First Step for Carbon Neutrality

Energy Conservation
Guidebook for Buildings
2022
Energy Conservation Procedures andEnergy Conservation Technologies

The Energy Conservation Center, Japan

The Guidebook has been prepared by the Energy Conservation Center, Japan as a partof energy conservation support for the purpose of providing information so that small- andmedium-sized businesses can address energy conservation autonomously.
It includes the energy conservation procedures, basic energy conservation measures andeffect estimation, tuning method, and so on. Together with our other energy conservation
support measures, we hope you will make use of the Guidebook to improve your energy
efficiency.

Contents
Ⅰ. Significance and Procedures of Energy Conservation
1. First-step Energy Conservation Activities for Carbon Neutrality........................................................................................... 1
2. Energy Conservation Procedure .......................................................................................................................................... 2
3. Energy Conservation Check List for Buildings ..................................................................................................................... 3
4. Utilization of Energy Audit .................................................................................................................................................... 7

Ⅱ. Energy Audit of Buildings and Results
1. Outline of Audited Buildings ................................................................................................................................................. 8
2. Number of Audit Cases by Type of Industry and Intended Use of Building .......................................................................... 9
3. Energy Intensity by Type of Industry and Intended Use of Building ..................................................................................... 9
4. Energy Consumption by Type of Industry and Intended Use of Building ........................................................................... 10
5. Improvement Proposal Items by Audit................................................................................................................................ 11
6. Energy Conservation Potentials by Type of Industry and Intended Use of Building........................................................... 12
7. Presentation Meeting of Energy Audits and Technologies ................................................................................................. 12
8. Utilization of Energy Conservation and Power-saving Portal Site ...................................................................................... 13

Ⅲ. Energy Conservation Improvement Proposals
A. Energy Conservation Activities, Management Structure, etc.
Case A-1: Practice of "Positive Energy Conservation" with Full Participation of the Employees and Operational
Improvement of Air Conditioning by Utilization of IoT ..................................................................................... 14
Case A-2: Activation of the Energy Conservation Activities by the Audit.......................................................................... 15
Case A-3: Energy Conservation Activities in View of the Facility Renewal Plan.............................................................. 15
B. Heat Source and Heat Transfer Facilities, etc.
Case B-1: Adjusting the Cold Water Outlet Temperature of the Gas Absorption Type Water Heater/Chiller ................... 16
Case B-2: Introducing Inverter-based Control for Chiller Cooling Water Pump ............................................................... 18
Case B-3: Controlling the Cooling Water Setting Temperature of the Chiller................................................................... 20
Case B-4: Introducing the Inverter for the Air Conditioner Fan ........................................................................................ 21
Case B-5: Controlling the Boiler Combustion Air Ratio .................................................................................................... 22
C. Air Conditioning and Ventilation Facilities, etc.
Case C-1: Stopping an Outside Air Intake during Warming Up Air Conditioning ............................................................. 24
Case C-2: Reducing the Solar Radiation Load through the Window Glass ..................................................................... 25
Case C-3: Improving the Total Heat Exchanger............................................................................................................... 26
Case C-4: Reducing the Outside Air Intake Volume by Indoor CO2 Concentration Management ................................... 27
Case C-5: Changing the Operating Method of the Ventilation Fan in the Parking Lot ..................................................... 28
D. Lighting Facilities, etc.
Case D-1: Replacing the Fluorescent Lamp Fixture with the LED................................................................................... 29
Case D-2: Introducing the LED Guide Light..................................................................................................................... 30
Case D-3: Introducing Task Ambient Lighting .................................................................................................................. 31
E. Power Receiving and Transforming Facilities, Power Leveling Facilities, etc.
Case E-1: Renewing and Integrating the Transformers ................................................................................................... 32
Case E-2: Peak Power Demand Control by Demand Monitoring .................................................................................... 34
Case E-3: Improving Waste Heat Utilization of the Cogeneration System ...................................................................... 36
F. ZEB, etc.
Case F-1: Realizing the Dissemination Type ZEB by Renewal of Medium-sized Office Buildings .................................. 38
G. Solar Power Generation, etc.
Case G-1: Introducing the Self-consumption Solar Power Generation System............................................................... 40
Reference
Description of the common matters ................................................................................................................................. 41

Ⅰ

Significance and Proceduresof Energy Conservation

Of energy environmental issues, the most crucial one will be to realize "carbon neutrality" toward 2050. To this end, it isimperative to switch fossil fuels accounting for the most of current energy supply/demand to carbon-free energy such as
renewable energy, while moving forward with thorough energy conservation.
The first-step energy conservation activities for "carbon neutrality" have the following advantages.

Social viewpoint· Fundamental measure for carbon neutrality
Toward "carbon neutrality" intended for zero emission of greenhouse gas totally by 2050, energy conservation as well as
introduction of renewable energy is a fundamental measure for low carbonization and decarbonization.

Economic viewpoint

Ⅰ Significance and Procedures ofEnergy Conservation

1. First-step Energy Conservation Activities for Carbon Neutrality· Compatibility with service improvement

Primary energy supply

Energy conservation and CO2 reduction are made compatible with service improvement by reviewing the service methods
from a viewpoint of energy conservation.
Energy85%

Thorough energy
conservation
Reduction of totalenergy used including
non-fossil energy

consumption

Fossil energy

15%
Currently[Reference]
Energy Consumption
Trend in Japan
Compared with the first oil crises
in 1973, total energy consumption
has been restrained toapproximately 1.1 times withrespect to the growth of the GDP,approximately 2.4 times; theindustrial sector has decreased its
ratio (0.8 times) and commercial(1.9 times), household (1.9 times)
and transportation (1.5 times)
sectors have increased theirratios.

2050

2030

Introduction of renewableenergyExpansion of non-fossil
energySolar power, solar heat,biomass, hydropower,
nuclear power

Transition of Final Energy Consumption and Actual GDP(In trillion yen, price in 2015)

GDP
FY1973-FY2020
2.4 times

(EJ)
18

600

Final energy consumption
FY1973-FY2020

15

500

Transportation sector
12

Ⅲ Energy Conservation
Improvement Proposals"Profits" can be secured by the costs saved by energy conservation. This effect is similar to a sales increase. Once anenergy conservation measure is taken, its effect continues for years.

Ⅱ Energy Audit of Buildings andResults· Cost reduction

Transportation sector

1.5 times
400

Household sector

Household sector
9300Commercial and other sectors
6200

Industrial sector

3

1.9 times
Commercial andother sectors

100

1.9 times

Corporate,
office andothersectors

Industrial sector
0.9
0.8 times times

1.1 times as a whole
0
1973

0
75

1980

1985

1990

1995

2000

2005

2010

2015

2020 (FY)

Source: "Energy White Paper 2022" (Fig. [No. 211-1-1]), Ministry of Economy, Trade and Industry

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1

2. Energy Conservation Procedure(1) Energy conservation technologies
Energy conservation technologies are intended to enhance energy usage efficiency and widely available for improvementof usage and energy management methods as well as higher equipment efficiency. Main items are shown in Section 3"Energy Conservation Check List".
"Energy optimized audit" provided by the Energy Conservation Center, Japan and presented in Section 4 is optimal to thebusiness operators who are going to address energy conservation.

(2) Energy management
Energy conservation requires implementation of steady energy management. Enhance a management structure, visualize
energy consumption and improve operation and maintenance of facilities, equipment, etc.

Management structure▪ Declaration of intention of top management ▪ Organization(duty assignment) ▪ Human resource development, etc.

Visualization of energy consumption

Operation management▪ Operation management
standards▪ Review of the standards,
etc.

Operation manual

Energymanagement
items

Maintenance management▪ Maintenancemanagement standards▪ Repair and renewal plan,etc.

▪ Data-sharing▪ Understanding and analysis ofdata▪ Energy intensity management,
etc.

Visualization

Measurement and recording▪ Energy consumption▪ Facility operating condition,
etc.

Measurement and recording

Maintenance management(3) PDCA
It is important to continuously upgrade energy management efforts through a PDCA cycle.

VerifyImplement
Implement an
improvement plan.
Manage aprogress.

Energymanagement
PDCA

Understand the effects.
Analyze differencesfrom the goals.

PlanManagement structure
Status quo analysis
Goals, improvement plan

2

Review
Review the improvement plan.
Review the management
method.

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3. Energy Conservation Check List for Buildings
As the first step of energy conservation efforts, begin with [I] What can be implemented in daily
operations, etc. As the next step, proceed from [II] Self-practicable efforts based on an expert's advice to[III] Efforts requiring capital investment.
[Legend] I. Efforts practicable in daily operations (almost no technological hurdle)
II. Self-practicable efforts (requiring technological knowledge such as short-term measurement, etc.) based on an expert's advice
III. Efforts requiring capital investment

2. Measurement,
recording andmaintenanceDo you have a system capable of continuing energy conservation
activities (energy conservation committee, etc.)?

○

Do you implement PDCA for energy conservation activities on the premise of participation of the management?

○

Do you decide a responsible person or a leader who promotes energy conservation?

○

Do you set energy conservation goals (reduction of XX%, reduction of XX tons, etc.)?

○

Do you post the energy consumption status so that employees can understand? [Case A-2]○

Do you set a policy and implementation plan for energy conservation measures? [Case A-3]○

Do you educate the personnel and conduct an energy conservation awareness campaign?

○

Do you observe Cool Biz*1 and Warm Biz*2?

○

Do you secure a time and a budget for addressing energy conservation?

○

Do you manage documents such as an equipment ledger and drawings?

○

Do you identify the energy conservation equipment to be concentratedly managed? [Case A-1]○

Do you have the operation records (daily reports monthly reports, etc.) of main facilities?

○

Do you decide the management values for checking the operating status and their ranges? [Case A-3]○

Do you conduct daily inspection and maintenance of the facilities?

○

Do you have the Energy Management Manuals of main facilities (air conditioning, ventilation, lighting, production facilities, etc.)?

○

Do you periodically calibrate the measuring instruments?

○

Do you periodically clean and replace the filters, strainers, etc.?
○

3. Energy
management

Do you aggregate (graph, etc.) and visualize monthly and annual energy consumptions?
○

Do you measure and record energy consumption by type and usage purpose to always monitor (visualize)?

○Do you measure hourly power consumption to manage peak power?

○

Do you analyze the energy consumption status in view of the outside temperature, etc.?

○[2] Heat source and heat transfer facilities

5. Management
cycle PDCA

1. Energy
conservation ofheat source
facilities[Case A-3]

Do you periodically repair the piping, etc. and check for a leakage (water, steam, compressed air, etc.)?

○

4. Energy intensity,
etc. management[Case A-2] [Case A-3]

Ⅰ Significance and Procedures ofEnergy Conservation○

Do you calculate the unit prices of energy common to business establishments (e.g.: yen/kWh, yen/liter, yen/m3)?

○

Do you manage the energy intensity ("energy consumption/total floor area", "energy cost/total floor area", etc.)?
○

Do you manage the energy intensity and cost by department?

○

Do you review energy conservation goals?

○

Do you examine the effects of the improvement measures that have been implemented in the past?

○

Do you review implementation plans for future facility improvements and measures?

○[Chiller/Water heater/chiller] Do you stop the equipment "at the office closing time" in compliance with the operation rules?
○[Chiller/Water heater/chiller] Do you stop the heat source one hour before ending heating/cooling and operate only the transfer equipment?

○[Chiller/Water heater/chiller] Do you relax the cold water outlet temperature when a cooling load is low? [Case B-1]○

[Chiller/Water heater/chiller] Do you adjust the cooling water inlet temperature to an appropriate value? [Case B-3]○

[Chiller/Water heater/chiller] Do you cover cold heat demand in the interim and winter periods by producing cold water in a cooling tower?

○[Chiller/Water heater/chiller] Do you consider renewal to the high-efficiency heat source facilities?

○[Chiller/Water heater/chiller] Do you introduce a heat storage system (nighttime heat storage) when an air conditioning load is high in summer?

○

Ⅲ Energy Conservation
Improvement Proposals[1] General management items

1. Energy
management
organization

Check item

Ⅱ Energy Audit of Buildings andResultsⅠ Ⅱ Ⅲ

Classification[Steam boiler] Do you make efforts to ensure an adequate blow rate such as managing the water quality?
○[Steam boiler] Can you lower a steam pressure setting value?
○[Steam boiler] Do you implement manual adjustment/automatic control to ensure that an efficient number of units are running?

○[Steam boiler] When a load fluctuates greatly, do you introduce an accumulator and a hot water storage tank?

○[Steam boiler] Do you consider introduction of the higher-efficiency boilers?

○[Combustion equipment] Do you check whether an air ratio is adequate, based on oxygen concentration in an exhaust gas? [Case B-5]○

[Combustion equipment] Do you carry out maintenance and inspection of the burners (cleaning, replacement of worn parts)?
○[Combustion equipment] Do you consider optimizing a burner capacity according to a changed load capacity, etc.?

*1 Cool Biz: Japanese government campaign encouraging the people to wear lighter clothes and the companies to set their air conditioners to 28°C
*2 Warm Biz: Japanese government campaign encouraging the companies to set their heater thermostats to 20°C during the winter

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3

Classification

Ⅰ Ⅱ Ⅲ
○

[Pump] Do you stop the pump "at the office closing time" in compliance with the operation rules?

○[Pump] Do you cut down on an excessive flow rate (margin ratio) by adjusting a valve and an impeller?

[2] Heat source and heat transfer facilities○

2. Energy
conservation ofheat transfer
facilities○[Pump] Do you adjust a flow rate by using the inverter, controlling the[Case B-2] [Case B-4]
number of running units and using the sensors?

○[Pump] Do you improve a route and seal the piping?

○[Fan] Do you stop the fan "at the office closing time" in compliance with the operation rules?

○[Fan] Do you cut down on an excessive airflow rate (margin ratio) by adjusting a damper?
[Fan] Do you adjust an airflow rate on weekdays and holidays, and during nighttime with an inverter, etc.?
○[Fan] Do you adjust an airflow rate by a combination of the inverter and sensors?

○[Fan] Do you improve a route and seal the ducts?

○[Piping system, load facilities] Do you check for a steam leak, etc. and take a measure?

○[Piping system, load facilities] Do you check the heat retaining material for peeling, wetting, etc. and repair or newly coat it?

3. Prevention of heatlosses and heatrecovery

1. Operation
management of air
conditioning[3] Air conditioning and ventilation facilities[Pump] Do you lower a flow rate on weekdays and holidays, and during nighttime with an inverter, etc.?

○

4. Cleaning andinstallation
environment○[Piping system, load facilities] Do you inspect and replace a steam trap regularly?

○

Do you change an outside air inlet rate according to the season?
○

Do you periodically manage the exhaust gas temperature and take a measure when it is high?

○Do you recover the steam drain and the heat from the exhaust gas?

○

Do you periodically clean the fins of the outside units?
○

Do you periodically clean the heat exchanger and the heat transfer surface and remove scales?
○

Do you properly manage the room temperature and humidity according to the season?

○

Do you set weekly and annual rules and observe the scheduled operation (prevention of forgetting to turn off the switch)?

○

Do you stop air conditioning in an unused area (including a stop of air conditioning after a meeting)?

