ZEB/ZEH ROADMAP- TECHNOLOGY AND INSTITUTION –March 2017

Table of contents
Executive summary ................................................................................................................ii
About the authors..................................................................................................................vi
Acknowledgement.................................................................................................................vi
1. Introduction ....................................................................................................................... 1
1.1 Objectives.................................................................................................................... 1
1.2 Background of the study .............................................................................................. 1
1.3 Significance of roadmaps in the ZEB and ZEH fields ................................................... 1
1.4 Survey of existing ZEB/ZEH roadmaps ........................................................................ 3
1.4.1 Roadmaps of international organizations .............................................................. 3
1.4.2 Roadmaps of governments ................................................................................... 5
1.4.3 Roadmaps of business communities ................................................................... 10
1.5 Definition and Goal of ZEB/ZEH ................................................................................ 12
1.6 Roadmap Variations by Climate and Air Conditioning ................................................ 15
1.6.1 Climate and Air Conditioning ............................................................................... 15
1.6.2 Roadmap variations ............................................................................................ 16
1.7 Concept of ZEB/ZEH Technology Roadmap.............................................................. 19
2. Where we are.................................................................................................................. 20
2.1 Perspectives of Technology for ZEB/ZEH .................................................................. 20
TOPIC1 ZEB Demonstration Building .......................................................................... 20
TOPIC2 Diffusion situation of ZEH in Japan today ....................................................... 59
2.2 Technologies for ZEB/ZEH ........................................................................................ 23
2.2.1 Passive technology ............................................................................................. 23
2.2.2 Active technology (Air conditioning)..................................................................... 30
2.2.3 Active technology (Water heating) ....................................................................... 40
2.2.4 Active technology (Lighting) ................................................................................ 42
2.2.5 Renewable Energy Integration ............................................................................ 47
2.2.6 Energy management ........................................................................................... 50
TOPIC3 Example of Energy Management in building sector ........................................ 51
2.3. Policies for promoting ZEB/ZEH introduction in the existing Road Maps .................. 56
2.3.1 Barriers in implementing and diffusing ZEB/ZEH ................................................. 56
2.3.2 Policy Elements for Promoting ZEB/ZEH Introduction ......................................... 57
3. Path to innovation and spread of technology ................................................................... 61
3.1 Directionality of technology innovation ....................................................................... 61
3.2 Technology roadmap ................................................................................................. 61
3.2.1 Roadmap for moderate and humid regions ......................................................... 62
TOPIC4 Air-conditioning system with separation of latent and sensible heat ............... 63
TOPIC5 Aerogel for ZEB/ZEH...................................................................................... 68
TOPIC6 ARPA-E’s commitment ................................................................................... 70
TOPIC7 Wind Thermal Power Generation and Application of ZEB/ZEH ...................... 72
3.2.2 Roadmap for cold regions ................................................................................... 75
3.2.3 Roadmap for hot regions ..................................................................................... 76
3.3 Future Policy Responses ........................................................................................... 77
4. Proposal.......................................................................................................................... 81
5. Abbreviations .................................................................................................................. 82
6. References ..................................................................................................................... 84iExecutive summary(1) Background and purposes
Energy consumption in the buildings sector accounted for 31% of the final energy demand in
the world in 2013. Its share is expected to reach 40% in 2050 according to a scenario close
to the business as usual trend (IEA ETP2016 6DS). To achieve the 2ºC goal, it is essential
to significantly reduce CO2 emissions. In order to pursue the possibility of achieving this goal,
we have studied technologies and systems necessary for realization of the ZEB/ZEH (Zero
Energy Building / Zero Energy House) concept intended to achieve net-zero energy
consumption.
(2) Structure and contents of technology roadmap
We surveyed roadmaps prepared by international organizations, national governments, local
governments, industrial associations, etc. It was found that their descriptions were mainly
focused on building envelopes and equipment installed. Most of their descriptions of air
conditioning are related to temperature control. However, in moderate and humid regions in
Asia, etc. where a huge increase in energy demand is expected in the future, indoor comfort
conditions cannot be achieved unless humidity is properly controlled. We proposed aroadmap for each climate zone with both temperature and humidity as important factors. We
divided technologies into four groups: Active (equipment), Passive (structures), Renewableenergy integration, and Energy management (Fig.ES-1,TableES-1,TableES-2), andindicated estimated periods for realization of each elements (Fig. ES-2). In the classificationof technologies, we represent differences caused by the status of new/existing buildings,
technical maturity, climatic conditions, etc.

(3) Research and development (R&D) and systems necessary for realizing ZEB/ZEH
In the buildings sector, various types of technologies are used and many stakeholders are
involved. In promoting ZEB/ZEH, more advanced technologies are expected to be added
and the number of stakeholders is estimated to increase. This trend can be summarized into
three points as shown below:- Involvement of stakeholders (coordination among stakeholders, support for skill
development, design guidelines)- Practical application of R&D results (realization of performance and/or costs exceeding thecurrent technology level, demonstration of elemental technologies and buildings systems,
mass-production technology)- Diffusion (making compliance with building standards obligations, economic incentives
such as subsidies and taxes, emphasis on non-energy benefits (human health, business
continuity plans (BCPs), real-estate value))(4) Recommendations
Formulation of the roadmap is consistent with purposes of ICEF. Roadmap direction is set
to the development and promotion of introduction of technologies aiming at the reduction of
CO2 emissions, a common goal to be pursued with worldwide cooperation, but not toindividual goals of national or local governments and industries. In this framework, we would
like to deliver the following three recommendations to the world:- Sharing among the entire society the importance of the concept that net energy
consumption in buildings should be zero;- Involvement of stakeholders in government, municipalities, and the private sector at an
early stage (taking into account building lifetimes and diversity of the parties concerned); and- Sharing of international technologies and policies for their diffusion based on the roadmap.

ii

Fig ES-1 Technology categories of ZEB/ZEH

Table ES-1 List of technologies included in the roadmap
 Passive technology
Heat insulation (envelopes, interiors, windows), light shielding, heat reflection (envelopes,
roofs, windows), transmission of heat, natural ventilation, realization of airtightness
 Active technology (air conditioning)
Boilers, solar heat source equipment, absorbing-type heat source equipment, heatpumps (electric type, internal combustion engine type), cogeneration (combined heat andpower; CHP) (internal combustion engine type, fuel cell type), dehumidifiers (heat pumps,
adsorbing type), heat storage
 Active technology (hot-water supply)
Boilers, solar water heaters, heat pumps, cogeneration (internal combustion engine type,
fuel cell type), heat storage
 Active technology (lighting)
Incandescent lamps, fluorescent lamps, LED, organic EL
 Energy management
Energy Management System (EMS), communication, equipment corresponding to EMS,
passive equipment control, linkage with EV batteries, linkage with smart grids, energy
storage unit Introduction of renewable energy
Photovoltaics, wind power generation, use of unutilized energyiii

Table ES-2 Technologies included in the roadmaps*1: Coefficient of Performance, Top level, IEA *2: Fuel Cell
*3: U value is the heat transmission coefficient or amount of thermal transmission per material area and unit temperature - W/m2K). UA is theaverage U value for wall, floor and roof, IEA*4: U value of whole window for ZEB, IEA*5:Solar reflectance, white *6:Air Change per hour *7:Photovoltaics *8 :Energy management system *9:Intenet of thingsiv

Fig.ES-2 ZEB/ZEH technology roadmap for moderate & humid region*1:Top level, IEA *2: System without hot water tank *3Avarage U value for wall and roof, IEA *4:U value of whole window for ZEB, IEA *5:Solar
Heat Gain Coefficient, IEA *6:Solar reflectance, white *7:Air Change per hour *8:Photovoltaics *9:Energy management system *10:Intenet ofthings *11:Power line communicationv

About the authors
This roadmap was created under the research contract of Ministry of Trade, Economy andIndustry (METI), by the following team to facilitate discussion at the 2016 Innovation for Cool
Earth Forum and for release at COP22:
The Institute of Applied Energy(http://www.iae.or.jp/e/)
The Institute of Applied Energy (IAE) is a nonprofit organization conducting technology
related research in broad energy areas. To secure stable energy supply and address global
environmental issues, strategic planning and implementation from long-term and global
perspectives are prerequisites. The IAE conducts studies and organizes projects with broad
network among industry, academia and the government. The activities of IAE are supportedby the contributions from the industry members and research contracts with government
agencies, private industries, etc.
Innovation for Cool Earth Forum(http://www.icef-forum.org/)
The Innovation for Cool Earth Forum (ICEF) is aimed at addressing climate change throughinnovation. ICEF investigates via discussion what innovative measures should be developed,
how innovation should be promoted and how cooperation should be enhanced among
stakeholders in fighting climate change.
ICEF is annual event in Tokyo, Japan. The ICEF Steering Committee helps make decisions
regarding the agenda and program to reflect the wide range of views of the international
community. Policymakers, businesses and researchers from around the globe participate.
The ICEF Roadmap Project helps to promote the development and deployment of clean
energy technologies with roadmaps released each year.

Acknowledgement
Some part of this Roadmap was written by the Institute of Energy Economics, Japan.
This Roadmap was prepared with the considerable efforts of Prof. Shin-ichi Tanabe of
Waseda University. Useful advice was also provided by Prof. Yoshiyuki Shimoda of Osaka
University and Prof. Tomoyuki Chikamoto of Ritsumeikan University. In addition, NEDO,
Azbil Corporation, Daikin Industries, Ltd., Osaka Gas Co., Ltd., Taisei Corporation,
Panasonic Corporation and Sekisui House, Ltd. provided valuable information for our work.
We would like to express our sincere appreciation to all the parties concerned.

vi

1. Introduction
1.1 Objectives
It has now become clear that greenhouse gas emissions worldwide will continue on an
increasing trend until about 2030, when summing up the goals of the countries (for 2025 or2030) for the reduction of greenhouse gases submitted, called INDC(Intended Nationally
Determined Contributions) in preparation for the 21st session of the Conference of theParties (COP21) to the United Nations Framework Convention on Climate Change.
On the other hand, it goes without saying that accelerated introduction of breakthroughtechnology related to energy and environment is essential on a long-term basis in order toachieve the goal of keeping the post-Industrial Revolution temperature rise at 2ºC or less inline with the Paris Agreement adopted in COP21. In COP21, “Mission Innovation” wasproposed with the support of 20 countries, resulting in agreement on further promotion of
investment in research and development. In addition, promotion of harmonization with
innovation activities in the private sector was advocated, which led to a renewal of theindustry’s understanding of the importance of breakthrough technology. In past ICEF
conferences, a “Statement” was issued on the last day of each conference to reemphasize
the importance of development of breakthrough technology.
In the ICEF conference in 2015, a “Roadmap” was reported where barriers to introduction to
the global market of photovoltaic cells and batteries combined are summarized for eachregion of the world. It is highly necessary in other fields as well to summarize a roadmap foreach field as an ICEF initiative.
As a result of a discussion made by the Steering Committee, it was decided in ICEF2016 todevelop a roadmap for facilitating development and introduction of technology related to
ZEB/ZEH together with CO2 utilization.

1.2 Background of the study
Roadmaps for facilitating development and introduction of technology related to ZEB/ZEH
have been formulated by international organizations, national or local governments,
industrial associations, non-governmental organizations, etc. To develop the ICEF2016
Roadmap this time, existing major roadmaps were referred to, and the directionality offacilitation of development and introduction of technology in targeted regions was evaluatedand organized.
In preparation for this Roadmap, our efforts were directed, in light of ICEF’s objectives, to thefacilitation of development and introduction of technology needed for achieving the common
goal of reducing CO2 emissions to be pursued with worldwide cooperation, but were notdirected to individual goals set by national or local governments and industrial circles.

1.3 Significance of roadmaps in the ZEB and ZEH fields
Figure 1.3-1 shows a conceptual diagram of the energy system of the building sector. It
shows that occupant comfort and other benefits are provided for residents and workers
through operation of various types of equipment using energy brought in from outside of thebuilding sector boundary and energy available within the boundary but not yet utilized.
Dotted rectangle represents urban energy system boundary, including three layers. They areurban, buildings, residents/workers. To satisfy services in buildings, end-use equipment
consumes energy. There are several energy carriers like electricity, gas, oil products.
Generally, oil, gas and electricity are supplied from outside of the boundary, while electricity
and heat can be supplied locally within the boundary. In this graph, traditional biomass is notincluded. However, it is still important supply source in developing regions.
1Fig.1.3-1 Energy system in building sector 1
As discussed later, when studying ZEB/ZEH, it is important to define the scope of benefits intotal in which zero energy should be achieved.
Figure 1.3-2 shows energy demand and CO2 emissions in buildings worldwide in eachscenario.
The share of building is 31% of final demand in 2013, while 40% in 2050 in 6DS, assuming 6
degree stabilization (6DS). Most of the growth is from that of developing regions. The main
drivers are number of household for residential, floor space for commercial, and applianceincrease in type, size and numbers, etc.

Fig. 1.3-2 Global Buildings Energy Demand and CO2 emissions from Buildings [1]However, deep CO2 cut are required to satisfy temperature rise target adopted in Paris
agreement. As for CO2 emissions reduction from building, IEA ETP’s assumption in 2DS, 2degree stabilization, is around 40% reduction with relative to 2013, and 45% reduction
compared to 6DS.
We have to pay attention that this number does not include emissions from grid electricity. In
that sense, low CO2 energy carrier development and its share increase is also crucial.
We propose ZEB/ZEH roadmap as a guide for international cooperation and stakeholder
involvement to assist deep cut challenge.

1

2

Modified from ’Urban Energy System’, Y.Shimoda(2014)

1.4 Survey of existing ZEB/ZEH roadmaps
Various roadmaps related to ZEB/ZEH have been formulated and made public by various
international organizations, national governments, local governments, industrial associations,non-governmental organizations, etc. Figure 1.4-1 shows organizations that have developed
representative roadmaps, by plotting them on a world map. It shows that, in particular, there
are many cases in Europe where this task has been addressed. In North America, industrial
circles are dominantly engaged. In Asia, Japan, South Korea, and Singapore have workedon the preparation of roadmaps.

Fig. 1.4-1 World atlas of ZEB/ZEH roadmaps

1.4.1 Roadmaps of international organizations
1.4.1.1 International Energy Agency (IEA)
1) Technology Roadmap Energy-efficient Buildings: Heating and Cooling Equipment[2]
Author: IEA
Date of publication: 2011
Summary:
A roadmap that requires improvement of efficiency of heat source equipment used forheating of buildings and a scenario for introduction of renewable energy. It specifies anintroduction goal to respond to the blue scenario.
2) Technology Roadmap Energy efficient building envelopes [3]Author: IEA
Date of publication: 2013
Summary:
Deals with efficient insulation technology applied to measures to save energy in buildingsthat require big investment. The roadmap focuses on performance metrics and contents that
help improve penetration into the market. However, behaviors of residents and issues ofmaintenance and durability are not considered here.
3) Transition to Sustainable Buildings Strategies and Opportunities to 2050 [4]Author: IEA
3

Date of publication: 2013
Summary:
Presents a detailed scenario and strategy for the shift to buildings with enhanced
environmental features toward 2050, including low-cost technology, electricity demand, andleveling of its peaks.
4) Modernising Building Energy Codes to Secure our Global Energy Future The IEAPolicy Pathway Series [5]Author: IEA
Date of publication: 2013
Summary:
Studies how to effectively spread methods of efficient energy use in buildings.
1.4.1.2 World Business Council for Sustainable Development(WBCSD)
1) ENERGY EFFICIENCY in BUILDINGS Business realities and opportunities [6]Author: WBCSD
Date of publication: 2010
Summary:States that businesses that promptly engage can win superiority in the market since they candramatically enhance their current energy efficiency using existing technology while actions
are urgently needed to reduce energy use in buildings. It also upholds NZEB as a goal.
2) EFFICIENCY in BUILDINGS Roadmap for a Transformation of Energy Use in
Business [7]Author: WBCSD/Energy Efficiency in Buildings project
Date of publication: 2009.8
Summary:
Summarizes and organizes activities recommended to reduce energy use in buildings foreach of short-term, medium-term, and long-term (until 2050) goals, targeting governments,
investors, entities pursuing development, employees, energy operators, manufacturers andsellers, and engineers.
1.4.1.3 United Nation Environment Programme (UNEP)
Integrating Solar Thermal in Buildings A Quick Guide for Architects and Builders [8]Author: UNEP
Date of publication: 2014
Summary:
A guide to spread the use of water heated by solar heat.
1.4.1.4 UNESCO
Roadmap on the Future Research Needs of Tall Buildings [9]Author: Council on Tall Buildings and Urban Habitat / CIB (International Council for
Research and Innovation in Building and Construction) / UNESCO Chair on Sustainability
Date of publication: 2014
Summary:This roadmap was developed for the purpose of clarifying what research is important for
high-rise buildings, how different the current study is from the actual status, and what theorder of priority is in working on challenges to be addressed.
1.4.1.5 Global Buildings Performance Network (GBPN)Best Practice Policies for Low Carbon & Energy Buildings Based on Scenario
Analysis [10]Author: Global Buildings Performance Network
Issuance: 2012
Abstract:
4

The author conducts scenario-based model analyses on the energy consumption andgreenhouse gas emissions in buildings and discusses the lock-in effect and actions thatneed to be taken in developing countries, urban areas, and each global region.

