Final Summary Report by Air Conditioner Evaluation Standard
Subcommittee, Energy Efficiency Standards Subcommittee of theAdvisory Committee for Natural Resources and Energy

The Air Conditioner Evaluation Standards Subcommittee conducted deliberations on judgment
standards for the manufacturers or importers (hereinafter referred to as “manufacturers”) concerning
performance improvement of air conditioners, and prepared a final summary report as below.
1. Evaluation of Current Standards
The weighted harmonic mean of energy consumption efficiency by the volume of shipmentsof air conditioners (limited to those of wall-hung type among non-ducted types whose cooling
capacity is 4.0 kW or lower out of air conditioners used for both cooling and heating) whose thetarget fiscal year finished in the 2004 freezing year was 5.05 (for products shipped in the 2004
freezing year).

It corresponds to improvement by 67.8%, when compared with the weighted

harmonic mean of the energy consumption efficiency by shipments prior to introduction of the Top
Runner Standard (i.e., products shipped in the 1997 freezing year), which was 3.01.

This meansthat improvements surpassing the energy consumption efficiency (5.00) and the assumed
improvement rate (66.1%), which was then assumed in case that Top Runner standards wereachieved.
In view of the above, energy-saving efforts in air conditioners (limited to those of wall-hungtype among non-ducted types whose cooling capacity is 4.0 kW or lower out of air conditioners
used for both cooling and heating) have been progressing well as a result of efforts by the
manufacturers for energy conservation, and thus we can evaluate that the current standards basedon the Top Runner Program are functioning effectively.
2. Target Scope [See Attachment 1]
This review shall cover air conditioners for household use (limited to those of wall-hungtype among non-ducted types whose cooling capacity is 4.0 kW or lower, out of air conditioners
used for both cooling and heating) whose the target year finished in the 2004 freezing year.
Air conditioners that use any energy other than electricity as a heat source for heating, highly
gas-tight/heat-insulating housing duct air-conditioning systems, and multi-functional heat pumpsystem air conditioners shall be excluded.
3. Items to be judgment standards for manufacturers(1) Target fiscal year [See Attachment 2]
It shall be the fiscal year 2010.
(2) Target standard values [See Attachments 3 to 4]
With regard to air conditioners that manufacturers ship within Japan for the target fiscal year, theweighted harmonic mean of the energy consumption efficiency (Annual Performance Factor(APF)) calculated in (3) by the volume of shipments for each manufacturer per category shown in
the table below shall not exceed the target standard value.
1Category

Unit FormA

Air Conditioners ofwall-hung type
among the non-duct
types (excluding
multi-type that
control operation ofindoor unit
separately)

B
C
D

Cooling Capacity

3.2 kW or lower

Over 3.2 kW and
4.0 kW or lower

Dimension Type ofIndoor Unit

TargetStandard
Value (APF)

Dimension-defined
type

5.8

Free–dimension
type

6.6

Dimension-defined
type

4.9

Free–dimension
type

6.0

Remarks: “Dimension Type of Indoor Unit” means that, with a standard Japanese wooden house asa model, air conditioner models whose indoor unit has horizontal width of 800 mm orless and height of 295 mm or less shall be defined as a dimension-defined type. Air
conditioners other than those of dimension-defined type shall be free-dimension type.
In addition, note that we decided to categorize air conditioners by dimension of indoor
unit, because it was feared that only those of free-dimension type might remain on themarket otherwise, resulting in a collision with household equipment.
(3) Energy consumption efficiency measurement method [See Attachment 5]
As an index of the energy consumption efficiency of air conditioners, Annual Performance Factor(APF) shall be used.

The measurement method shall be a calculation method specified inJapanese Industrial Standards C9612: 2005 Room Air Conditioner.
(4) Display items and others
Items to be displayed shall follow the provisions in the Household Good Quality Labeling Law.
The items concerning energy saving shall be as follows:
1) Display items:a) Categoryb) Cooling capacityc) Cooling power consumptiond) Cooling energy consumption efficiencye) Heating capacityf)

Heating power consumptiong) Heating energy consumption efficiencyh) Cooling/heating average energy consumption efficiencyi)Annual Performance Factorj)

Manufacturer’s name(Note) Regarding the display of a) and i) in the above, revision of the Electric Machinery and2Appliance Quality Labeling Regulations is required.
2) Compliance itemsa) The cooling capacity shall be displayed in kilowatts measured by the method specified
in the cooling capacity test in Japanese Industrial Standards B8615-1.

In this case, theallowable range shall be up to minus 5% of the displayed value.
b) The heating capacity shall be displayed in kilowatts measured by the method specified
in the heating capacity test in Japanese Industrial Standard B8615-1.

In this case, theallowable range shall be up to minus 5% of the displayed value.
c) The cooling power consumption shall be in watts or kilowatts measured by the method
specified in the cooling power consumption test in Japanese Industrial Standard B8615-1.
In this case, the allowable range shall be up to plus 10% of the displayed value.
d) The heating power consumption shall be in watts or kilowatts measured by the method
specified in the heating power consumption test in Japanese Industrial Standard B8615-1.
In this case, the allowable range shall be up to plus 10% of the displayed value.
e) The cooling energy consumption efficiency or heating energy consumption efficiency
shall be a numeric value obtained by dividing the cooling capacity in kilowatts measured
by the method specified in a) above by the cooling power consumption in kilowatts
measured by the method specified in c) above.

The obtained value shall be displayed

to two places of decimals.
f)

The heating energy consumption efficiency shall be a numeric value obtained by
dividing the heating capacity in kilowatts measured by the method specified in b) aboveby the heating power consumption in kilowatts measured by the method specified in d)above. The obtained value shall be displayed to two places of decimals.

g) The cooling/heating average energy consumption shall be obtained by summing thecooling energy consumption efficiency and the heating energy consumption efficiency
and then dividing it by 2.

The obtained value shall be displayed to two places ofdecimals.
h) Annual Performance Factor shall be obtained by dividing the sum of heat quantity to be
removed from indoor air and that to be added to indoor air throughout cooling period
and heating period by total energy consumption to be consumed during the same period;
these heat quantities are obtained by the test and calculating method for seasonal energy
efficiency specified in Japanese Industrial Standards C9612: 2005. The obtained APF
shall be displayed to one place of decimal.
i)

Should any difference arise in measurements specified in a) to h) above due to different
rated frequencies, measured values would be displayed for every rated frequency.

j)

The display items listed in 1) above shall be clearly placed on prominent positions in
catalogues or instruction manuals so that consumers can refer to them when selecting
equipment.
3

4. Proposals for energy saving(1) Actions of users
1) Through effective use of information such as “energy-saving labels”, etc, users areencouraged to make an attempt to not only select an air conditioner with excellent energy
consumption efficiency but also reduce energy by using it appropriately and efficiently.
2) Users shall attempt to select an air conditioner while considering the setting or size of a room
to install it in, in order to make full use of its capacity.
(2) Actions of retailers
1) Retailers shall attempt to not only distribute air conditioners with excellent energy
consumption efficiency but also provide appropriate information for users to select themthrough use of “energy-saving labels”, etc.