○

Do you ensure that air conditioning starts just before the office opening time (e.g. 15 min. before opening the office)?

○

Do you manage air conditioning during overtime hours?
○

When cooling is required during an intermediate period or winter, do you utilize cooling with the outside air?

○Is an outside air inlet rate adequate (example of the management standard: Indoor CO2 concentration = 800 to 950 ppm)?

○[At warming up before daily operation] Do you stop an intake of the outside air?

[Case C-1]

[At warming up before daily operation] Can you shorten an operating time?
○

Do you shut off an entry of the outside air from an opening such as a door, which is left open all the time?

○

Do you quantitatively understand the irregularity of indoor temperature distribution?

○

Do you shield the outdoor units from the sunshine and sprinkle water to them in summer?

○

Do you restrain an entry/leak of the heat from a window during daytime and in the early morning by utilizing a window blind?

○

2. Improvement of air
conditioning
efficiency

Do you periodically clean the filters?
○

Do you attach light-shielding films to the window glasses, and plant by the windows? [Case C-2]○

Do you allow the low-temperature outside air into the room at night in summer (nighttime purge)?

○

Do you prevent mixture of heating and cooling in an identical room?
○

Is it possible to reduce an air-conditioned area (partitions, lining of the high ceiling, etc.)?

○

When there are not many people in a spacious air-conditioned area, do you use a spot cooler?

○

Do you employ the walls and ceilings, etc. with high insulation?

○

Are the window glasses properly heat-insulated (double glass, etc.) and airtight?

○

Do you prevent an entry of draft into the air-conditioned area?

○

Do you upgrade to the higher-efficiency air conditioners?

○

Do you stop ventilation of an unused area or when not used?
○

Do you introduce and utilize the total heat exchanger?

○

Do you adjust a ventilation rate by an optimized ventilation frequency, intermittent operation, etc.?

○

For ventilation fans in the electric room, machine room, etc., do you implement room temperature control operation?
○

4

Are there no objects blocking ventilation of the outside units?

○○

3. Management andefficiency
improvement of theventilation facilities

Check item

Do you locally exhaust for the heat generation equipment?

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[Case C-3]

[Case C-4]○

Do you change ventilation rate control from a damper system to an inverter system?

○

As a measure to prevent an excessive ventilation rate in a parking lot, do you implement
intermittent operation or ventilation rate control based on the CO and CO2 concentrations?

Do you set adequate setting temperature rules for the goods and cargos in the freezers and refrigerators to manage them?

○

Can you reduce a door opening/closing frequency, door opening time and take-in/-out frequency?

○

Do you secure a cold air flow in the freezers and refrigerators (overloaded or not)?
○1. Freezers andrefrigerators

Can you reduce frequency of defrosting according the season?
○

Do you install an air curtain, etc. to the door to reduce an entry of the outside air?

○

Do you reduce heat generation of facility internal lighting (e.g. introduction of LEDs)?

○

Are there any frozen parts due to heat insulation failure in heat insulation treatment of the wall surface or door?

○

Do you introduce the higher-efficiency freezers and refrigerators?

○

Do you close a nighttime cover at night?
○

2. Showcases

Can you reduce frequency of defrosting according the season?
○

Do you install an air curtain?

○

Do you upgrade to the higher-efficiency showcases?

○

Is the hot water tank temperature adequate?

○

Do you stop the water heating system and a circulation pump during nighttime and on holidays?

○

Do you stop feeding hot water during other than the winter (for washing hands, etc.)?
○

1. Water heating
system

Do you periodically remove inner scales from a water heater?
○

Do you utilize the waste heat of the combustion exhaust gas (preheat of the combustion air, feedwater, etc.)?

○

When heating less water, can you change from a centralized water heating system to an individual water heating system?

○

Do you employ a higher-efficiency water heater (latent heat recovery type water heater, EcoCute, etc.)?
Do you install a water-saving device (water-saving packing, water-saving shower head, etc.)
in a bathroom, kitchen, hand-washing sink, etc.?

○
2. Water supply/drain
system

○Are the feed water flow rate and pressure adequate?
Do you recycle drainage (toilet flushing, water sprinkling, floor cleaning, car washing, etc. after drainage treatment)?

○

Do you decide and manage a luminosity standard for each room?

○

Do you turn off the lights by the windows (utilization of daylight)?

○

Do you turn off the lights when they are unnecessary such as in an empty room and during a lunch break?

○Do you adjust the lighting time and number of outdoor lights according to daylight hours?

1. Management and ○energyconservation of thelighting facilities

Do you clean the lighting apparatuses and replace the old lamps?
○

Do you use a motion detector to turn on/off the lighting in toilets, warehouses, etc.?

○

Are the lighting fixtures properly positioned (height and layout) with respect to required luminosity?
○

Do you subdivide a lighting circuit to turn off the lights in an empty area, etc.?

○

Do you dim or turn off the lights with automatic dimmer control?

○

Do you replace with LED lighting?

○

Have you considered task ambient lighting? (All-room lighting → Overall + Hand lighting) [Case D-3]○

2. Management andenergyconservation of the○power receiving
and transforming
facilities[Case D-1] [Case D-2] [Case D-3]

Ⅰ Significance and Procedures ofEnergy Conservation[Case C-5]○○
[6] Lighting, power receiving and transforming facilities, electric facilities

Do you control an outside air inlet rate with a CO2 sensor, etc.?

Ⅱ Energy Audit of Buildings andResults[3] Air
conditioning
and ventilation
facilities[4] Freezing/refrigeration facilities[5] Water heating and watersupply/drain systems○

3. Management andefficiency
improvement of theventilation facilities

Check item

Ⅲ Energy Conservation
Improvement Proposals

Ⅰ Ⅱ Ⅲ

Classification

Do you manage power consumption for each department (monthly and daily) (understanding of the actual situation, graph, etc.)?
○

Do you use a demand monitoring device to reduce contract demand?

○

Is the power-receiving end of the electric equipment at the rated voltage (necessary to adjust the voltage when too high or low)?

○

Is a power factor adequate (e.g. a measure is necessary if it is less than 95%)?
○[Case E-2]

When load fluctuations are great (low nighttime power, etc.), do you install an automatic power factor regulator?
[Transformer] Do you shut off the primary-side power of an unnecessary transformer?

○[Transformer] When a load factor has a margin, do you integrate the transformers[Case E-1]
or optimize the transformer capacity?

○[Transformer] Do you strike a load balance among three phases?

○[Transformer] Do you examine the load factor to level the load (load control)?
○[Transformer] Do you upgrade to the higher-efficiency transformers?

[Case E-1]

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5

[7] Elevators,
etc.

[6] Lighting, powerreceiving andtransforming facilities,
electric facilities

Classification

Ⅰ Ⅱ Ⅲ

○
3. Energy
conservation of the ○automatic vending
machines

Do you turn off the backlight?
Do you stop operation on holidays and during nighttime (timer function)?
○○
4. Management of
the OA equipment
1. Management of
the elevators
2. Management of
the escalators[8] Optimized energy utilization

6

Do you set to the energy-saving mode (nighttime/holidays)?
○○

Do you replace with a power-saving type?
During a lower-use period on holidays, at night and on weekdays, do you operate fewer units?

○

Do you stop them less frequently at the floors with lower use frequency?

○

Do you operate fewer units on holidays and at night?
○

Are they automatically operated with a motion detector?

○

Have you considered peak shifting in power use? Have you reviewed an operation form
(working hours, operation system, operation rate, load factor, etc.)?

○

Have you considered lowering demand response and raising demand response in view ofyour own daily power load curve?

1. Load leveling○

Have you considered introduction of a heat storage unit?

○

Have you considered introduction of an absorption type water heater/chiller?

○

Have you considered introduction of storage batteries (lithium-ion batteries, NAS batteries, etc.)?
Do you improve the operation after checking an operating condition (dependency rate,
power generation efficiency, exhaust heat utilization rate, overall efficiency, etc.)?

○○○

Have you considered introduction of a cogeneration system?

[Case E-3]

Have you considered purchasing various menus of renewable energy electricity?

○

Have you considered purchasing a certification of renewable energy electric power?
○

3. Renewable energy

4. Utilization ofunused heat

Do you request a supplier to upgrade to an energy-saving type (heat pump type, etc.)?
Do you turn off the power when unnecessary (holidays, etc.)? [Except for fax machines]○

2. Cogeneration

Check item

Have you considered introduction of wood-burning stoves and pellet-burning stoves?
○

Have you considered introduction of solar power generation?

○

Have you considered introduction of a solar water-heating system?

○

Have you considered introduction of earth thermal/underground water heat pump air conditioning?

○

Have you considered switching to heat supply by a heat pump?

○[Case G-1]

Have you considered utilization of the waste heat from the building (electrical room) for heating and hot water supply?
○

Have you considered utilization of the low-temperature waste heat, using a heat pump or a binary power generator?

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4. Utilization of Energy Audit• Apply for an audit menu suitable to the usage of electricity and fuels of the factory, building, etc. to be audited.
• After confirming payment of an audit expense, our visit schedule will be coordinated to dispatch experts.
• At site, we will check the actual operating status and management status of the facility to prepare an audit report.
• We will explain the audit results at a briefing and give advice for implementation of proposals.

Application and payment

After about 2 weeks

About 1 month after audit

On-site audit

Submission of report

Audit results briefing

Audit menu

Audit content

Guide of annual energy consumption(crude oil equivalent)

Audit expense

Menu to be audited by one expert

Less than 300 kl¥10,450 (tax included)*1

Menu to be audited by two experts
Audit B *2 (briefing held by one expert)

300 kl to less than 1,500¥16,500 (tax included)*1

Extensive Menu to be audited by two experts
after a prearrangement meetingaudit(with one expert)

1,500 kl or more

¥23,100 (tax included)*1

Audit A

*1 A bank transfer fee for the audit expense shall be borne by an applicant.
*2 Even the annual energy consumption is less than 300 kl, business establishment having a lot of equipment using the heat such as boilers and large air
conditioners, or relatively large-scale business establishment(2) Business operators eligible for the audit
Those meeting one of the following conditions• Small- and medium-sized enterprises (those stipulated by the Small and Medium-Sized Enterprise Basic Act)
Those falling under *1 are excluded.

Ⅱ Energy Audit of Buildings andResults(1) Flow of the audit

Ⅰ Significance and Procedures ofEnergy Conservation"Energy optimized audit" conducted by ECCJ is a project by the Agency of Natural Resources and Energy, "Subsidies for
Promotion of Optimized Energy Utilization for Small- and Medium-sized Enterprises in FY2022".
Energy conservation is the most effective means for decarbonization. Moving one step further forward, "energy optimized
audit" is a new service intended to accelerate decarbonization by adding "renewable energy proposals" to reduction ofenergy consumption by "energy audit".

(Even if less than 100 kl, acceptable in case of receiving low-voltage power, high-voltage power or extra high-voltage power)*1 ① Small- and medium-sized business operators whose stocks are directly or indirectly possessed 100% by a corporate body with acapital or investment of ¥500,000,000 or more
② Small- and medium-sized business operators whose annual average taxable income of each year or each fiscal year of the mostrecent past 3 years exceeds ¥1,500,000,000■Application form
Select "Energy Optimized Audit" at the Energy Conservation and Power-saving portal site (https://www.shindan-net.jp),
followed by "Factory" or "Building". Particularly, in the case of a small-scale building, select and download an application
form for "Simplified Version for Buildings" and send it by e-mail, fax or postal mail to apply.

Ⅲ Energy Conservation
Improvement Proposals(The small- and medium-sized enterprises falling under the conditions in *1 are also acceptable if they meet the following conditions.)• Factories, buildings, etc. with annual energy consumption (crude oil equivalent) of 100 kl to less than 1,500 kl inprinciple■Address (Contact information)
Igarashi Building 5F, 2-11-5 Shibaura, Minato-ku, Tokyo 108-0023 Japan
Secretariat of Energy Audit, The Energy Conservation Center, Japan
Phone: +81-3-5439-9732
Fax: +81-5439-9738
E-mail: ene@eccj.or.jp

Energy optimized audit
Free dispatch of lecturer
Download eachapplication form from here

Energy Conservation and Power-saving Portal Site

* Download the application form at the website, fill in withnecessary information and send it to each secretariat bye-mail or fax to apply.

Energy audit

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7

Ⅱ

Energy Audit of Buildings
and Results

The following outlines the energy audits of buildings (commercial facilities) implemented by the Energy Conservation
Center, Japan. Utilize them as reference data for management of the energy consumption and energy intensity, andconsideration of improvement proposals.

1. Outline of Audited Buildings
The left figure below shows the ratio of energy audits of buildings (FY2017 to FY2021) by region. The right figure
below classifies the scale of audited buildings by total floor area.
Shikoku Kyushu,
3% Okinawa Hokkaido
6%7%Over 20,000 m2
7%
10,000 to 20,000 m2
11%

Chugoku
10%2,000 m2 or less39%

Tohoku34%

FY2017 to FY2021
1,898 cases

Kinki
11%

Hokuriku
1%5,000 to 10,000 m2
18%

FY2017 to FY2021

Tokai
9%
Kanto,
Koshinetsu
22%

2,000 to 5,000 m2
25%

Ratio of audits by region

Ratio of audits by scale

The following shows the distribution of annual energy consumption (crude oil equivalent value) of the audited buildings(FY2017 to FY2021). The number of cases of less than 50 kl is the highest.
100%

700

90%
600
80%
70%
60%

400

50%
300

40%

Cumulative ratio

Cases

500

30%

200

20%
100

〜1450

〜1350

〜1250

〜1150

〜1050

〜950

〜850

〜750

〜650

〜550

〜450

〜350

〜250

〜150

0 〜50

0

1500 〜

10%
0Energy consumption in crude oil equivalent (kl/year)

8

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2. Number of Audit Cases by Type of Industry and Intended Use of Building
The following shows the number of energy audit cases of buildings by intended use in FY2017 to FY2021.
General offices

338

Nursing care and welfare facilities

303

Commercial buildings, etc.
Hotels, accommodation facilities,
etc.
Hospitals, medical treatment
facilities
Government office buildings (main,branch and miscellaneous)

162
144
Ⅰ Significance and Procedures ofEnergy Conservation

133
123

Assembly halls, etc.

106

Sports facilities
Primary, junior-high, highschools, etc.

86
73

Distribution facilities, etc.

67

Barbershops, beauty parlors,
bathhouses, etc.

58

Research institutes

57

Libraries, museums, etc.
Universities, vocational schools,
etc.
Supermarkets, shopping malls,
etc.

52
51
17

Miscellaneous

91
0

50

100

150

200

250

300

350

Cases

3. Energy Intensity by Type of Industry and Intended Use of Building
The energy intensity is an important index for evaluating the energy management status. This is indicated by energy
consumption per total floor area in the following. Refer to the following values when evaluating the energy intensity.
Barbershops, beauty parlors,
bathhouses, etc.

3659

Amusement facilities, etc.

3569

Commercial buildings, etc.

3402

Research institutes

2606

Hotels, accommodation facilities, etc.

2579

Sports facilities

2031

Nursing care and welfare facilities

1923

Hospitals, medical treatment facilities

1909

Libraries, museums, etc.

1285

Distribution facilities, etc.

