, EcoDesigner downloads its weather data from an online weather server and adds it to the built-in content for future reference.

The activity type defines the building function or multiple functions (offices, residential buildings, hospitals, schools, various industries, etc.) to assign day-by-day internal temperature and internal heat gain profiles

(including human and equipment-related heat loads) to the project.

4.5. MEP systems & energy Information about heating, cooling, ventilation, hot water generation and interior lighting is essential for accurate calculations. The correct definition of energy prices and sources enable EcoDesigner to calculate the building's annual energy supply costs and carbon footprint accurately.

Fig. 12: MEP systems and energy related data forecast

Various energy sources can be specified - natural gas, propane, oil, wood, coal, electricity or pellet - for the purpose of heating, cooling and hot water generation, respectively. More than one energy source for a function can also be provided by defining the proportion of each source used so that they add up to 100% in the energy source dialog.

Different heating type options as well as their efficiency and target can be described for the building’s heating system. The natural heating option has been developed for warm climate countries, where the annual energy required for heating is very low. The installation of a heating system is not necessary, provided that inhabitants can tolerate the fact that internal air temperature drops below the prescribed level on a couple of chilly nights or mornings a year. The local boiler or water heater option should be selected if these energy supplies are provided by a local system that only feeds the design project. District heating means that the evaluated building’s heating and/or hot water needs are supplied by an external plant in the form of hot water or steam through a pipeline. If scaled and designed correctly, district heating is a more efficient alternative to local boilers.

Various cooling options can be used to describe the building’s cooling system. Natural cooling involves no MEP systems; natural air currents are used to cool the building. Even though this method is considered the most eco-friendly, it has its limitations, as the temperature of the external air is not always sufficient for cooling purposes. Mechanical cooling means that some type of air conditioning system is to be installed in the building. For air conditioning type, either water-cooled or air-cooled may be defined. If the building is planned to be connected to external cooling system - where the conditioned air is obtained from an external plant - district cooling system should be specified. Heat pump for cooling can also be specified to achieve cooling using sustainable energy. In such case the appropriate energy source must also be selected: groundwater, sea, soil, external air or exhaust air.

The type of ventilation and the hourly air change rate can also be specified. This target value depends on national standards, and will vary depending on the building’s function and the local climate. Natural ventilation involves no MEP systems: natural air currents drive fresh air into the building and used air out of it. From an ecological point of view, natural ventilation is preferable to mechanical solutions, but due to its limited controllability its use is largely limited to residential buildings. For building functions other than residential, the standards usually prescribe strict target air exchange values, which necessitate a mechanical ventilation system. This can be an “exhaust-only systems” - reling on fans to extract used air from the rooms; or “supply and exhaust systems” - mechanically controlling both the air intake and outlet procedure, thus enabling the exact programming of the Air change per hour.

The cold and hot water temperature target values can also be provided. The calculation engine uses this data to calculate the energy consumption related to hot water generation.

Various interior lighting options are offered to enhance the accuracy of calculations. The default lighting power densities (LPD) assigned to the lighting fitting types appear in the editable LPD field. This field allows designers to fine-tune the default LPD value if the lighting design of the project is already available at the time of the evaluation.

Country and region specific energy costs and electricity sources can be specified. The carbon footprint evaluation dialog the prices of purchased energy can be defined. These prices, of course, vary by location and therefore must be entered numerically by the architect. Multiple energy sources can also be handled.

4.6. Green energy Substituting fossil fuels with green energy sources not only lower the carbon footprints of buildings, but can be very economical, too. EcoDesigner is capable of dynamically calculating the effect of the installation of air-to-air recovery systems, solar collectors and various heat pump types on the energy household of buildings. Combine several green MEP systems, or use them for multiple purposes simultaneously, to evaluate the resulting carbon emission reductions and cost benefits.

Fig. 13: Green energy sources can be specified for the design project

Solar thermal collector panels are designed to collect heat by absorbing sunlight and converting the energy in solar radiation into a more usable form. The collector geometry data is required for the calculations, it can

be specified by the collector’s area, angle to the South (or to the North, for southern hemisphere locations) and by its tilt angle. Space heating, hot water generation and fresh air heating can be specified for the targets for the recovered solar energy.

An air to air energy recovery system can regain a percentage of the heat content of mechanically expelled ventilation air. Three types of such air to air energy recovery system can be defined: fixed plate, rotary or coil. These controls are available only if a ventilation system has been chosen that involves mechanical exhaust. If the selected ventilation type is set to natural (see MEP systems and energy) these controls are inactive and a warning appears, informing the user that air to air recovery requires installed mechanical ventilation.

Heat pump can also be utilized for the design. In such case a heat source must also be specified. The available options are groundwater, sea, soil, external air and exhaust air. Various targets can also be defined: space heating, fresh air heating, hot water generation

All the previously specified calculation input data can also be exported in PHPP as well as in VIP Energy file format for further calculations.