When using the energy-saving labels, as air

conditioners vary in performance depending on areas where to be used, retailers shallcarefully display labels in a manner that users can easily understand and get no false
impression by means of, for example, showing conditions for calculating energy consumption
efficiency.
(3) Actions of manufacturers
1) Manufactures shall promote technological development toward energy saving of air
conditioners and attempt to develop products with excellent energy consumption efficiency.
2) From viewpoint of promoting the spread of air conditioners with excellent energy
consumption efficiency, manufacturers shall attempt to provide appropriate information to
encourage users to select air conditioners with excellent energy consumption efficiency, bydisplaying “energy-saving labels” in a catalogue, etc.

As air conditioners vary inperformance depending on areas where to be used, in implementing the energy-saving labels,
manufacturers shall carefully display them in a manner that users can easily understand andget no false impression, by means of, for example, showing conditions for calculating energy
consumption efficiency.
3) To respond to improved energy-saving performances such as insulation performance ofbuildings, etc. in recent years, manufacturers shall review guideline for applicable room sizes
according to cooling capacity and heating capacity.
4) Since Annual Performance Factor (APF) adopted in this report is based on numeric values
computed under certain conditions, manufacturers shall attempt to improve the measurement4

method in the future as well, so that evaluation can be carried out in a condition closer toactual use.
(4) Actions of Government
1) From viewpoint of promoting the spread of air conditioners with excellent energy
consumption efficiency, the government shall attempt to take necessary action such as the
spread and enlightenment activities, in order to promote actions of users and manufacturers.
2) The government shall periodically and continuously monitor the implementation status of thedisplay items by manufacturers and attempt at appropriate operation of the law so that
information on energy consumption efficiency can be provided to users in a correct and easily
understandable manner.
3) The energy-saving standard based on the Top Runner Program is a very effective approach forenergy saving of products.

Therefore, the government shall make efforts to spread it

internationally by catching appropriate opportunities.

5

Attachment 1

Target Scope

This review shall cover air conditioners for household use (limited to those of wall-hung type
among non-ducted types whose cooling capacity is 4.0 kW or lower, out of air conditioners used forboth cooling and heating) whose the target year finished in the 2004 freezing year.
Note, however, that air conditioners that meet under the following requirements shall be
excluded.
1) Air conditioners that use any energy other than electricity as a heat source for heating
Air conditioners being composite products that use electricity for cooling and use
combustion heat of gas, oil, etc, as a heat source for heating.

They are in limited use incold region where heating by heat pumps cannot accommodate heating load.
Presently no international standard regarding the measurement method for theseproducts exists, and no national standard has been established, either.
* Transition in shipments (2004 freezing year): Approximately 10,000 units
2) Ducted air-conditioning systems for highly gas-tight/heat-insulating housing
Air conditioners being dedicated for highly gas-tight/heat-insulating housing and withheat exchange capability between exhaust air and intake air, etc., for which no evaluation
method has been established yet.
* Transition in shipments (2004 freezing year): Approximately 3,500 units
3) Multi-functional heat pump system air conditioners
Air conditioners being capable of floor heating and/or hot-water supply through theuse of heated water produced through their heat pump systems.

Their shipment number isstill small although they are expected to spread in future.
* Transition in shipments (2004 freezing year): Approximately 2,000 units

6

Attachment 2

Target Year, etc, of Air Conditioners

1. In general, a considerable improvement in energy consumption efficiency is made when a modelchange takes place, and a typical development period of these new products is approximately 2 to
3 years.

For this reason, consideration should be given so that manufacturers can take 1 to 2

opportunities of bringing out new models before the next target fiscal year.
With the above in mind, it is appropriate to set the target year of air conditioners to fiscal year
2010 (Heisei 22), which is five years after establishment of the standard values.
2. In addition, it is expected that improvement rate of energy consumption efficiency in the target
fiscal year will be approximately 22.4% based on an assumption that there will be no change
from current volume of shipments (results of fiscal year 2005) as well as model composition ofeach category.
<Overview of Estimation>(1) Energy consumption efficiency estimated from values of actual achievements of air
conditioners shipped in fiscal year 2005: 4.9(2) Energy consumption efficiency estimated from the target standard values of air conditioners
to be shipped in the target fiscal year: 6.0(3) Improvement rate of energy consumption efficiency(6.0 − 4.9) × 100 = Approximately 22.4%
4.9

7

Attachment 3

Classification of Air Conditioners
1

Basic Idea
Idea of classification for overall air conditioners under the current standard is based on thefollowing:
1) Classification by basic function2) Classification by unit form
3) Classification by cooling capacity
In the scope of this review, air conditioners are classified as shown below:

Unit Form

Cooling Capacity

Air conditioners of wall-hung type

2.5 kW or lower

among the non-duct types(excluding multi-type air
conditioners that control operationof indoor unit separately)Over 2.5kW,
3.2 kW or lower
Over 3.2kW,
4.0 kW or lower

Table 1: Current classification in the scope of this review
Air conditioners shall be classified, taking into consideration the fact that heat exchangers
recently have been growing in size in order to improve energy-saving performance.
2. Specific Classification Method(1) Classification by design concept accompanying increased size of heat exchangers
The growing size of heat exchangers shall be a major factor in improvement of energy
consumption efficiency.

Thus, current products (products that have satisfied the current

standard) are roughly divided based on the design concept, as shown below:
1) Models that meet the current standard values in terms of energy saving while considering
installation space and/or resource saving as well2) Models that pursue energy-saving performance with no limit being imposed in terms of
installation space and/or resource saving
If this classification was not made in this review, it was feared that only air conditioners
8

categorized in 2) having excellent energy saving performance might remain on the market,
possibly leading to a disharmony with housing setup. Thus, with a standard Japanese wooden
house as a model, air conditioners shall be classified as follows: (See Figure 1)
1) Dimension-defined type: Models whose indoor unit is 800 mm or less in horizontal widthand 295 mm or less in height.
2) Free-dimension type: Models other than those mentioned above

Annual Performance Factor (APF)
通年エネルギー消費効率（ＡＰＦ）

7.00◆Dimension-defined Type■Free-Dimension Type

6.50
6.00
5.50
5.00
4.50
4.00

2.2

2.5

2.8

3.6

4.0

Cooling
Capacity (kW)
冷房能力（ｋＷ）
Figure 1: Cooling Capacity – Annual Performance Factor (APF) (Products in FY 2005)(Reference: Basis for thresholds in dimension categories of indoor units)
Given a standard Japanese wooden house as a model, the thresholds of indoor units are 800 mm orless in horizontal width and 295 mm or less in height. The rationale for them is as follows:
1. Basis for height being 295 mm or less
1) Building Standards Law, Enforcement Ordinance, Article 21 (Ceiling height of a livingroom)
The ceiling height should be 2.1 m or more.
2) Standard window height is 1.8 m.
3) Approximately 5 mm is needed as a clearance for preventing an air conditioner frominterfering with ceiling.
With the above in mind,9