1254

Assembly halls, etc.

1083

General offices

1051

Government office buildings (main,branch and miscellaneous)

945

Universities, vocational schools, etc.

859

0

Ⅲ Energy Conservation
Improvement Proposals

7014

Supermarkets, shopping malls, etc.

Primary, junior-high, high schools,etc.

Ⅱ Energy Audit of Buildings andResults

37

Amusement facilities, etc.

569
1000

2000

3000

4000

5000

6000

7000

8000

Energy intensity (MJ/m ･ year)
2

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9

4. Energy Consumption by Type of Industry and Intended Use of Building
The following shows the energy consumption of the audited buildings in FY2017 to FY2021 in the form of the scatter
diagram based on the total floor area. Refer to it when comparing with other facilities.

3
Hospitals, medical facilities
Nursing care and welfare facilities

2

1

0

0

10

20

30

40

50

General offices
Energy consumption (1,000 kl/year)

Energy consumption (1,000 kl/year)

Nursing care and welfare facilities, hospitals,
medical treatment facilities
3

2

1

0

0

10

Total floor area (1,000 m2)

Energy consumption (1,000 kl/year)

Energy consumption (1,000 kl/year)

3

2

1

0

10

20

30

40

50

1

0

0

10

Commercial buildings
Supermarkets and shopping malls

2

1

30

40

50

Energy consumption (1,000 kl/year)

Energy consumption (1,000 kl/year)

50

Amusement facilities, etc.

2

1

0

0

10

20

30

Schools

Assembly halls
Libraries, museums, etc.

2

1

0
30

Total floor area (1,000 m2)

1040Sports facilities

Assembly halls, etc.

2050Total floor area (1,000 m2)

3

10

40

3

Total floor area (1,000 m2)

030Sports and amusement facilities
Energy consumption (1,000 kl/year)

Energy consumption (1,000 kl/year)

Commercial buildings, etc.

20

20

Total floor area (1,000 m2)

3

10

50

2

Total floor area (1,000 m )

0

40

3

2

0

30

Government office buildings (main, branch andmiscellaneous)

Hotels, accommodation facilities, etc.

020

Total floor area (1,000 m2)

40

50

3
Primary, junior-high, high schools, etc.
Universities, vocational schools, etc.

2

1

0

0

10

20

30

40

Total floor area (1,000 m2)

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50

5. Improvement Proposal Items by Audit

The following figure itemizes the proposals for each classificationof target facility.
For the air conditioning/ventilation facilities, optimization of thesetting temperature is proposed much more than the others. For
lighting, renewal to LEDs is proposed very much.

Water supply/drain andsanitary facilities
5%

Miscellaneous
9%

Demand control
8%

Air conditioning/ventilation
37%

Power receiving andtransforming facilities
6%
Boilers, water heating
and piping
7%
Lighting
28%

Improvement proposals by energy
audits of buildings

Optimizing the setting temperature

Air conditioning
and ventilation
facilities

Ⅱ Energy Audit of Buildings andResults

Upgrading to the higher-efficiency
equipment
Introducing inverters for the fan and pump

Ⅰ Significance and Procedures ofEnergy Conservation

After investigating the status quo of the building, the energy audit
presents an improvement proposal.
The right pie chart shows the ratio of the recent improvement
proposals for each facility. There are many proposals for the air
conditioning and lighting facilities, basically reflecting the ratio ofenergy consumption of the buildings.

Cleaning the fins of the outdoor unit
Stopping unnecessary facilities
Reducing an outside air intake rate
Optimizing the hot/cold water temperatureand cooling water temperature
Optimizing the air ratio of the absorption
water heater/chiller
Cleaning the filter of the outdoor unit
Reducing the standby power

Replacing with LEDs
Replacing with LED guidelights
Turning off unnecessary lights and motion
detectors
Thinning out the lights and individual
switchesTurning off the lights by the window

Ⅲ Energy Conservation
Improvement Proposals

Lighting
facilities

Heat retention and insulation

Boilers, water
heating andpipingPower receiving andtransforming facilities

Optimizing an air ratio
Upgrading to the higher-efficiency boilers
Optimizing the steam temperature andpressureUpgrading to the higher-efficiency
equipment
Integration and suspension

Introducing a demand monitoring system

Demandcontrol,water
supply/drain andothersUtilizing the demand monitoring system
Sanitary facilities (toilet seat temperature,
toilet flushing sound simulator)
Renewing the automatic vending
machines, etc.
Saving shower water
Reducing the standby power for the PCs,
etc.

0

50

100 150 200 250 300 350 400 450
Proposals

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11

6. Energy Conservation Potentials by Type of Industry and Intended Use of Building
The following compiles the energy conservation rate of the improvement proposals based on the energy audits for eachindustry type and intended use. This energy conservation rate is a ratio of proposed energy conservation to energy
consumption of the audited facilities. This indicates an energy conservation potential for that facility. Refer to it whenaddressing energy conservation activities.

Energy conservation potentials by intended use (%)
26.2

30

21.9
19.5

25

17.2
14.1
12.6

15.6

13.3
11.4

11.0

15

18.9

18.1

17.3
15.8

20

8.2

10

Amusement facilities, etc.

Supermarkets, shopping malls, etc.

Universities, vocational
schools, etc.

Libraries, museums, etc.

Research institutes

Barbershops, beauty parlors,
bathhouses, etc.

Distribution facilities, etc.

Primary, junior-high, high schools, etc.

Sports facilities

Assembly halls, etc.

Government office buildings(main, branch and miscellaneous)

Hospitals, medical
facilities

Hotels, accommodation
facilities, etc.

Commercial buildings, etc.

0

Nursing care and welfare facilities

5

General offices

Energy conservation potentials (%)

20.5

7. Presentation Meeting of Energy Audits and Technologies
The "Presentation Meeting of Energy Audits and Technologies" has been held throughout the country since FY2014 for the
purpose of providing energy conservation technologies and information for small- and medium-sized businesses acrossJapan.
It provides the information on the successful energy conservation cases with an energy audit as an opportunity, latest
energy conservation technologies, viewpoints of energy conservation promotion and specific implementation methods.
The Presentation Meeting for FY2022 is planned to be held in Tokyo and Osaka regions with attendance of presenters andbe streamed online at a later date. For the dates and details of presentation, see the Energy Conservation andPower-saving portal site "shindan-net.jp".

Appearance of the meeting in FY2019

12

Held online in FY2021 (video streaming)

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8. Utilization of Energy Conservation and Power-saving Portal Site
Useful information is provided for promoting energy conservation and power-saving, such as introduction of audit casesand video-based tuning methods in addition to introduction of detailed energy conservation support services andapplication methods. Also, a self-audit tool allows you to compare the energy intensity with other company in the same
industry.

Energy conservation support service
Ⅰ Significance and Procedures ofEnergy Conservation

Different services are presented such as the energy optimized audit
and free dispatch of lecturer. Apply for them from here.

Self-audit tool
By inputting the information of your own facility, you can easily
calculate CO2 emissions and see the position of energy intensity
and specific energy conservation measures with respect to othercompany in the same industry.
<Example of general office>Total

914.8 t-CO2/year

Scope 1

1.24 t-CO2/year

Scope 2913.6 t-CO2/year

Energy consumption (crude oil equivalent 1,000 kL/year)

Annual CO2 emissions

Ⅱ Energy Audit of Buildings andResults

Annual energy consumption (crude oil equivalent kL) 500.6 kL/year

Ⅲ Energy Conservation
Improvement Proposals

Total floor area (1,000 m²)

Introduction of the energy audit cases
Based on the energy audit cases, many successful cases arepresented as to the viewpoints and specific practicable methods ofenergy conservation promotion, company-wide energy
management, approaches to energy conservation, etc. The cases
can be searched for each major type of industry, facility, energy
conservation technology, etc.

Energy conservation animation channel
Auditing and a typical energy conservation tuning method arepresented in videos for easy understanding.

Energy optimized audit
Free dispatch of lecturer
Download eachapplication form from here

Energy Conservation and Power-saving Portal Site

* Download the application form at the website, fill in withnecessary information and send it to each secretariat bye-mail or fax to apply.

Energy audit

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13

Ⅲ

Energy Conservation
Improvement Proposals

The following describes the typical energy conservation improvement cases and helpful energy conservation activity casesin the energy audits provided by the Energy Conservation Center, Japan (the information has been changed for the
public).

A. Energy Conservation Activities, Management Structure, etc.
Case A-1: Practice of "Positive Energy Conservation" with Full Participation of the Employees and Operational Improvement of Air Conditioning by Utilization of IoT
1. Background to approaching the activities
Since the facilities prioritize comfort of users, energy conservation activities had not been promoted because of different
anxieties such as "We have awareness of energy conservation, but we are too busy to spare time", "There is no full-timeadministrator", "How we can manage to strike a balance between comfort and energy conservation?" and "How we cancontinue to greatly save energy in operation and management of air conditioners". With the opportunity of having known
the IoT-based energy conservation measures for air conditioning, however, they addressed those activities.

2. Improvement measure
MeasureImplementation items and effects

Generalmanagement items
Implemented byfacility personnel

Business was conducted in casual wear (Cool Biz) with cooperation of the users in extremely hot summer to manage the setting
temperature goal of the air conditioners. When casual wear was not enough, the setting temperature was changed to cope with the situation.
The air conditioners and floor heating are combinedly used in winter. Since floor heating consumes much electric power, however, a rule wasmade to increase the setting temperature of the air conditioners and reduce the use of floor heating with cooperation of the users when it is cold.

Energy conservation
for air conditioning
and ventilation
facilities(employment of IoT)

The air conditioners which often failed or malfunctioned due to aging were put through maintenancework such as replacement of parts to restore normal performance.
Because there were no full-time personnel for the air conditioners, a controller was added to automatically operate them.
A management company employed IoT to visualize the operating status of the air conditioners of the facilities, thereby setting the temperature suitable
for the facilities and automating the setting to cut down on useless operation. This allows immediate remote response to a sudden change of a facility
operation schedule and utilization of weather forecast information to implement optimum automatic energy conservation operation for the day.

Visualization of the operating status connecting the air conditioners and the control center of the management company(overview of IoT)
Control
centerInternet
Automatic
extraction ofuseless operation

Report service
Customer (facility
administrator)▪ Provision of detailed power consumption and air
conditioner operation data
▪ Energy conservation consultation based on data analysis

Weather forecast
information
Approx. 850
points acrossthe country

Repo

rt

Japan Weather
Association▪ Automatic energy conservation control in view of weatherchange■Connect the air conditioners and the air conditioning management company via the Internet to monitor andaccumulate operation data.
■Automatically control daily operation optimumly based on the operation data and the weather forecast
information on a relevant area.

①Upper- and lower-limit control of
Setting
examplethe setting temperature
In the case of setting 24 to 30ºC for cooling and 20 to 26ºC
for heating
CoolingHeating

Setting②Prevention of forgetting to turn off
exampleIn the case of stopping operation at 9:00 p.m.
Office under operation

Stop at 9:00 p.m.!

Even if operated again …

Stop at 10:00 p.m.!

Set a stopping time frequently at not only 9:00 p.m., but also 10:00 p.m.,
11:00 p.m., and so on to prevent forgetting to turn off. It is also possible to set
a stop every 30 minutes with a timer.

3. Results
All employees addressed these energy conservation activities together to "work out usage so as to maintain minimum
comfort". As a result, their awareness of energy conservation was heightened to produce different ideas of energy
conservation. Electric power cost was reduced by optimized air conditioning, allowing the surplus to be allotted formaintaining and improving services. From now on, we would like to think about development to demand management.

14

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Case A-2: Activation of the Energy Conservation Activities by the Audit
1. Background to approaching the activities
As a result of taking the energy audit as an opportunity and launching an Energy Conservation Promotion Committee toaddress, energy conservation has been greatly enhanced throughout the facilities, changing the employees’ awareness ofenergy conservation.

Implementation items and effects

Energy conservation promotion
structure (Full-participation energy
management structure)

Taking the energy audit as an opportunity, the Energy Conservation Promotion
Committee was launched to enhance the facility employees’ awareness of energy
conservation. As a result of activities, tap water and power consumptions and theircosts were actively posted to enlighten the personnel.

The following readily practicable measures were addressed first as the activities.
▪ Turn off unnecessary lighting by the window, etc. during daytime.
▪ Reduce an annual lighting time by thorough management of lighting time.
▪ Stop an electric toilet seat in a warm season.
▪ Adjust a water volume for adjustable water faucets.

3. Results
Awareness of energy conservation awakened by the energy audit has prevailed throughout the facilities. The wastes werenumerically indicated to motivate the employees to do what they can do now. A change of awareness of energy
conservation has an effect on the daily remainders to the employees (paying attention to the switches for lighting and air
conditioning, and so on). The significance of energy conservation was realized in view of the numerical values of
implemented energy conservation effects.

Case A-3: Energy Conservation Activities in View of the Facility Renewal Plan

Ⅱ Energy Audit of Buildings andResults

MeasureⅠ Significance and Procedures ofEnergy Conservation

2. Improvement measureThis is a case of preparing a long-term (12 years) facility renewal plan to promote energy conservation in a planned way,addressing high-efficiency lighting and introduction of the demand monitoring equipment.

2. Improvement measure
MeasureImplementation items and effects

Management structure,goal setting and capital
investment plan

The long-term facility renewal plan (12-year plan) has been prepared for major facilities. In line with the plan,
they have been addressing the capital investment (higher-efficiency lighting, introduction of the demand
monitoring equipment).

Energy Management
Manuals for major facilities

Ⅲ Energy Conservation
Improvement Proposals

1. Background to approaching the activities

For the practicable measures for workers such as stopping the AHU fans in the lobby during nighttime andthinning out the lights in the corridor, the rules have been prepared and the responsible personnel wereappointed to implement.
For boiler units control and optimization of the air ratio, the operation and management standards have been prepared to manage.

Management structure andassessment of energy
conservation by the review
meeting

On the bases of the usage of electricity, gas and tap water, energy conservation has been evaluated every
other month as to how it reflected the impact of the climate, number of users and renewal of facility during
the term. If an error is found, it has been verified and improved together with the personnel in eachdepartment and on-site personnel.

3. Results
A long-term plan will be prepared and implemented for energy conservation cases expected of large effects andassociated with capital investment. It is planned to introduce the demand monitoring equipment, replace the fluorescentlamps with the LEDs, renew the evacuation guide lamps and introduce the absorption chillers.

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15

B. Heat Source and Heat Transfer Facilities, etc.
Case B-1: Adjusting the Cold Water Outlet Temperature of the Gas Absorption Type Water Heater/Chiller
1. Current problem
In certain elderly welfare facilities (total floor area of 3,900 m2), a water heater/chiller has its cold water outlet temperature
set to 7°C during a cooling period without being changed.