1.4.2 Roadmaps of governments
1.4.2.1 Japan
1) ZEB Roadmap [11]Author: Agency for Natural Resources and Energy, Ministry of Economy, Trade and Industry
Date of publication: 2015.12
Summary:
Summarized by the ZEB Roadmap Study Committee in December 2015 so as to achieve thepolicy objective of “seeking to realize ZEB in newly constructed public buildings, etc. by 2020
and in newly constructed buildings on average by 2030” as specified in the Basic Energy
Plan (April 2014). It states that a definition should be established within FY2016, and thegoal is set at realizing autonomous spread of ZEB toward FY2020 through subsidized
projects, initiatives for introduction of ZEB into newly constructed public buildings, branding,training of engineers, setting up of voluntary goals in the private sector, etc.
2) ZEH Roadmap [12]Author: Agency for Natural Resources and Energy, Ministry of Economy, Trade and Industry
Date of publication: 2015.12
Summary:
Summarized by the ZEB Roadmap Study Committee in December 2015 so as to achieve thepolicy objective of “seeking to realize Net Zero Energy House (ZEH) in newly built ordinary
residences by 2020 and in newly built residences on average by 2030” as specified in the
Basic Energy Plan (April 2014). It states that a definition should be established by 2016, andthe goal should be to realize ZEH in a majority of newly built residences in 2020 throughexecution of policies on subsidy for construction, establishment of know-how in builders’
offices, branding, adoption of standard specifications, voluntary action plans set by industry
groups, periodic reporting, etc.
3) Energy Efficiency Technology Strategy 2016 Formulated [13]Author: Agency for Natural Resources and Energy, NEDO
Date of publication: 2016.9
Summary:
Formulated as a guide for turning Japan to an energy-saving nation of the highest level inthe world and promoting economic growth through development of energy efficienttechnology that contributes to “building of a multi-layered and diversified flexible energy
supply-demand structure,” “realization of an intensive energy-saving society,” etc. andthrough steady spread of introduction and global deployment of the technology. It also
specifies important fields that can truly contribute to promotion of energy saving, sinceenergy conservation technology related to wide and various fields needs to be prioritized.
For selection of key technologies, the target is technologies that are expected to produce a
big effect in 2030, and ZEB and ZEH are positioned as key technological fields in thehousehold and business sectors. It also appraises as cross-sectoral technologies “innovative
energy management technology,” “power electronics,” and the “next-generation heat pumpsystem.”4) Roadmap for Energy-related Technical Development [14]Author: Advisory Committee for Natural Resources and Energy, Ministry of Economy, Tradeand Industry
Date of publication: 2014.11
Summary:5

Revises appreciation of the technical development project and others that were summarized
in the “Innovation Plan for Environmental Energy Technology” (decided in September 2013by the Council for Science and Technology Policy), based on the above-stated issues
subject to the Fourth Basic Energy Plan. As for energy-saving residences and buildings, it
describes the intention to develop energy-saving technology, optimization technology forheat-insulating materials and windows, and construction technology suitable for the climate
and natural features of Japan to achieve the goal of realizing ZEB/ZEH in newly constructed
residences and buildings on average by around 2030.
5) Innovation Plan for Environmental Energy Technology [15]Author: Council for Science and Technology Policy, Cabinet Office
Date of publication: 2013.9
Summary:
Summarized for the G8 Hokkaido Toyako Summit of 2008. It states that there is a need forresearch and development of innovative technologies in addition to further spread of existing
technologies. As for energy-saving residences and buildings, it describes in the attachedroadmap its intention to develop energy-saving technology, optimization technology for heatinsulating materials and windows, and construction technology suitable for the climate andnatural features of Japan to achieve the goal of realizing ZEB/ZEH in newly constructed
residences and buildings on average by around 2030.
6) About Future Energy-Saving Measures for Houses and Buildings（First Report）[16]
Author: Infrastructure Development Council
Issuance: 2015
Abstract:
The author discusses regulatory approaches to the promotion of energy savings in buildings
and, in combination with other supportive measures (incentives, information provision, etc.),
suggests policy directions. The author also suggests measures for new and existingbuildings and different measures for privately-owned and leasehold buildings.
1.4.2.2 USA
1) Research & Development Roadmap for Emerging HVAC Technologies [17]Author: DOE / BTO 2 ＆EERE 3 / Prepared by Navigant Consulting, Inc.
Date of publication: 2014.10
Summary:
BTO has made it a goal to reduce primary energy consumption related to buildings by 50%
by 2030 in comparison with 2010, and especially set the HVAC energy-saving objective at
reduction by 12% by 2020 and by 24% by 2030. In order to achieve the goal and objective,
this Roadmap extracts challenges in related fields, prioritizes the challenges to be addressed,
and specifies guidelines for necessary activities.
2) Research & Development Roadmap for Emerging Water Heating Technologies [18]Author: DOE / BTO＆EERE / Prepared by Navigant Consulting, Inc.
Date of publication: 2014.9
Summary:
BTO has made it a goal to reduce primary energy consumption related to buildings by 50%
by 2030 in comparison with 2010, and especially set the heated-water energy-saving
objective at reduction by 19% by 2020 and by 37% by 2030. In order to achieve the said
goal and objective, this Roadmap extracts challenges in related fields, prioritizes thechallenges to be addressed, and specifies guidelines for necessary activities, including
2
3

6

Building Technologies Office, DOE
Office of Energy Efficiency and Renewable Energy

formulation of systems that are simple and low cost, easily used by the entities who installthem and end-users, and based on an understanding of the relationship between water andenergy.
3) Windows and Building Envelope Research and Development: Roadmap for
Emerging Technologies [19]Author: DOE／BTO＆EERE/ Prepared by Energetics Incorporated
Date of publication: 2014.2
Summary:
Commercial buildings for residence, the number of which is 85 million, account for about
40% in carbon dioxide emissions from the primary energy in the US. Construction of thistype of buildings continues, and it is expected that their number will exceed 100 million by
2035. The 2013 State of the Union Message stated that energy loss in this sector would be
reduced by 50% in the next 20 years, and it also developed a roadmap for technicaldevelopment to address this issue. The main target of the technical development is heatinsulation using heat-insulating materials and window glass.
4) Solid-State Lighting R&D Plan [20]Author: DOE／BTO＆EERE
Date of publication: 2015.5
Summary:
A technical development plan for LED lights. The goal is set at 250 lm/W, and it is intended
to carry out improvement of materials, heat-resistant sealing materials, optical radiation
structures, integration technologies, etc., where cost reduction is also taken into account.
Budgetary measures have been taken with 25.8 million dollars allocated to Solid-state
lighting (SSL) research and development in FY2015, with the industrial sector given 90%
and universities given 10% of the amount.
5) Manufacturing Roadmap Solid-State Lighting Research and Development [21]Author: DOE/Prepared by Bardsley Consulting, Navigant Consulting, SB Consulting, and
SSLS, Inc.
Date of publication: 2014.8
Summary:
A technical development roadmap for LED lights and OLED 4 where a very detailed analysis
is made related to the current status of a wide range of technologies, covering materials,
methods of manufacture, and costs, and thereby challenges to be addressed are extracted.
It estimates that costs can be reduced by 50%, with a view to 2020, through integration ofvarious types of technical development.
6) Research & Development Roadmap for Next-Generation Appliances [22]Author: DOE / BTO＆EERE / Prepared by Navigant Consulting, Inc.
Date of publication: 2014.10
Summary:This roadmap was developed under the recognition that previous efforts towards energy
saving were insufficient, although equipment for household use, such as refrigerators,
dishwashers, and washing machines, accounted for 12% of the primary energy consumption
in the residential sector. It focuses on deployment of innovative technologies, including linear
compression machines, vacuum insulation, magnetic refrigeration, HP drying machines,
control equipment, etc.
7) Research & Development Roadmap for Next-Generation Low Global Warming
Potential Refrigerants [23]4Organic Light Emitting Diode

7

Author: DOE / BTO＆EERE / Prepared by Navigant Consulting, Inc.
Date of publication: 2014.11
Summary:
A roadmap for the development of an alternative refrigerant.
8) Final Report Federal R&D Agenda for Net Zero Energy High-Performance Green
Buildings [24]Author: Approved by the NSTC 5 Committee on Technology
Date of publication: 2008.9
Summary:
A U.S. government document that defines the contents needed for Net Zero Energy Building
and establishes the directionality of the technical development needed to achieve thesecontents.
9) INDOOR ENVIRONMENTAL QUALITY RESEARCH ROADMAP 2012–2030: ENERGYRELATED PRIORITIES [25]Author: for California Energy Commission
Date of publication: 2013.6
Summary:
The objective is to verify the 2002 Report and clarify needs of the Indoor Environmental
Quality (IEQ) study for policies to achieve full introduction of ZEB/ZEH into newly
constructed buildings.
10) Quadrennial Technology Review, An Assessment of Energy Technology andResearch Opportunities, Chapter 5 — Increasing Efficiency of Buildings Systems andTechnologies [26]Author: DOE
Date of publication: 2015
Summary:
The author describes energy-saving technologies of buildings comprehensively andsummarizes the current status and future direction of research and development. In addition
to technological issues, the author discusses how to improve the inefficient behavior of
consumers and, in this context, suggests energy-saving measures from the viewpoint of
behavioral science using big data.
1.4.2.3 EU
1) ENERGY EFFICIENT BUILDINGS Multi-annual roadmap for the contractual PPP
under Horizon 2020 [27]Author: EU International Non for Profit Industrial Association E2B European Construction
Technology Platform
Date of publication: 2013
Summary:
It intends to contribute to a 50% reduction in energy and an 80% reduction in carbon dioxide
in comparison with 2010 through establishment of 40 or more new technologies and theirproduct commercialization, aiming to achieve the strategic goal of fostering a highly efficientbuilding industry and raising energy efficiency to a sustainable level.
It also refers to the innovation of ICT with cross-sectional functions in addition to
improvement of efficiency of individual technologies related to structure, heat insulation, heatsource, etc.
2) How to Refurbish All Buildings by 2050 Final Report [28]Author: THINK 6 EU
58

National Science and Technology Council

Date of publication: 2012.6
Summary:
Summarized in the SET Plan 7 as support for a policy decision by EC.
3) Draft of Innovation and Research Roadmap [29]Author: READY4SmartCities 8 EU
Date of publication: 2015.9
Summary:This report is a draft of innovation and research roadmap suggesting research and technicaldevelopment (RTD) and innovation activities in short, medium and long term for ICT
supporting energy systems of smart cities. This document is purposed to be used as a draft
roadmap for expert consultations.
4) EREADY4SmartCities - ICT Roadmap and Data Interoperability for Energy Systems in
Smart Cities [30]Author: EVTT Technical Research Centre of Finland
Date of publication: 2014
Summary:
The author discusses energy systems in ICT-based smart cities and offers suggestions
about future buildings in this context. The author enumerates actions that need to be taken
by each group of stakeholders including citizens, the building industry, energy companies,
and local governments and points out the importance of coordination among all stakeholders.
1.4.2.4 Swiss
Future Energy Efficient Buildings & Districts-Research and Innovation Roadmap [31]Author: Swiss Competence Center for Energy Research
Date of publication: 2015.3
Summary:
Specifies each work plan for penetration of the insulation structure, energy management, thedistributed energy system, and technology with the target set at a 63% reduction in energy
demand and a 77% reduction in carbon dioxide emission in 2050.
1.4.2.5 Singapore
1) 3rd GREEN BUILDING MASTERPLAN [32]Author: Building Construction Authority, Singapore
Date of publication: 2014.9
Summary:This is a master plan concerning the Green Building concept launched by the Singaporean
government, and it specifies an ideal state of Green Buildings. It describes guidelines forestablishing technology suitable for tropical and subtropical zones, processes to manage
resource usage, the marking system for Green Buildings, and education and training ofexperts while stating that budgetary measures should be taken with support from subsidies,etc.
2) Building Energy Efficiency R&D Roadmap [33]Author: Building Construction Authority, Singapore / NATIONAL RESEARCH FOUNDATIONPRIME MINISTER’S OFFICE / National Climate Change Secretariat Prime Minister’s Office
Date of publication: 2013
6

THINK was an FP7-financed project that advised the European Commission (DG Energy) on adiverse set of energy policy topics from June 2010 until May 2013. In total, 12 reports were produced
over this period
7
The European Strategic Energy Technology Plan (SET-Plan), aims to accelerate the development
and deployment of low-carbon technologies.
8
ICT Roadmap and Data Interoperability for Energy Systems in Smart Cities financed by FP79

Summary:
Mainly aims at providing short-term (2013-2016), medium-term (2016-2020), and long-term(2020-2030) recommended policies while determining the gap with the current technology,
prioritizing issues, and creating a roadmap to enhance the energy efficiency of buildings.
1.4.2.6 Korea
Korea Energy Efficiency Policies [34]Author: Ministry of Trade, Industry and Energy / Korea Energy Agency
Date of publication: 2014.9
Summary:
Specifies the energy standards and the labeling system in South Korea and states theintention to spread them. It also introduces policies adopted by other countries in order todisseminate them. The labeling system is also applied to buildings.

1.4.3 Roadmaps of business communities
1.4.3.1 HVAC industry
1) REHVA nZEB technical definition and system boundaries for nearly zero energy
buildings, 2013 revision for uniformed national implementation of EPBD recast
prepared in cooperation with European standardization organization CEN Report No.4
[35]
Author: REHVA 9
Date of publication: 2016.6.15
Summary:
Summarized and compiled, with a focus on ZEB, mainly for related definitions by the
Refrigeration and Air Conditioning Industry Association of the EU in cooperation with theEuropean Committee for Standardization (CEN 10).
2) ASHRAE’s Sustainability Roadmap The approach to defining a leadership positionin sustainability [36]Author: ASHRAE 11
Date of publication: 2006.1
Summary:
A technical development roadmap of the American Society of Heating, Refrigerating, and
Air-Conditioning Engineers (ASHRAE). Its focus is on education.
3) ASHRAE Vision 2020, Providing tools by 2020 that enable the building community
to produce market-viable NZEBs by 2030 [37]Author: ASHRAE
Date of publication: 2008.1
Summary:
The American Society of Heating, Refrigerating, and Air-Conditioning Engineers presents its
visions for achieving Net Zero Energy Building (NZEB) by 2030.
1.4.3.2 Chemical industry
ICCA Building Technology Roadmap, The Chemical Industry’s Contributions to
Energy and Greenhouse Gas Savings in Residential and Commercial Construction[38]
Author: ICCA 12
9

Federation of European Heating, Ventilation and Air Conditioning Associations
Comité Européen de Normalisation
11
American Society of Heating, Refrigeration and Air-Conditioning Engineers, Inc.
12
International Council of Chemical Associations
10

10

Date of publication: 2014.8
Summary:
Presented by an international organization of the chemicals industry to summarize
technologies applicable by 2050 so as to contribute to reduction in CO2 emissions in thebuildings sector.
1.4.3.3 Others
Intelligent Buildings: The Pase and the Future [39]Author: CABA 13
Date of publication: 2015.9
Summary:
An effort arranged by the industry of building instrumentation, where the directionality of
Building Energy Management System (BEMS) is summarized.

13

Continental Automated Buildings Association

11

1.5 Definition and Goal of ZEB/ZEH
ZEB or ZEH is acronym of net zero energy building or house, assuming annual net energy
consumption is nearly zero. The goal is net zero consumption in buildings around midcentury to prepare long-term zero emission target.

Fig.1.5-1 Images of ZEB & ZEH

12It will be achieved by energy conservation and renewable energy integration, but criteria of
certain degree of energy conservation should be satisfied.
There are several ZEB/ZEH definitions. Four examples from US, Europe and Japan were
picked up and listed in Table 1.5-1.
Table 1.5-1 Definitions of ZEB/ZEH 14
DOE 15, USA

NREL 16, USA

REHVA 17, Europe

Japan15

Year

2015

2006/2010

2013

2015

Design or
Operation

Operation

Design/Operation

DesignDesignTargetDevices

HVAC ,
Water heating,Lighting,
Power outlet,
Energyexchanged andtransformed inbuilding

HVAC,
Water heating,Lighting,
Power outlet,
Energyexchanged andtransformed inbuilding

HVAC,
Water heating, Lighting

HVAC,
Water heating,Lighting, Elevatorsand moving stairs

Renewable
EnergyIntegration

On-site,On-site + Offsite (for small
houses)Categorized
On-siteOn-site + Off-site

Only On-site

Only On-site

Categoryof ZEBs

ZEB: annual
primary energy
use isrecovered byon-siterenewableenergyZEB: annual
energy use isrecovered byrenewableenergyNear ZEB: built
as ZEB, but does
not met becauseof weather andoperation etc.

PEB : net AnREU <2
0kWh/m yr
ZEB: AnREU <2
0kWh/m yr, self
sufficientnZEB: net AnREU =2
0kWh/m yr
2nnZEB: 0kWh/m yr <net AnREU < limit ofindividual country

ZEB/ZEH: PEC isless than 100% fromthe standards
Nearly ZEB/ZEH: PEC
is less than 75% fromthe standards
ZEB ready: PEC isless than 50% form
the standards

Building
types

Building,
Campus,Portfolio,
Community

Building

Building

ZEB: Building
ZEH: Detached house

18

19

20

21

There exist some differences in assessment phase (design and operation), target devices,
as well as treatment of renewable energy integration (on-site and off-site). Some differencesin ZEB/ZEH categories and building types are found. About categorization, some focus on
net primary energy, while European REHVA indicator is annual non-renewable energy use.

14

ZEB/ZEH roadmap committee report, Dec,2015(in Japanese)
Department of Energy
16
National Renewable energy Laboratory
17
Federation of European Heating, Ventilation and Air Conditioning Associations
18
Heating, Ventilation and Air Conditioning
19
Plus energy building
20
Annual non-Renewable Energy Use
21
Primary energy consumption
15

13

Fig 1.5-2 Technology categories for ZEB/ZEH

We propose four technology categories indicated in Fig.1.5-2. They are passive, active,
renewable energy integration and energy management. Most of our work focuses on passive
and active. As for renewable integration and energy management, we thought most issues
are covered by existing energy roadmaps such as photovoltaics and smart grid.

14

1.6 Roadmap Variations by Climate and Air Conditioning
1.6.1 Climate and Air Conditioning
One of the characteristics of new roadmap proposal is representation in air conditioning.
Most roadmaps in the past had little attention to humidity in air conditioning. Bothtemperature and humidity should be controlled within proper ranges, to satisfy the comfort,
health and productivity objectives.

Fig.1.6.1-1 Average temperature map of the world 22

Fig.1.6.1-2 Heating and Cooling demand of the world 23

Figure 1.6.1-1 shows the global average temperature. There is a difference in averagetemperature of 60°C among regions where people live. Figure 1.6.1-2 shows thegeographical distribution of demand for heating and cooling. The world map on the left
shows demand for heating, and the deeper the red color of a region is, the larger thedemand in the region is; the world map on the right shows demand for cooling, and the
deeper the blue color of a region is, the larger the demand in the region is. In most of theroadmaps presented so far, demand for air conditioning has been judged based on
temperature.
The objective of use of air conditioning in buildings is to properly prepare and set an
environment so that people can live comfortably and work efficiently for their business.
Environmental factors that have an influence on people’s comfort are the four elements,
namely temperature, humidity, air current, and radiation, in addition to factors on the humanside, the metabolic quantity (quantity of work) and the amount of clothing. The environmental
factor next to temperature that has the largest influence on people’s comfort is humidity.

22
23

Source: Wisconsin U. original data from CRU, U. East Anglia
Source: WRI

15

Fig.1.6.1-3 Discomfort index
Figure 1.6.1-3 shows the Discomfort Index (DI) distribution. DI is expressed by the following
formula.
DI = 0.81T＋0.01H(0.99T-14.3)＋46.3
Where T is the ambient temperature in Celsius and H is the relative humidity
Although it is said that, generally speaking, everybody feels discomfort and work efficiency
decreases when the DI exceeds 80, attention should be paid to the fact that the DI becomes
80 at a temperature of 37℃ with a relative humidity of 20% but also at 27℃ with a relative
humidity of 90%, which shows a temperature difference of 10℃. This temperature differenceis expanded to 15℃ between 0% and 100% of relative humidity. When using the current
technology, the amount of energy needed for air conditioning changes significantly subject todifference between ambient temperature and temperature inside the room. Therefore, there
is a technical possibility that energy for air conditioning can be substantially reduced while
maintaining comfort by reducing the difference between temperatures inside and outside theroom while properly controlling humidity.