2,100mm－1,800mm－5mm＝295mm
2. Basis for horizontal width being 800 mm or less
1) Inter-column module dimension according to the old Japanese measuring system(Shaku-Kan system) is 910 mm.
2) Dimension of a 3.5-sun (sun: one of the units in Shaku-Kan system) column is 106.75 mm.
3) Approximately 5 mm is needed as a clearance for preventing an air conditioner frominterfering with ceiling.
With the above in mind, 910mm－106.75mm－5mm≒800mm

3.5-sun column

3.5-sun column

3. Setting of Basic Classification Proposal
With the above in mind, we shall define a basic classification proposal, as shown in the following
table:
Temporary
Category
A
B
C
D
E
F

Cooling
Capacity

Unit form
Air conditioners of wall-hung type
among the non-duct types (excluding
multi-type air conditioners that control
operation of indoor unit separately)10

2.5 kW or lower
Over 2.5kW,
3.2 kW or lower
Over 3.2 kW,
4.0 kW or lower

Dimension Type ofIndoor Unit
Dimension-defined typeFree-dimension type
Dimension-defined typeFree–dimension type
Dimension-defined typeFree-dimension type

Attachment 4

Target Standard Values of Air Conditioners

1. Idea on Establishment of Target Standard Values(1) Basic idea
We shall set target standard values based on the idea of Top Runner Method.

The specificpolicy shall be as follows:
1) Target standard values shall be set for every category that has been defined appropriately.
2) As for categories where future technological advances are expected to improve efficiency,
the target standard value shall allow for as much improvement as possible.
3) Target standard values shall not conflict among categories.
(2) Target fiscal year
In general, a considerable improvement in energy consumption efficiency is made when amodel change takes place, and a typical development period of these new products isapproximately 2 to 3 years.

For this reason, consideration should be given so that

manufacturers can take 1 to 2 opportunities of bringing out new models before the next target
fiscal year.
With the above in mind, it is appropriate to set the target year of air conditioners to fiscal year
2010 (Heisei 22), which is five years after establishment of the standards.
(3) Room for improvement of energy consumption efficiency by future technology advances
Technology development of air conditioners has been undertaken primarily forestablishment of a comfortable living environment.

Although technology development related

to improvement of energy-saving performance has been implemented to accomplish the current
target standards, development of each elemental technology has almost reached its limit and thus
innovative technology development is hardly expected.
[Main examples of technologies for improving efficiency of air conditioners] (See reference 2)･ Compressors: High-efficient compression technology, neodymium magnet, improvement ofmotor winding, low-iron-loss magnetic steel sheet, reduction of mechanical loss,
reduction of pressure drop in suction/discharge, sine-wave drive control

11

･ Fan motor: Introduction of DC brushless motor, increased number of poles/introduction ofslots, optimization of core shape, reduction of circuit loss, optimal energization･ Electronically controlled valve･ Heat exchanger: Three-row arrangement of an indoor unit, multi-stage bending, improvementof fin shape, improvement of piping process
Although these technologies have been introduced into the current Top Runner equipment,
it can be said that there still remains room for efficiency improvement in individual technologies,
considering the fact that these introduced technologies differ depending on manufacturers andthat each manufacturer is taking its own approach for further improvement of efficiency.
Taking into consideration the fact in comprehensive manner that these factors might contribute tohigher efficiency, we set the target standard value by 3% up from the current Top Runner Valuefor the dimension-defined type and by 4% for the free dimension type.
2. Specific Target Standard Values
Target standard values of air conditioners shall be represented in real numbers.
To be specific, for each category the best value of energy consumption efficiency shall be a Top
Runner Value, and a value obtained by adding improved efficiency to the Top Runner value shallbe a target standard value.
In both the dimension-defined type and free dimension type, the category for cooling
capacity of 2.5 kW or lower and the category for cooling capacity of over 2.5kW and 3.2 kW orlower shall be integrated, because their Top Runner Values are at almost same level.
Table 1: Top Runner Values of Air Conditioner
Temporary
Category

Unit Form

Cooling Capacity

Air Conditioners of

2.5 kW or lowerAB

wall-hung type among theDimension Type of

Top Runner

Indoor Unit

Value(APF)

Dimension-defined type5.65

Free–dimension type

6.40

C

non-duct types (excludingOver 2.5kW,3.2 kW

Dimension-defined type

5.60

D

multi-type air conditioners

or lower

Free–dimension type

6.40

Over 3.2kW,

Dimension-defined type

4.80

4.0kW or lower

Free–dimension type

5.80

that controls operation ofEFindoor unit separately)12

Table 2: Target Standard Value of Air Conditioner
CategoryA
B
C
D

Unit Form
Air conditioners ofwall-hung type
among thenon-duct types(excluding
multi-type air
conditioners that
control operationof indoor unit
separately)

Cooling
Capacity

3.2kW or lower

Over 3.2kW,
4.0kW or lower

Dimension Typeof Indoor Unit

Top Runner
Value (APF)

Improved
Efficiency(%)

TargetStandard
Value
(APF)

Dimension-defined
type

5.65

3.0

5.8

Free–dimension
type

6.40

4.0

6.6

Dimension-defined
type

4.80

3.0

4.9

Free–dimension
type

5.80

4.0

6.0

13

AnnualPerformance Factor (APF)
通年エネルギー消費効率（ＡＰＦ）(Reference 1)

7.00
Target Standard Value (5.8)

6.00
5.65

Target Standard
Value（4.9）

5.00
4.80

4.00

2.2

2.5

2.8
Cooling
Capacity(kW)
冷房能力（ｋＷ）

3.6

4.0

Figure 1: Top Runner Values and Target Standard Values in Categories A and C (forAnnual Performance Factor (APF)

通年エネルギー消費効率（ＡＰＦ）

Dimension-defined Type)

7.00

Target Standard
Target Standard

Value（6.6）

Value（6.0）

6.40

6.00
5.80

5.00

4.00

2.2

2.5

2.8

3.6

4.0

Cooling
Capacity (kW)
冷房能力（ｋＷ）

Figure 2: Top Runner Values and Target Standard Values in Categories B and D (for Free-Dimension
Type)

14

(Reference 2)
Examples of Main Technologies for Improving Efficiency of Air Conditioners(1)Compressor
1)High-efficient compression technology
The compressor is the heart of an air conditioner and requires high-precise
processing technology.
Although a rotary compressor with rotary method was widely adopted before, a twinrotary method or scroll method with better compression efficiency has now beendeveloped and adopted.

Twin Rotary Compressor

Scroll Compressor[Reduction of mechanical loss]
Sliding loss is reduced by improving precision in process of a sliding unit.

In ascroll compressor, swirling scroll and fixed scroll are made to stick together, thereby
reducing leak.
increases.

When the sticking force is strong, sliding loss between these scrolls

On the other hand, when the sticking force is weak, a gat appears and causes

increasing leak.