2. Improvement measure
Alleviate the cold water outlet temperature within the range of not running short of an air conditioner’s capacity in anintermediate period during which a cooling load drops, thereby lowering the energy consumption of a chiller. Raise thecold water outlet temperature from 7 to 9°C during the low-load period in May to June and October to reduce the fuelconsumption of the gas absorption type water heater/chiller.
Fuel consumption rate (%)

Fuel consumption (m3/month)

Fuel consumption of water heater/chiller in FY2013
Heating
Cooling

Month

Fig. 1 Fuel consumption of water heater/chiller

Cold water outlet temperature (°C)

Fig. 2 Cold water outlet temperature andfuel consumption rate

3. Effect estimation(1) Calculation formula
Fuel reduction: Current fuel consumption (m3/year) x (Current fuel consumption rate (%) – Improved fuel consumption
rate (%))(2) Prerequisites for calculation
Fuel consumption in the intermediate period: 12,800 m3/year, See Fig. 1 (62 m3 (May) + 4,800 m3 (Jun.) + 7,905 m3(Oct.) = 12,767 m3)
Fuel consumption rate: See Fig. 2 (Currently 7°C, 100% → 9°C, 94.1% after improvement)
Fuel heating value: City gas 13A

4. Effects

16①

Fuel consumption (current)

12,800m3/year②

Fuel consumption (improved)

12,040m3/year③

Reduced fuel consumption

760

m3/year④

Energy conservation rate

5.9

%

⑤

Saved amount of money78\1,000/year⑥

Reduction in crude oil equivalent

0.9

kL/year⑦

CO2 reduction

1.7

t-CO2/year

Fig. 1③/①③ x \102/m3③ x 44.8 MJ/m3 x 0.0258 kL/GJ③ x 44.8 MJ/m3 x 0.0136 x (44 / 12) t-CO2/GJ

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[Reference] Comfort of air conditioning
Energy conservation is achieved by optimizing the air conditioning setting temperature, but you may feel uncomfortabledepending on the room requirements. To improve comfort in such a case, there is a method to utilize an air current with acirculator, etc. If an air conditioner can vary the evaporation temperature of its refrigerant, you can maintain comfort by
separately controlling the temperature and humidity. One of comfort indicators is PMV. In the following cases, it is possible
to make energy conservation compatible with comfort.
A: Current settingSpecific enthalpy (kJ/kgDA)(1) Improvement of comfort
When the room temperature setting is
Humidity (%)
increased to 28°C, you may feelWind velocity (m/s)
uncomfortable (A → D). Comfort can befurther enhanced by methods such as thefollowing compared to the conventional ones.

◎Humidity control method (outline)i) When cold water is utilized for air
conditioning: Increase the cold water outlet
temperature of the chiller.
ii) When the refrigerant is utilized for air
conditioning: Adjust an expansion valve toincrease the evaporation temperature of therefrigerant.

Comfortableenergyconservation
proposalConventional
proposalLess
comfortable

Current setting

Energyconservation
Comfortable

Uncomfortable(Note) Enthalpy (EH): Indicates the total energy of the atmosphere.
Cooling is performed to lower EH.

Fig. 3 Relations among temperature, humidity, wind velocity and comfort(Note: For details of adjustment, consult or inquire a professional contractor.)(2) PMV (Predicted Mean Vote)
PMV is a windchill index proposed by Professor Fanger of Technical University ofDenmark as evaluation of human feelings. It is calculated from 6 elements:
temperature, humidity, average radiation temperature, air current velocity, amount ofclothing and amount of activity (Fig. 4).
PMV = 0 indicates a state neither hot nor cold and free from thermal discomfort, withwhich 95% of residents are satisfied. In the range of PMV = –0.5 to +0.5, 9 of 10
persons feel comfortable (Fig. 5).
（％）
80
60

PMV
1.51 or more
0.51 to 1.51
–0.50 to 0.50
–1.51 to –0.50–1.51 or less40
Comfortable

P
P 20
D

5
4

Hot

Cold

10

-2.0

-1.5

-1.0

-0.5

0
PMV

0.5

1.0

1.5

Environmentalside

Ⅱ Energy Audit of Buildings andResults①28°C setting + Effective utilization of the air
current (circulator, fan, etc.) (D → C)
②Increase the humidity and decrease thetemperature when the humidity can becontrolled. (D → B)

Ⅰ Significance and Procedures ofEnergy Conservation

D: Conventional proposal

Room temperature (°C)

Human side

Temperature
Humidity
Radiation
Air current

Amount ofclothing
Amount ofactivity

Fig. 4 Six elements of PMV
calculation

Hot/cold feeling
Hot
Slightly hot
NeutralSlightly cold
Cold

Ⅲ Energy Conservation
Improvement Proposals

Requirement

2.0

Fig. 5 PMV and hot/cold feeling

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17

Case B-2: Introducing Inverter-based Control for the Chiller Cooling Water Pump
1. Current problem
A chiller in a commercial building (total floor area: 12,900 m2) has high piping pressure losses because the discharge
valve of a cooling water pump is throttled to control a flow rate.

2. Improvement measure
Valve-based flow rate control is done by changing a piping resistance. To the contrary, inverter-based flow rate control
changes pump characteristics, producing high energy conservation effects. Introduce the inverter to control the flow rateby controlling the rotating speed of the pump, and open the valve fully to save the energy.
Pe

rfor

ma

nce

cur

Pump head (m)

ve

(Af

ter

Actual pump head

(cu

rre

intr

odu

nt)

cin

g th

e in

Cooling tower

ver

ter)

l)
e
rv trocu con
ce ed
n
ta as
)
sis e-beden
Re alv
op
(v
lly

lve

Chiller

fu

Flow
meter

Pressuregauge

Pressure
gauge

Valve

(Va

Actual pumphead
Cooling water pump

Flow rate (m3/min)Fig. 1 Pump characteristic curve

Fig. 2 Conceptual diagram of cooling water piping

3. Effect estimation(1) Calculation formula
Current power consumption: Pump motor power (kW) x Operating time (h/year)
Improved power consumption: Power consumption (current) x Ratio of current power to improved power / Inverter
efficiency(2) Prerequisites for calculation
Pump motor power (current): 30.6 kW
Inverter efficiency: 0.95
Operating time: 800 h/year
Pump power (valve fully opened): 37 kW
Flow rate ratio (Q2/Q1): 1/1.25, See Fig. 1.
Pump heat (H3): 30 m, Ditto
Actual pump head: 3 m, See Fig. 2
Ratio of current power to improved power (H2/H1): 0.654, See Fig. 1.

4. Effects① Power consumption (current)

24,500kWh/year② Power consumption (improved)

16,900kWh/year③ Reduced power consumption

7,600

kWh/year①−②③/①④ Energy conservation rate31%

⑤ Saved amount of money144\1,000/year⑥ Reduction in crude oil equivalent

2.0

kL/year⑦

3.4

t-CO2/year

CO2 reduction*③ x \19/kWh③ x 9.97 GJ/1,000 kWh x 0.0258 kL/GJ③ x 0.453 t-CO2/1,000 kWh(* For the CO2 emission coefficient, use the one provided by your contracted power company.)

18

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5. Implementation of the proposal and tuning
Flow rate
Q (m3/h)50% valve
opening

Pressure P (kPa)
Destinationof useIn implementing the proposal, measure the current flow rate,pressure (pump head), power consumption, etc. to examine
energy conservation effects thoroughly. After installing theinverter, control the rotating speed to a conventional coolingwater rate and measure the actual results of energy
conservation effects.

100% rotating
speed (Commercial
operation)(2) Measurement items (See Fig. 4.)①When a flowmeter is not installed, install an external
ultrasonic flowmeter, etc. which is not accompanied byfacility remodeling.
②Utilize an existing pressure gauge for the pressure (pumphead). When continuous measurement is required,remove and reinstall the existing pressure gauge.
③Use a pump current and power for monitoring a pumpovercurrent and checking an energy conservation volume.
There is also a clamp type wattmeter which measures a
voltage with a clip.

Pressure at each point (before adjustment)

Flow rate
Q (m3/h)Full valve
opening(100%)

Pressure P (kPa)
Destinationof use70% rotating
speed (Rotating
speed control)
Requiredpressure
for
destination of use

Pressure

Pressure at each point (after adjustment)

Fig.
3 3 Concept of inverter frequency control
Pressure measuring
instrument

Ultrasonic flowmeter

Pressuretransmitter

Display

Pressuregauge

Clamp type wattmeter

Data logger

Current clamp
Transmitter

Cock
Heat-retaining
material

PipingHeat-retaining
material

Voltage clip

PipingElectric motor or freezer

Fig. 4 Main measuring instruments(Source: Newly published Energy Conservation Tuning Manual, The Energy Conservation Center, Japan)(3) Tuning procedure①Preparation (understanding of the status quo)
▪ Check and record the current operating condition through measurement. To make it double sure, record the valve
opening so as to restore the status quo.
▪ Check the current operating level on the pump performance curve.
②Implementation▪ Start operation under the current operating requirements (control the flow rate with a regulating valve and ensure
100% rotating speed of the pump).
▪ Checking that there is no abnormality with the pump current, etc., open the regulating valve gradually and lower therotating speed of the pump to adjust the destination pressure to the same as the status quo.
▪ After fully opening the regulating valve, check that the flow rate, pressure (pump head), current (electric power), etc.
are compatible with the characteristics of the pump performance curve.
▪ Changing the rotating speed within the possible range, measuring the flow rate, pressure and pump electric energy,
and organizing them in a graph, etc. will be useful for future operation.
▪ By forecasting the rotating speed and pump electric energy for each operating condition throughout the year, it ispossible to calculate reduced electric energy when the pump is controlled by the inverter.

Unauthorized reproduction prohibited, all rights reserved. Copyright (C) The Energy Conservation Center, Japan 2022

Ⅲ Energy Conservation
Improvement Proposals

Receiver

Ⅱ Energy Audit of Buildings andResults(1) Tuning point
Change flow rate control from a method to control opening witha control valve to the one to control the flow rate by controlling
the rotating speed of the pump with the inverter. Gradually
opening the valve, lower the pump rotating speed by the
inverter. Checking that there is no abnormality, fully open thevalve at the end. (See Fig. 3.)

Ⅰ Significance and Procedures ofEnergy Conservation

Requiredpressure
for
destination of use

Pressure

19

Case B-3: Controlling the Cooling Water Setting Temperature of the Chiller
1. Current problem
A turbo chiller in an office building (total floor area: 22,400 m2) operates with the cooling water inlet temperature of 30°C
throughout the year.

2. Improvement measure
Required compressor power (%)

Current operation 72.6%

Chiller efficiency is improved by lowering the cooling watertemperature.
Finely control the cooling water setting temperature at the peakcooling load time and during other light cooling load period toimprove chiller efficiency.

Cooling water
inlet temperature[Requirements] Coldwater outlet
temperature = 7°C
Constant cooling water
rate and cold waterrate

3. Effect estimation

Refrigeration capacity (%)(1) Calculation formula
For the required power (%) after changing the cooling watertemperature, read the value at the predetermined refrigeration capacity
in Fig. 1.

Fig. 1 Cooling water temperature andcompressor power(Source: Air conditioning and Sanitary Engineering
Handbook (1987))(1987)

Table 1 Compressor power and cooling water temperature of turbo chiller
Month

6
7
8
9
Total

Cooling water inlet temperature °C

Current power
consumption
kWh

Averagetemperature°C

Relative
humidity%

Wet-bulb
temperature°C

Current

Improved

Improvement
value

Required
power%

Reduction
rate%

Reducedelectric
energy kWh

27,936
26,86229,01125,788109,597

23.8
27.3
28.9
25.6

66.8
68.0
65.0
66.7

19.4
22.8
23.7
21.1

30
30
30
30

25
28
29
27

5.0
2.0
1.0
3.0

66
70
71
68

9.1
3.6
2.2
6.3

2,542
967
638
1,625
5,772

The reduction rate indicates reduction from the current required power (%).
Lower cooling water temperature results in higher power for a cooling tower fan, but it was excluded from the effect estimation because it isassumed to be approximately several percent of the overall reduced electric energy.

(2) Prerequisites for calculation
Current cooling water inlet temperature setting: 30°C
Chiller load factor (refrigeration capacity): 80%
Current required power: 72.6% (See Fig. 1.)
Improved cooling water inlet temperature setting: 25 to 29°C (See Table 1.)

4. Effects① Power consumption (current)

109,600

kWh/year

Table 1

② Power consumption (improved)

103,800

kWh/year①–③③ Reduced power consumption

5,800

kWh/year

Table 1

④ Energy conservation rate

5.3

%

③/①

⑤ Saved amount of money110\1,000/year⑥ Reduction in crude oil equivalent

1.5

kL/year⑦ CO2 reduction*

2.6

t-CO2/year③ x \19/kWh③ x 9.97 GJ/1,000 kWh x 0.0258 kL/GJ③ x 0.453 t-CO2/1,000 kWh(* For the CO2 emission coefficient, use the one provided by your contracted power company.)

20

Unauthorized reproduction prohibited, all rights reserved. Copyright (C) The Energy Conservation Center, Japan 2022

Case B-4: Introducing the Inverter for the Air Conditioner Fan
1. Current problem
The airflow rate of the air conditioners in an airport lobby remains set to 80% (constant damper opening) regardless ofbusy and quiet hours of departure and arrival.

Power ratio (%)

D

ed

roll

Busy hours
er

ert

Inv

nt
-co

Quiet hours

Airflow ratio (%)

Fig. 1 Airflow ratio and power ratio of fan

3. Effect estimation(1) Calculation formula
Current power consumption: Fan motor capacity (kW) x Motor load factor (%) x Power ratio (current) x Operating time (h/year)
Improved power consumption: Power consumption (current) x Ratio of current power to improved power / Inverter efficiency(2) Prerequisites for calculation
Fan motor capacity: 55 kW
Motor load factor: 80%
Air feed ratio: (Current) 90% (Improved) Busy hours 80%, Quiet hours 56%
Power ratio: (Current) 95.7% (Improved) Busy hours 51.2%, Quiet hours 17.6%
Motor operating time: (Current) 2,736 h/year (Improved) Busy hours 2,052 h/year, Quiet hours 684 h/year
Inverter efficiency: 0.95
Ratio of current power to improved power: 0.447 = (2,052 x 0.512 + 684 x 0.176) / (2,736 x 0.957)

Ⅱ Energy Audit of Buildings andResults

d

rolle

cont

eramp

Ⅲ Energy Conservation
Improvement Proposals

Rotating speed control of an air conditioner fan can reduce more power consumption than airflow rate control by damper
opening. Introduce an inverter and control the rotating speed in 2 stages during busy and quiet hours.

Ⅰ Significance and Procedures ofEnergy Conservation

2. Improvement measure

4. Effects①

Power consumption (current)

129,600

kWh/year②

Power consumption (improved)

60,980kWh/year③

Reduced power consumption

68,620kWh/year①−②④

Energy conservation rate

53

%

③/①

⑤

Saved amount of money

1,304\1,000/year⑥

Reduction in crude oil equivalent

17.6

kL/year⑦

CO2 reduction*

31.1

t-CO2/year③ x \19/kWh③ x 9.97 GJ/1,000 kWh x 0.0258 kL/GJ③ x 0.453 t-CO2/1,000 kWh(* For the CO2 emission coefficient, use the one provided by your contracted power company.)