1.6.2 Roadmap variations
Figure 1.6.2-1 shows the average relative humidity distribution in the world. It shows thatheavily populated regions such as southern China, Southeast Asia, India, and tropic Africa /Latin America have high relative humidity. Figure 1.6.2-2 shows a difference in energy
demand for cooling between different scenarios, which was summarized by IEA in ETP2016.
The growth of demand for cooling is very large in non-OECD countries and, furthermore, thedifference between the 6°C and 2°C scenarios in these countries is also large, so that theyneed to cut the demand by half. Even from this point of view, it is important to suppress
energy demand for air conditioning in non-OECD countries. Of course, it is important tosuppress energy demand for air conditioning in OECD countries, and, specifically in the 2°C
scenario, energy saving of 10% or so from the current level of energy used is required.

16

Fig.1.6.2-1 Average Relative Humidity of the world 24

Fig.1.6.2-2 Cooling energy demand and savings, 6DS to 2DS [1]Efforts to examine climate zones with humidity added in a detailed manner and to study
effects of cutting carbon dioxide have been made by the Global Buildings Performance
Network, etc., but they have been made mainly through desk study analysis.

24

Source: Wisconsin U. original data from CRU, U. East Anglia

17Fig.1.6.2-3 Composite Climate Split [10](Note. CDD: Cooling degree days HDD: Heating degree days)

In this study of roadmap types, focus was placed on the following three regions, since thisRoadmap spotlights technical development:*Moderate & humid Region (Heating, cooling & dehumidification)*Cold Region (High heating demand, Only heating)*Hot Region (High cooling demand with dehumidification, Only cooling)
Considering air conditioning from the viewpoint of comfort, reduction in energy for air
conditioning by separating control of humidity from control of temperature was taken into
account.

18

1.7 Concept of ZEB/ZEH Technology Roadmap
As stated above, the situation surrounding the ZEB/ZEH Roadmap was studied based on
which the concept of this Roadmap is summarized in the following way.

1) Climate zones
It was decided to divide the climate zones roughly into three and formulate a roadmap foreach of the three zones. In particular, since energy demand in regions of moderate to hightemperature and humidity would increase drastically, the focus was placed on humidity
control.
2) Technology categories
Technologies were grouped into four major categories. Technologies available at the time ofdesign were taken into account, but equipment, devices, etc. to be added during operation
were excluded from consideration.
Active - Air conditioning, hot water, lighting
Passive - Envelope, aperture
Energy Management
Renewable energy integration

3) Technology indicators
As criteria for judgment of technologies, efficiency, cost, fuel, and maturity were taken into
account. Correspondence to climate zones based on the characteristics of being moderate &humid, cold, and hot was also taken into consideration.
4) Building vintage
Addressing retrofitting, while adopting technologies applied to new construction as a basis,
was taken into consideration.
5) Common technological elements for ZEB and ZEH
Technologies that can be applied to both ZEB and ZEH were intended. However, realizationof ZEH could be faster than ZEB, because of its relatively low energy density.
6) References
Consistency with major roadmaps developed by IEA [1] [2] [3] [4] [5] , METI [11] [12] [14],NEDO [13], etc. was taken into account to the extent possible.

192. Where we are
2.1 Perspectives of Technology for ZEB/ZEH
A wide range of technologies has been applied to buildings, but there are many types ofadvanced technologies that have not been adopted due to the need to suppress costs. As
stated in Section 1.5, technologies are summarized into four categories for clarification:
passive, active, energy management, and renewable energy integration. In addition, airconditioning and hot-water supply technologies needed at the design phase were included
as targets, while technologies (including devices that use receptacle outlets, etc.) to be
added during operation are excluded from consideration.
TOPIC1 ZEB Demonstration Building25
・Building Outline
In recent years, the number of ZEB in Japan is increasing. Following example is ZEB
demonstration building as an office building located in TAISEI Technology Center in
Yokohama, Japan, completed in May 2014. This building was constructed in order to verify
the feasibility of urban ZEB. And demonstration tests for energy saving technologies toward
ZEB have been conducted. Rational design was aimed in the plan by the co-operation
among the designers, structural engineers and mechanical engineers. One of the importantdesigns factors is balcony in each floor. This balcony enables collecting sunlight, introducing
outer fresh air, using photovoltaics and working outside. Skeleton ceiling introduced byadopting reversed beam and flat slab is used for multiple purpose such as diffusing surfaceof daylighting system and radiating surface of the thermal active building system.(see Table
T1-1 and Fig. T1-1)
Table T1-1 Outline of the building
Location

Yokohama city, JAPAN

Building Area

427.57 ㎡

Total Floor Area

1,277.32 ㎡

Structure
Number of Stories

Reinforced concrete
structure
3 (Penthouse is 1 story)

Building Use

OfficeConstruction
PeriodAugust 2013 - May 2014

Fig. T1-1 Building facade

・Technologies Outline
Energy consumption was minimized by the basic principle of the HVAC and lighting load
reduction by passive designs and energy efficient equipment. This principle includes active
usage of natural energy and task ambient control using human detection sensor. Also, inorder to enhance the comfort while reducing the energy use, individual controlling system
was introduced so that office workers could adjust their thermal and lighting environment
according to their preference.

25

Taisei Corporation

20

Lighting system
Low-illumination task and ambient lighting system was introduced to enhance its brightness
with low illuminance (Fig. T1-2). To obtain maximum effect with minimal light, the role of thelight was separated into two types: enhancing the impression of brightness in the room andproviding the illumination necessary for office work. Hence, lighting system consists of four
light sources and controls. Fundamental brightness impression is realized by daylighting
system. The rest of the luminance on the ceiling surface was added by LED indirect lighting.
As for the illumination for office work, LED direct lighting is used with automated ON/OFF
control by human detection sensor. In addition, organic EL lighting is also used with manualcontrol by the office workers.

Fig. T1-2 Outline of the lighting system
HVAC
Japan is located in a temperate climate, so it is necessary to install both cooling and heating
system in the buildings. Also high performance HVAC which is high in periodical
performance and partial load efficiency is needed. In addition, high value -added HVAC likepersonal air-conditioning system is popular recently.(Fig. T1-3)
In this building, separation process of latent and sensible heat and task and ambient systemdeal with the fluctuating cooling and heating load efficiently throughout the year. In addition,
during intermediary season, natural ventilation work and reduce the cooling load.

Fig. T1-3 Outline of the air-conditioning system
21

Power generation
The concept of power generation includes maximum utilization of renewable energies, theusage of high efficient power generators and securing the business continuous plan (BCP).
For the ZEB dissemination into high rise buildings in the future, photovoltaics was installedon the wall in addition to the roof so that the amount of photovoltaics could be
maximized.(Fig. T1-4)

Fig. T1-4 BIPV by the organic thin film
Energy performance
Actual primary energy balance in 2015 was shown in fig. T1-5. Annual primary energy
consumption was reduced by 77% compared to that of the normal conventional building.
Annual primary energy consumption was 439 [MJ/m2] for all end uses and 386 [MJ/m2] withthe exclusion of plug load. And the amount of annual power generation was 484 [MJ/m2] inprimary energy. In total, annual primary net energy balance was 45 [MJ/m2], can be called“Positive Energy Building (PEB)”.There is a room for further energy saving in operation
phase not considered in design phase. Currently, operation data is analyzed aiming at
miscellaneous end use energy saving such as like standby power.
As for the award, this building got the platinum certification in LEED -NC by USGBC. And
this was the first platinum certification in the new buildings in Japan. Also, this building wascertified as the highest rank in Building Energy-efficiency Labelling System (BELS) in Japan.

HVAC

1817

Referencebuilding

Lighting
Appliances

439
TAISEI’s
ZEB

Others

▲77％

-2000

-1500

-1000

484

-500

0

PV
500

[MJ/㎡・a]Fig. T1-5 Annual Energy Performance in 201522

2.2 Technologies for ZEB/ZEH
2.2.1 Passive technology
Classification as a passive technology was based on technological features, such as heatinsulation, heat reflection/transmission of heat, ventilation, airtightness, etc., that can prevent
external influences or allow use of natural energy as it is. These technologies have been
employed for a long time according to the regional environment. However, there is a casewhere different technologies should be selected from a different point of view such as fire
safety and earthquake resistance. In addition, efforts are being made to enhance
performance through development of new materials.
Table 2.2.1-1 shows installation locations of passive technology, distinction in application
between newly constructed and existing buildings, degrees of maturity of the technology,
and applicable climate zones. In terms of heat insulation and reflection, efforts to enhancematerial technology are still being made. Ventilation and use of shade must be allowed for at
the design phase due to the need for matching with the design of the buildings. Details are
discussed below.

Table 2.2.1-1 Present status of Passive technology
Technology

Installation
locationNew
Retrofit*

Maturity**

Climate***Insulation

Envelope
Interior
Window

NR
R
NR

M-H
M-H
M-H

C,M,H
C,M
C,M,H

Window

NR

L-M

M,H

Window, Envelope
Window roof
Roof

NR

M-H

M,H

NR

M-H

M,H

Roofs, Lattice
Window, Envelope,
Door

N
NR

M-H
H

M,H
C,M,H

Insulated
Window
Shading
Thermalreflection

Ventilation
Air sealing

Other Information

Reduce thermalradiation input
Reflective glass
Integrated to PV
panels* N:New R:Retrofit / **L:Low, M:Midium, H:High / ** C:Cold, M:Moderate & Humid, H:Hot
2.2.1.1 Insulation
The insulation efficiency of building materials is expressed by the U value (heat transmission
coefficient or amount of thermal transmission per material area and unit temperature W/m2K), and the smaller the U value is, the higher the efficiency is. In many cases, theinsulation performance of a residence is expressed by the UA value (average heattransmission coefficient or amount of thermal transmission per total area, including theenvelope and openings of a residence, and unit temperature - W/m2K), and it is judged thatthe smaller the UA value is, the higher the efficiency is.
The recommendation for ZEB in IEA’s roadmap is UA < 0.35 and Uw < 0.6.
2.2.1.1.1 Insulation of envelope
Various types of materials are used for heat insulation of building envelopes. Some
examples of materials that are commercially available are shown below.

23

Table 2.2.1.1.1-1 Insulation materials commercially available for building envelope 26
Name
Material/form
Heat
ThermalPrice
conductivity
resistanceratio(W/m･K)(m･k/W)27
Glass wool 40K
Mineral fiber form
0.034
22-30
3.75
Glass wool 24K
Mineral fiber form
0.036
22-30
1.5
Glass wool 16K
Mineral fiber form
0.038
22-30
1
Rock wool
Mineral fiber form
0.038
20-27
1
Cellulose fiber
Wood fiber form
0.040
20-26
2
Wool
Wood fiber form
0.040
2
Beaded polystyrene foam
Polystyrene foaming
0.034
2
Extruded polystyrene foam Polystyrene foaming
0.028
2
Rigid urethane foam
Urethane foaming
0.024
38-45
2.5-3
Polyethylene foam
Polyethylene foaming 0.039
20
1.5
Phenol foam
Phenol foaming
0.020
33-48
3

Heat-insulating materials of buildings suppress heat transfer mainly by preventing air
convection. Currently distributed and used are the fibrous form type that confines air
between fine fibers and the foamed plastic type that confines air in independent air bubbles.
Heat-insulating materials of buildings need to have not only high insulation efficiency but
also fire safety and fire resistance, durability, sound absorbability, etc., and specific materials
should be selected according to the features of the applicable location.
In the research and development (R&D) of heat-insulating materials of buildings, various
types of technological development are being carried out, for example, to mass produce
materials based on advanced technologies used in the space field at allowable costs and toutilize natural resources or waste. Table 2.2.1.1.1-2 shows examples of materials having
high insulation efficiency that are now under R&D for practical use.
Table 2.2.1.1.1-2 Building insulation materials 28
material
Material/form
Thermal resistance(m･K/W)
Vacuum insulated panel
Metal membrane wall filled with highly- 208-346
porous material
Silica aerogel
Highly-porous silica
69

A vacuum-insulated panel is a board-shaped container made with a metal film and filled witha material having a high void ratio and low heat conduction, and it has heat resistance about
10 times that of glass wool and other heat-insulating materials. However, in the current
status, its manufacturing cost is high, and care is required to prevent damage to its film so as
to maintain the vacuum, resulting in a drawback in its application method.
Silica aerogel is synthetic porous ultralight silicon oxides derived from a gel, in which theliquid component of the gel has been replaced with a gas. Although it has insulation
efficiency twice or more that of current insulation materials, it is fragile in the current status,
resulting in a drawback in its application method, etc.

26

Source: http://dannetsujyutaku.com/basic/knowledge/material
Source: https://en.wikipedia.org/wiki/Building_insulation_materials
28
Source: https://en.wikipedia.org/wiki/Building_insulation_materials
27

24

2.2.1.1.2 Insulated interiors
For heat insulation of interiors, insulating panels to be pasted inside, curtains, and the likeare used. They can easily address the need for retrofitting, but matching with the design
weighs heavily in adoption of either of them, so the taste of residents has an influence on
whether to adopt such materials. For insulating panels to be pasted inside, some envelopeinsulating materials can be used.
2.2.1.1.3 Insulated windows
Window insulation efficiency depends on thedesign of a whole window. In particular, insulation
efficiency differs widely depending on whether or
not a window can be opened. Windows accountfor a large share of heat release from a building,so North European countries situated in coldweather regions set a strict minimum standard(Uw < 1.0 to 2.0) for window insulation efficiency.
Uw indicates the overall U-value of the window.
The heat transfer coefficient Uw relates to theentire window. This value also incorporates the Uvalues for the glazing and the frame Uf. The
overall value Uw is also influenced by the linear
heat transfer coefficient (g = glazing) and the sizeof the window. In recent years, movements to
Fig. 2.2.1.1.3-1 Triple glazing window
introduce insulated windows are spreading
globally as China recommends Uw < 2.0 andSouth Korea recommends Uw < 1.6.
In regions with four seasons, windows that can be
widely opened are needed. For single-layer glass
aluminum sashes with the common structure of a
glass-fitted Japanese shoji that can be opened,
Uw = 6.5, and for double-layer glass aluminumsashes, Uw = 4.7 or so. Therefore, it isunderstood that the North European standard isvery stringent. In summer, in general detachedhouses in moderate & humid regions, nearly 70%
of hot air heated by solar insolation passes
windows to enter the room. In winter, nearly 50%
of air warmed in a house passes through windows
to escape outside. 29 Accordingly, heat insulationof windows that can be opened is an important
issue.
A window consists of glass and a window frame,
so insulation efficiency of the glass and that of thewindow frame are both important. Due to Fig. 2.2.1.1.3-2 Insulated glass sashes withtechnology development in recent years, vacuum the structure of a glass-fitted Japanese shoji
triple-layer glass having a resin window framewith Uw < 1 30 has been commercialized. However, the price of the current product is fairly
high, so development of a technology to realize cost reduction is needed.
It is also important to take measures to address the need for retrofitting of existing buildings,
including technology to make construction easy.

29
30

YKK AP http://www.ykkap.co.jp/info/pvc-windows/summary/YKK AP http://www.ykkap.co.jp/apw/apw430/variation/sliding.html

25

2.2.1.2 Shading
Shading is a method of blocking solar insolation using means such as eaves, side fins, etc.,
and there are many cases where residents of detached houses employ this method byinstalling bamboo blinds, etc. after they start living in their houses. It can easily address theneed for retrofitting, but matching with the design weighs heavily in adoption of either ofthese means, so the taste of residents has an influence on whether to adopt such means.
On the other hand, in the case of buildings, it is difficult to address the need for retrofitting,so it is necessary to study this issue at the design phase.
Considering the directionality of technology development, it is possible to apply some of theheat reflection technology.
2.2.1.3 Reflection
Reflective performance of buildings is evaluated using the SR value. Solar reflectivity or
reflectance (SR) is the ability of a material to reflect solar energy from its surface back into
the atmosphere. The SR value is a number from 0 to 1.0. A value of 0 indicates that thematerial absorbs all solar energy and a value of 1.0 indicates total reflectance. In regionswith strong solar insolation, this technology is demanded for application to reflection
materials to be used especially for roofs and walls. If windows are installed in a region withfour seasons, reflection is needed in the summer, while passing of heat rays is needed in thewinter.
2.2.1.3.1 Reflection materials of envelopes and roofs
The efficiency of reflection materials is basically related to color, and the initial SR value isroughly 0.7 for metallic luster, 0.6 for white, and 0.2 for black. When actually installed andthen exposed to rain and wind, the efficiency of reflection materials decreases. In R&D,
emphasis is placed on how to provide durability so as to keep the initial efficiency.
In addition, especially when reflection materials are used for an envelope or a roof installedwith a high slope degree, reflection from them may cause the neighborhood annoyance, so it
is necessary to study this issue at the design phase.
2.2.1.3.2 Heat reflection by windows
Figure 2.2.1.3.2-1 shows images of heat reflection by windows and passing of heat rays.
“Low-e” means that the amount of heat radiation is small. In cold-weather regions, heatreflection by windows reflects heat in the room and keeps it inside and thereby enhances theheat-insulating effect. To realize this, a reflection film should be formed on the glass surface
on the room side. In this case, it is effective to pass solar heat from the outdoors into theroom. Passing of solar heat will be discussed in the following item, but it is evaluated using
solar heat gain coefficient (SHGC). For transmission of solar heat, it is effective to form anantireflection film on the glass surface on the outdoor side and adopt glass featuring low
absorption of heat rays.
On the other hand, in high-temperature regions, if heat entering the room is reduced byreflecting sun rays and outdoor heat, the heat-insulating effect is enhanced. In this case,from a technical point of view, it is effective to form a heat reflection film on the glass surface
on the outdoor side.
The challenges for Low-e technology are cost reduction and durability improvement.

26

Fig. 2.2.1.3.2-1 Schematic images of Low-e glazing 31
In regions with four seasons, it is necessary to change the direction of the side of glass
where a heat reflection film is formed when the season changes between summer andwinter, which makes it difficult to effectively introduce Low-e technology. However,technology development is ongoing, aiming at control of reflection performance according to
the change in seasons by applying an electric field to the reflection film or making contact
between the film and a reactant gas.
2.2.1.4 Transmission of heat
This technology, whose technical aspects are discussed in 2.2.1.3.2, is effective in coldweather regions.
2.2.1.5 Natural ventilation
There are two methods of implementing natural ventilation. They are wind-induced
ventilation that uses a pressure gap caused by outdoor wind, etc. between an inlet and an
exhaust port; and density-difference ventilation that uses ascending air current generated bydensity difference in air caused by the heat generated in the room, etc.
Air conditioning by wind-induced ventilation can be conducted by opening an inlet and an
exhaust port and thereby securing a ventilating route, when there is wind outdoors and theindoor environment has suitable temperature and humidity. Air conditioning by wind-induced
ventilation is affected by natural conditions, so alternative means are necessary in cases
where natural conditions are unsuitable for air conditioning.
Air conditioning by density-difference ventilation takes advantage of air ventilation thatmakes use of air density difference caused by heat from residents or their equipment, andtherefore it is not readily affected by natural conditions such as presence/absence of wind.
When designing a building, the focus should be placed on design of locations where heat is
generated and ducts that lead ascending air current to ventilation. In such a case as when
the intended purpose of using a building is changed, the effect of the ventilation will be lost.
Figure 2.2.1.5-1 shows an image of density-difference ventilation in a building.