4.7. Calculation engine The runtime of the energy simulation uses the VIP-Core calculation engine, developed by StruSoft R&D, www.strusoft.com. It incorporates all the previously described weather data, building location, building function, materials, structures, openings, MEP systems as well as green energy (PV panels, heat pumps). The dynamic energy analysis - that determines the building's energy balance at every hour, throughout one year - is performed within seconds, even on large projects or on multiple buildings.

4.8. Energy evaluation results The Building Energy Balance Evaluation report is created by literally “one-click” – quick and easy enough for designers to get a quick feedback about the energy characteristics of their project at any stage of the design. The report is an accurate, easy to read representation of the yearly energy balance simulation results, instantly available in PDF format.

Fig. 14: Energy Balance Evaluation report: Key Values

The Key Values displays basic information, such as project name, location, activity type and the date of the evaluation. Furthermore, the treated floor area and ventilated volume, outer heat capacity, the minimum and maximum heat transfer coefficients for every building structure group and for the openings on the building shell are also shown. Also in the key values section, the minimum and maximum values of the calculated heat transfer coefficients are listed for the entire building, for every building structure group (see Model review) and for the openings on the building shell (see Openings).

The Energy Consumption section of the Evaluation Report contains a table and a pie chart. The table’s leftmost column lists energy sources by type (renewable, fossil and secondary) and name, plus their color

codes used in the pie chart. The table’s leftmost column lists energy sources by percentage, plus their color codes used in the pie chart. The two Yearly total columns list the magnitude [e.g. kWh/year] and price [currency/year] of each energy source consumed in one year. The two Yearly specific columns contain a similar list of values projected to a unit area of the building [e.g. kWh/m2, year and currency/m2, year]. The Energy Consumption pie chart displays the percentage distribution of used energy sources graphically. Below the pie chart, the two most important numeric values (yearly total and unit-specific amounts of consumed energy) are also displayed.

Fig. 15: Energy Balance Evaluation report: Energy Consumption and Carbon Footprint

The Energy Balance Evaluation report displays the Carbon Footprint index to provide information on the carbon dioxide emissions resulting from the building’s operation over the course of a year. The magnitude of equivalent CO2 absorbent vegetation is also displayed on the Energy Balance Evaluation. EcoDesigner selects the display unit from three options automatically, according to project magnitude:

Tab. 1: Carbon Footprint magnitudes used by EcoDesigner

Magnitude of equivalent CO2 absorbent vegetation area (VA)

Unit of equivalent CO2 absorbent vegetation displayed

VA > 0,5 football field Football field of tropical forest 0,5 football field > VA > 0,5 tennis court Tennis court of tropical forest

0,5 tennis court > VA Developed pine tree

The Monthly Energy Balance bar chart is a graphical display of the amount of energy the building emits (top part of chart), as well as the building’s Supplied energy: the amount of energy it absorbs from the environment and its own internal heat sources (bottom part of chart), by month. The Emitted energy and Supplied energy bars must be equal every month. The vertical axis of the chart shows an energy scale. Along the horizontal axis, the twelve months of the year are shown.

The number and type of these energy balance components that appear on a particular Energy Evaluation Report depends on the data entered for the evaluated building’s MEP systems (see MEP systems and energy and Green energy).

Fig. 16: Energy Balance Evaluation report: monthly Energy Balance

These results displayed by the Energy Balance Evaluation report show less than 5% deviation compared to the results of the PHPP (www.passivhaustagung.de) calculation method.

5. Sustainable future

"As environmentally conscious architects, the ability to quickly and effectively perform energy analyses on our building models is beneficial to us and it adds tremendous value to our clients."8

The economical use of resources is critical, to the survival of human and biotic communities, it makes sense to take a new look at how to design our built environment.

With the help of GRAPHISOFT EcoDesigner (www.graphisoft.com) architectural designers can control the energy characteristics of their design project right from the very first concept design. EcoDesigner makes the comparison of several different design variations possible. The evaluation process is quick, designers can receive an immediate, energy-oriented feedback about design alternatives and decisions.

Fig. 17: Support for all climate conditions

Both the global ecological and economic environments require architects, engineers and builders to create more sustainable buildings. Therefore, GRAPHISOFT has developed EcoDesigner, a BIM-integrated energy evaluation tool for sustainable design that can be used in all climate conditions, everywhere.9

8 Russ Sanders, AIA, Orcutt | Winslow, U.S. 9 This paper is connected to the scientific program of the "Development of quality-oriented and harmonized R+D+I strategy and functional model at BME" project. This project is supported by the New Széchenyi Plan (Project ID: TÁMOP-4.2.1/B-09/1/KMR-2010-0002).