Unauthorized reproduction prohibited, all rights reserved. Copyright (C) The Energy Conservation Center, Japan 2022

21

Case B-5: Controlling the Boiler Combustion Air Ratio
1. Current problem
A hot water boiler for air conditioning in an education facility (total floor area: 10,400 m2) has 8.8% high exhaust gas
oxygen concentration, being operated at an excessive air ratio*. If a combustion facility has an excessive air ratio, its
combustion temperature and efficiency drop.
(* Air ratio: Ratio of a theoretical air volume to an actually used air volume)

2. Improvement measure
Control the air ratio to 1.3, the range specified by the EC Guideline of the Energy Conservation Act (fuel is a city gas).

Air ratio

Fuel reduction rate (%)(Exhaust gas temperature: 200°C)

Exhaust gas oxygen concentration (%)

Air ratio

Fig. 1 Exhaust gas oxygen concentration and air ratio (13A gas)

Fig. 2 Air ratio and fuel reduction rate (13A gas)

3. Effect estimation(1) Calculation formula
Air ratio: 21 / (21 – Exhaust gas oxygen concentration (%))
Fuel reduction: Current fuel consumption (m3/year) x Fuel reduction rate by improved air ratio (%)(2) Prerequisites for calculation
Current boiler fuel consumption: 72,100 m3/year (city gas 13A)
Exhaust gas oxygen concentration: Currently 8.8%, Improved to 4.8%
Air ratio: Currently 1.72, Improved to 1.30
Exhaust gas temperature: 200°C (constant)
Fuel reduction rate by improved air ratio: 2.7%, See Fig. 2.

4. Effects

22① Fuel consumption (current)

72,100m3/year② Fuel consumption (improved)

70,200m3/year③ Reduced fuel consumption

1,900

m3/year④ Energy conservation rate

2.6%

⑤ Saved amount of money194\1,000/year⑥ Reduction in crude oil equivalent

2.2

kL/year⑦ CO2 reduction

4.2

t-CO2/year③/①③ x \102/m3③ x 44.8 MJ/m3 x 0.0258 kL/GJ③ x 44.8 MJ/m3 x 0.0136 x (44 / 12) t-CO2/GJ

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5. Implementation of the proposal and tuning(1) EC Guideline of the Energy Conservation Act
The Energy Conservation Act stipulates the standard air ratio and standard waste gas temperature as the "EC Guidelines"
as listed in Table 1 as to boiler combustion management and the like. Check if the boiler meets these Guidelines (O2concentration corresponding to the air ratio is added for your reference by the Energy Conservation Center, Japan).
Table 1 Standard air ratio and standard waste gas temperature of boilers (excerpts*1)

General 10 t/h or more and less than 30 t/hboilers*2

Liquid fuelGaseous fuelAir ratio

O2 concentration(%)

Waste gas temperature(°C)

Air ratio

O2 concentration(%)

Waste gas temperature(°C)*250 to 100

1.1 to 1.25

1.9 to 4.2200

1.1 to 1.2

1.9 to 3.5

170

50 to 100

1.15 to 1.3

2.7 to 4.8

200

1.15 to 1.3

2.7 to 4.8

170

5 t/h or more and less than 10 t/h

50 to 100

1.2 to 1.3

3.3 to 4.8

220

1.2 to 1.3

3.3 to 4.8

200

Evaporation volume of less than 5 t/h

50 to 100

1.2 to 1.3

3.5 to 4.8

250

1.2 to 1.3

3.5 to 4.8

220

100

1.3 to 1.45

4.8 to 6.5

250

1.25 to 1.4

4.8 to 6.0

220

Small once-through boilers*3*1 Public notice by METI: Excerpted from EC Guideline of Business Operators for Rationalization of Energy Use at Factories, etc., Appendix Table
1(A), (1) for air ratio, and Appendix Table 2(A), (1) for waste gas temperature.
▪ The standard air ratio values in this table set the air ratio measured at the exhaust outlet of the furnace when combusting at near the rated
load after inspection or repair.
▪ The standard waste gas temperature sets the waste gas temperature in combustion at a 100% load factor under the 20ºC inlet temperature of
the boiler ventilator after periodic inspection.
*2 Boilers other than small ones (See the Order for Enforcement of the Industrial Safety and Health Act, Article 1, Paragraph 4.)*3 Of small boilers, those defined by the Order for Enforcement of the Air Pollution Control Act, Table 1 (Article 2 related), Clause 1.
There are exemptions of the air ratio and the waste gas temperature. See "Remarks" in their respective tables.

(2) Boiler combustion control
Operate a fuel and an air volume required for
combustion in order to maintain the steampressure in a constant range, which fluctuates
depending on steam consumption.
Steampressuresetting

Air

Combustion
control (valve,
etc.)

Fuel

BoilerSteampressure

Feedback
Ⅲ Energy Conservation
Improvement Proposals

Fig. 3 Boiler combustion control

3

Total heat lossesst ga
aus es
h
x
s
E los

tion

(4) Air ratio control
Because the air ratio fluctuates depending on the load factor, season(outside air temperature), etc., it is necessary to consult a boiler
manufacturer, etc. to control it. Too low the air ratio results in troubles suchas dust and soot or heat losses due to imperfect combustion (Fig. 4).

us
omb
ct c
erfe losses
Imp▪ Even if multiple boilers are installed, measurement needs to be
conducted so that the values of individual boilers will be correctly
evaluated. With other boilers stopping, if measurement is made in theexhaust gas collecting piping, etc., the oxygen concentration may
become higher than the reality due to leak air.
▪ It is necessary to measure when a boiler load is stable in the range inTable 1. Generally, the oxygen concentration is higher at low load.
▪ When measuring air pollution such as dust and soot, and NOx, careshould be taken to check if these requirements are met.

Heat losses(3) Measurement of the exhaust gas oxygen
concentration
Small- and medium-capacity boilers used forgeneral industries and buildings are notprovided with an oxygen densitometer, andmost of them do not have feedback operationby continuous measurement. To check if the air
ratio is adequate, accordingly, it is necessary to
prepare an oxygen densitometer to measureoxygen concentration in the exhaust gas. You
may ask a boiler manufacturer, etc. formeasurement in many cases. In measurement,
however, note the following.

Air control(damper, etc.)

Ⅰ Significance and Procedures ofEnergy Conservation

Evaporation volume of 30 t/h or more

Loadfactor (%)Ⅱ Energy Audit of Buildings andResults

Category

Air ratio

Fig. 44 Composition of combustion( losses(example))

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23

C. Air Conditioning and Ventilation Facilities, etc.
Case C-1: Stopping an Outside Air Intake during Warming Up Air Conditioning

Air conditioning energy (%)

1. Current problem
In an office building (total floor area: 14,500 m2), a total heat exchanger is also
operated to take in the outside air during warming-up operation one hour before(8:00 a.m.) starting daily work. At start-up time when there is almost no one in therooms, it is hardly necessary to take in the outside air, wasting air conditioning
energy by taking in the outside air in the high-temperature, high-humidity state insummer and low-temperature dry state in winter (Fig. 1).

2. Improvement measure
Stop operating the total heat exchanger during warming-up operation not to take inthe outside air, thereby reducing power consumption of air conditioning and that of
the total heat exchanger.
Exhaust fan

0:00

08:00

19:00

Fig. 1 Start-up image

Total heatexchanger

IndoorExhaustTable 1 Current outside air intake volume
Type

Air feed fan
Outsideair

Air conditioner

Area 1
Area 2

Outside conditioner

Specifications of total heat exchanger
Air feed 20,720 m3/h x 15 kW
Exhaust 16,400 m3/h x 11 kW
Air feed 21,220 m3/h x 15 kW
Exhaust 16,900 m3/h x 11 kW

Fig. 2 Example of total heat exchanger system2

3. Effect estimation(1) Calculation formula
Reduced power consumption is as follows.
Air conditioner: Outside air intake volume (kg/h) x Difference in specific enthalpy of indoor and outdoor air (kJ/kg) x(1 – total heat exchanger efficiency) x Operating time (h/year) / Air conditioning facility COP / 3,600 (kJ/kWh)Total heat exchanger: Total heat exchanger fan power (kW) x Operating time (h/year)(2) Prerequisites for calculation
Outside air intake volume: 41,940 m3/h (See Table 1.) → 50,328 kg/h (air density at 20°C: 1.2 kg/m3)
Total heat exchanger efficiency: 0.55, Total fan motor capacity: 52 kW (See Table 1.)
Operating time: 176 h/year for heating, 88 h/year for cooling
Air conditioning facility COP: 3.5 for heating, 3.0 for cooling
Difference in specific enthalpy of indoor and outdoor air: 17.8 kJ/kg (average value) for heating, 8.7 kJ/kg (averagevalue) for cooling(Note) Specific enthalpy of the air: Total heat quantity possessed by the air including steam (with reference to 0°C, 1-kg dry air)

4. Effects

24① Reduced power consumption

21,000② Energy conservation rate−%

③ Saved amount of money④ Reduction in crude oil equivalent399\1,000/year

5.4

kL/year⑤

9.5

t-CO2/year

CO2 reduction*

kWh/year① x \19/kWh① x 9.97 GJ/1,000 kWh x 0.0258 kL/GJ① x 0.453 t-CO2/1,000 kWh(* For the CO2 emission coefficient, use the one provided by your contracted power company.)

Unauthorized reproduction prohibited, all rights reserved. Copyright (C) The Energy Conservation Center, Japan 2022

Case C-2: Reducing the Solar Radiation Load through the Window Glass
1. Current problem
In the buildings located in the areas where cooling consumes more power than heating does, there is ahigh solar radiation load through the southwestern windows during a cooling season, consuming high electric power
during cooling.

Apply a light-shielding film to the window glass to reduce the solar
radiation load in summer. (When heating in winter, heating energy
increases.)

IndoorOutdoorTransparent
glass (5 mm)

3. Effect estimation

Light-shielding
filmFig. 1 Window glass andlight-shielding film

(1) Calculation formula
Incident heat quantity: Amount of solar radiation (kWh / (m2•day)) x Solar radiation heat acquisition rate x Glassarea (m2)Reduced air conditioning heat quantity: When cooling, current indoor heat input (kWh) – Improved indoor heat
input (kWh); reversed when heating
Reduced power consumption: Total of reduced air conditioning heat quantity / Air conditioner COP* Amount of solar radiation: Data cited from NEDO
"National Solar Radiation Data Map" (Azimuth: 45°
from the due south, Angle of inclination: 90°).

Month

Table 1 Calculation of indoor heat input
Amount of solar radiation* Incident heat quantity (kWh/day) Air conditioning Air conditioned days

(kWh/m2•day)

Current

Improved

Mode[Days][Data point: Hiroshima]

Indoor heat input (kWh)Current

Improved

Reduced air
conditioning
heat qty. (kWh)HeatingHeatingNo
heating/cooling

Ⅱ Energy Audit of Buildings andResults27%

2. Improvement measure

Ⅰ Significance and Procedures ofEnergy Conservation

Solar radiationload (100%)

Cooling
Cooling

Cooling
Cooling
Cooling
CoolingNo
heating/cooling

Heating(2) Prerequisites for calculation
Window glass: Azimuth = 45° from the due south, Angle of inclination = 90°, Thickness = 5 mm, Area = 200 m2
Solar radiation heat acquisition rate: (5-mm glass) 0.86, (Glass + light-shielding film) 0.27
Air conditioner COP: 3.5 for cooling, 3.7 for heating

Ⅲ Energy Conservation
Improvement Proposals

Cooling

4. Effects① Reduced power consumption

6,495② Energy conservation rate−

③ Saved amount of money%

127\1,000/year④ Reduction in crude oil equivalent

1.7

kL/year⑤ CO2 reduction*

2.9

t-CO2/year

kWh/year① x \19/kWh① x 9.97 GJ/1,000 kWh x 0.0258 kL/GJ① x 0.453 t-CO2/1,000 kWh(* For the CO2 emission coefficient, use the one provided by your contracted power company.)[Reference] Introduction of new technology
A technology of spraying transparent coating on a glass surface to form a film and use it to reduce a load from
insolation has been developed. The film can be formed on special glasses, such as a curved glass on which a normal
film cannot be pasted properly. Another one is a "Low-E pair glass" with improved thermal insulation in addition to an
improved heat shield property.
Unauthorized reproduction prohibited, all rights reserved. Copyright (C) The Energy Conservation Center, Japan 2022

25

Case C-3: Improving the Total Heat Exchanger
1. Current problem
In an assembly hall (total floor area: 5,200 m2), a total heat exchanger in a hall air conditioning line is not functioning. A
heat load due to the outside air accounts for 20 to 30%, there is a high ratio of an air conditioning load in general officebuildings. Furthermore, more outside air is required in a room with many people such as an assembly hall, with the heatload accounting for higher percentage of the air conditioning load.

2. Improvement measure
Recover the function of the total heat exchanger and enable
heat recovery from air conditioning exhaust to reduce an
outside air load.
The total heat exchanger is an effective measure to achieveboth precautions for COVID-19 and reduction of the air
conditioning load through ventilation. Recently, some totalheat exchanger models with higher flexibility in installation arecommercialized. They include a model having a humidifying
function with low energy consumption and a model consuming
less power during partial load operation by controlling air
volume using a high efficiency motor.

Heat-storage
hygroscopic material

Rotor

ExhaustReturn air

Feed airOutside air

Fig. 1 Rotary total heat exchanger

3. Effect estimation(1) Calculation formula
Calculate for heating operation and cooling operation by the following formula and totalize the results.
Heat source gas reduction: Outside air intake volume (kg/h) x Difference in specific enthalpy of indoor and outdoor air(kJ/kg) x Heat exchange efficiency of total heat exchanger (%) x Operating time (h/year) / Lower heating value of fuel(MJ/m3) / Hot/cold water generator COP(2) Prerequisites for calculation
Outside air intake volume: 26,352 kg/h (21,960 m3/h)
Air conditioning time (h/year): 170 h/year for cooling, 170 h/year for heating (2 hours/day)Hot/cold water generator COP: 1.0 for cooling, 0.8 for heating
Difference in specific enthalpy of indoor and outdoor air: 13.9 kJ/kg (average value) for cooling, 31.5 kJ/kg (averagevalue) for heating(Note) Specific enthalpy of the air: Total heat quantity possessed by the air including steam (with reference to 0°C, 1-kg dry air)Heat source fuel heating value: City gas 13A, 40.5 MJ/m3 (lower heating value)
Heat exchange efficiency of total heat exchanger: 60%

4. Effects① Reduced fuel consumption

3,500② Energy conservation rate

−

%

357

\1,000/year

4.0

kL/year7.8

t-CO2/year③ Saved amount of money④ Reduction in crude oil equivalent⑤ CO2 reduction

26

m3/year

City gas 13A① x \102/m3① x 44.8 MJ/m3 x 0.0258 kL/GJ① x 44.8 MJ/m3 x 0.0136 x (44 / 12) t-CO2/GJ

Unauthorized reproduction prohibited, all rights reserved. Copyright (C) The Energy Conservation Center, Japan 2022

Case C-4: Reducing the Outside Air Intake Volume by Indoor CO2 Concentration Management
1. Current problem

Maintain CO2 at 1,000 ppm or less.

Air conditioner
Outside air

Exhaust* Personal CO2 emissions range from 10 to 90 L/(h ▪ person), depending on an amount of activity.