31

Source: http://www.efficientwindows.org/lowe.php

27

Fig. 2.2.1.5-1 Schematic images of natural ventilation for a building
On the other hand, as for houses, their intended use cannot be substantially changed,
making it easy to apply density-difference ventilation to them for air conditioning. Figure
2.2.1.5-2 shows an example of application of natural ventilation as a means of air
conditioning to a detached house built in a region with four seasons. In this application, inthe summer, by forming the first vent layer outside the heat-insulating material of the building
envelope, it is possible to discharge heat received from the sun to outdoors throughventilation, and by forming a second vent layer inside the heat-insulating material of thebuilding envelope, it is possible to wrap the interior in cool air; in the winter, formation of aheat-insulating layer of air is possible by blocking these vent layers with a shape-memory
alloy, etc.

28

Fig. 2.2.1.5-2 Schematic images of natural ventilation for a house
Necessary care should be taken at the design phase in the case of either buildings orhouses, and efforts should be made to adopt advanced design using fluid simulation, etc.
and to lower the costs of construction based on the design.
2.2.1.6 Introduction of airtightness
Introduction of airtightness is a technology considered especially important in cold-weather
regions and outdoor places in harsh environmental conditions. From a technical viewpoint,
this technology is in completed status, so it is important to consider how to include thistechnology in design.
In addition, there are cases, depending on the region, where no difference is found between
the amount of energy saved by introduction of airtightness and the amount of energy
increased in order to properly implement humidity conditioning and ventilation. So,
standardization is needed in terms of what regions can effectively adopt introduction of
airtightness and what level of airtightness is needed.
2.2.1.7 Natural lighting
Technologies of natural lighting are in matured stage, so it is important to consider how toinclude this technology in building design.

29

2.2.2 Active technology (Air conditioning)
The active technology is summarized as a technology that provides air conditioning mainly
by use of energy brought in from the outside. The main pillar of active technology innovationin application to ZEB/ZEH is thorough pursuit of energy saving through improvement ofequipment efficiency. Although there are various forms of heating, including fireplaces,
hearths, heaters, and ondols, technologies difficult to apply to ZEB/ZEH were excluded.
The current status of the active technology for air conditioning is presented in Table 2.2.2-1.
Table 2.2.2-1 Present status of Active technology (Air Conditioning)Technology

COP
32
%

Equipment
cost*

Fuel
type**

Fuel
cost*

Maturity*

Climate***Other Information

Boiler

70-88

L

G/O/B

M-H

H

C,M

Floor, Panel heating

Absorption
Chiller

70120

M

G/O/B

M-H

H

M,H

Heat
Pump(Electr
icity)Heat
Pump(Engine)33
CHP (Engine)200600

L-M

E

M-H

H

All

120200

L-M

G/O/B

L-M

H

All

70-90

M-H

G/O/B

L-M

H

All

with Elec. supply

CHP(FC)

80-90

H

G/H

L-H

M

All

with Elec. supply

Dehumidifier

n.a.

H

E

H

M-H

M,H

Humidifier

n.a.

L-H

G/E/O

L-H

H

heat pump,desiccant,compressor, wetevaporation, steam,ultrasonic

Solar
System

n.a.

H

S

0

L-M

All

Renewables

Outdoor air
cooling

n.a.

H

E

L

L-M

All

* L:Low, M:Midium, H:High ** G:gas, O:Oil, B:Biomass, S:Solar, E:Electricity, H:Hydrogen,*** C:Cold M:Moderate & Humid H:Hot
2.2.2.1 Boilers
Boilers are heat source equipment that generates steam and warm water in heating systems
based on heat exchange at a floor heating system or a panel heater set in the room as well
as at a fan convector.
In the basic structure of boilers, water is fed to a heat exchanger and then high-temperature
combustion gas, produced by burning fuel, is passed through the heat exchanger, in order toheat water. As a result, warm water and steam are generated. When gas is used as fuel,dew may form on the heat exchanger where cool water passes, because combustion gas
contains water generated from hydrogen included in the fuel. Usually, heat exchangers are
manufactured using copper and aluminum, which causes deterioration of the equipment
32

Coefficient of Performance, same as efficiency, COP=Qo/Qi where Qo is the heat supplied to or
removed from the reservoir and Qi is the heat supplied to the system operation. Qi is supplied byelectricity to heat pump(electricity) and by fuels to others.
33
Combined heat and power

30

because rust is generated if dew formation continues. For this reason, heat exchangers inordinary boilers are designed so as to prevent dew formation. However, in this case, thetemperature of the exhaust gas discharged after heat exchange is about 200°C and theefficiency is about 70%. Put simply, this is a major factor that prevents efficiency
improvement of boilers.
Furthermore, combustion gas contains sensible heat generated by the temperature
difference in the gas and latent heat in the form of water steam. If sensible heat is recoveredby a heat exchanger designed to withstand dew formation, the exhaust gas temperature
would be about 80°C and the efficiency would be enhanced to almost 90%. Figure 2.2.2.1-1
shows the basic structure of a latent heat recovery-type boiler. However, the manufacturingcosts of this boiler are high because it is equipped with additional components, namely adurable heat exchanger that can cope with dew formation to recover latent heat and amechanism to treat dew condensation water.
The directionality of technology development is set to cost reduction; for this reason, mass
production should be put into operation by promoting deployment of this type of boiler.

Fig2.2.2.1-1 Schematic diagram of condensing boiler
2.2.2.2 Absorption chiller
Absorption chillers are refrigerating machines to realize low temperature through the effect ofa refrigerant being vaporized due to low pressure generated by high-absorbency liquid when
it absorbs another refrigerant in a different location. In addition, an absorption chiller can bealso used as a heat-driven heat pump. As for cooling media and/or absorbing liquid,
products made of the water-lithium bromide system for air conditioning and the ammoniawater system for refrigeration have already been commercialized. When an absorption
chiller is used for heating, warm water is often produced by applying heat exchange to ahigh-temperature heat medium as it is, which is provided by a high-temperature regenerator
without using a refrigerating cycle.
Figure 2.2.2.2-1 shows an absorption chiller system. In its basic cycle, cold water and cold
liquid are produced through evaporation of a refrigerant in an evaporator set at low
31temperature and low pressure, and the evaporated refrigerant is then absorbed by absorbing
liquid in an absorber (this absorption causes a low-pressure state that makes the refrigerant
evaporate in the evaporator). When the absorbing liquid that has absorbed the refrigerant isheated by a regenerator, the refrigerant is evaporated and separated, and the relevant
solvent is returned to the absorber. The refrigerant, after evaporation and separation, is
cooled and liquefied in a condenser and then reused in the evaporator.
As for a system using an absorption chiller for air conditioning, it has been confirmed thatwhen using the water-lithium bromide system, which is an absorbing liquid currently
regarded as the most appropriate, the efficiency or the coefficient of performance (COP) canbe enhanced to around 160% in a system where the absorption cycle is increased to threetiers (for triple effect). However, the manufacturing costs for this system are higher, and it istherefore required to develop a technology that can enhance the efficiency at low cost.

Fig.2.2.2.2-1 Schematic diagram of absorption chiller.
2.2.2.3 Heat pump
Heat pumps can be widely defined as a technology to transfer heat from a low-temperaturepart to a high-temperature part using a heat medium, a semiconductor (Peltier device), etc.
and are characterized by various types of system such as the vapor compression type, theStirling type, the absorption type, the absorption type, the chemical reaction type, etc. When
discussing air-conditioning systems, a heat pump is usually of the vapor compression type.
Therefore, here, the focus is on this type as well.
The working principle of a heat pump is illustrated in the following figure showing four
elements: a compressor, a condenser, an expansion valve, and an evaporator. The
compressor driven by electric power compresses a refrigerant, and the refrigerant now athigh pressure is then led to the condenser for heat exchange to be cooled, resulting incondensation of the refrigerant. At this time, condensation heat is released to the outsidefrom the condenser. The refrigerant in liquid form expands at the expansion valve and issent to the evaporator. The expanded refrigerant decreases in temperature, and theevaporator is thereby cooled and starts to absorb heat from the outside. After that, this cycle
is repeated with the refrigerant evaporating, undergoing heat exchange, and returning to thecompressor. A valve mechanism can be used to switch the configuration so that theevaporator works on the room side and the condenser works on the outdoor side for coolingand so that the evaporator works on the outdoor side and the condenser works on the roomside for heating.
32

Fig.2.2.2.3-1 Schematic diagram of heat pump
Chlorofluorocarbons (CFCs) were used at the initial phase of commercialization of thistechnology as a refrigerant that can be evaporated and condensed at ranges of temperatureand pressure convenient for constituting a refrigerating cycle in air conditioning. Currently,
however, substitutes for CFCs are used as cooling media, since CFCs are substances thathave a large GWP34.
In theory, the efficiency (COP) of heat pumps has an upper limit specified by the reverse
Carnot cycle and it is expressed using the following formula in the case of cooling.
COP = TC / (TH - TC)
TC: temperature of a refrigerant during absorption of heat (evaporation temperature, on theroom side)
TH: temperature of a refrigerant during heat release (condensation temperature, on theoutdoor side)
In actual equipment, efforts to enhance efficiency can be consolidated into the following two
activities:
1) Efficiency improvement of heat exchangers
Evaporators and condensers have their own heat exchangers to perform heat exchange
between a refrigerant and air. In high-performance heat exchangers, the difference intemperature between a refrigerant and air is small. By indicating the temperature differencesin an evaporator and a condenser by ΔTEV and ΔTCD, respectively, the efficiency of actual
equipment can be expressed using the following formula:
COP∝ (TC - ΔTEV / {(TH + ΔTCD) - (TC - TEV)}
If expressed briefly, the smaller the ΔTEV and ΔTCD are, the higher the performance of a heatexchanger is. In particular, since the installation space is limited in a room, further
improvement of smaller and higher-performance heat exchanger technology is required.
2) Efficiency improvement of compressors
For the efficiency of compressors, the focus should be placed on a technology to suppress
power loss caused by friction. Today, scroll compressors are one of such examples thathave been commercialized as high-efficiency compressors.
34

Global Warming Potential33

2.2.2.3.1 Electric heat pumps
Electric heat pumps are equipment that uses an electric motor for driving a compressor. In
recent years, there are examples of using a drive system with a combination of inverter
control and a high-efficiency motor built with a strong permanent magnet and a magnetic
steel sheet whose loss is small.
For efficiency improvement of electric heat pumps, it is necessary to further enhance theefficiency of electric motors and their drive control system.
2.2.2.3.2 Internal-combustion engine heat pumps
Internal-combustion engine heat pumps are equipment that uses a reciprocating engine fordriving a compressor. In recent years, there are examples of using high-efficiency
reciprocating engines of the high-compression-ratio type.
For efficiency improvement of internal-combustion engine heat pumps, it is necessary tofurther enhance the efficiency of internal-combustion engines.
2.2.2.4 Combined Heat and Power
Cogeneration (combined heat and power) is a system that simultaneously uses motive
power or electric power as well as waste heat generated by motors, fuel cells, etc. Thissystem is applied to ships, motor vehicles, factories, cities, buildings, etc. In the buildings
sector, motive power is converted to electric power that is used as part of the electric power
to be supplied to a building. Heat is used for direct heating or converted to cold heat by anabsorption chiller and then used for cooling.
2.2.2.4.1 Internal-combustion engines and gas turbines
Typical internal-combustion engines used for combined heat and power are reciprocating
engines and gas turbines. However, due to conditions on the ratio between generated
electric power and heat and the system scale, there are many cases where reciprocating
engines are adopted for systems to be applied to buildings. The following figure shows anexample of a combined heat and power system of the reciprocating engine type.

Fig.2.2.2.4.1-1 Reciprocating engine type combined heat and power for buildings

In this system, the engine generates motive power that is converted to electric power by agenerator. Electric power is linked to systems in a building and used by power-consuming
equipment such as personal computers. The reciprocating engine generates heat in the formof combustion exhaust gas and cooling water both of which are sent to a heat exchanger torecover heat and then used for heating, or for cooling after converting it to cold water by anabsorption chiller. Energy contained in fuel is used as electric power and heat at a highefficiency of between 70 and 90%. When using a combined heat and power system, if the34

ratio between generated electric power and heat matches the ratio between electric powerand heat required by a building, energy efficiency is increased. Therefore, it is necessary to
promote wider deployment of this method by use of appropriate engineering.
2.2.2.4.2 Fuel cells
The fuel cell type of combined heat and power system is a combined heat and power systemthat is realized by replacing the internal-combustion engine described in the preceding itemwith a fuel cell. Fuel cells have a cell structure where electrodes are arranged at both endsof an oxygen ion conductor or a hydrogen ion conductor. Electric power is generated due tovoltage caused by localization of electrons generated on both electrodes through amechanism whereby fuel is introduced into one side (fuel electrode) of the electrodes so thations near the fuel electrode and fuel enter an electrochemical reaction to exchange
electrons; on the other hand, on the opposite electrode (air electrode), oxygen in the air andions enter an electrochemical reaction to exchange electrons. Depending on the type of ionic
conductor, the temperature at which cells work properly varies. For example, it is about 80°C
for polymer electrolyte fuel cell (PEFC 35 ), the most widely used type, and about 700 to
900°C for solid electrolyte fuel cell (SOFC 36 ). According to these conditions, different
systems are used for utilization of exhaust gas. The basic structure of a PEFC stack and its
electrode part is shown in the figure below.

Fig.2.2.2.4.2-1 Cell stack of PEFC

35
36

Polymer electrolyte fuel cell
Solid electrolyte fuel cell35

Fig.2.2.2.4.2-2 Configuration of PEFC cellIn this system, DC power is generated in the fuel cell, which is linked with the systemthrough an inverter. The generated power is then used by power-consuming equipment. On
the other hand, the fuel cell generates waste heat from exhaust gas after reaction, which isrecovered by a heat exchanger to be utilized for heating. However, in PEFC whose
operating temperature is low, absorption chillers cannot be operated with waste heat. On theother hand, in SOFC and the like whose operating temperature is high, it is possible to builda system where absorption chillers can operate after generating power with an expansion
turbine using waste heat.
Energy contained in fuel is used as electric power and heat at a high efficiency of between
80 and 90%. High-efficiency systems can be more easily built with the fuel cell type of
combined heat and power system, because this type has a ratio between generated electric
power and heat that is closer to the ratio between electric power and heat required by abuilding than the internal-combustion engine type. Promotion of wider deployment is needed
through cost reduction, development of high-efficiency technology, and appropriate
engineering.
2.2.2.5 Humidity control equipment
Humidity control equipment is air-conditioning equipment that is used for humidity
conditioning and performs dehumidification during the hot and humid seasons andhumidification in the dry season. There are various dehumidification systems such as thecooling method where dehumidification is achieved by lowering the temperature offunctioning parts with a refrigerating machine below the dew-point temperature;adsorption/absorption methods where dehumidification is achieved by passing air through asolid substance or liquid to which moisture content can easily adhere; and the compression
method where air is compressed by a compressor to generate dew drops and dew
condensation water is then removed. In the buildings sector, the cooling method and theadsorption method are adopted.

36

Fig.2.2.2.5-1 Schematic diagrams of dehumidifier

Methods of humidification are as follows: the steam method where water vapor is sprayed;
the vaporization method where humidification is achieved by heating and vaporizing water;
and the water spray method where humidification is achieved by spraying water in a finemisty form with an ultrasonic spray system or a high-pressure spray.
As for dehumidification technologies, the dehumidification performance of the desiccant typeof technology keeps acceptable level even if the ambient temperature is low; however, since
the amount of energy used for thermal regeneration is large, it is required to develop
materials whose thermal regeneration is easy.
As stated in Item 1.6.1, although it is said that, generally speaking, everybody feels
discomfort and work efficiency decreases when the DI exceeds 80, attention should be paid
to the fact that the DI becomes 80 at a temperature of 37°C with a relative humidity of 20%
but also at 27°C with a relative humidity of 90%, which shows a temperature difference of
10°C. As stated in Item 2.2.2.3, in the heat pump type of cooling now widely used, efficiency
during cooling is inversely related to the difference between outdoor temperature and indoor
temperature. As for effective application of dehumidification technology, there is a technicalpossibility of significantly reducing the amount of energy used for air conditioning while
maintaining comfort by reducing the difference between outdoor temperature and indoor
temperature while properly controlling humidity.
As for heating, it is also said that people feel warm even when the temperature set for air
conditioning is low, if humidification is conducted properly. Therefore, it is necessary todevelop air-conditioning technology where humidity conditioning is properly integrated.
2.2.2.6 Heat storage
Heat storage means storing heat in a heat storage tank and using the stored heat at the timeof maximum demand so as to allow for reduction in the capacity of heat-source equipment
and efficient operation with a constant load. In addition, in mobile facilities, installation oroperation of heat-source equipment can be omitted while meeting demand only with stored
heat.
Familiar examples of heat storage in households are water heaters of the hot-water storage
type as well as ice making and cold storage in a cool box with refrigerants. Various media
are used for heat storage, including water (ice) in heat storage tanks, latent heat storage
materials, space in the underground, and building frames. However, installation of a heatstorage tank is often avoided due to its large size, so it is necessary to develop high-density
thermal energy storage technology. It can be used as an elemental technology to reduce theamount of total energy in cooperation with EMS to be discussed later.
37

2.2.2.7 Solar systems
Solar air-conditioning systems collect solar heat with a heat collection panel and store theheat in a heat storage tank.
For heating, the stored heat is transferred by a heat medium to a heat exchanger where it
forwards a heat-exchange process with air in the room, and the room is consequently
warmed.
For cooling, the heat stored in a heat storage tank is provided for the absorption-type cooler
or desiccant-type cooler so as to generate cold heat that is carried by a refrigerant to a heatexchanger where it enables a heat-exchange process with air in the room, and the room isconsequently cooled.
An example of a solar air-conditioning system is shown in the figure below.

Fig.2.2.2.7-1 Schematic diagram of solar air conditioning system

The system shown in the figure is equipped with a large solar heat collection panel because
the density of energy obtained from sunlight is small. In addition, to address variation andlack of heat caused by weather changes, it is also equipped with a heat storage tank andauxiliary heat sources. Heat provided by the sun and then stored is usually of low
temperature and the efficiency of conversion to cold heat through a chiller is thus low, so thesize of the chiller has to be large. For this reason, solar air-conditioning systems have acomplicated mechanism and their size is large, resulting in high costs for system structurebuilding and thus the slow spread of such systems. To promote wider deployment, it isnecessary to establish efficiency improvement technology of chillers and technology to
reduce system costs.