Thus, in order to maintain the minimum sticking force to reduce sliding

loss, there is provided a control valve for controlling pressure on the back of the swirlingscroll so that there will be appropriate back pressure according to operating state.
[Reduction of pressure loss in suction/discharge]
An attempt to reduce a pressure loss is being made by improving a shape of passage.
For instance, a suction passage is made to be tapered for a suction opening, and adischarge opening is stepped to be expanded.

15

2)

Compressor motor[Neodymium magnet]
An attempt to improve motor efficiency is made by changing ferrite that has been
conventionally used in a rotor to neodymium that has high magnetic flux density.
[Improvement of line area ratio of winding]
A proportion of total coil sectional area within the stator to a stator slot area isreferred to a line-area ratio.

If the line-area ratio could be increased, the coil sectional

area could be expanded, thereby reducing copper loss.
In the past, as coil was threaded through a narrow space within a closed stator andwinded, there remained a large dead space in the stator slot.

However, development of a

new manufacturing method allows for the high line-area ratio by winding the coil to thestator divided and spread out.
In addition, coil covering an end face of a stator core can be reduced by directly
coiling the stator (intensive winding), thus also reducing copper loss.

[Low-iron-loss magnetic steel sheet]
One of the factors of iron loss is eddy-current loss caused by eddy current generated
in an iron core.

Attempts have been made to prevent this current from flowing easily bymeans of, for example, adoption of silicon steel plates and/or thin laminated steel sheets.
3)

Sine-wave drive control of compressor motor
In the past, the square wave drive system, which switches current-conducting phases at
every 60 degrees, was adopted as an operating method of a compressor for an inverter air
conditioner. With this system, a position of a rotor could be sensed from induced voltageof the motor while motor current was not conducting, and thus the motor speed could bechanged easily.
In this system, however, the square motor current caused reduced motor efficiency.
To respond to this, recently, coupled with improved arithmetic performance of the
microcomputer, the sine wave driving of motor current was made possible throughdevelopment of the control technology to estimate a rotor position from motor current.

16

Waveform of Motor Current of Square-Wave

Waveform of Motor Current of Sine-Wave

Driving System

Driving System(2)
1)

Blowers
Indoor blower
Various types of fans depending on unit form are used for blowers of indoor units. A“cross flow fan” is used for most of the wall-hung type air conditioners.
[Cross Flow Fan]
Although a cross flow fan was composed of blades that were processed metal sheets inthe past, an attempt to increase air volume has been made through introduction of plastic
blades having a wing-shaped section and growing size of fan diameter, while controllingnoise.
The layout and molding of a fan and blades have also been improved, by having
random spacing between blades, angling a fan shaft, etc.
Random Pitch

Unequal pitch
Close-up17

2)

Outdoor blower
In general, a propeller fan is used for an outdoor unit of an air conditioner.

Althoughit was made of processed metal sheets in the past, it is now made of plastics. An attempt toincrease air volume has been made by improving a blade shape, while suppressing noise.
3)

Fan motor
For fan motors for both indoor and outdoor units, an efficient DC brushless motor has
replaced a conventional AC motor.

In addition, to improve efficiency of a DC brushless

motor, techniques that were developed for a compressor motor having high power
consumption are incorporated, and optimization efforts have been made to achieve the mostefficient combination of technologies, such as increased number of poles/slots, a devised coreshape, reduction of circuit loss, optimal energization, etc.
Example of Increased Number ofPoles/Slots

4-pole 6-Slot(3)8-pole 12-Slot

Electronically controlled expansion valve
A decompressor is a component to create high-pressure and low-pressure states in arefrigerant circuit.

Until now a capillary tube has been used primarily.

A capillary tube

refers to a thin and long copper pipe being about 0.2 to 2 m long and having an inside
diameter of 1 mm to 2mm.

This pipe generates pipe resistance and achieves throttling

action (decompression).
A capillary tube has been widely used for a room-air conditioner as it can be
implemented with a simple structure.

However, adjustment of appropriate degree ofthrottling according to number of revolutions is not possible because the degree of throttlingis constant even when the number of revolutions of a compressor varies.
Thus, an electronically controlled expansion valve has become used, which enables
18appropriate degree of throttling based on an electronic signal from a microcomputer
determining the operating state of an air conditioner.

The valve is such structured that apulse motor rotates based on an electronic signal, and a gap between the valve and a valve
seat is adjusted by converting the rotation into up-and-down motion, thereby controlling thedegree of throttling.
This could achieve efficient control of the refrigerant flow, depending on the operatingstate, such as the changing number of revolutions of a compressor used in an inverter air
conditioner. Thus, the electronically controlled expansion valve has become mainstream.

Pulse Motor

Main Body
Valve Seat

Valve

(4)

Heat exchanger
A heat exchanger is one of the important components of an air conditioner.

Itexchanges heat between indoor air and a refrigerant in an indoor unit, and between outdoor
air and a refrigerant in an outdoor unit.
A fin-tube-type heat exchanger in which a copper tube for the refrigerant penetrates aplate-like aluminum fin for air is used as the heat exchanger.
1) Fin for heat exchange
Initially, a flat aluminum plate (plate fin) was used for a fin of a heat exchanger.
Then, a corrugated fin and a slit fin with cutouts were adopted, and improvement of the slit
shape has been made. In addition, in case that wind speed of air passing through a heatexchanger is nonuniformly distributed, improvement has been carried out to increase theoverall heat exchange capacity by equalization of the wind speed distribution, such asincreasing the height of a fin facing faster wind speed and lowering the height of a fin facing
slower wind speed.

19

Plate Fin

Corrugated Fin

Slit Fin

Improvement of Slit Shape2)

Copper tube for heat exchange
Initially, a smooth tube, inner surface of which was not processed like a copper tube,
in general, was used for a heat exchanger.

For saving energy, a tube with internal groove

was developed and optimization of a groove shape has been pushed forward.
Smooth Tube

Tube with Internal Groove

Optimization of a Groove Shape20

In addition, in order to improve heat conduction with a refrigerant and a copper pipe,
reduction of a pipe diameter has been implemented.
[Example]

Pipe Diameter

9.5mm →

7.0mm →

6.3mm

Improvement has also been made to reduce pressure loss, and thereby increase the totalheat exchange capacity, by reducing a pipe diameter for a part of liquid state and increasing it
for a part of gas state, depending on the condition of refrigerant liquid and gas passing
through the piping.
3)

Form of heat exchanger
In separate wall-hung type indoor units that account for most of the room-air
conditioners, a cross section of the conventional heat exchanger was molded like a plate.
However, in order to expand heat exchange area in a limited space, bent one and one molded
like a curved surface have been developed.

Heat exchanger

Cross flow fan

In addition, the heat exchanger in the initial indoor unit was arranged in two columns.
However, improvement has been made to increase a heat transmission area and augment theheat exchange capacity by partially arranging it in three columns, if an indoor unit structure
can afford enough space for it.

21

Attachment 5

Energy Consumption Efficiency of Air Conditioners and Measurement Method

1. Basic Idea
When air conditioners were designated as equipment for the Top Runner Standard in 1998
(Heisei 10), “COP (Coefficient of Performance)” was adopted as an index related to energy
consumption efficiency.