Fig. 1 CO2 concentration control by introduction of outside air

3. Effect estimation(1) Calculation formula
Totalize the respective outside air reductions in cooling and heating operations.
Outside air reduction rate: 1 – {(Current indoor CO2 concentration – CO2 concentration of outside air) / (Improved
indoor CO2 concentration – CO2 concentration of outside air)}
Reduced outside air volume: Current outside air intake volume (kg/h) x Outside air reduction rate
Fuel reduction: Reduced outside air volume (kg/h) x Difference in specific enthalpy of indoor and outdoor air (kJ/kg) x(1 – Heat exchange efficiency of total heat exchanger) x Operating time (h/year) / Lower heating value of fuel (MJ/m3) /Hot/cold water generator COP(2) Prerequisites for calculation
CO2 concentration: Current indoor air 600 ppm, Improved indoor air 800 ppm, Outside air 400 ppm
Air density (20°C): 1.2 kg/m3
Current outside air intake volume: 20,000 m3/h x 1.2 kg/m3 = 24,000 kg/h
Heat exchange efficiency of the total heat exchanger: 55%
Air conditioner operating time: 750 h/year for cooling, 1,000 h/year for heating
Hot/cold water generator COP: 1.0 for cooling, 0.8 for heating
Difference in specific enthalpy of indoor and outdoor air: 12.1 kJ/kg (average value) for cooling, 30.2 kJ/kg (averagevalue) for heating

Ⅱ Energy Audit of Buildings andResults

Increase an indoor CO2 concentration control value to 800 ppm and control an outside air intake volume within the range
of not exceeding this standard value to lower an outside air load during heating/cooling.
An effective measure to prevent COVID-19 requires the environment that is not a "closed and ill-ventilated space". Notethat a space with the indoor CO2 concentration equal to or less than 1,000 ppm is considered to be not the "closed andill-ventilated space".

Ⅲ Energy Conservation
Improvement Proposals

2. Improvement measure

Ⅰ Significance and Procedures ofEnergy Conservation

The indoor CO2 concentration of an assembly hall (total floor area: 19,600 m2) is 600 ppm, well below the concentration
standard (1,000 ppm or less) specified by the "Act on Maintenance of Sanitation in Buildings" (an outside air intake
volume is excessive). An excessive intake of the outside air increases a cooling load in summer and a heating load in
winter.

(Note) Specific enthalpy of the air: Total heat quantity possessed by the air including steam (with reference to 0°C, 1-kg dry air)

Fuel heating value: City gas 13A, 40.5 MJ/m3 (lower heating value)

4. Effects① Reduced fuel consumption

6,200② Energy conservation rate−%

③ Saved amount of money632\1,000/year④ Reduction in crude oil equivalent

7.2

kL/year⑤ CO2 reduction

13.9

t-CO2/year

m3/year

City gas 13A① x \102/m3① x 44.8 MJ/m3 x 0.0258 kL/GJ① x 44.8 MJ/m3 x 0.0136 x (44 / 12) t-CO2/GJ

Unauthorized reproduction prohibited, all rights reserved. Copyright (C) The Energy Conservation Center, Japan 2022

27

Case C-5: Changing the Operating Method of the Ventilation Fan in the Parking Lot
1. Current problem
To feed and exhaust the air into/from the underground parking lot of a government office building, both air feed andexhaust fans are intermittently operated 3 times a day in the time period during which official vehicles enter and leaveintensively.

2. Improvement measure
Because there is a vehicle approach path widely open to outside the parking lot, stop the air feed fans and operate only
the exhaust fans. As a result of checking the CO concentration in the parking lot in this state, it was found out that thisapproach path could be utilized to introduce a required outside air volume and maintain an environment. When the COconcentration increases, operate the air feed and exhaust fans temporarily.

Outside air from
openedapproach path
Air feed fan
Exhaust fan

Exhaust fan

CO, CO2

Fig. 1 Schematic diagram of parking lot

3. Effect estimation(1) Calculation formula
Electric energy consumption: Fan power (kW) x Average load factor (%) x Operating time (h/year)(2) Prerequisites for calculation
Status quo: All the air feed fans and exhaust fans are operated.
After improvement: Only the exhaust fans are operated.
Air feed fan: 5.5 kW x 2 units
Exhaust fan: 5.5 kW x 2 units
Average load factor: 80%
Fan operating time: 1 h/each x 3 times/day x 310 days/year = 930 h/year

4. Effects① Power consumption (current)

16,400kWh/year② Power consumption (improved)

8,200

kWh/year③ Reduced power consumption

8,200

kWh/year①−②④ Energy conservation rate

50

%

③/①

156

\1,000/year

2.1

kL/year

3.7

t-CO2/year⑤ Saved amount of money⑥ Reduction in crude oil equivalent⑦ CO2 reduction*③ x \19/kWh③ x 9.97 GJ/1,000 kWh x 0.0258 kL/GJ③ x 0.453 t-CO2/1,000 kWh(* For the CO2 emission coefficient, use the one provided by your contracted power company.)

28

Unauthorized reproduction prohibited, all rights reserved. Copyright (C) The Energy Conservation Center, Japan 2022

D. Lighting Facilities, etc.
Case D-1: Replacing the Fluorescent Lamp Fixture with the LED

Power consumption for obtaining the illuminance equivalent to a type with two 40 W lamps

Development of integrated-type
LED lighting fixture

Improvement of straight-tube
LED lighting fixture
Improvement ofintegrated-type LED
lighting fixture

Significant
improvement inenergy saving as
compared with earlymodels of the LED
lighting fixture

Development of straight-tube
LED lighting fixture

Improvement of Hf lamp and inverter

Development of Hf lamp and inverter

Improvement of low-power consumption ballast and lamp

Improvement of ballast

Replace the conventional fluorescentlamps with LED lamps to enhanceenergy conservation.
In response to the request of the facility
side, use the reflectors, frames, etc. of
the current fluorescent lamp fixtures
without changing the appearance of theceiling, replace a stabilizer with a DC
power unit, replace plug sockets, andattach straight-tube LEDs.
These replacement work requires aqualified electrician.

Improvement of lighting circuit

2. Improvement measure

Fig. 1 Transition of power consumption of lighting fixture(Example of power consumption for obtaining the illuminance equivalent to two 40 W lamps)(Source: Japan Lighting Manufacturers Association)

Ⅱ Energy Audit of Buildings andResults

Conventional fluorescent lamps are used in the conference rooms, lobby, guest rooms, offices of the hotel-type facilities
intended for lodging and training. Having been 15 years since their installation, it is about time to replace them.

Ⅰ Significance and Procedures ofEnergy Conservation

1. Current problem(1) Calculation formula
Current power consumption: Power consumption (current) (W/unit) x Quantity (units) x Lighting time (h/year)
Improved power consumption: Power consumption (improved) (W/unit) x Quantity (units) x Lighting time (h/year)(2) Prerequisites for calculation
Power consumption (current): 86 W/unit
Power consumption (improved): 30 W/unit
Quantity: 800 units
Lighting time: 8.3 h/day x 358 days/year = 2,970 h/year

Ⅲ Energy Conservation
Improvement Proposals

3. Effect estimation

4. Effects① Power consumption (current)

204,300

kWh/year②

Power consumption (improved)

59,400kWh/year③ Reduced power consumption

144,900

kWh/year①−②③/①④ Energy conservation rate71%

⑤ Saved amount of money

2,753\1,000/year⑥ Reduction in crude oil equivalent

37.3

kL/year⑦ CO2 reduction*

65.6

t-CO2/year③ x \19/kWh③ x 9.97 GJ/1,000 kWh x 0.0258 kL/GJ③ x 0.453 t-CO2/1,000 kWh(* For the CO2 emission coefficient, use the one provided by your contracted power company.)

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29

Case D-2: Introducing the LED Guide Light
1. Current problem
Many conventional fluorescent guide lights are installed in a certain museum. Being continuously energized andinefficient, they consume plenty of electric power.

2. Improvement measure
Replace them with high-efficiency LED guide lights toenhance energy conservation. They shall be replaced withthe guide lights of the same class. When replacing, it isnecessary to notify the competent fire station in advance.

Fig. 1 Appearance of fluorescent (left) and LED (right)
guide lights

3. Effect estimation(1) Calculation formula
Current power consumption: Power consumption/unit (current) (kW) x No. of installed units x Energizing time (h/year)
Improved power consumption: Power consumption/unit (improved) (kW) x No. of installed units x Energizing time(h/year)(2) Prerequisites for calculation
Table 1 lists the detailed specifications of the guide lights.
Lighting time: 24 h/day x 365 days/year = 8,760 h/year
Table 1 Current and improved power consumption and reduced electric energy of guide lights
Current
Specifications

Type

B-class large-sized, one-sided 40 W fluorescent lamp
B-class medium-sized, one-sided 20 W fluorescent lamp
C-class one-sided 10 W fluorescent lamp

ImprovedPower
consumption (W)

Type

43.0
23.0
15.0

LED
LED
LED

Power consumption

No. ofPower
consumption (W) units

3.5
2.7
2.3

Total

3
60
8
71

Current(kWh/year)

Improved(kWh/year)

Reduction(kWh/year)

1,130
12,0891,051
14,270

92
1,419
161
1,672

1,038
10,670890
12,598

4. Effects① Power consumption (current)

14,300kWh/year② Power consumption (improved)

1,700

kWh/year③ Reduced power consumption

12,600kWh/year①−②③/①④ Energy conservation rate88%

⑤ Saved amount of money

239\1,000/year⑥ Reduction in crude oil equivalent

3.2

kL/year⑦

5.7

t-CO2/year

CO2 reduction*③ x \19/kWh③ x 9.97 GJ/1,000 kWh x 0.0258 kL/GJ③ x 0.453 t-CO2/1,000 kWh(* For the CO2 emission coefficient, use the one provided by your contracted power company.)

30

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Case D-3: Introducing Task Ambient Lighting
1. Current problem

Use a desk lamp toilluminate the desk surfaceof the seat in use.

High illuminance across the room(including empty seats)

Lower theilluminance acrossthe room.

(b) Task ambient lighting system(a) Overall lighting system

Fig. 1 Overall lighting system and task ambient lighting system

3. Effect estimation(1) Calculation formula
Current power consumption: Power consumption of the fluorescent lamp (W/unit) x Current quantity (units) x Lighting
time (h/year)
Improved power consumption: Power consumption of the fluorescent lamp (W/unit) x Improved quantity (units) x
Lighting time (h/year) + Power consumption of the desk lamp (W/unit) x Quantity (units) x Lighting time (h/year) x
Lighting rate(2) Prerequisites for calculation
Power consumption: Fluorescent lamp 86 W/unit, LED desk lamp 12 W/unit
Quantity (current): 33 fluorescent lamps (current)
Quantity (improved): 17 fluorescent lamps (improved) (16 units thinned out), 36 LED desk lamps
Lighting time: Daily work hours of 13 h x 293 days/year = 3,800 h/year
Desk lamp lighting rate: 50% (assumed to be a seat occupancy rate)
Note: Completely shut off the power for the thinned-out lamps.

4. Effects① Power consumption (current)

10,800kWh/year② Power consumption (improved)

6,400

kWh/year③ Reduced power consumption

4,400

kWh/year①−②④ Energy conservation rate

41

%

③/①

84

\1,000/year⑤ Saved amount of money⑥ Reduction in crude oil equivalent

1.1

kL/year⑦ CO2 reduction*

2.0

t-CO2/year

Ⅱ Energy Audit of Buildings andResults

Thin out the existing fluorescent lamps attached to the ceiling to switch to ambient lighting which illuminates the entireroom, and newly install a low-power consumption LED desk lamp at each desk for task.

Ⅲ Energy Conservation
Improvement Proposals

2. Improvement measure

Ⅰ Significance and Procedures ofEnergy Conservation

Fluorescent lamps are attached to the ceiling of an office. Because they double as task lighting to illuminate the working
surface, the entire room has high illuminance, including an empty area, wasting the lighting power.

③ x \19/kWh③ x 9.97 GJ/1,000 kWh x 0.0258 kL/GJ③ x 0.453 t-CO2/1,000 kWh(* For the CO2 emission coefficient, use the one provided by your contracted power company.)[Reference] Introduction of new technology
A new lighting system capable of reducing LED ambient power consumption based on three elements (sensor, lightdimming, and lighting duration) are commercialized. The system allows a user to check the power consumption oflighting on a tablet. It also has a function of visualizing low-traffic areas detected by sensors and controlling illuminationin the areas.
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31

E. Power Receiving and Transforming Facilities, Power Leveling Facilities, etc.
Case E-1: Renewing and Integrating the Transformers
1. Current problem
Transformers in an electric room have been installed and used for 25 years or more. Compared with the recent ones, they
are less efficient and subject to higher power losses. One of them is used under a considerably light load; its power losses
are not low.

2. Improvement measure
Integrate low-load No. 2 with No. 1 and renew No. 1, No. 3, No. 4 and No. 5 to high-efficiency top runner II transformers.
Current (made in 1990)
Integrate
Renew

Load factor
For electric light

For power

Fig. 1 Configuration of transformers

3. Effect estimation(1) Calculation formula (Calculate on each of current and improved transformers. Fig. 2 shows the results.)
Load losses: Load losses (W) x {(Working load factor)2 x Working hours (h/year) + (Load factor on holidays
and at night)2 x Nighttime and holiday hours (h/year)}No-load losses: No-load losses (W) x Energizing time (h/year)
Power consumption (Total losses): Load losses (kWh/year) + No-load losses (kWh/year)(Total losses)(2) Prerequisites for calculation
Table 1 shows the specifications and load factor of the transformer.
Working hours: 14 h/day x 364 days/year = 5,096 h/year
Energizing time: 24 h/day x 365 days/year = 8,760 h/year
Nighttime and holiday hours: 8760 h – 5,096 h = 3,664 h/year
Table 1 Current and improved specifications and load factor of transformers
Name

Transformer rating

Current (made in 1990)
Generated losses at rating (W)Load factor (%)
Load losses No-load losses

No.1
No.2
No.3
No.4
No.5

32

500 kVA, single phase, 60 Hz
300 kVA, single phase, 60 Hz
300 kVA, single phase, 60 Hz
500 kVA, three-phase, 60 Hz
300 kVA, three-phase, 60 Hz

5,262
3,372
3,372
6,685
4,250

817
562
562
998
784

During working
hours

Nighttime andholiday

29
17
30
49
36

6
3
6
20
15

Improved (Top runner II)
Generated losses at rating (W)Load factor (%)
Load losses No-load losses

3,540
2,195
3,710
2,530

During working
hours

430
39
Integrated with No.1
340
30
565
49
415
36

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Nighttime andholiday8
620
15

Load losses (kWh/year)

No-load losses (kWh/year)

Total losses (kWh/year)

Current

Current
Current

Improved

Improved

Fig. 2 Power losses of each transformer (current and improved)

4. Effects
49,400kWh/year② Power consumption (improved)

26,200kWh/year③ Reduced power consumption

23,200kWh/year

①−②

47

%

③/①

441

\1,000/year④ Energy conservation rate
⑤ Saved amount of money⑥ Reduction in crude oil equivalent⑦ CO2 reduction*

6.0

kL/year10.5

t-CO2/year③ x \19/kWh③ x 9.97 GJ/1,000 kWh x 0.0258 kL/GJ③ x 0.453 t-CO2/1,000 kWh(* For the CO2 emission coefficient, use the one provided by your contracted power company.)