38

2.2.2.8 Outdoor air cooling
Outdoor air cooling is an HVAC control technology that uses cool natural outdoor air inintermediate seasons such as spring, autumn, as well as winter.
The HVAC system consists of a Chiller Plant that provides chilled / hot water and Air
Handling Units that supply chilled / hot air to rooms for cooling / heating by utilizing heatgenerated by the chiller plant.
Outdoorair
Exhaust air
Air conditioning facilities
Return air fan
dampercooling uses an
air damper toReturn air duct
controlcool
Return air
Supply air duct
Indoor air
outdoorairdamper
Supply air
Return air
24℃volumetocontrolthedesired room
IndoorChilled air
air
Outdoortemperature.
(18 ℃)Mix
air
Therefore,
ing
8℃
Outdooroutdoorair
air
coolingwill
damper
AHU
achieve large
energy savings
becausethe
HVAC system
Possible tois able to omit completely stoptheuseof the chiller plant
chilledwater equipment during
for cooling and outdoor air
cooling.
evenChiller Plant
completely stop
the chiller plant.
Fig.2.2.2.8-1 Air Conditioning Facility with Outdoor Air Cooling
2.2.2.9 Refrigerant distribution control
Power to run pumps is required for transporting a refrigerant from a heat source to heatexchangers such as the Air Handling Unit (AHU) coil. Optimizing flow rates of refrigerant foreach AHU enable effective reduction of pump power consumption. One resolution is to apply
an Intelligent Control Valve, a motorized two-way valve with flow measurement and control
function as a temperature control valve for the AHU coil.
This built-in sensor measures pressure across the valve
and utilizes it to measure the flow rate and contribute to theenergy saving measures as stated below.
1. Reducing power consumption by water distribution
An Optimized flow rate control reduces excess water supply
and pump power consumption.
2. Improving chiller efficiency
An Optimized flow rate control assures differences between
supply and return water temperatures and improves chiller
COP.
3. Providing data of each AHU for energy management
Visualization of energy consumption at each AHU showswhere energy is wasted most. That helps the Energy
Manager to consider countermeasures to save energy.
Fig.2.2.2.9-1 Intelligent Control Valve39

2.2.3 Active technology (Water heating)
The target of the Active technology (for water heating) is hot water, and its temperature
range in use is thus different from that of air-conditioning technology. In addition, coolingtechnology is not included in this technology as a target. However, the engineering principle
to be applied to this technology is almost the same as that of air-conditioning technology,
and the main pillar of innovation of the active technology for water heating is also to pursue
energy saving to the extent possible through efficiency improvement.
The present status of the active technology for water heating is shown in the table below.
Table 2.2.3-1 Present status of active technology (Water heating)Technology

COP%

Equipment
cost*

Fuel
type**

Fuel
cost*

Maturity*

Climate***Boiler

70-95

L

GOB

M-H

H

All

Heat
Pump(Electr
icity)
CHP(Engine)

200600

M-H

E

M-H

H

All

70-95

M-H

G/O/B

L-M

H

All

with Elec. supply

CHP(FC)

80-95

H

G/H

L-H

M

All

with Elec. supply

ThermalStorage

50100

L-H

M

All

Solar
System

n.a.

L-H

M-H

All

S

0

Other Information

Renewables* L:Low, M:Midium, H:High ** G:gas, O:Oil, B:Biomass, S:Solar, E:Electricity, H:Hydrogen,*** C:Cold M:Moderate & Humid H:Hot
Detailed explanations for each technological item are given below.
2.2.3.1 Boilers
Boilers for water heating are almost the same as those for heating. However, as cold water
is boiled to generate hot water in boilers for water heating, they can suppress exhaust gas
temperature to a level lower than that required for heating, leading to higher efficiency.
2.2.3.2 Heat pump typeHeat pump-type water heaters can be realized based on almost the same mechanism asthat of equipment for heating, but since their temperature ranges for heating are different
from each other, it is necessary to change the refrigerant and optimize the heat exchanger.
In addition, to realize instant hot-water supply, they are currently equipped with an additional
system to store warm water in a hot-water tank. Although the energy source that this typeuses is electricity only, they feature high efficiency, so wider deployment of this type is
expected.
Because warm-water storage in a hot-water tank causes heat radiation loss and becomes afactor in cost increase, it is required to develop a technology that realizes instant hot-watersupply without using a hot-water tank.
2.2.3.3 Combined heat and power
Water heaters using the combined heat and power system can also be realized based on
almost the same mechanism as that of equipment for heating. However, the combined heatand power type where the thermal load is appropriate and continuous operation can berealized only by adding a heat exchanger for hot-water supply to equipment for air
40

conditioning. Its efficiency of using primary energy is high, so wider deployment of this typeis expected. In household applications, most of the thermal load is generated by hot water,
making installation of a hot-water tank essential. Therefore, it is desirable to develop highinsulation technology for hot-water tanks.
2.2.3.4 Heat storage
This is equivalent to the heat storage technology used in air conditioning.
2.2.3.5 Solar water heaters
Solar water heaters have already been widely deployed, including an inexpensive type,because they can be realized by use of only the heat collection panels and hot-water tanks
mentioned in Item 2.2.2.7 “Solar systems.” However, costs will increase if the amount of hot
water and the water pressure must be kept at comfortable levels.

41

2.2.4 Active technology (Lighting)Lighting efficiency is expressed by total luminous flux (lm/W) per input energy. The present
status of high-efficiency lighting technology is presented in the table below. Depending on
the light source, objects under lighting look different. The influence of lighting on how an
object looks is called color rendering. Generally speaking, incandescent lamps emitting lightincluding various wavelengths are said to have excellent color-rendering properties.
Table 2.2.4-1 Present status of Active technology (Lighting)Technology

Luminous
Efficiency(lm/W)

Efficiency(%)

Maturity*

Other Information

2-18
20-26

0.3-2.6
2.9-3.8HH

5-100W type40-95

5.9-14

H

110

16.1

H

At High frequency

Metal halide39
lamp

80-13011.7-19.0

H

Slow start40

30-100

4.4-14.6

M-H

102

14.9

L

Incandescent lamp 37
Fluorescent
38
lamp

LED

Organic EL

Advanced
technologies

HalogenInverter41* L:Low, M:Midium, H:High
2.2.4.1 Incandescent lamps
Incandescent lamps have a structure with atransparent heat-resistant container in which afilament (a metallic wire) made of tungsten, etc. isarranged and they have a ball-like shape, while theircontainer is vacuum-filled or filled with inert gas. A
filament is heated by Joule heat generated byenergization in order to emit light. In ordinary
filament lamps, the higher the temperature of thefilament is, the higher the luminous efficiency is.
However, the high temperature accelerates metallic
evaporation from the filament and shortens the
product lifetime, setting a limit on improvement of
the luminous efficiency.
Incandescent lamps cannot be replaced by othertypes in applications that require good colorrendering properties and thus have deeply rooted
Fig.2.2.4.1-1 Structure of Incandescentdemand. Accordingly, replacement with halogen
lamp
lamps is expected.
One example of efficiency improvement technologies of incandescent lamps is halogen
lamps leveraging the halogen cycle. Their containers are made of high-temperature-resistantmaterials and are filled with a small amount of iodine, bromine, or other halogen element.
Metal evaporated from the filament reacts with the halogen inside the container or on the
37

Ushio Inc. https://www.ushio.co.jp/documents/technology/lightedge/lightedge_22/ushio_le22-07.pdf
http://www.prince-d.co.jp/feature/helpful/39
http://page2.cextension.jp/c4061/book/index.html#target/page_no=131
40
https://ja.wikipedia.org/wiki/%E7%99%BA%E5%85%89%E5%8A%B9%E7%8E%87
41
Universal Display Corp.
38

42

container wall and then turns into a metallic
halide. The vapor pressure of metallic halide
is high, so it evaporates from the container
wall and floats inside the container. A metallic
halide that reaches the vicinity of a filament
decomposes due to high temperature,discharging metal to the filament and turning
itself back into a halogen gas. Due to thismechanism, the filament lifetime is extended,and the filament temperature can thus beincreased, resulting in improvement ofluminous efficiency. It is possible to enhancethe efficiency to almost 1.5 times that ofordinary incandescent lamps.
Incandescent lamps cannot be replaced byother types in applications that require goodcolor-rendering properties and thus have
deeplyrooteddemand.
Accordingly,
replacement with halogen lamps is expected.

Fig.2.2.4.1-2 Structure of halogen lamp

2.2.4.2 Fluorescent lamps
Fluorescent lamps are light sources where ultraviolet rays are generated through electric
discharge, irradiated to a fluorescent substance, and converted to visible light. The type offluorescent lamp most widely used has a structure with electrodes set in a glass tube (theinternal electrode type) and uses 253.7 nm light generated by arc discharge in a lowpressure mercury vapor. The luminous efficiency of fluorescent lamps is 40 to 95 lm/W evenfor old types where a choke coil is used as ballast; this value is about eight times that ofincandescent lamps, which is making fluorescent lamps popular. Fluorescent lamps emit
light with wavelengths unique to the fluorescent substance used therein, so their colorrendering properties are limited compared with incandescent lamps. Accordingly, technology
development is underway with a focus on improving color-rendering properties, for example,
by combining multiple fluorescent substances.

Fig.2.2.4.2-1 Structure of Fluorescent lamp

In efforts to enhance efficiency, inverters have been adopted for a ballast to control light
generation, resulting in commercialization of products with efficiency exceeding 110 lm/W.
These products have luminous efficiency higher than that of the LED lights widely used
today, so it is desirable to update old types of fluorescent lighting fittings to the inverter type.

43

2.2.4.3 Metal halide lamp
Metal halide lamps are lamps that use lightemitted by arc discharge in mixed vapor
consisting of mercury and metal halide.
Metal halide lamps have the same basic
structure as that of mercury lamps that use
light radiation generated by arc discharge inmercury vapor within a quartz glass tube.
They leverage emission of light caused byelectron transition in sodium, scandium,and other metallic elements to improve thecolor-rendering properties of mercury lamps.
For metal halides, sodium iodide, scandium
iodide, etc. are used. Because these colorrendering properties can be adjusted bychanging the type and the ratio of metal
halides, they are adopted for baseFig.2.2.4.3-1 Structure of Metal halide lamp
illuminating lamps in open-ceiling spaces orindoor atriums of large commercial facilities
and high-rise buildings. In recent years,
production of metal halide lamps has been promoted on a commercial basis for the
automobile sector.
Metal halide lamps are lighting devices that have the highest luminous efficiency among
those now in commercial use, but because they take some time to light up to full brightness,they are not used for lighting in living spaces. As for the directionality of technology
development, translucent ceramics are used for arc-discharge tubes to enhance durability
and luminous efficiency. Metal halide lamps have the highest luminous efficiency amonglighting equipment that illuminates a wider area, so the development of technology to further
enhance the efficiency is expected.
2.2.4.4 LED lights
Since the invention of blue light-emitting diodes,
development of technology for LED lights has
been accelerated and put into commercial use
for living spaces and automobiles.
LED lighting has been improved so that it hascome to show a luminous efficiency of the samelevel as, or a little lower level than, that offluorescent lamps, leading to its wider use as analternative lighting method to incandescentlamps. Because white light cannot be emitted
from a single LED, a combination of a blue LEDwith a luminous body that absorbs blue colorand emits yellow color is adopted for products
to be widely used. A product based on a
combination of two luminous bodies that emit
red and green colors, respectively, has
excellent color-rendering properties but low
luminous efficiency.
LEDs can have the following properties if theyFig.2.2.4.4-1 Structure of LED lamp
are properly designed and manufactured:- Longer lifetime- High impact resistance- High-speed lighting- No use of mercury unlike fluorescent lamps and metal halide lamps
44

- Higher luminous efficiency than incandescent lamps
Their drawbacks are:- Lower color-rendering properties than incandescent lamps- Low resistance to heat (requiring a sophisticated heat radiation mechanism)- High price- Possibility of harm to human health due to too strong a blue color
As for the directionality of technology development, efforts are needed in various areas
covering semiconductor technology, heat radiation technology, circuit design technology,
and fluorescent substance technology in order to enhance luminous efficiency and colorrendering properties. It is estimated that luminous efficiency can be enhanced to twice tothree times the current level, so the future development of this technology is highly expected.
2.2.4.5 Organic EL
The luminous principle of organic electroluminescence (EL) is that voltage is applied to eachof the cathode and the anode so that each electrode moves electrons or holes, respectively.
Electrons and holes pass their transport layers and are then bonded in the luminous layer.
Luminescence material in the luminous layer is excited to upper energy level. When an
excited state returns to the ground state, light is emitted. The light emitted in transit from anexited state (singlet) to the ground state is fluorescence, and the light emitted in transit froma singlet state to the ground state via a triplet state at an energy level a little lower than the
singlet state is used as phosphorescence. For the cathode, aluminum, silver-magnesium
alloys, calcium, and other metallic thin films are used, while transparent metallic thin films,
such as indium tin oxide (called ITO), are used for the anode. Generated light is reflected
onto a reflecting surface, penetrates through transparent electrodes and a substrate (a glass
plate, a plastic plate, etc.), and finally escapes outside.
In reality, this technology is put into practical use as organic EL displays where light isemitted from individual fine elements. Unlike liquid crystal, they do not use polarized light, sothey allow for a wider viewing angle.

Fig.2.2.4.5-1 Structure of Organic EL Element45

Although organic EL is not currently applied to lighting, there is a possibility that it will be
used for high-efficiency lighting due to the significant improvement of luminous efficiency inrecent years. Therefore, experimental introduction has been started.
In particular, due to the features of organic EL such as “surface emission,” which cannot berealized with LED lighting, as well as “no restriction on shape” and “transparency,” it isconsidered that there is a possibility that separation of usage between organic EL and LED
lighting will proceed in the future or that organic EL will be used more widely than LEDs.
There are organic EL products that can be flexibly bent, which is realized by adopting plastic
films and similar substrates instead of the glass substrates currently used as the mainstream
substrates for organic EL. The printing of organic EL on flexible materials can be found inlarge screen TVs as products.
As for technical problems now faced by organic EL, efficiency of emitting light is low ataround 25%; variation in temperature and electric current occurs depending on the locationof the luminous plate, leading to luminance variation; and indium as a scarce resource (usedas ITO of transparent conductive film) whose alternative substance does not exist in thedisplay sector is consumed in large quantity, so there are concerns that indium resources
might be exhausted.
As for the directionality of future technology development, improvement of luminous
efficiency, technology to replace indium with other substances, etc. are required; therefore,
many businesses are working on these issues. Accordingly, it is necessary to take support
measures to promote technology development.

46

2.2.5 Renewable Energy Integration
Renewable energy is a type of energy recognized as capable of being used on a permanent
basis as an energy source and is in the forms of solar light, wind force, hydraulic power,
geothermal power, solar heat, heat in the air, other types of heat in nature, biomass, etc.
Examples of renewable energy that can be applied to ZEB/ZEH are solar light, solar heat,wind force, and unutilized thermal energy in sewage water and ground heat.
The status of application of renewable energy to buildings is shown in the table below.

Table 2.2.5-1 Present status of Renewable Energy Integration
Technology

Installation site

Maturity**

Climate

Roof

New /
Retrofit*
NR

PV

M-H

All

PV

Wall

N

L-M

All

Wind power

Roof, Wall

NR

L

All

Sewage water/groundheat recovery

Heat source

N

M

All

Solar thermal system

Roof

NR

L-M

All

Other
Information

Active technology(reprint)* N:New R:Retrofit ** L:Low, M:Midium, H:High
2.2.5.1 Photovoltaics
Photovoltaics is a power generation method of converting solar light directly to electricity
through photovoltaic cells. Solar cells provide DC power only when solar light is available.
For this reason, electric power generated in the daytime is stored in storage batteries for use
during the night, or it is consumed or sold by households that have electricity generated
through a connection to an electric power system.

Fig.2.2.5.1-1 Schematics of PV system

47

Mass production of PV systems to be
mounted on roofs for use in buildings isnow substantially expanding due to asynergy of technology development forenhancing efficiency and measures taken
to promote introduction of feed in tariff(FIT), etc., resulting in lower unit prices for
power generation. However, it isnecessary to further advance thetechnology for cost reduction. On the other
hand, for PV systems to be mounted onwalls as building-integration PV (BIPV), it
is necessary to take into account matterssuch as matching with the external
appearance of buildings, so it is also
necessary
topursuetechnology
development with an emphasis on
excellent design.

Fig.2.2.5.1-2 Building with wall installed PV

2.2.5.2 Wind power
Wind power generation is a method of
converting natural wind kinetic energy into
electric power using windmills and power
generators. The magnitude of wind energy
is proportional to the cube of wind velocity,
and windmill efficiency is proportional to
the square of its diameter. Wind power
generation
facilitiesoflarge-scale
windmills have usually been located on
mountain peaks and the coast because
these locations have strong wind. Powergeneration costs for large-scale windmills
are said to be lower than those for PV
systems. On the other hand, there has
been no smooth deployment of wind
Fig.2.2.5.2-1 Building with Wind power system
power generation facilities on buildings
due to wind conditions more adverse thanthose on mountain peaks and the coast, concerns about scenery and safety, high costs ofpower generation facilities, etc. Development of technologies necessary for high-efficiency
wind power generation systems for ZEB is an urgent issue.

48

2.2.5.3 Use of unutilized energy
Unutilized energy is a general term for energy that has not been used so far despite apossibility of effective use, including factory exhaust heat, exhaust heat from cooling andheating systems used in underground railways and underground malls, river and sewage
water having a temperature difference from the outdoor temperature, and snow and ice heat.
An image of use of unutilized energy is shown below. Unutilized energy has the feature of“wide and thin” distribution and its sources of supply are often remote from areas of demand,so technologies to effectively use the energy are required. Specifically, these technologies
include heat pump technology, technology to use snow and ice, off-line heat supply(transfer) technology, technology to use the temperature difference of seawater/lakewater,
etc.

Fig.2.2.5.3-1 Schematics of waste thermal energy utilization system

For application of unutilized energy to ZEB/ZEH, a study has been made on the forms ofrecovery of heat to sewage water and utilization of earth thermal. In either form, it isnecessary to start studying its introduction at the building design phase. In addition,measures to facilitate introduction of these forms should be taken, and their standardization
is desirable.

492.2.6 Energy management
Energy management means, in a broad sense, to organically combine generation,
conversion, accumulation, transfer, and consumption of various forms of energy and linkthem to one another so as to achieve efficient energy use. With a focus on areas related to
ZEB/ZEH, energy management can be understood as a system to control introduction ofactive energy, passive energy, and new energy in the most effective manner. The tablebelow shows the present status of technologies related to energy management that can beapplied to ZEB/ZEH.
Table 2.2.6-1 Present status of Renewable Energy Management System for ZEB/ZEH
Technology

Key Component

EMS(Control
protocol)EMS(ICT)

Home server

EMS(communication
terminal)

Integration withother system

Communication
methods
Electric
appliances
Passivetechnology
Energy saving
control
Batteries in EVs
Interface between
smart grids

New/
Retrofit*
NR

Maturity**

Other Information

M

Including architecture

NR

M-H

Wireless, PLC

NR

M-H

NR

L-M

NR

M-H

NR
NR

L-M
L-M

* N:New R:Retrofit ** L:Low, M:Midium, H:High

50

Auto controlled window
shading etc.