The COP is represented by either a numeric value obtained by dividing

cooling capacity (kW) by cooling power consumption (kW) (hereinafter referred to as “cooling
COP”) or a numeric value obtained by dividing heating capacity (kW) by heating power
consumption (kW) (hereinafter referred to as “heating COP”).

The COP of acooling-cum-heating air condition is a mean of the cooling COP and the heating COP.
However, said index is an evaluation approach principally featuring constant-speed models.
Thus, in recent years when inverter models have become a mainstream, it is pointed out that theindex is no longer necessarily an appropriate evaluation approach.

Thus, it is consideredreasonable to newly adopt the Annual Performance Factor (APF) that is an energy saving
evaluation standard better representing the reality.
2. Specific Energy Consumption Efficiency and Measurement Method
An index related to energy consumption efficiency of air conditioners shall be “Annual
Performance Factor (APF)”, and a measurement method thereof shall be in accordance with thecalculation method specified in Japanese Industrial Standards C9612: 2005 Room Air
Conditioners.
3. Annual Performance Factor (APF)
A performance index in the current Energy Saving Law uses COP of rated conditions ofcooling and heating.
However, the capacity of air conditioners changes according to ambient air and also to thenumber of revolutions of a compressor in case of inverter models, which are the current
mainstream (room-air conditioners of capacity variable type); therefore, evaluation in a mannerclosely reflecting actual use is difficult to be achieved only with the rated conditions.

22

Cooling Capacity– Example of COP Characteristic (2.8kW Class)
冷房能力－ＣＯＰ特性の例（２．８ｋWクラス）
7.5

Cooling
COP
冷房ＣＯＰ

7
Interme中間
diate

6.5
6

定
格
Rated

5.5
5
4.5
4
0

500

1000

1500

2000

250 0

30 00

冷房能力W
Cooling
Capacity W

Figure 1: Cooling Capacity – COP Characteristic (2.8 kW Class)Thus, Annual Performance Factor (APF) was provided to enable evaluation of energy
consumption efficiency that is well representing actual use, by means of considering occurrencetime of outside air temperature during cooling/heating period and efficiency of air conditioners
according to capacity change that is a characteristic of inverter models.
Shown below is a comparison between COP and APF:
Calculation
MethodMeasurement
PointsFeatures

Cooling/Heating Average COP
Cooling/heating average COP = (cooling
rated COP + heating rated COP)/2
where a rated COP refers to a value
obtained by dividing capacity (W) at a
rated point by then power consumption(W).
(Evaluation in both cooling and heating
conditions)Two points Cooling rated
Heating rated

Annual Performance Factor (APF)
A proportion of summation (Wh) of heat quantity
to be subtracted from and added to indoor air
throughout cooling and heating periods to total
electric energy to be consumed during the same
periods.

Five points

Cooling rated Cooling intermediate
Heating rated Heating intermediate
Heating low temperature
・ Measurements points are only a few, ・ Measurements points are many, i.e., 5 points
i.e., 2 points and the measurement isand thus measurement takes time.
simple to conduct.
・ Since the method calculates efficiency
・ They are efficiencies of fixed points
considering intermediate performance thatand hardly representing actual use at
frequently occurs in actual use, it is possibleall.
to calculate efficiency closer to reality.
Table 1: Comparison of COP and APF(1) Calculation conditions for Annual Performance Factor (APF)
The prerequisite for calculation of Annual Performance Factor (APF) shall be as follows:･Outside air temperature: setting Tokyo’s as a model･Indoor set temperature: 27℃ when cooling/20℃ when heating･Period: Cooling period: 3.6 months (June 2 to September 21)
Heating period: 5.5 months (October 28 to April 14)･Operating Time: 18 hours, from 6:00 to 24:00･Housing: An average wooden house according to Japanese Industrial Standards C9612 (facesouth)
23

Capacity
能力

Capacity
能力

Building
建物負荷＝ load = Capacity
neededheata要building
建物を暖房to
する
のに必な能力

Building
load
Capacity
建物負荷＝
建物=
を冷
房するのに
neededto力cool a building
必要な能Cooling
冷
房定格
rated
能
力
capacity

●
○

rated
暖Heating
房定格
能力
capacity条
件 condition

Equivalent
to相heating
暖房定格能力当
rated capacity

-7

-10

-5

0

7

5

10

●

○

17

15

25

23

30

33

外気
温度（℃air） temperature (℃)
Outside35

Outsidetemperature
(℃)
外気air
温度
（℃）

Figure 2: Characteristics of Heating/Cooling Capacity Needed for Air-conditioning a Building, According to

350

350

300

300

250

Occurrence Time (h)Frequencyof
期間を通じてみた場合、
operation at rated
定格能力を行う頻度はcapacity throughout
少ない。
theperiod is low.

200
150

発生時間(h)発生時間(h)Occurrence Time (h)Outside Air Temperature

100

250
200

Frequencyof
期間を通じてみた場合、
operation at rated
定格能力を行う頻度はcapacity throughout
少ない。
theperiod is low.

150
100
50

50

0

0
-1

0

1

2

3

4

5

6

7

8

9

24

10 11 12 13 14 15 16

Outside Air外気温度℃
Temperature (℃)

25

26 27

28

29 30

31

32 33

34

35 36

37

38

Outside Air外気温度℃
Temperature (℃)

Figure 3: Relationship of Outside Air Temperature and its Occurrence Time in Tokyo
By adding intermediate performance evaluation points that are the most frequent, energy
consumption efficiency throughout a period can be calculated simply and accurately.
(2) Calculation of energy consumption efficiency during cooling period1)

The capacity of an air conditioner for every outside air temperature associated withbuilding load is calculated, considering a change in capacity according to outside airtemperature, which is determined from capacities at a rated and an intermediate capacity
evaluation points.

24

2)

Similarly, power consumption of an air conditioner for every outside air temperatureassociated with building load is calculated, considering a change in power consumption
according to outside air temperature, which is determined from power consumptions at a
rated and an intermediate capacity evaluation points.

Building
Load
建物負
荷

Capacity
能力
Maximum
Capacity
エアコ
ンのCharacteristic
of性
最大能力特
Air Conditioner

○

●
Rated
定
格
Evaluation
Point
評
価点

○

●
Intermediate中間
Evaluation
Point
評価
点

23

25

30

35
Outside Air Temperature (℃)
外気温度（℃）

Figure 4: Outside Air Temperature – Capacity When Cooling
The heat quantity (kWh) when an air conditioner cools a building is calculated for every
outside air temperature from capacities an air conditioner shows per outside air temperatureand their occurrence time.

Then, the sum total of heat quantities needed for cooling abuilding at each outside air temperature (Cooling Seasonal Total Load (kWh)) is determined.