Iron core[Reference] Structure and losses of the transformer(1) Principle and structure of the transformer
Fig. 3 shows the structure of the transformer.
An iron core made of layered thin silicon steel
sheets is insulated and a conductor (normally,
copper wire) is coiled around it. If an AC voltage isapplied to the primary coil, a magnetic flux is
generated in the iron core, and the AC voltage is
induced to the secondary coil. The figure illustrates
quantitative relations between the AC voltages E1
and E2, and coil turns N1 and N2.

VoltageinducedAC voltage

Excitation current
Secondary coilTurns of the primary coilTurns of the secondary coilPrimary coil

Magnetic flux

Fig. 3 Structure of transformer(2) Losses of the transformer, and highest-efficiency load factor
Once the AC voltage is applied to the primary coil to generate the magnetic field in the iron core, there occur thelosses (iron losses: no-load losses) due to an alternating magnetic field generated in the iron core. Furthermore, theinduced voltage generated on the secondary side causes a load current to run to the secondary coil, producing Joulelosses (copper losses: load losses) to the primary and secondary coils.
These two points are the main losses of the transformers. Because the operating time of the transformer is long,
no-load losses and load losses tend to be considerably high; energy conservation measures are effective.
The highest-efficiency load factor k depends on no-load losses and load losses, having the relations of the following
formula. In the conventional transformers, k was largely around 0.5. In the recent high-efficiency transformers,
however, it tends to be 0.3 to 0.4, getting closer to a low-load operating point.

Ⅲ Energy Conservation
Improvement Proposals① Power consumption (current)

Ⅱ Energy Audit of Buildings andResults

Ⅰ Significance and Procedures ofEnergy Conservation

Improved

k 2 x Load losses (at rating) (W) = No-load losses (W)Unauthorized reproduction prohibited, all rights reserved. Copyright (C) The Energy Conservation Center, Japan 2022

33

Case E-2: Peak Power Demand Control by Demand Monitoring
1. Current problem
The maximum demand power of a certain inn was 300 kW in the previous year. It has been increasing year after year
because of insufficient demand (maximum demand power) control, adding to the basic charge of the power cost.

2. Improvement measure
Equipment

Monitor a demand to control it under a target value.
When it is likely to exceed the target value, stop theallowable facilities. Aim to reduce 10 kW from thestatus quo to 290 W.
This measaure corresponds to lowering demand
response (DR) in optimization of electricity demand.

Concept of prioritizing the stoppable facilities

LightingAir
conditioner

Installation
site

Power
consumption(kW)

Specification

OfficeFluorescent lamp FLR 40

Common
area
Guest
room

Fluorescent lamp FDL18

Bath room

330 W

Parking lot

330 W

Entirebuilding

Guide light

OfficeAir conditioner 1

Common
area
Guest
room
Banquethall

Qty.

Total power
consumption(kW)

Electric
power
(kW)

Load factor(at peak, %)Power
saved atpeak

Halogen lamp

Air conditioner 2
Air conditioner 3

Fig. 2 Example of monthly power consumption

21 to 2218 to 19

15 to 16

12 to 139 to 106 to 73 to 44 5 6 7 8 9 10 11 12 1 2 3 (Month)

350
300
250
200
150
100
50
0
0 to 1

350
300
250
200
150
100
50
0

Electric power (kW)Electric power (kW)Air conditioner 4
List and prioritize the stoppable facilities. The
Bath room
Air conditioner 5following describes the general consideration
KitchenFreezer/
procedure.
refrigerator
Butlery①Organize the rated power consumption, actual
working load power (load factor), quantity, etc. of
main facilities (Fig. 1).
Fig. 1 List of main equipment②Examine the season (Fig. 2) and time period
when the maximum power is required. Hourly
power consumption data will be collected byinstalling a demand monitor, etc. in the future(Fig. 3).
③The demand is calculated every 30 minutes. Taking the above season and time period into account, consider if any
equipment can be stopped for about 1 hour at that time.
④For air conditioning, there are other methods such as tentatively alleviating the setting temperature (raise in summer andlower in winter) and reducing an outside air intake volume, in addition to stopping. However, note that the effects change
depending on the indoor-outdoor temperature difference, etc.

(Hour)

Fig. 3 Example of hourly power consumption

3. Effect estimation(1) Calculation formula
Basic charge: Contract demand (kW) x Basic charge rate (yen/kW•month) x (185 – pf) / 100(2) Prerequisites for calculation
Contract demand: Current 300 kW, Target 290 kW (Reduced power 10 kW)
Power factor (pf), basic charge rate: 100%, \1,500/kW•month (amount of money depends on the contract)

34

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4. Effects① Contract demand (current)

300

kW

② Contract demand (improved)

290

kW

③ Reduced contract demand

10

kW/year①−②④ Reduction rate

3.0

％

③/①

⑤ Saved amount of money*

153\1,000/year③ x \1,500/kW x (185–100) / 100 x 12

Power
receiving
point

Commercial
watt-hour meter
Demand monitor

Pulse countTransformer

Electric
energypulse

Alarm-handling

Monitoring andcontrol device

Display
Automatic
controlManual(2) Optimization of electricity demand
In recent years, variable renewable energies such as solar
power generation, are significantly increasing, resulting in asurplus of renewable energy.
It is provided in the revised Energy Conservation Act thatelectricity demand should be optimized by: during the periodwith the surplus, shifting the demand to the period (raising DR);
during the period with tight electricity supply, limiting thedemand (lowering DR: corresponding to the conventional
measure against demand peak) (Fig. 5).

XX pumpXX air conditioning

XX lighting

Stop
Lower flowrate setting

Stop
Alleviated setting
temperatureLight-out

During output
control(3) Use of the weighted
thermal emission
coefficient to promote thelowering DR.

DemandRenewableenergyFig. 4 Configuration of demand monitoring control

Hydro
Nuclear■Outline of the system (Draft)
Basic concept(Objectives)

・Utilizing surplus power from renewable energy (raising DR)
・Limiting demand during the period with a tight demand andsupply balance (lowering DR)

Specificmeasures・Evaluate the demand shift to the period with the renewableenergy output control and the reduction of demand during theperiod with a tight demand and supply balance, such as an
improvement in intensity with optimized electricity demand.
* Reporting of the intensity with optimized electricity demand isrequired, and it is evaluated along with the improvement ofregular intensity.
* The government develops calculation rules and tools forsupporting the report.
* Study for establishing a simple reporting method.

Electricity
conversion
coefficient・The coefficient takes account of the situation on the supply side.
* For example, the following are applied.
(1) A renewable energy coefficient is used during the period withthe renewable energy output control.
(2) An average thermal emission coefficient is used during othertime.
(3) A weighted average thermal emission coefficient (×α) is usedduring the period with a tight demand and supply balance.

During the periodwith a tight demandand supply balance

Thermal(2) Use of the averagethermal emission
coefficient during theperiod without
renewable energy
output control

Manualswitch(Source: Energy Management Training, "New Training" textbook)■Exemplary image of the optimization of electricity demand(1) Use of the renewableenergy coefficient topromote utilization ofelectricity derived fromnon-fossil sources

Automatic

Ⅱ Energy Audit of Buildings andResults(1) Outline of the demand monitor
Fig. 4 shows the configuration of the demand monitor (alsoreferred to as a demand control system).
This device counts the pulses output from the commercial
watt-hour meter of the power company according to electricenergy and outputs an alarm, etc. when approaching a preset
demand. Normally, this device can be connected to a PC to"display", "output a warning", "output a load opening/closing
signal", and "record and tabulate data". Furthermore, it allows
the remote operation by utilizing IoT technology, such as stop of
unnecessary facilities according to an alarm signal, etc. output
from the demand monitor.

Ⅲ Energy Conservation
Improvement Proposals[Reference] Demand monitor and peak power demand control

Ⅰ Significance and Procedures ofEnergy Conservation(* For the basic charge rate, use the value provided by your contracted power company.)

Fig. 5 Optimization of electricity demand(Source: Agency for Natural Resources and Energy, "Act on the Rational Use of Energy in the Future (Dec. 24, 2021)")

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35

Case E-3: Improving Waste Heat Utilization of the Cogeneration System
1. Current problem
A research institute (total floor area: 24,000 m2) has a cogeneration system (CGS), utilizing its waste heat for air
conditioning through heating/cooling switching GENELINK(Note).
Because there is a demand for both cooling and heating in the intermediate period (spring and autumn), however, asimultaneous heating/cooling type gas absorption water heater/chiller is separately used in place of GENELINK.
Accordingly, the CGS waste heat is radiated from a cooling tower and not used in the intermediate period.
(Note) GENELINK is an alias of the waset heat input type absorption water heater/chiller which uses waste heat hot
water generated from the cogeneration system as a heat source. (Source: Japan Society of Refrigerating and Air
Conditioning Engineers)
MonthRemarkHeating

GENELINK type gas absorption
water heater/chiller
Simultaneous heating/cooling type gas
absorption water heater/chiller

Heating

Cooling
Simultaneous
heating/cooling

Simultaneous
heating/coolingGas consumption (m3/day)

900 (m3/day) on averageFig. 1 Operating condition of simultaneous heating/cooling type gas absorption water heater/chiller

2. Improvement measure
In order to respond to a simultaneous demand for heating and cooling in the intermediate period, utilize a waste
heat-based heat exchanger to produce hot water out of the waste heat. GENELINK allows you to produce both hot andcold water by producing cold water. The waste heat can be recovered in the intermediate period as well (Fig. 2).
Cooling
towerElectric
power

LossesCooling
tower

Generator

Gas turbine

Radiation

Surplus radiation

LossesHeat
exchanger

Hot water

Exhaust gas
boiler

GENELINK type gas
absorption water
heater/chiller

Cold water or
hot water(switching)

Simultaneous heating/cooling type gas absorption
water heater/chiller

Hot water andcold water(simultaneous)

City gas

Fig. 2 CGS energy flow

3. Effect estimation(1) Calculation formula
Concerning the simultaneous heating/cooling type gas absorption water heater/chiller in the intermediate period
Heating gas reduction: Heating load (MJ/day) / Lower heating value of gas (MJ/m3) / Hot water production COP
Cooling capacity by the waste heat: (CGS waste heat recovery (MJ/day) – Heating load (MJ/day)) x GENELINK
COP(Note)
Cooling gas reduction: (Cooling capacity by cooling load or by exhaust heat, whichever is lower) (MJ/day) / Lower
heating value of gas (MJ/m3) / Cold water production COP
Fuel reduction: (Heating gas reduction (m3/day) + Cooling gas reduction (m3/day)) x No. of annual operating days
(days/year)(Note) The CGS waste heat is first used for the waste heat-based heat exchanger to produce hot water, and theremaining waste heat is used for GENELINK to produce cold water. When the cooling capacity exceeds thecooling load, utilize it, taking the cooling load as an upper limit.

36

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4. Effects①

Fuel consumption (current)②

Fuel consumption (improved)

35,700m /year③

Reduced fuel consumption

43,500m3/year④

Energy conservation rate

55%

m3/year(Fig. 1) 900 m3/day x 88 days/year

3

③/①

⑤

Saved amount of money

4,437\1,000/year⑥

Reduction in crude oil equivalent

50.3

kL/year⑦

CO2 reduction

97.2

t-CO2/year③ x \102/m3③ x 44.8 MJ/m3 x 0.0258 kL/GJ③ x 44.8 MJ/m3 x 0.0136 x (44 / 12) t-CO2/GJ[Reference] Energy efficiency of the cogeneration system

Ⅱ Energy Audit of Buildings andResults

79,200Ⅰ Significance and Procedures ofEnergy Conservation(2) Prerequisites for calculation
Concerning the simultaneous heating/cooling type gas absorption water heater/chiller in the intermediate period
No. of annual operating days: 22 days/month x 4 months/year = 88 days/year
Gas consumption: 900 m3/day (Fig. 1)
COP: 0.85 for hot water production, 1.0 for cold water production
Fuel use ratio: Cooling : Heating = 50% : 50%
Heating load: 900 m3/day x 50% x 40.5 MJ/m3 x 0.85 = 15,491 MJ/day
Cooling load: 900 m3/day x 50% x 40.5 MJ/m3 x 1.0 = 18,225 MJ/day
CGS power output: 4,000 kWh/day (operation record)
CGS efficiency: 32.0% (power generation efficiency), 42.3% (heat recovery efficiency) (Fig. 2)
CGS waste heat recovery: 4,000 kWh/day x (42.3% / 32.0%) x 3.6 MJ/kWh = 19,035 MJ/day
GENELINK COP: 0.5
Lower heating value of gas (13A): 40.5 MJ/m3

Cogeneration system (example)
Primary energy(Gas, etc.)

Electric energy

Transportation
Cogeneration

Thermal energy
Conventional system
Primary energy(LNG, etc.)

Grid power(power station)

Primary energy(Gas, heavy oil, etc.)

Transportation

Total primary energy

Overallefficiency
74.3%

Power
transmission

BoilerElectric energy

Efficiency
40%

Thermal energy

Efficiency
90%

Ⅲ Energy Conservation
Improvement Proposals

The CGS is a system to simultaneously obtain electricity and heat from an internal combustion engine (gas turbine, gas
engine, etc.) or a fuel cell. By fully utilizing electric energy and thermal energy generated by the CGS, energy efficiency isimproved compared to a conventional system which separately feeds the heat from a boiler and the electric power fromthe grid power (see Fig. 3).

* Calculated according to the example of the cogeneration system, assuming
the power generation efficiency of the grid power to be 40% and the energy
efficiency of the boiler to be 90%.

Fig. 3 Efficiency comparison between cogeneration system and conventional system (example)

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37

F. ZEB, etc.
Case F-1: Realizing the Dissemination Type ZEB by Renewal of Medium-sized Office Buildings
1. Current problem
Aiming at carbon neutrality in 2050, Japan has been emphasizing the ZEB(Net Zero Energy Building) as an energy policy in order to greatly reduceenergy consumption in the buildings and establishing subsidized projects,
certification systems and registration systems to promote it. Constructed 23
years ago, the said building needs realization of the ZEB, but there aremany issues.

2. Improvement measure
4 stories above the ground plus 1-story
penthouse, total floor area of 2,620 m2
Various energy conservation technologies are easily introduced andMedium-scale
office building (Fukuoka prefecture)spread in new buildings. However, renewal has many restrictions, settingback realization of the ZEB. Accordingly, we have tried to realize the ZEB
by simply renewing the equipment combined with general-purpose technologies. As a procedure, we have analyzed andconsidered the existing equipment, etc. based on the actual energy usage, selected highly general-purpose products, andtaken the initiative in the dissemination type ZEB such as building a management system, thereby achieving this.