TOPIC2 Example of Energy Management in building sector 42
In Amarin Plaza in Bangkok, Thailand, a BEMS has been introduced since 2014. BEMS
controls the HVAC system for a large-scale building complex (including offices and a
shopping mall), and saves energy by efficient control of the facilities (see the figure below).

Fig. T2-1 BEMS Scheme at Amarin PlazaThe BEMS transmits measured and control data on site to main servers in Japan via thevirtual private network (VPN). The Energy Manager in service department in Japan
specifically analyzes data and reports the results with issues found. Then sales engineers in
Thailand provide the reports to customers. Furthermore, service engineers on site are able
to retrieve data stored in the server via VPN. The BEMS will help service engineers to carryout timely facility maintenance.
This BEMS was introduced for the purpose of optimizing the chiller plant facility operation
as an ESCO project 43. This system saves energy by 4% for the total building complex, andeven 50 to 60 % of the energy consumed by the chilled water pumps.

42

Azbil Corporation
In an ESCO (energy service company) project, the service provider guarantees energy savings andprovides comprehensive energy services at plants or buildings. For an ESCO project, a BEMS is an
essential tool for attaining energy conservation, as well as for measurement and verification (M&V).
43

51

2.2.6.1 Energy management system
The Energy Management System (EMS) is a system that manages energy consumed byseveral types of buildings. EMS differs depending on the use for building types such as“HEMS” for homes, “BEMS” for commercial buildings, and “CEMS” for communities (for both
homes and other types of buildings).
An HEMS is able to visualize the amount of electricity both generated and consumed aswell as the consumption of gas and water, on a monitor. That also controls electric
appliances and other home equipment. In Japan, EMSs have been developed and are
gaining popularity as a part of smart community demonstration projects. On the other hand,development of the BEMS was based on the building automation system (BAS), which wasintroduced in the 1970s, with the addition of energy management features in order to
respond to the trend toward energy conservation. Its development is accelerated greatly inline with international climate change issues arising in the 1990s. In Japan, most buildings
larger than a certain size have a BEMS because of amendments to energy legislation andbecause of promotion by NEDO. Recently, with the spread of IT technologies and services,
the BEMS has begun to use cloud computing technology. This allows the energy
management of not only single buildings, but also multiple buildings regardless of the time or
location.
Furthermore, remote support services that provide energy conservation by specialists andthe utilization of automated demand response (ADR) systems are being promoted.
A cluster energy management system, also called a community energy management system(CEMS) enables the effective use of renewable energies, heat, electricity, and energy byleveling the load in order to regulate supply and demand and reduce CO2 emissions.
Demonstration projects for the concept of the smart community have appeared, andexperiments for its implementation are being carried out worldwide for many types ofdevelopment area, from microgrids for a whole area to cluster types for scattered facilities.

HVAC

Switchboard

Fig.2.2.6.1-1 Schematics of HEMS in the market

Efforts should be made towards optimization of control, performance evaluation,
standardization, etc.
2.2.6.2 Communication
In order for an EMS controller to intercommunicate with various types of home electronics
and household equipment, common communication specifications should be adopted. As
examples of such specifications, SEP2.0 is used in the U.S. and KNX is used in Europe. In
Japan, ECHONET Lite was recently established. KNX has been applied to qualify more than
7,000 types of products manufactured by 370 or more companies worldwide, and KNX itself
52was approved by the standardization bodies of Europe, China, and the U.S. as well as by
the international organization ISO. SEP2.0 was formulated based on its preceding
specification “ZigBee Smart Energy Profile 1.0,” and it allows for some general control suchas turning on/off of equipment. Currently, organizations such as ZigBee Alliance, Wi-Fi
Alliance, and HomePlug Alliance that use the SEP2.0 specification have established aconsortium to discuss mutual operation of their products and their tie-ups.
If EMS standards are unified across nations and regions, it will encourage smart houses andtheir related equipment to be used more widely. As for ECHONET Lite, it is said that it has
advantages in the ability to control equipment in a more detailed manner than otherspecifications, raising expectations of future applications.
On the other hand, BEMS manufacturers have used proprietary protocols for communication
protocols throughout the 40 years of BEMS history. But now, BEMS uses standard
communication protocols such as Modbus, LonWorks, and BACnet in order to integratebuilding facilities and realizes an open environment using ICT technologies. In particular,
BACnet was developed by ASHRAE in the U.S. and standardized as ANSI/ASHRAE.
BACnet has been recognized as a useful protocol for BAS/BEMS and is gaining popularity
worldwide. It is now registered as the international standard ISO 16484-5. In accordancewith the evolution of communication technology and customer requirements, BACnet iscontinually enhanced and updated in its protocol architecture, objects, and services. Various
protocols for communication among HEMSs, BEMSs, and CEMSs are being studied widely.
In Japan, JIPDEC proposes a standard protocol. JIPDEC supports BACnet as the protocol
for use between a BEMS and CEMS. Also, IEEE 1888 (a standard protocol for generalfacilities) and OpenADR, which enables automatic demand/response, are being studied asinternational standards.
2.2.6.3 Equipment corresponding to EMS
Equipment corresponding to EMS has a function as a communication terminal tocommunicate with EMS. It is desirable to globally unified communication standards in order
to increase the number of equipment corresponding to EMS i.e. interoperability.
As mentioned above, since BACnet is now a global standard and device manufacturers are
implementing it for BEMSs, BACnet will enable the establishment of an open interoperability
environment for central monitoring systems, sub-controllers, devices in the field, and intersystem communication. However, the service life of facility equipment in buildings varies
depending on the product, so it is necessary to connect the existing devices that use oldcommunication protocols such as Modbus and LonWorks to the EMS.
2.2.6.4 Equipment control based on the passive technology
Air conditioning based on the passive technology uses light shielding, natural ventilation, etc.,
but it is usually implemented by human who use window shades or open/close windows. If
air-conditioning equipment can be activated by control devices equipped with EMS terminals,
there is a possibility of realizing optimum control. It is expected that this type of device will be
widely used along with the advancement of EMS.
2.2.6.5 Energy saving control
There are many energy-saving technologies for automated air conditioning control systems,
including heat sources in relatively larger scale buildings. The technologies can be
categorized into 3 groups as follows: (See the following table and figure.)(1)Technologies to control generation of the heat load in rooms(2)Technologies to efficiently remove the generated heat load(3)Technologies to efficiently generate and transfer the required heat/cold
It is very important to prioritize the application of these three technology groups to obtainenergy savings in buildings. It is important to take the following steps: (1) reduce the heatload as much as possible, (2) minimize the required amount of heat/cold as much as
possible by improving the heat load handling process, and (3) generate the required heatefficiently.
53

Table 2.2.6.5-1
Group(1) Suppresses
heat load
generated

Energy-Saving Technologies for HVAC

Automatic control technology
for energy conservation
Automatic adjustment of room
temperature set point
Demand based control (CO2)AHU control according tohuman presence
Lighting control according tohuman presence
Automatic dimmer control for
lighting(2) Efficiently
removes thegenerated heatload

Outdoor air cooling
VAV control
AHU variable air volume
control
Humidification Cooling Control(3) Efficiently
generates andtransfers heats

Chiller Number Control
Chiller load distribution control
Temperature setpoint control
for the outlet of chillers
Variable condenser water
volume control
Airflow control for the cooling
tower fans
Controls the number ofoperating water pumps
Variable water volume control
for water pumps

EnergyDescription
Automatically reduces the heat load by changing
excessive temperature setpoints.
Controls the volume of ventilation according to the CO2
concentration in order to reduce the outdoor air load.
Reduces air conditioning in zones where no humanpresence is detected in order to reduce the load.
Turns off lights in zones where no human presence is
detected in order to reduce the load.
Lowers brightness in a room when there is abundantambient light (such as in daytime) in order to reduce theload.
Utilize cool outdoor air to reduce the load for coolingrooms.
Controls the supply air volume for each zone to reduce
AHU fan power consumption.
Using VSD to reduce AHU fan speed to save power
consumption
Generates chilled air using vaporization type humidifier toreduce AHU load.
Runs only the number of chillers required for air
conditioning.
Allocates more load for the heat sources that efficiently
generate heat.
Improves the efficiency of chillers by reducing thetemperature setpoint at their outlet.
Controls the volume of condenser water according to theamount of generated heat.
Reduces the cooling tower fan airflow according to theradiated heat from the chillers.
Operates only the number of pumps required forconveying heat.
Controls the water pressure required for conveying heat.

Chilled / hot water

AHUs

Chiller plant32
Efficiently
generates andtransfers heats

Low
Fig. 2.2.6.5-1
54

28.0
℃

Chilled / hot air

Efficiently
removes thegenerated heat

Priority ofcountermeasures

Rooms
1

Suppresses
heat load
generatedHigh

Applicable Area of Energy-Saving Technologies for HVAC

2.2.6.6 Linkage with EV batteries
If EMS has an internal electricity storage function, renewable energy can be used more
efficiently. Therefore, electric vehicles (EVs) that can be linked with EMS are expected to be
more widely used. EV charging system basically works in stand-alone, but, it may workthrough a cloud management especially in commercial buildings. Though some standalone
EV charging systems already have interface with BACnet, it is necessary for cloud-base EV
charging systems to develop interface between BEMS and cloud center. It is desirable tostandardize V2B (Vehicle to Building) like V2G (Vehicle to Grid).
2.2.6.7 Linkage with smart grids
Although this is a different issue from the purposes of ZEB/ZEH, it is effective for efficiency
improvement at the grid level to link EMS systems with smart grids. So, it is desirable topromote technology development aiming at effective linkage of EMS design architecture withsmart grids. One of the typical examples of interface between EMS and Smart Grid is DR(Demand Response) which is popular in the United States and elsewhere.
OpenADR etc. is adopted as the communication standard for DR, but further technicaldevelopment is desired.

55

2.3. Policies for promoting ZEB/ZEH introduction in the existing Road Maps
2.3.1 Barriers in implementing and diffusing ZEB/ZEH
On November 4th 2016, a new climate change policy framework beyond 2020, “Paris
Agreement under United Nations Framework Convention Climate Change (UNFCCC)”,came into effect, backed by over 190 countries worldwide. The Agreement has established ashared long-term global GHG reductions target for limiting temperature rises below 2℃. Thisrequires us to make great changes to the way we live and run our economy, starting withenergy policy. With final energy consumption remaining high in developed countries, andenergy demand also expected to increase in developing countries as they push for economic
growth, the building sector is especially in need of tougher energy-efficiency policies.
We have noted the following barriers in relation to the implementation and diffusion of
ZEB/ZEH. Firstly, information regarding the costs and benefits of products applicable to
ZEB/ZEH is not being put out effectively, meaning that levels of awareness andunderstanding among consumers are failing to rise. Secondly, the roles of the many
government ministries involved in ZEB/ZEH policy remain blurred, and thirdly, insufficient
cost estimations can be carried out and the feasibility of ZEB/ZEH cannot be properly
assessed. Fourthly, there is a human capacity problem as few architects, technical experts
and equipment installers either have sufficient knowledge of energy-saving and low-carbon
technologies, or possess the relevant capability to design ZEB/ZEH and calculate its energysaving potentials. A host of challenges thus remains as to how to plan the implementationand diffusion of ZEB/ZEH in developing countries where energy demand is vastly increasing.
(Outreach)
The average consumer is simply not expanding his or her knowledge about the costs andbenefits of ZEB/ZEH products. Specifically, the average consumer lacks awareness andunderstanding of the components of ZEB/ZEH and therefore cannot appreciate theperformance and energy-efficiency aspects of such products. This means that we are unable
to sufficiently insist the benefits such as reductions in energy expenses, improvements tohealth and comfort stemming from better insulation and resilience (contribution to BusinessContinuity Planning) based on energy self-sufficiency.
(Governance)
Long-term budget commitments are necessary if we have to achieve lifecycle optimums.
Unfortunately, a great number of government ministries are involved in ZEB/ZEH policy, butwith a lack of clarity in their respective roles. Government sector cannot make an appropriate
estimation of ZEB/ZEH profitability and other investment benefits, which give insufficientmotivation to building owners (decision-makers to develop and construct ZEB). Furthermore,
although some countries have established several support and labeling schemes forenvironment-friendly or energy-efficient housings and buildings, some people seemingly failto grasp the difference made by such schemes, meaning that effectiveness has been limited.
In addition, from the standpoint of privacy protection, there is a need for sufficientconsideration over the private data about energy behavior disclosure. Yet the government
sector must provide more details on security regulations.
(Costs)As there is a lack of cost estimations on ZEB/ZEH, the feasibilities for ZEB/ZEH are difficult
to be assessed. As diffusion of ZEB/ZEH has been so limited, market competition remains
weak and costs have remained high, the building owners who develop and design ZEB/ZEH
cannot cover its additional costs. Moreover, as buildings are not mass-produced goods,
there appears great difficulty in sharing information about costs of buildings.

56

(Lack of human resources)
It is also difficult to encourage implementation and diffusion of ZEB/ZEH due to a humanresource shortage. Few architects, technical experts and equipment installers either havesufficient knowledge of energy-efficiency or low-carbon technology, or possess the requisite
capability to design ZEB/ZEH and calculate its energy-saving potentials.
(Landlord-tenant problem)
This has occurred within rented properties, whereby even though the building owners mustcover the costs of ZEB conversion, the benefits are accrued by the tenants in terms of lower
energy costs.
(Behavior)Significant behavioral and lifestyle changes are required to reduce building energy demand.
(Regional Difference)
In future, the major increase in energy use and consequent CO2 emissions will come fromthe developing world. However, in developed countries, the depth of building renovation is
also crucial, as retrofit buildings will command the largest share of total building stock by
2050. There is thus enormous potential for emissions reduction within the cool and moderate
climate zone in which most rich countries are located. Urban areas will account for most of
the growth in energy use, both in developed and developing countries. However, rural
regions also have a crucial role to play.

2.3.2 Policy Elements for Promoting ZEB/ZEH Introduction
Many policies and measures are already listed within the existing roadmaps. However, thefollowing diffusion/deployment policies, which are common in many roadmaps, can be listed
as important policy elements.
2.3.2.1 Stakeholder Involvement
Firstly, for governments and other stakeholders who play a role in shaping the ZEB/ZEH
market:i. Policy coordination in public sector, stakeholder participation, and governance reform.
In many countries, ZEB/ZEH policy-making responsibilities are divided between various
ministries such as those for Energy and Building / House Construction. In order for thesepolicies to be positively driven forward, it is important to clarify the authorities among theseministries.
The diffusion/deployment of ZEB/ZEH will require market alterations. In addition to improving
the availability and relevance of information provided to decision-makers, policies areneeded to improve the knowledge and ability of private sector actors involved with ZEB/ZEH.
Quality assurance in that sector should be increased to foster greater trust among
consumers.
ii. Improving the availability, quality and effects of information provided by stakeholders todecision-makers, and ZEB/ZEH-related public information
The ZEB/ZEH market is characterized by incomplete information. In conjunction withimprovements to information provided to consumers, we need more robust ways to measure
and analyze the energy and CO2 reductions and the lifecycle financial benefits from the useof ZEB/ZEH technology. User-friendly information must be provided to buyers andconsumers.
57

iii. Improving knowledge in private sector within the construction industry and amongequipment installers; building infrastructure and human resources; drawing up and diffusing
design guidelines and increasing knowledge sharing; and developing technical experts
People involved with ZEB/ZEH such as architects, technical experts and equipment
installers need to improve their knowledge and capability on energy-saving and low-carbon
technologies. It is important to widely diffuse knowhow, especially among small-scalebuilding owners and architectural firms, by preparing and updating design guidelines basedon information gathered on technologies, design methods, and costs and benefits. We must
train up individuals who can propose ZEB/ZEH to technical experts, building owners andtenants involved in ZEB/ZEH.
Embedding new technologies into products and successfully penetrating them into themarket requires policies appropriate to the maturity of market. At the R&D anddemonstration phase, R&D promotion and case studies will be key policies, while market
incentives and mandatory building codes must form the kernel of policy at the
diffusion/deployment and marketization stage.
2.3.2.2 Research, Development and Demonstration(R&D and Demonstration Phase)iv. Enhanced technology R&D, demonstration programs, development of technology which
beyond BAT (Best Available Technology); development of innovative technology throughR&D promotion and case studies; development of technology for higher performance andlower cost
It is essential to both improve the performance of and lower the cost of component
technology by the development of technology and for production on a larger scale.
2.3.2.3 Diffusion/Deployment(Diffusion/Deployment and Marketization Phase)v. Diffusion regulations and policies; the drawing up, publication and enforcement of
mandatory building codes; the use of financial incentives; incentives to building owners; andclarifying benefits of ZEB/ZEH.
We must implement policies which make use of economies of scale to accelerate diffusion
and lower costs. The policy most used to ensure energy efficiency in new buildings is theintroduction, publication and enforcement of mandatory building codes, while the main direct
policy for promoting deep renovation of existing energy-inefficient buildings consists offinancial incentives. A certain level of subsidies to the introduction of highly insulated
envelope and higher performance equipment and appliances has proved effective in
triggering building owners to convert to ZEH. Benefits other than energy saving such as
improvements to health and comfort, labor productivity and market value may also become
good incentives. It is necessary to clarify benefits other than reductions in energy expenses
such as improvements in: resilience through independent energy provision; comfort/healthand labor productivity through enhanced quality of the indoor environment; and real-estatevalue. We also need to increase understanding of these benefits among building owners,
tenants and consumers.

58

TOPIC3 Diffusion situation of ZEH in Japan today
Definition and Technology for ZEH
A ZEH is a house with an annual net energy consumption around zero (or less) by saving as
much energy as possible keeping comfortable living. As shown in Figure below, this can beachieved through better heat insulation, high-efficiency equipment, and creating energy withphotovoltaic power generation etc. [12] The concept of ZEH has been widely accepted anddiffused the numbers of ZEH built is increasing.

As little energy consumption
as possible

Fig. T3-1 Conceptual diagram of ZEH 44

ZEH requires energy saving of 20% or more and creating the rest to attain net zero energy.
High-performance insulating materials of the envelope and highly-insulated windows etc. are
used
for
low
consumptionofenergy and highefficiency equipmentof the house such as
airconditioner,
ventilator,
lighting
and water heater isintroduced to use
energymore
efficient.
Photovoltaic
ismainlyusedtocreate power for
ZEH. Nearly ZEH
status(75%
reduction of energy)
is introduced to savepoor sunshine area.
Fig. T3-2 Schematic diagram for the definition of ZEH44

Sustainable open Innovation Initiative, as of 2016/11/22
https://sii.or.jp/zeh28/file/doc_1122.pdf
4459

Diffusion policies
Diffusion policies settled by Agency for Natural Resources and Energy (METI Japan) are
shown in the chart below. The goals in FY2020 are autonomous diffusion of ZEHs andattainment of 50% or more of ZEBs in newly-built houses. In the policies, establishment of
the definition of ZEH, subsidies for construction, training policy of construction engineers areincluded as the role of national government. Public relations, technology development(adapting ZEH as a standard specification) and setting voluntary action plan for diffusion of
ZEHs are required for construction company.