冷房能力×発生時間(kWh)Cooling
Capacity x Occurrence Time (kWh)

3)

300
250

Interme▼中間
diate

200
150
100
▼定格
Rated

50
0

24 25 26 27 28 29 30 31 32 33 34 35 36 37 38
Outside Air
Temperature℃
外気温度℃

Figure 5: Heat Quantity which Air Conditioner Needed to Cool a Building (Example)
25

4)

The consumed energy (kWh) for cooling a building is calculated for every outside airtemperature from power consumptions of an air conditioner and their occurrence time atbuilding load points. Then, the total sum of energy consumed by cooling operation at every

消費電力×発生時間(kWh)Power
Consumption x Occurrence Time ((kWh)outside air temperature (Cooling Seasonal Energy Consumption (kWh)) is determined.

35

Interme▼中間
diate

30
25
20
15
10

Rated
▼定格

5
0
24 25 26 27 28 29 30 31 32 33 34 35 36 37 38
Outside Air Temperature℃
外気温度℃

Figure 6: Energy Consumed by Cooling Operation (Example)
5)

Cooling Seasonal Performance Factor (CSPF: commonly known as Cooling APF) isdetermined from Cooling Seasonal Total Load and Cooling Seasonal Energy Consumption.
Cooling Seasonal Total Load (CSTL)CSPF ＝
Cooling Seasonal Energy Consumption (CSEC)(3) Calculation of energy consumption efficiency during heating period1)

The capacity of an air conditioner and its power consumption at each outside airtemperature associated with building load is calculated from values at a rated andanintermediate capacity evaluation points.
Similar to the idea for the cooling period, the capacity an air conditioner shows and its
power consumption are calculated for every outside air temperature. They will additionallybe calculated at a low temperature evaluation point, which is one of the capacity evaluation
points.

In addition, as for heating operation, when outside air temperature is low, an air

conditioner’s capacity and power consumption shall be calculated by adding performanceloss due to defrosting a heat exchanger of an outdoor unit.

26

Capacity drop due
to defrosting
霜取り運転によoperation

Capacity
能力

Building
建物負荷
Loadる能力ダウン●

エアコンのCharacteristicofmaximum
capacity of
最大能力特性
air conditioner
Low
低温
Temperatur

●

Rated
定格
Evaluatio
n評価点
Point

○●

Intermediate
中間
Evaluation
評価点
Point

○
○

-7

-10

-5

0

7

5

10

15

17

Outside Air Temperature (℃)
外気温度（℃）

Figure 7: Outside Air Temperature – Capacity When Heating
2)

The heat quantity (kWh) when an air conditioner heats a building is calculated for every
outside air temperature from capacities an air conditioner shows per outside air temperatureand their occurrence time.

Then, the sum total of heat quantities needed for heating thebuilding at every outside air temperature (Heating Seasonal Total Load (kWh)) is

暖房能力×発生時間(kWh)Heating
Capacity x Occurrence Time (kWh)determined.

500

Interme-

▼中間
diate

450
400
350
300
250
200
150

Rated
定格▼

100
50
0
-1 0

1

2

3

4

5

6

7

8

9 10 11 12 13 14 15 16

Outside Air Temperature
(℃)
外気温度℃

Figure 8: Heat Quantity an Air Conditioner Needed to Heat a Building (Example)
3)

The consumed energy (kWh) for heating a building is calculated for every outside airtemperature from power consumptions of an air conditioner and their occurrence time atbuilding load points.

The total sum of energy consumed by heating operation at every
27

Power Consumption
x Occurrence Time (kWh) (kWh)消費電力×発生時間(kWh)outside air temperature (Heating Seasonal Energy Consumption (kWh)) shall be determined.

80
Interme▼中間
diate

70
60
50
40
30

定格▼
Rated

20
10
0
-1 0

1

2

3

4

5

6

7

8

9 10 11 12 13 14 15 16

Outside Air Temperature ℃

外気温度℃

Figure 9: Energy Consumed by Heating Operation (Example)

4)

Heating Seasonal Performance Factor (HSPF: commonly known as Heating APF) shallbe determined from Heating Seasonal Total Load and Heating Seasonal Energy
Consumption.
Heating Seasonal Total Load (HSTL)
HSPF＝
Heating Seasonal Energy Consumption (HSEC)(4) Annual Performance Factor (APF)
Annual Performance Factor shall be calculated from the total load and the seasonal energy
consumption of cooling and heating operations.

Cooling Seasonal Total Load + Heating Seasonal Total Load
APF＝
Cooling Seasonal Energy Consumption + Heating Seasonal Energy Consumption

28

Attachment 6

Air Conditioner Evaluation Standard Subcommittee
Energy Efficiency Standard Subcommittee of the Advisory Committee for Natural Resources and Energy
Background of Holding

First Subcommittee Meeting (August 8, 2005)-

Disclosure of the Air Conditioner Evaluation Standard Subcommittee-

Achieving status of air conditioners-

Current situation of air conditioners-

Scope of air conditioners to be covered-

Energy consumption efficiency and measurement method

Second Subcommittee Meeting (December 9, 2005)-

Categories for target setting of air conditioners-

Target standard values and target fiscal year of air conditioners

Third Subcommittee Meeting (January 31, 2006)-

Interim summary report29Attachment 7

Air Conditioner Evaluation Standard Subcommittee, Energy Efficiency Standards Subcommittee ofthe Advisory Committee on Natural Resources and Energy
List of Members
Chairman: TAKANORI SAITO

Professor Emeritus, University of Tokyo

Members: HIROSHI ASANO

Professor in Department of Mechanical Engineering,
Graduate School of Engineering, University of TokyoKAZUO UENO

Assistant Research Department Head, Energy Technology
Research Department, National Institute of Advanced
Industrial Science and Technology

AKIRA OKAGAKIJapan Building Mechanical and Electrical Engineers
Association

MAKOTO KAIBARAPJ Leader, Domestic Air Conditioner Energy Saving PJ,
Japan

Refrigeration

and

Air

Conditioning

Industry

Association
MASAHIKO SASAKURA

Chairman, Package Air Conditioner Technology Ad Hoc
Committee, Japan Refrigeration and Air Conditioning
Industry Association

HARUKI SATO

Professor, Department of System Design Engineering,
Faculty of Science and Technology, Keio University

KIKUKO TATSUMIManaging Director of Nippon Association of Consumer
Specialists

EIJI TOBIHARA

Professor Specialized in Environmental Studies, Graduate
School of Frontier Science, University of Tokyo

YOICHI HORI

Professor, Institute of Industrial Science, University of
Tokyo

TOSHIHISA MASUDA

General Manager, Technology Dept, Energy Conservation
Center, JapanCHIHARU MURAKOSHI

Director and General Manager of Laboratory, Jyukankyo
Research Institute Inc.
30

Reference 1

Current Situation of Air Conditioners

Air Conditioner Market
Market Trend of Air Conditioners(1)

Scope of air conditioners
Air conditioners (AC) shall be roughly divided into those for buildings and those fortransports.
Shown below are an overall view of air conditioners and an overview of shipment
volume:ElectricType

Residential Air
Conditioners
6,723,072

Those Other
than
Electric Type

General Air Conditioners
for Buildings（Unit: Number of units, 2004 Freezing Year）

Air Conditioners forTransports

1-1

Air Conditioners

1.