3. Effect estimation
We have achieved the ZEB Ready by employing highly general-purpose products and technologies, and building amanagement system.
(1) Employment of a latent-sensible heat separation air conditioning system by high-efficiency multi air conditioners forbuildings and desiccant outdoor units
By processing the humidity through the desiccant outdoor units and specializing in processing of the sensible heat throughthe multi air conditioners for buildings, temperature control and humidity control have been separated and individuallycontrolled by high-efficiency equipment respectively, realizing compatibility between energy conservation and comfort.
(2) Employment of a unified management system of air conditioning, ventilation and lighting by a high-function controller
By controlling air conditioning, ventilation and lighting with one controller, schedule control was allowed such as preventionof being left turned on even in small- and medium-sized buildings with no administrator.
(3) Capacity optimization of air conditioners by analyzing air conditioning data with a remote monitoring system
In order to avoid inefficient operation (overengineering) by renewing the equipment to an air conditioning system with thesame capacity as before, we have measured the operating condition of the air conditioners before renewal through aremote monitoring system, reviewed design requirements in comparison with before renewal, and considered and selected
the air conditioning equipment, thereby renewing them.

Privatecommunication
Air conditioner

Ventilation

Intelligent touch
Private communication manager
DALI*
LED lighting

Fig. 1 Unified management system of air conditioning, ventilation and lighting* General-purpose and extensible international standard for communication specifications for lighting control. Bidirectional
communications and control are enabled even between the products of different manufacturers, allowing high-level lighting control using
a dimming function.

38

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Air
conditioning

After
renewalBeforerenewalAfterrenewalBeforerenewalAfterrenewalBeforerenewalAfterrenewalBeforerenewalHeat quantity (W/m2)

Air conditioning load [W/m2]

Office average

Track record in FY2017

Primary energy intensity [MJ/m2]

Reference value

FY2017

Cumulative primary energy intensity[MJ/m2](4) Approaches to further energy conservation①Introduction of a solar power generation system
Aiming at the Nearly ZEB, a solar power generation system has been introduced to try additional 6% energy
conservation to a reference value.
②Arrangement of inner windows
In order to improve amenity and control a setting temperature change, double windows have been introduced into an
office area. An overall heat transmission coefficient has been improved from 5.0 W/(m2•K) to 3.0 W/(m2•K).
③Installation of a hot/cool space for outside personnel
A cool space has been installed near the 1st-floor entrance to control a setting temperature change of air conditioners bycooling down before entering the office.
④Thorough visualization by a ZEB monitor• Battery-free temperature, humidity and CO2 sensors have been connected to an air conditioning monitoring controller
to manage an indoor environment.
• In order to understand power consumption by purpose such as air conditioning, ventilation, lighting and elevators,
totally 130 wattmeters have been attached to the distribution boards on each floor to improve operation bymeasurement and analysis.
• Measurement data have been displayed on the ZEB monitor installed in front of the 1st-floor elevator to improve theemployees’ awareness of energy conservation.

FY2018* Excluded other than 7:00 a.m. to 9:00 p.m. on weekdays (standby power included)

Fig. 4 Transition of primary energy intensity

4. Effects① Reduced energy② Saved amount of money

32

kL/year

2,600\1,000/year

Ⅱ Energy Audit of Buildings andResults

Fig. 3 Selection of air conditioning equipment

Ⅲ Energy Conservation
Improvement Proposals

Fig. 2 Analysis of air conditioning data
(Before renewal)

Ⅰ Significance and Procedures ofEnergy Conservation

Outdoor temperature [°C]

In renewing air conditioning of a medium-scale office building with a total floor area of 2,620 m2 constructed in September
1996 (25 years ago), only already marketed air conditioners, ventilators and lighting equipment have been used to realize
the ZEB Ready.
(1) Primary energy consumption calculated by the WEBPRO (energy consumption performance calculation program(non-housing version)) has achieved 55% reduction in comparison with the reference value, 1,267 MJ/(m2•year), by
simply renewing lighting equipment, air conditioners and ventilators.
(2) Solar power generation, double windows, ZEB monitor, etc. have been installed, further energy conservation has beenaddressed by operational improvement, and primary energy consumption has been reduced 61% from the reference
value (67% including solar power) one year after renewal, achieving the ZEB Ready.

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39

G. Solar Power Generation, etc.
Case G-1: Introducing the Self-consumption Solar Power Generation System
1. Current problem

Photovoltaic array(Power sale)(Power purchase)

Introduction of a solar power generation system isunder consideration, however, it involves someissues such as a large initial investment cost, timeand expense required for management andmaintenance, and time-consuming internal
procedures/approvals.

Power
conditioner

Distribution
board

Photovoltaic array
Load at regular
operation
Load at autonomous
operation

2. Improvement measure

Fig. 1 Example of solar power generation system configuration

A general configuration of a solar power
generation system is as shown in Fig. 1. A
self-consumption solar power generation system
is designed in principle to self-consume theentire amount of electricity it generates.
However, it is also possible to sell electricity
while it has a low power load during a
non-business day. The methods of introducing
the system are classified as shown on Table 1.
In the case of using the on-site PPA model or alease model, none of the initial investment costand expenses for management andmaintenance during a contract period areneeded as a rule.

3. Effect estimation

Table 1 Methods of introducing solar power generation system
Advantages

Methods

Disadvantages●Best investment recovery efficiency in the longterm.
Selfinvestment on ●It is possible to dispose or replace the systemwith internal decisions only.
the system●Surplus electricity exceeding self-consumption
can be sold.

●An initial investment cost is needed.
●An impact on the financial indicator occurs due to anincrease in fixed assets.
●Time and expense for operation, management, andmaintenance are required.

●No initial investment cost is needed as a rule.
●Time and expense for operation, management,
and maintenance are not required.
●Only self-consuming part of the entire amount ofOn-site PPA
generated power can be purchased.
model●The system is not considered as an asset andkept off the balance sheet.
●Low-price carbon-free power can be usedwithout spending any initial investment costs.

●A lot of arrangements and coordination with a PPA
operator are required.
●It is not possible to replace or dispose the systeminternally.
●A long-term contract must be concluded (typically for 17
years or longer).
●After expiration of the contract, additional time andexpense are required for operation, management, andmaintenance of the system.

●No initial investment cost is needed as a rule.
●Expense for operation, management, andmaintenance is not required.
Lease model ●Surplus electricity exceeding self-consumption
can be sold.

●It is not possible to replace or dispose the systeminternally.
●A long-term contract must be concluded.
●A lease fee must be paid even when no power isgenerated.
●The system must be managed and recorded as a leased
asset.

An effect obtained in a case where a solar power generation system with a 50 kW capacity is introduced in a businessestablishment with a contract power demand of 200 kW is calculated.
(1) Calculation formula
Calculation of generated electric energy (kWh) at an intended facility
Reduced electric energy: Daily generated electric energy (kWh/day) x Self-consumption rate (%) of daily generated electricenergy x No. of operating days (days/year)
Daily generated electric energy: Photovoltaic array output (kW) x Daily amount of solar radiation of array surface (kWh/(m2・day))*1 x Total design coefficient*2 / Intensity of solar radiation (1 kW/m2)*1: NEDO "Solar Radiation Amount Database Browsing System", *2: JIS C 8907:2005 "9. Total Design Coefficient of Photovoltaic Array"(2) Prerequisites for calculation
Installation condition of photovoltaic array: Location in Chiyoda-ku, Tokyo, Array azimuth 0º (due south), Inclination angle 30º
Operating condition: No. of annual operating days 365, Self-consumption rate 100%
Amount of solar radiation of array surface: 4.39 (kWh/(m2・day)), Total design coefficient 0.8

4. Effects①

Reduced power consumption

64,094②

Energy conservation rate−③

Saved amount of money

1,218\1,000/year④

Reduction in crude oil equivalent

16.5

kL/year⑤

CO2 reduction*

29.0

t-CO2/year

kWh/year%① x \19/kWh① x 9.97GJ/1,000 kWh x 0.0258 kL/GJ① x 0.453 t-CO2/1,000 kWh(* For the basic charge rate, use the value provided by your contracted power company.)[Reference] What is on-site Power Purchase Agreement (PPA) model?
It is a mechanism, based on a PPA Agreement concluded between an electricity generation
utility (PPA operator) and an owner of a facility, in which the PPA operator installs a solar power
generation system on-site and is responsible for the entire operation, maintenance, andmanagement of the system, and is also called "third-party-owned model" or "power selling
contract model". The power generation system is owned by the PPA operator, and the facility is
only required to provide a space for installing the solar power generation system. Without
spending any initial investment costs, the facility can purchase the electric power from renewableenergy generated by the system at a fixed price from the PPA operator for a long time.

40

Power company
Electric
power

SurplusPV
Self-consumption

Factory

Unauthorized reproduction prohibited, all rights reserved. Copyright (C) The Energy Conservation Center, Japan 2022

PPA
operator[Reference] Description of the common matters

Fuel and electric power in crude oil equivalent (example)
Crude oil equivalent volume (kL)
Qty.

Heavy oil A

1 (kL)LPG

1 (t)City gas 13A**
Electric energy(daytime)***Electric energy(nighttime)***Heating value*×39.1 (GJ/kL)

×50.8 (GJ/t)Heat qty. (GJ)

⇒

39.1

⇒

50.8

⇒ 1.009⇒ 1.311
×0.0258(kL/GJ)

1 (1,000 m )×44.8 (GJ/1,000 m )

⇒

44.8

1 (1,000 kWh)×9.97 (GJ/1,000 kWh)

⇒

9.97

⇒ 0.257

1 (1,000 kWh)×9.28 (GJ/1,000 kWh)

⇒

9.28

⇒ 0.2393

3⇒ 1.156(The calculations in the cases are partly simplified. For official reports such as periodical ones, comply with the respective methods.)*: The heating value is defined by the enforcement regulations for the Act on the Rational Use of Energy.
**: The heating value of the city gas uses the actual value of the supplied gas. Figures shown in the table are cited from the ministerial ordinance related to
calculation of greenhouse gas emissions associated with the business activities of the business operators.
***: In the cases provided in this Guidebook, the electric power is always converted on the basis of daytime values.

(3) CO2 emissions[For the fuel]As mentioned above, multiply a fuel amount by the heating value to calculate the heat quantity. Multiply this by a carbon
emission coefficient to calculate a carbon amount. Furthermore, for conversion of molecular weight, multiply by 44/12 to
calculate a carbon dioxide amount.
Carbon emission coefficient*(t-C/GJ)

Type

Qty.

Heat qty. (GJ)

Heavy oil A

1 (kL) ⇒39.1

× 0.0189⇒ 2.71LPG

1 (t) ⇒

50.8

× 0.0161⇒ 3.001 (1,000 m3) ⇒44.8

× 0.0136⇒ 2.23

City gas 13A

CO2 emissions (t)* Figures shown in the table are cited from the ministerial ordinance related to calculation of greenhouse gas emissions associated with the business activities of thebusiness operators (Ministerial Ordinance No. 3, 2006 by the Ministry of Economy, Trade and Industry/the Ministry of the Environment, Ministerial Ordinance related
to Calculation of Greenhouse Gas Emissions associated with the Business Activities of the Business Operators, Appended Table 1).

[For electric energy]
Multiply the electric energy by the CO2 emission coefficient.
Electric
energyCO2 emission coefficient*

1 (1,000 kWh) × 0.453 (t-CO2/1,000 kWh)

CO2 emissions

Remarks⇒0.453 (t)The emission coefficient 0.453 is used in the cases, but normally, use the value of the contracted power company.

Ⅲ Energy Conservation
Improvement Proposals

Type

Ⅱ Energy Audit of Buildings andResults(2) Crude oil equivalentThis is used to evaluate energy amounts of electricity and different fuels by a common scale.
・Convert the heat quantity of the fuel (quantity x heating value), 1 (GJ), as crude oil, 0.0258 (kL).
・For electric power, convert the heat quantity of fuel required for generating and transmitting that electric energy into
crude oil. (Energy of electric power, not heat quantity)

Ⅰ Significance and Procedures ofEnergy Conservation(1) Electric energy unit price and fuel unit price
The electric energy unit price (average unit price including a basic charge) and fuel unit price are unified in the cases. Useyour actual unit prices for your on-site consideration.

* The Act on Promotion of Global Warming Countermeasures obligates a business operator exceeding a certain scale or output to report the CO2 emissions of theprevious year. The actual emission coefficient and post-adjustment emission coefficient used for reporting should be annual values for each electric utility (**).

For the latest emission coefficient, see "Pages Related to Emission Coefficient by Electricity Utility"(https://ghg-santeikohyo.env.go.jp/calc/denki), etc. The emission coefficient, 0.453 (t-CO2/1,000 kWh),mentioned/used in this guidebook is an alternative value (most recent 5-year average, calculated by thegovernment, of the total emission coefficient of utility generation and private power generation in Comprehensive
Energy Statistics) in "Emission Coefficient by Electricity Utility (results in FY2020, published by the Ministry of theEnvironment and the Ministry of Economy, Trade and Industry on Jan. 7, 2022, partially revised on Feb. 17, 2022,
partially added and updated on Jul. 14, 2022)".

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41

Where to Apply and Contact for Energy Audit
The Energy Conservation Center, Japan provides an energy optimized audit(there are certain requirements).
Download an application form from the Energy Conservation and Power-saving portal site(https://www.shindan-net.jp) and send it to the following address by fax, postal mail or E-mail.
■Headquarters(Energy Audit Department)

Igarashi Building, 2-11-5 Shibaura, Minato-ku,
Tokyo 108-0023
Hokkaido Keizai Center Building, 2-2 Kitaichijo-Nishi,
Chuo-ku, Sapporo 060-0001

Phone: +81-3-5439-9732
Fax:+81-3-5439-9738■Tohoku Branch

Main Denryoku Building, 3-7-1 Ichibancho, Aoba-ku,
Sendai 980-0811

Phone: +81-22-221-1751
Fax:+81-22-221-1752■Tokai Branch

Ito Building, 3-23-28 Marunouchi, Naka-ku, Nagoya
460-0002

Phone: +81-52-232-2216
Fax:+81-52-232-2218■Hokuriku Branch

Toyama Kogin Building, 5-13 Sakurabashi-dori,
Toyama 930-0004

Phone: +81-76-442-2256
Fax:+81-76-442-2257■Kinki Branch

Yotsuhashi KF Building, 1-13-3 Shinmachi, Nishi-ku,
Osaka 550-0013

Phone: +81-6-6539-7515
Fax:+81-6-6539-7370■Chugoku BranchInoue Building, 8-20 Kamihacchobori, Naka-ku,
Hiroshima 730-0012

Phone: +81-82-221-1961
Fax:+81-82-221-1968■Shikoku Branch

Takamatsu Kotobukicho Prime Building, 2-2-10
Kotobukicho, Takamatsu 760-0023

Phone: +81-87-826-0550
Fax:+81-87-826-0555■Kyushu Branch

Asako Hakata Building, 1-11-5 Hakataeki-Higashi,
Hakata-ku, Fukuoka 812-0013

Phone: +81-92-431-6402
Fax:+81-92-431-6405■Hokkaido Branch

Phone: +81-11-271-4028
Fax:+81-11-222-4634

Energy Conservation and Power-saving Portal Site

The Energy Conservation Center, Japan
Energy Conservation Technology Division

Phone: +81-3-5439-9733 Fax: +81-3-5439-9738
https://www.eccj.or.jp/
E-mail: ene@eccj.or.jp
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Copyright (C) The Energy Conservation Center, Japan 2022
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