Diffusionof ZEHs

Autonomously diffuse ZEHs/
More than half of newly –built houses will be ZEHs

Fig. T3-3 Chart of ZEH diffusion policies in Japan44

ZEH is becoming popular and reached nearly 15,000 cases on the basis of subsidy grant
decision in FY2016 owing to those policies.

Fig. T3-4 Numbers of annual ZEH support cases in Japan.44

60

3. Path to innovation and spread of technology
3.1 Directionality of technology innovation
As stated in 2.1, various technologies are applied to buildings; yet there are manysophisticated technologies that have not been applied to buildings in order to suppress costs.
There are also domains in the buildings sector where high performance is achieved at low
cost by introducing innovative technologies.
This technology roadmap shows issues to be addressed in the future with a focus on
innovative technology, cost reduction, and development of high-efficiency technology.

3.2 Technology roadmap
Technology roadmaps shown below indicate the expected years when the advanced
technologies should be available in the market put into use. Many of them are consistent to
the road maps of IEA and Energy Efficiency Technology Strategy 2016 Formulated (ANRE /NEDO).
Table 3.2-1 shows the technologies included in the each climate zone roadmap. Especiallyin the Moderate and Humid region, all technologies pointed out in this roadmap are required
for realizing ZEB/ZEH.
Table 3.2-1 Comparison of the roadmaps by the climate zone

*1:Top level, IEA *2: Avarage U value for wall and roof, IEA *3: U value of whole window for ZEB, IEA *4:Solar reflectance, white *5:Air Change
per hour *6:Photovoltaics *7:Energy management system *8:Intenet of things613.2.1 Roadmap for moderate and humid regions.

Fig.3.2.1-1 ZEB/ZEH technology roadmap for moderate & humid regions*1:Top level, IEA *2: System without hot water tank *3: Average U value for wall and roof, IEA *4:U value of whole window for ZEB, IEA *5:Solar
Heat Gain Coefficient, IEA *6:Solar reflectance, white *7:Air Change per hour *8:Photo voltaics *9:Energy management system *10:Intenet ofthings *11:Power line communication

62

Figure 3.2.1-1 shows a roadmap for moderate and humid regions.
As stated in 1.6, there are many cases where application of energy in the ZEB/ZEH fields inmoderate and humid regions is directed to reduction in humidity, so various types oftechnology are adopted as targets in the roadmap.
3.2.1.1 Active technology
A) Air conditioning
Equipment necessary to be considered for technology development and promotion ofdiffusion of the active technology (air conditioning) are high-efficiency heat pumps,
absorption chillers, and dehumidification technology.
High-efficiency heat pumps can be realized by leveraging technology development mainly in
two fields: optimization of heat exchangers (including development of high-efficiency coolingmedia and design of refrigeration cycles suitable for the media) and efficiency improvementof compressors.
In principle, the more the performance of heat exchangers is improved, the more theefficiency of heat pump cycles is enhanced. In contrast, however, costs increase. Therefore,
the key point is technology for material and structure design of heat exchangers that helps
achieve high efficiency while keeping costs at a minimal level.
For efficiency improvement of compressors, emphasis should be placed on technology tosuppress power loss caused by friction. Although scroll compressors and the like are put into
practical use as high-efficiency compressors, it is also necessary to develop compressorsthat feature higher efficiency and that are suitable for refrigeration cycles in highperformance cooling media. In addition, in humid regions, dehumidification is conductedsimultaneously with cooling when using heat pumps for cooling, which causes an increase in
the energy required for air conditioning. Therefore, it is necessary to develop control
technology with optimization of dehumidification taken into account.
Absorption chillers are refrigerating machines that can use various types of heat sources, but
a technology to remove cold energy at high efficiency from relatively low-temperature heatsources such as solar heat is required. In addition, since their heat exchangers are of large
size, development of a compactification technology and a control technology where
optimization of dehumidification is taken into account like in heat pumps is also required.
Currently, there are many cases where dehumidification in cooling is often not taken into
account, but the mainstream is adoption of a cooling control method based on temperature
setting. For this reason, there are cases where energy is wasted in some facilities byconducting excessive dehumidification, etc. To improve this situation, in parallel with
development of material technology, namely a key technology to realize dehumidification
technology, it is desirable to promote development of a control system to achieve energy
saving and provision of comfort simultaneously by, for example, separately conducting
dehumidification and temperature control.
TOPIC4 Air-conditioning system with separation of latent and sensible heat
Concept of air-conditioning system with separation of latent and sensible heat
The purpose of air-conditioning is to control the temperature, humidity, cleanliness and flowof the air in a place to improve the comfort of humans and help with industrial activities inhandling goods, such as those related to production, management and storage. In the airconditioning of office spaces, it is necessary to take in the outside air to remove carbon
dioxide generated from human activities. It is necessary to cool the outside air to remove
humidity in the summer and to heat and humidify the outside air in the winter to keep theindoor temperature and humidity at an appropriate level. Figure T4-1 schematically shows
the change in the outside air temperature and humidity during air-conditioning. To take an
example of an outside air temperature of 37°C and an outside air relative humidity (RH) of
75% in the summer, the absolute humidity of the outside air, which is the ratio of the mass ofwater vapor to the mass of dry air, is 0.030 kg/kgDA. The absolute humidity of the air in an63environment comfortable forhumans is 0.011 kg/kgDA.
To achieve this, it isnecessary to lower thetemperature from 37 to 25°C
and reduce the absolute
humidity by 0.019 kg/kgDA.
To dehumidify and cool the
air with a commonly usedcooling coil, air conditioning
involves the process of (I)cooling, (II) cooling plus
dehumidification and (III)heating. In Step I for cooling,
the outside air is cooled tothe temperature at which
dehumidification is started.
Thereafter, in Step II, theFig. T4-1 Image of air conditioning on psychrometric chartoutside air is cooled anddehumidified
until
the
absolute humidity decreases to 0.011 kg/kgDA. At this point, condensation occurs near thecooling coil. The outside air is cooled and dehumidified along the saturated vapor pressure
curve of air with a relative humidity of 100%. The absolute humidity reaches 0.011 kg/kgDA
at a temperature of 15°C. Therefore, to perform Step II of the process, the cooling coiltemperature needs to be lowered to 15°C or less. In actual cooling, the cooling coil is cooled
to about 7°C considering the cooling rate. This contributes to the decrease in the coolingefficiency. To perform Step III following Step II, the air needs to be heated to 25°C by theheating coil at a temperature of 25°C or higher. This step also consumes energy. If anothermethod is used for reducing humidity, the humidity can be reduced by directly lowering theoutside air temperature from 37 to 25°C. This allows the temperature of the cooling coil to be
set to a higher temperature to increase the cooling efficiency. This is the concept of airconditioning
systemwithseparation of latentand sensible heat.
An example of thesystemistheprocessof(i)desiccantdehumidification
plus (ii) cooling. If
theenergyefficiency
ofdesiccantdehumidification ishigh, the coolingefficiency of thissystemdramaticallyincreases.
Figure T4-2 is aflow diagram of an
air-conditioning
Fig. T4-2 Air conditioning system with a desiccant rotor
systemwithadesiccant rotor. A system that uses the dehumidification process of a desiccant rotor is huge64and expensive, and it is difficult to say that such a system is widely used for the actual
process.
High-efficiency air-conditioning system with Hybrid Heat Exchangers
A high-efficiency dehumidification/humidification system with a heat exchanger integrated
with a desiccant element is commercially available. 45 As shown in Figure T4-3, the system
has two hybrid heat exchangers, with each heat exchanger integrated with a desiccantelement. They make up a compression heat pump. In the dehumidification mode in theFig. T4-3 Schematic images of DESICA systemsummer, one hybrid heat exchanger is cooled and moisture from outside is adsorbed. The
cooled and dehumidified outside air is brought inside. At the same time, the other hybrid
heat exchanger is heated and the adsorbed moisture is discharged outside, regenerating thedesiccant. The continuous operation of the system is possible by changing the direction of
the air flow and switching between cooling and heating at the same time. The use of hybrid
heat exchanger allows for highefficiency dehumidification with aheat pump at the temperature on
the heat-releasing side and on
the heat-absorbing side.
In the humidification mode in
the winter, the air flow in thedehumidificationmode
isreversed and moisture isreleased into the inside air,whereas moisture in the insideairisadsorbed
inthedehumidification mode.
Figure T4-4 shows the change
in temperature and humidity
when the air is cooled by thesystem. The outside air is cooledby the process from (ⅲ) to (ⅳ). Fig. T4-4 Image of DESICA system on psychrometric chart
Since it goes through step (ⅲ),
45

DAIKIN INDUSTRIES, LTD.

65

this system, which is an adsorption dehumidification system, can dehumidify the air without
increasing the temperature and thus can reduce the load of the cooling process in (ⅳ). Theenergy efficiency of the process in (ⅲ) is high, and the energy efficiency of the system as awhole is high. A system such as this is effective in regions where dehumidification is an
important element of cooling.

B) Hot-water supply
Equipment necessary to be considered for promotion of diffusion of the active technology(hot-water supply) is hot-water heaters of the latent heat recovery type and CHP. Both allow
for more efficient use of energy than ordinary hot-water heaters, but their equipment costs
are high. It is necessary to formulate measures to promote the spread of the equipment.
Other equipment candidates are heat pumps and fuel-cell CHP.
Although the fundamental principles of a heat pump are the same as those of air
conditioning, the required temperature range is different between air conditioning and hotwater supply, so it is necessary to further achieve higher efficiency through optimization ofrefrigeration cycles and cooling media. In addition, since output from current hot-water
heaters of the heat pump type is small, heat accumulation in a hot-water tank is necessary.
Due to radiation loss from the hot-water tank, it is also necessary to develop a technology toachieve high efficiency and high output that can eliminate the need for hot-water tanks.
Fuel-cell CHP offers higher generating efficiency than other types of CHP and enables easy
high-efficiency operation in ZEB/ZEH. Moreover It is possible to operate fuel cell CHP withhigher efficiency when surplus electric power is reversed to the grid. Therefore, it is desiredto accelerate deployment of this technology through development of cost reduction
technology and institution to accelerate grid connection. If CO2-free hydrogen is used, no
CO2 is emitted from fuel-cell CHP, so it is also desired to develop technology for, andpromote deployment of, hydrogen supply systems.
C) Lighting
Lighting has a special feature called color-rendering properties that have an influence onhuman senses like comfort in air conditioning. Basically, human beings have a preference
for an aggregate of light having various wavelengths such as sunlight. However, current
technology cannot satisfy both high levels of color-rendering properties and luminous
efficiency.
LED lamps and inverter-based fluorescent lamps have relatively good color-rendering
properties and work with high efficiency, so it is expected that they will be widely used. As fororganic EL, it can become a highly efficient light source having good color-rendering
properties due to its working principles, so it is hoped that innovation of organic EL
technology will be accelerated and that the technology will be widely deployed.

66

3.2.1.2 Passive technology
A) Ventilation and shading
Promotion measures should be taken so that natural ventilation and shading are fully taken
into consideration at the construction design stage. It is also desirable to take promotion
measures for introduction of this technology through adoption of the sophisticated Passive
technology by linkage with EMS, etc. and for common use of parts through standardization.
B) Insulation
Technology development for insulation in building sector has been made for mass
production of the materials at acceptable costs based on advanced technologies that havebeen used in the space sector and for utilization of natural materials and waste. Vacuum
insulation panels are made by filling a board-shaped container made of metal films withmaterial having a high void ratio and low heat conduction and by vacuating the inside of thecontainer, and they have a thermal resistance about 10 times that of other insulating
materials such as glass wool. However, at the present time, their manufacturing costs are
high, and special care to prevent damage to the films is necessary so as to maintain thevacuum state, posing a problem for construction methods.
Silica aerogel is a synthetic porous ultralight silicon oxide derived from a gel in which theliquid component of the gel has been replaced with a gas. It has insulation efficiency morethan twice that of current insulating materials, but in the present state, it is fragile, thus
posing a problem for construction methods, etc. Therefore, it is necessary to develop
technologies to solve these material problems and create new materials.

67

TOPIC5 Aerogel for ZEB/ZEH
Transparent Insulation Material

Fig. T5-1 Appearance and structure of typical silica aerogel 46

Thermal conductivity/W m−1 K−1Aerogel is a low-density solid with transparent appearance which exhibits the lowest thermal
conductivity among all solidus substances (See Figs. T5-1,2).
The first report on the synthesis of silica (SiO2) aerogel dates back to 1931 47. Although
being highly tenuous with 80-90 % porosity, the well-controlled pores smaller than 50 nm indiameter suppress the heat conduction by gas molecules as well as the scattering of visible
light travelling through the
0.10
solid.
Despite theseunique physical properties,
aerogel has suffered fromits mechanical friability
which prevents its use as apractical thermal insulationmaterial.
Aerogels are
0.05
prepared by removing thesolvent liquid contained
initially in the nanoscalepores frameworked by very
thin
(~10
%)
solid
components (See Fig. 1),0which necessitates the“supercriticaldrying”
process. The costly andtime-consuming
dryingprocess
kept
aerogelcommercially undeveloped
for over many decades.
Fig. T5-2 Thermal conductivities of insulating materials 48
Hybrid Aerogel
As silica has been the most popular composition of aerogels, numerous attempts have been
made to reinforce or chemically modify the fragile gel network. Some of them weresuccessful in improving the mechanical strength to a large extent, but instead, the46Partly taken from T. Shimizu, K. Kanamori, K. Nakanishi, Chem. Eur. J., in press (2017).
S. S. Kistler, Nature 127,741(1931)
48
Numerical data were taken from M. Koebel, A. Rigacci, P. Achard, J. Sol-Gel Sci. Technol 63, 315339 (2012).
47

68

transparency and thermal insulation property have been sacrificed. A recent breakthroughwas made by the use of organically-modified siloxane (Si-O-Si) compositions – organicinorganic hybrid – in place of pure silica. In the typical poly(methylsilsesquioxane), PMSQ,
composition, nanoscale networks composed of three siloxane bridges and one terminal
methyl group connected to the central Si atom exhibit higher flexibility than those of puresilica with rigid four siloxane bridges. The flexible network further enabled one to remove thesolvent liquid without utilizing the supercritical drying; transparent, low-density xerogels
equivalent to the aerogels can now be obtained by “ambient pressure drying” 49 .
Well processed aerogels exhibit the thermal conductivity of 0.012W/mK and the > 90 %visible light transmission at 10 mm thickness. Heat insulating windows utilizing aerogels
have been limited to those with double-glass window with its gap filled with granular silica
aerogels with hydrophobic surface modification, which exhibit substantially higher thermal
conductivity and much lower transparency than those of monolithic aerogel tiles. Using the
hybrid aerogel tiles with 25 mm thickness, it is possible to fabricate a highly transparent
double-glass window (an aerogel tile sandwitched between protecting glasses) with a Uvalue of 0.5-0.6 W/m2K at ca. 30 mm total thickness. The equivalent performance is only
possible with the state-of-the-art quintuple-glass window with the thickness of 66-68 mm and
50 % visible transmission (See Fig T5-3). Much simpler setup, light weight and no need ofgas-tight structure will be favorable in their application to ZEB windows. Provided that theconstant manufacture of hybrid aerogel tiles with large enough area and optical homogeneity
becomes possible at a reasonable cost, those “aerogel window” will take a substantial
market share.
LEGARIS (The flagship model of LIXIL)
Dimension: W1690×H1370

Conceptual hybrid aerogel window
Under development by Tiem Factory Inc.

U-value

0.53

W/m2・K

Fig. T5-3 Estimated performance of hybrid aerogel window 50

49
50

K. Kanamori, K. Nakanishi, Chem. Soc. Rev. 40, 754-770 (2010).
LIXIL corporation, Tiem Factory Inc.

69

C) Reflection
This technology is required for producing reflectors, especially for roofs and walls in regions
where solar insolation is strong. Windows subjected to four seasons are required to reflectsolar insolation in the summer but pass heat rays in the winter. Technologies for reflection
include paint application and surface treatment of glass. These technologies meet
specifications at an early stage of construction but, after long periods, performance
deterioration often occurs due to pollution and degradation of performance. Therefore, it isnecessary to develop a technology that can maintain a specified performance for a long
period of time.
TOPIC6 ARPA-E’s commitment 51
What is ARPA-E
ARPA-E, or Advanced Research Projects Agency-Energy, is a program of the U.S.
Department of Energy (US DOE) to support the development of technologies that could
potentially impact the energy industry but are relatively risky. ARPA-E, which covers energy
technology in general, began substantial activities in fiscal 2009 with an annual budget ofnearly 300 million dollars. Its budget request for fiscal 2017 is 500 million dollars.
ZEB/ZEH-related programs
As many as 39 programs have been prepared, under which several to several tens ofprojects are implemented. The ARPA-E programs with specific objectives include BEETIT(Building Energy Efficiency Through Innovative Thermodevices) aimed at improving theefficiency of heat source equipment; DELTA (Delivering Efficient Local Thermal Amenities)
aimed at improving the energy efficiency of buildings; GENSETS (Generators for Small
Electrical and Thermal Systems) aimed at the proliferation of combined heat and power(CHP) systems; and SHIELD (Single-Pane Highly Insulating Efficient Lucid Designs) aimed
at improved insulation of windows. ARPA-E has also implemented OPEN 2009, OPEN
2012, and OPEN 2015 programs, which are not designed for specific objectives, to support
projects related to a wide range of technologies.
Radiative coolers for rooftops
and cars 52
One such high impact project,funded under the ARPA-E OPEN
2012 program, is aimed atenabling passive cooling forcommercial
andindustrial
buildings, 24 hours a day.
This passive cooling technology
is based on a multi-layered filmthat reflects 97% of solar energy
and radiates heat to the sky andouter space. This is known as thesky cooling effect and enables
Fig. T6-1: Image of radiative cooling during the day
passive cooling during the day
and at night.
An initial experiment conducted at Stanford University on a winter day in California, showed
40 W/m2 in heat rejection and a temperature drop of 3 to 5°C compared with the ambient air
temperature. Experiments since then with their new films have cooled as much as 15°C
51

https://arpa-e.energy.gov/?q=arpa-e-site-page/about
Radiative Coolers for Rooftops and Cars https://arpa-e.energy.gov/?q=slick-sheet-project/radiativecoolers-rooftops-and-cars
5270below the ambient temperature on similar hot days. Based on such findings, the developersof this technology have founded a venture business called SkyCool Systems, which isdeveloping rooftop panels that cool fluids passively. When their panels are combined withexisting cooling systems, they improve the underlying cooling efficiency by 20 to 30 percent.