Service Air
Conditioners
731,795

Gas Engine Heat Pump Air Conditioners
39,703

Air Conditioners
for Automobiles
4,883,685

Air Conditioners
for Buses
12,319Air Conditioners forRailway Vehicles(Number of units unknown)

Source: Japan Refrigeration and Air Conditioning Industry Association

31

(2)

Transition in the number of shipments of air conditioners
1) Residential air conditioners
Although shipments of residential air conditioners tend to be greatly affected by climate
factors, they have been stabilized around 7.0 million units for the past ten years.
(Unit: 1,000 units)(Unit: 1,000 units)
Freezing
Year
冷凍年度

1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004

国内出荷合計
3,673
3,982
4,605
4,734
5,932
7,092
6,249
5,048
6,724
7,697
8,116
7,154
6,551
6,496
7,019
7,677
6,902
6,774
6,723

Total of Domestic Shipments（Freezing Year）

2) Service air conditioners
Although shipments of service air conditioners tend to be affected by economic trends,
they have been stabilized around 700,000 units for the past 10 years.
(Unit: 1,000 units)(Unit: 1,000 units)
Freezing
Year
冷凍年度

1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004

国内出荷合計
557
600
707
786
930
1,081
928
785
745
805
830
786
682
624
684
734
668
659
732

Total of Domestic Shipments（Freezing Year）

Source: Japan Refrigeration and Air Conditioning Industry Association

32

(3)

Shipment volume of air conditioners by function/form/cooling capacity[By Function]
1) Residential air conditioners
A cooling-cum-heating type accounts for 99% of the total shipments.
(Unit: Number of units 2004 freezing year)
Dedicated for Cooling

Cooling-cum-Heating

Total

90,4586,632,614

6,723,072

Source: Japan Refrigeration and Air Conditioning Industry Association
2) Service air conditioners
A cooling-cum-heating type accounts for 92% of the total shipments.
(Unit: Number of units 2004 freezing year)
Dedicated for Cooling

Cooling-cum-Heating

Total

90,201

674,594

731,795

Source: Japan Refrigeration and Air Conditioning Industry Association[By Form]
1) Residential air conditioners
Among air conditioners that have a one-to-one combination of indoor unit and outdoor
unit, those having a wall-hung type indoor unit account for 98% of the total shipments.

(Unit: Number of units 2004 freezing year)

Single (one to one)

Total

Multiple typeWall-hung type

Built-in type

6,562,333(98%)

90,754(1%)

69,985(1%)

6,723,072(100%)

Source: Japan Refrigeration and Air Conditioning Industry Association
2) Service air conditioners
Air conditioners that have a cassette-type indoor unit account for 63% of the total
shipments.
(Unit: Number of units 2004 freezing year)
Floor-installed Ceiling-susp

Wall-hung

Cassette

type-ended type

type

type

46,646(4%)

152,373(15%)

101,054(10%)

660,168(63%)

Built-in type

Duct type

Total

38,881(4%)

42,653(4%)

1,041,775(100%)

Source: Japan Refrigeration and Air Conditioning Industry Association

33

[By Cooling Capacity]
1) Residential air conditioners
The residential air conditioners whose cooling capacity is in 2.2kW class (mainly for a
six-tatami-mat room) has the largest shipment, accounting for 39.8% of the total
shipments.
(Unit: Number of units 2004 freezing year)
Applicable Room Size inTerms of the Number ofTatami-Mats

Cooling Capacity (kW)Less than 6Less than 2.2

6

2.2

2,675,862 (39.8 %)

8
10
11
12
14

2.5
2.8
3.2
3.6
4.0

Over 14Over 4.0

1,071,935 (15.9 %)1,489,616 (22.2 %)7,907 (0.1 %)280,523 (4.2 %)670,664 (10.0 %)455,874 (6.8 %)6,723,072 (100.0 %)Total (Number of Units)

70,691(1.1 %)Total

Source: Japan Refrigeration and Air Conditioning Industry Association
2) Service air conditioners
Depending on diversity of business buildings, cooling capacities widely range.
However, air conditioners having cooling capacity up to 28 kW accounts for 94.1% of
the total shipment.
(Unit: Number of units 2004 freezing year)

Cooling Capacity (kW)

Total

~ 4.5
~ 5.0
~ 6.3
~ 8.0
~ 11.2~ 14.0~ 16.0~ 22.0~ 28.059,66879,55344,520113,107
88,398105,537
63,32945,812
88,773~ 40.0~ 56.0~ 63.0~ 80.0~ 160
Over 160
Total(8.2 %)(10.9 %)
(6.1 %)(15.5 %)
(12.1 %)
(14.4 %)
(8.7 %)(6.3 %)(12.1 %)

22,365(3.1 %)
17,365(2.4 %)
838(0.1 %)
1,198(0.2 %)
746(0.1 %)
586(0.1 %)
731,795 (100.0 %)Source: Japan Refrigeration and Air Conditioning Industry Association34

(4) Transition in the number of imported air conditioners
1) Residential air conditioners
The majority of imported air conditioners for household use are from overseas
production bases of Japanese manufacturers.

The percentage of residential air

conditioners that are manufactured overseas and sold in Japan has been increasing, and
it is expected to be approximately 40% in 2004.

Import

Unit: Number of units
Calendar Year

2000

2001

2002

2003

2004

Total

450,354

1,030,780

2,045,781

2,211,207

2,682,811

China

210,839

252,940

1,561,341

1,808,583

2,371,002

Thailand

121,912225,474

198,026

151,834

222,592

Malaysia

50,853

190,100

152,202112,181

9,250

Source: Ministry of Finance, Customs Statistics(Reference)
Freezing Year

2000

2001

2002

2003

2004

7,018,512

7,676,629

6,901,805

6,774,002

6,723,072

Domestic
Shipments

Source: Japan Refrigeration and Air Conditioning Industry Association

2) Service air conditioners
There has been almost no import.
(5)

Penetration of residential air conditioners and number of air conditioners owned perhouseholdIt can be said that now air conditioners prevail among almost every household.
According to the statistic survey of housing/lands by the Ministry of Internal Affairs andCommunications, the number of rooms per house is 4.77 rooms, and the number ofowned air conditioners will possibly increase in the future.

In 2004, the number of air

conditioners owned per household has reached 2.8 units per household.