Fig. T6-2: Radiative cooling panels operable during the day 53

D) Sealing
From a technical viewpoint, this technology is in a matured stage, and the focus is on how it
should be considered at the design stage. Depending on the region, in some cases, there isno difference between the amount of energy saved through air sealing and that needed forappropriate humidity conditioning and ventilation. Therefore, standardization is needed as towhat regions allow for effective air sealing and what level of air sealing is needed.
3.2.1.3 Renewable Energy IntegrationA) PV
Mass production of PV systems to be mounted on roofs for use in buildings is now
substantially expanding due to synergy of technology development for enhancing efficiency
and measures taken to promote introduction of FIT, etc., resulting in lower unit prices for
power generation. It is necessary to further advance the technology for reducing costs. On
the other hand, for PV systems to be mounted on walls, it is necessary to take into accountmatching with the external appearance of buildings, so it is also necessary to pursue
technology development with an emphasis on excellent design.
B) Wind power
There has been no smooth deployment of wind power generation facilities on buildings due
to wind conditions more adverse than on mountain peaks and the coast, concerns about
scenery and safety, high costs of power generation facilities, etc. Development oftechnologies necessary for high-efficiency wind power generation systems for ZEB is anurgent issue.
53

ARPA-E Innovation Summit 2017 SkyCool Systems, Inc.

71

TOPIC7 Wind Thermal Power Generation and Application of ZEB/ZEHWorking of Wind Thermal Power Generation
The concept of using thermal storage to address the instability of renewable power
generation and to use stable and economical energy sources is wide spreading.
Concentrated solar power (CSP) plants, which can stably supply 300 MW of power for 6hours after sunset are being underoperation in the United States. 54 In
a CSP plant, solar energy isconverted to heat and stored in thethermal storage and electric poweris stably generated by a steam
turbine.
The
thermoelectric
conversion efficiency of CSP is as
low as about half that of batteries,
but the equipment cost is muchless than that of batteries. Thus,
CSP is more economical than the
combination of solar cells andbatteries.
Local
industryindeveloping
countries,
where
electric power demand is expected
Fig. T7-1 Schematic of wind thermal power generation
to grow significantly, can utilize
CSP.
The concept of employing the thermal storage for wind power is advantageous like solar
power stated above. For example, German Siemens started to develop a system to store
surplus power from wind power generation and the grid with electric heaters to stabilize theoutput power and generate power when needed. 55 This concept was further developed intowind thermal power generation as shown in Fig. T7-1. Intermittent wind energy is directly
converted to thermal energy by a heat generator at the top of the wind turbine tower. Theintermittent thermal energy is stabilized by the thermal storage and produce stable electric
power like the CSP system. The heat generator employs the principle of eddy current, whichmakes it possible to achieve a very light-weight and robust direct drive system as well as
further cost reduction. In the most simple and lightweight type, only heat is generated at the
top of the wind turbine tower and electric power is generated by a steam turbine
downstream of the thermal storage. 56
Application to ZEB and its Issues
The system described above is a system with a view to large-scale power generation.
Furthermore, it can be applied to small ZEB systems with the main purpose of supplying
heat. The demand for heat accounts for about half of the energy demand in buildings andhomes, and there is a problem that renewable energy has not been harnessed to meet thedemand for heat. To meet the demand, thermal storage tanks are required to supply arequired amount of heat when needed. If heat storage is carried out at about 100°C, to use aheat pump with a high coefficient of performance (COP) can be regarded as an alternative
method. However, due to the low energy density, large hot water storage tanks are required.
With power supply from wind turbines, the performance factor of the heat pump is low and
54

M. Mendelsohn, T. Lowder, B. Canavan “Utility-scale concentrating solar power and photovoltaics
projects: a technology and market overview” NREL/TP-6A20-51137 April 201255
http://www.siemens.com/press/pool/de/pressemitteilungen/2016/windpowerrenewables/PR2016090419WPEN.pdf (Retrieved Dec. 9, 2016)56
Toru Okazaki, Yasuyuki Shirai, Taketsune Nakamura “Concept study of wind power utilizing direct
thermal energy conversion and thermal energy storage” Renewable Energy, 83 (Nov. 2015) pp. 332338

72

the operating cost becomes high. Wind
thermal power generation can beapplied to this case. A wind turbine isinstalled on the rooftop of a building orhouse and a heat generator is used as aheat source. An air-cooled heatgenerator with an output power of a few
hundred kW has been put into practicaluse as an automotive brake for large
vehicles (See Fig. T7-2).
The following are the advantages,
disadvantages and issues of windthermal power generation.
Advantages
・The heat generator is simple, robustand easy to maintain. If multiple windturbines are installed on the rooftop of abuilding, they can be maintained withease.
・The heat generator can deliver heat at
a temperature of up to 650°C. This
realizes the thermal storage tank smaller
than that of the hot water tank. The tanksize can be reduced to 1/3 to 1/10.
・The stored energy can be used forvarious applications such as direct heatuse, stable electric power generation
andheat
treatment
processes.
Depending on the heat storage material,
the exergy density increases by nearlyseveral dozen times, expanding its
application. Affordable nitrates orcarbonates, which have been used in
CSP, are used as the heat storage
material. A small heat storage system
for heat source of cooking as shown in
Fig. T7-3 that uses a molten nitrate has
been put into a practical use.

Fig. T7-2 Auxiliary brake for large vehicles(Courtesy of NSSMC)

Disadvantages
Fig. T7-3 480°C molten nitrate thermal
・This is a new technology and has notstorage system (Courtesy of IIC / IHI)
been used yet. Therefore, when actual
engineering design and construction are
implemented, the cost of wind thermal power generation may increase due to unexpectedfactors. Its performance and cost need to be evaluated in detail.
・Pipes to connect multiple wind turbines are required. Thick pipes taking account of heatinsulation capacity are required to connect wind the turbines, whereas thin electrical cables
are required for commonly used wind turbines.

]
73C) Waste energy use
For application of utilization technologies of unutilized energy to ZEB/ZEH, a study has been
made on the forms of recovery of heat discharged into sewage water and utilization ofunderground heat. In either form, it is necessary to start study of its introduction at thebuilding design phase. In addition, measures to facilitate introduction of these forms should
be taken, and their standardization is desirable.
3.2.1.4 Energy ManagementA) EMS and IoT
EMS has been developed uniquely in each region in concurrence with dedicated controllers
and communication standards. Though it is for different purposes from those of EMS, aconcept called IoT is proposed for connecting each of the devices existing in buildings. It is
desired to develop standards for both communication and terminals that allow for addition of
EMS functions. A technology to store energy (electricity storage) has been developed in theautomobile and power sectors, and further development of this technology including heatstorage is expected.
B) Grid connection
Though it is for different purposes from those of ZEB/ZEH, linkage between EMS systems
and smart grids is effective for efficiency improvement at the community level and the gridlevel. It is hoped that technology development is pursued in a manner that allows for
effective linkage between EMS design architecture and smart grids.

74

3.2.2 Roadmap for cold regions
Figure 3.2.2-1 shows a roadmap for cold regions.
Because it is not necessary to take into account the need for dehumidification in cold regions,targets of technology development and support for promotion of spread of technology inthese regions are different from those in other regions. However, the technical contents are
the same as those indicated in the preceding items. Therefore, an explanation of them isomitted.

Fig.3.2.2-1 ZEB/ZEH technology roadmap for cold regions75

3.2.3 Roadmap for hot regions
Figure 3.2.3-1 shows a roadmap for hot regions. It is not necessary to take into account theneed for individual dehumidification because dehumidification is performed simultaneouslywith cooling at high demand. Therefore targets of technology development and support formarket diffusion of technology are different from those in other regions.

Fig.3.2.3-1 ZEB/ZEH technology roadmap for hot regions763.3 Future Policy Responses
Actions
A diverse set of actions are required for R&D, and subsequent dissemination of ZEB/ZEH in
the market to take place. It is crucial to ensure that all these individual actions are taken inline with long-term targets that provide a shared vision among stakeholders and market
certainty. There must also be a supportive governance structure with a clear division of roles
and responsibilities among relevant ministries and municipalities, and sound communicationand coordination among stakeholders. As ZEB / ZEH only achieves optimization in “whole”
form rather than as a compilation of diverse technologies, coordinated actions are necessary.
For example, advanced insulation technologies would lower the requirements for air
conditioner capacity, thus resulting in overall cost reductions. The ZEB / ZEH supply chain
also involves various stakeholders such as developers, designers, builders and appliancemanufacturers. It is therefore imperative to create a platform for these diverse actors tocommunicate and coordinate towards achieving the common goal of ZEB / ZEH conversion.
Figure 3.3-1 provides an overview of the actions to be taken by the various stakeholders,
including government, business, academia and civil society.

Urban
Planning

Deregulation

Gov. Procurement
R&D

Incentives

Standard& Labeling

GovernanceFunding
Education& Training

EM&V
Demo.
Project

Long-term Target

Behavior
ChangeVoluntary
Programs
Information

Communication & Coordination Among Stakeholders

Fig.3.3-1 Overview of the Actions(Note. EM&V: Evaluation, Measurement and Verification)

Role of Each Stakeholder
Each stakeholder should play an active role in the successful dissemination of ZEB / ZEH.
Table 3.3-1 shows the available policy tools and suggested actions for relevant stakeholders.
As humid regions will see the highest increase in both population and energy demand, thisICEF Road Map focused on humidity. From this standpoint, the following policy tools andsuggested actions can be considered particularly important in humid developing countries.
- Establishing Strict Building Codes
A large portion of the increase in energy use and CO2 emissions is expected to come fromdeveloping countries and, especially, new buildings within those countries. It is therefore vitalthat we adopt strict building codes sensitive to the local climate, as well as building
certification and labeling. We must also boost technology transfer and research by expert
architects, and even offer financial incentives.
- Connecting this to Urban Planning
As most of the increase in energy consumption is forecasted to come from urban areas indeveloping countries, we need urban plans embracing zoning.
In cold and moderate climate, where the potential to reduce CO2 emissions is huge,
extensive renovation programs must take place. The following policy tools and suggested
actions can be considered of key importance.
77

- Various Incentives for Low-energy Renovation
In conjunction with various incentives (subsidies and tax breaks etc.) to encourage lowenergy renovation, we also need to clarify the benefits other than energy saving, withrespect to health and comfort, labor productivity, and market values.
Table 3.3-1 Available policy tools and suggested actions for relevant stakeholders

Government
General Policy• Set a long-term target of ZEB / ZEH dissemination which provides both a sharedvision among diverse stakeholders and market certainty• Streamline the policy-making process with a clear division of roles andresponsibilities among relevant ministries.
• Promote R&D in the private sector and academia through financial and fiscal
incentives• Provide financial support for demonstration projects• Create demand for ZEB / ZEH and lead by example through public procurement
policy• Provide financial and fiscal incentives. Financial incentives can take the form ofsubsidies or tax credits, while fiscal incentives could involve accelerated
depreciation of ZEB / ZEH. Incentives for replacement of inefficient buildings are
crucial for improvement of the entire building stock• Provide information to consumers for the following purposes: Raising awareness of the benefits of ZEB / ZEH
 Notifying consumers via available support mechanisms and avoiding confusion
arising from the implementation of multiple schemes
 Promoting energy-efficient behavioral change• Lead the development of expertise required to achieve ZEB / ZEH. Provide
financial incentives for business to train their employee where necessary
For Energy Ministries• Create methodologies for evaluation, measurement and verification of the energy
performance of ZEB / ZEH• Establish test facilities for appliances• Set mandatory energy efficiency standards for appliances• Set additional voluntary standards which recognize manufacturers’ efforts toimprove the energy efficiency of their products• Mandate appliance and building providers to disclose the energy performances of
products to consumers• Mandate utilities to offer prices that reward owners/tenants
For Construction Ministries• Set mandatory energy-efficient building codes with labelling system andstrengthen these codes over time. Create monitoring systems to verify the
implementation of building codes
For Municipalities• Incorporate ZEB / ZEH into urban planning. Zoning for ZEB / ZEH implementation
can be especially effective in achieving community-based energy efficiency
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International Organizations• Facilitate communication among governments to share knowledge andexperiences• Promote cooperation in R&D and trials/demonstrations. Cooperation under similar
climatic conditions can be effective in avoiding duplication of initiatives• Harmonize energy efficiency standards for appliances. This allows manufacturers
to produce products that can be sold in the global market, resulting in cost
reductions due to scale merits

Business
For Developers• Conduct R&D for ZEB / ZEH and the relevant technology• Conduct trial/ demonstration projects• Measure and quantify the benefits of ZEB / ZEH through lifecycle assessments.
Together with improved energy performance and the resultant cost reductions,
incorporate co-benefits of using ZEB / ZEH, such as improvements to the comfort
and health of residents and workers. Embodied emissions should also be
calculated• Disclose energy performance of buildings to the owners and tenants• Incorporate energy efficiency from the design stage. Developers should reward
designers• Provide information to consumers for the following purposes: Raising awareness of benefit of ZEB / ZEH
 Promoting energy-efficient behavioral change• Create a viable business model for ZEB / ZEH• Train employees and engineers for implementation and operation of ZEB / ZEH• Increase participation in voluntary programs. Voluntary certification programs
such as LEED(the US Green Building Council's Leadership in Energy andEnvironmental Design programme) and BREEAM(the UK Building Research
Establishment's Environmental Assessment Method) have been very effective inincreasing recognition of advanced sustainable buildings
For Utilities• Measure and quantify the positive impact of ZEB / ZEH on the electric grid, suchas peak cuts and improved reliability• Provide pricing that rewards ZEB / ZEH owners/tenants• Provide consumers with energy performance data in a way that stimulates
energy-efficient behavior. Outsource such services where appropriate
For Finance• Provide financing to ZEB / ZEH developments• Consider the lifecycle costs of ZEB / ZEH when assessing provision of loans

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Academia••••

Conduct research on advanced and more affordable technologies
Participate in demonstration projects as experts
Provide expertise in evaluation of ZEB / ZEH and standardization
Monitor and assess actions by government and business. Make
recommendations where necessary• Educate students, Outreach citizens and engineers

Civil Society
For Non-Profit Organizations• Lead voluntary efforts to improve energy efficiency through certification of ZEB /ZEH• Lead communication among stakeholders, assess their efforts and makerecommendations where necessary• Outreach citizens regarding the benefits of ZEB / ZEH and energy-efficient
behavior
For Citizens• Gain knowledge of ZEB / ZEH through participation in education and information
campaigns• Incorporate energy-efficient behavior into every aspect of their lifestyle. Create aculture of energy efficiency
For Building Owners and Tenants• Communicate with each other regarding energy-efficient construction projects.
Seek adequate cost and benefit sharing. (This is especially important in the caseof retrofits)
As many of the above actions are not exclusive to a certain group of stakeholders,
communication and coordination among diverse stakeholders is vital.

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4. Proposal(Sharing net zero energy building as a concept)
We can adapt ZEB/ZEH concept in newly constructed buildings and houses in the future, in
addition, renovation to ZEB/ZEH at retrofitting timings would lead to achievement of net-zerobuilding stocks as a whole in the long-run.
(Immediate action via stakeholder involvement)
There are a lot of challenges for ZEB/ZEH market creation. Some elemental technologies
have been available already. Retrofit to ZEB/ZEH is big challenge. We can add theequipment after the completion of construction. However, large-scale renovation related tothe envelope of the building requires a great deal of expense in usual situation. Immediate
actions of public and private sectors are essential in terms of institution and technology,
because the life of building is long and stakeholders are diverse.
(International technology collaboration and roadmap)
We can collaborate to accelerate the ZEB/ZEH diffusion. Various kinds of measures areavailable such as technology collaboration network outreach, diffusion policy comparison,
harmonization with urban policies and establishment of international standards.
Transparent approaches via roadmap sharing among global regions and ZEB/ZEH roadmap
reflection to climate policy will bring huge benefits through good practices and capacity
building of stakeholders.

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5. Abbreviations
2DS
6DS
AC
AHU
ANRE
ASHRAEBEMS
BATBCP
BREEAM
BTO
CABA
CEN
CFC
CHP
CIB
CN-PPV
COP
COP21
COP22
DC
DI
DOE
ECHONET Light
EERE
EL
EM&V
EMS
ETP
EV
FC
FP7
GWP
HEMS
HP
HVAC
IAE
ICCA
ICEF
ICT
IEA
KNX
LED
LEED
82

the 2 ºC scenario
the 6 ºC scenario
Alternative current
Air Handling Unit
Agency for Natural Resources and Energy, Ministry of Economy, Tradeand Industry, Japan
American Society of Heating, Refrigeration and Air-Conditioning
Engineers, Inc.
Building energy management system
Best available technology
Business continuity plan
the UK Building Research Establishment's Environmental Assessment
MethodBuilding Technologies Office, DOE
Continental Automated Buildings Association
Comité Européen de Normalisation, EU
Chlorofluorocarbon
Combined Heat and Power, Cogeneration
International Council for Research and Innovation in Building andConstruction
Cyano-Polyphenylene vinylene
Coefficient of performancethe 21st session of the Conference of the Parties
the 22nd session of the Conference of the Parties
Direct current
Discomfort Index
Department of Energy, USAIntelligent building control system for all areas in which people live andwork, Japan
Office of Energy Efficiency and Renewable Energy, DOE
Electroluminescent
Evaluation, Measurement and Verification
Energy management system
Energy Technology Perspectives
Electric vehicle
Fuel cell
7th Framework Project, EU
Global Warming Potential
Home energy management system
Heat pumpHeating, Ventilation and Air Conditioning
The Institute of Applied Energy
International Council of Chemical Associations
Innovation for Cool Earth Forum
Information communication technology
International Energy Agency
Intelligent building control system for all areas in which people live andwork, EU
Light emitting diodethe US Green Building Council's Leadership in Energy andMEA
MEH-PPV
METI
NEDO
NREL
NSTC
NZEB
OLED
PEB
PEC
PEFC
PPV
PV
R&D
READY4
SmartCities
RHEVA
RSI
SEC2.0
SHGC
SOFC
SR
THINK

UNEP
UNESCO
U
UA
UW
ZEB
ZEH
VT
WBCSD
WH
WRI

Environmental Design programme
Membrane electrode assembly
Poly[2-methoxy-5-(2- ethylhexyloxy)-1,4-phenylenevinylene]
Ministry of Economy, Trade and Industry, Japan
New Energy and Industrial Technology, Japan
National Renewable energy Laboratory
National Science and Technology Council, USA
Net Zero Energy Building
Organic Light Emitting Diode
Plus energy building
Primary energy consumption
Polymer electrolyte fuel cell
Polyphenylene vinylene
Photovoltaics
Research and development
ICT Roadmap and Data Interoperability for Energy Systems in Smart
Cities financed by FP7
Federation of European Heating, Ventilation and Air Conditioning
Associations
Thermal resistance indicated by SI unit
Intelligent building control system for all areas in which people live andwork, USA
Solar Heat Gain Coefficient
Solid electrolyte fuel cellSurface Reflection
FP7-financed project that advised the European Commission (DG
Energy) on a diverse set of energy policy topics from June 2010 until
May 2013.
United Nation Environment Programme
United Nations Educational, Scientific and Cultural Organization
heat transmission coefficient or amount of thermal transmission permaterial area and unit temperature - W/m2K
Average of U
U of Window
Zero Energy Building
Zero Energy House
Visible light Transmission
World Business Council for Sustainable Development
Watt-hour meter
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