Year/Month

Ownership Rate（％）

Number of Owned

1984/March

49.3

75.2

Number of Owned
Air Conditioners Per
Household1.5

1989/March

63.3

110.7

1.7

1994/March

74.2

151.6

2.0

1999/March

84.4

200.7

2.4

2004/March

87.1

245.3

2.8

Air Conditioners

Number of Owned Air Conditioners: per 100 households
Source: Cabinet Office, Survey of Consumer Behavior
35

1-2

Main Domestic Manufacturers

1. Residential Air Conditioners
・Corona Corporation
・Sanyo Electric Air Conditioning Co., Ltd.
・Sharp Corporation
・Daikin Industries, Ltd.
・Chofu Seisakusho Co., Ltd.
・Toshiba Carrier Corporation
・Hitachi Appliance, Inc.
・Fujitsu General Co., Ltd.
・Matsushita Electric Industrial Co., Ltd.
・Mitsubishi Heavy Industries, Ltd. ,・Mitsubishi Electric Corporation(In the order of Japanese Syllabary)

2. Service Air Conditioners
・Sanyo Electric Co., Ltd.
・GAC Corporation
・Sharp Corporation
・Daikin Industries, Ltd.
・Toshiba Carrier Corporation
・Nippon PMAC Co., Ltd.
・Hitachi Appliance, Inc.
・Matsushita Electric Industrial Co., Ltd.
・Mitsubishi Heavy Industries, Ltd.
・Mitsubishi Electric Corporation(In the order of Japanese Syllabary)

36

2.

Energy Saving Efforts in Residential Air Conditioners until Now
2-1(1)

Response to the Current Energy Saving Law
Status of achieving target
At the end of March, 1998, new target values were set according to the Top Runner
Program, and the 2004 freezing year was set to be the target year of residential air
conditioners.
Although they were high target values requiring considerable improvement, because ofefforts made by each of the industrial association member companies, all the member
have achieved the target.

Cooling-cum-Heating Type (Heat Pump)
Weighted Harmonic Mean of Cooling/Heating Average COP
Category
Achievements of the Industry
FiscalFiscalFiscalFiscalFiscalFiscalCooling
Unit Form
Year
Year
Year
Year
Year
Year
Capacity
1999
2000
2001
2002
2003
2004
2.5 kW or
3.17
3.24
3.37
3.49
3.75
5.33
lower
Wall-hungTypes Among Over 2.5kW,
3.47
3.63
3.83
4.00
4.18
5.14
Non-ducted
3.2kW or lower
Types
Over 3.2kW,
3.07
3.37
3.57
3.92
3.99
4.10
4.0kW or lower
Category
Achievement Rate (%)
FiscalFiscalFiscalFiscalFiscalFiscalCooling
Unit Form
Year
Year
Year
Year
Year
Year
Capacity
1999
2000
2001
2002
2003
2004
Wall-hungTypes Among
Non-ducted
Types

2.5kW or lower
Over 2.5kW,
3.2kW or lower
Over 3.2kW,
4.0kW or lower

60.2

61.5

63.9

66.2

71.2

101.1

70.8

74.1

78.2

81.5

85.3

104.9

84.1

92.3

97.8

107.4

109.3

112.3

TargetValues

Source: Japan Refrigeration and Air Conditioning Industry Association

37

5.27
4.90
3.65

(2)

Background to achievement of target
The demand for products that place higher priority on a price than on energy saving
performance was strong in the market.

Thus, before the target year, in order to ensure

the achievement of standards of the Energy Conservation Law, the industry prepared aself-action plan to increase the share of shipments of models that satisfied the standard.
Transition of Efficiency Distribution of 2.8kW Air Conditioners

Modelswhose
production was stopped
in 2004 as they could
not achieve the target in
2003: Approximately
70 modelsApproximately
2.0
million units

COP Highest AC
COP Lowest AC
Weighted Harmonic Mean

2-2

Comparison with Overseas Energy Saving Regulations
Because of the Top Runner Program implemented by the Energy Conservation Law, theenergy saving performance of Japanese air conditioners is at substantially high level in theworld.

Shown below is a comparison with various overseas standards, for reference:

Explanatory Note

Japan
Japan
ThailandTaiwanAustralia
China

Thailand

Regulation
Value
Regulation
Value

China

Regulation
Value

Regulation
Value

Regulation
Value

Australia

TaiwanCooling Capacity (kW)

38

2-3
(1)

Technological Approach to Energy Saving of Residential Air Conditioners in the Future
Technology for improving performance of compressor
The efficiency of a compressor is represented by “efficiency of motor” in a power output
section and by “total heat-insulating efficiency” indicating how much compression
actually takes place without loss using the obtained motive energy.
The “compressor motor efficiency” is approximately 95% and “total heat-insulating
efficiency” is over 80%.

Motor Efficiency

Total Heat Insulating Efficiency

Cooling Rated Condition

Cooling Rated
Condition（社）日本冷凍空調工業会調べ
Freezing YearFreezing Year

(2)

Technology for improving performance of a fan motor
The efficiency improvement in “blower motor efficiency” is greater than 80%.

(Mean of Indoor/Outdoor Motors)

Motor Efficiency（社）日本冷凍空調工業会調べ
Freezing Year

39

(3)

Growing size of heat exchangers
An attempt to save energy has been made by increasing size of a heat exchanger and thus
alleviating the compression ratio.
(Reference)
Total of Values for Indoor and Outdoor Units
Mass

Cubic Capacity
Highest-COP AC

Lowest-COP AC

Highest-COP AC

Lowest-COP AC

Year

Year

Source: Japan Refrigeration and Air Conditioning Industry Association（社）日本冷凍空調工業会調べ

ＣＯＰ最高機とＣＯＰ最低機の寸法と質量

Dimensions and Mass of Highest-COP and Lowest-COP Air Conditioners

Lowest-COP AC in 2002

Highest-COP AC in 2004

Unit of Dimensions: 8mm

Source: Japan Refrigeration and Air Conditioning Industry Association

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2-4
(1)

Approach to Reduction of Standby Power Consumption
Independent declaration by the industry
In January 2001, Japan Electronics and Information Technology Industries Association,
Japan Electrical Manufacturers’ Association, and Japan Refrigeration and Air Conditioning
Industry Association made an independent declaration for reducing standby power
consumption.

It stated that for anchor products of residential air conditioners, “they will

make efforts toward the target which is to decrease the standby power consumption below
1W by 2004 freezing year”.
(2)

Status at the end of 2004 freezing year in response to the independent declaration of theindustry
Targeted models

191 models

Achieved models

191 models

Achievement rate

100%

Mean of Standby power consumption

0.81W

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3. Future Approach to Energy Saving and Challenges
As it now stands, improvement of energy saving by increasing size of a heat exchanger is a key
factor.
3-1(1)

Various Problems Accompanying Growing Size of Air Conditioners
Installability
Considering the fact that intra-column dimension of half-ken width (“ken” is a unit in
Shaku-kan method) of a Japanese house is 800 mm, it is concerned that an air conditioner
will not be suitable for being used as household equipment if its width exceeds 800 mm.

(2)Comfort
It is concerned that the further growth in size of a “heat exchanger/blower” might damage
the basic comfort; such as, “evaporation temperature rises and thus humidity in a room isdifficult to be cleared” in the case of cooling operation.

(3)

Resource saving
Increased size of equipment might also increase usage of copper and aluminum, inparticular, which are materials for a heat exchanger.

Thus, from the standpoint of resourcesaving, the problem still remains.
3-2

Relationship between Difference in Running Cost and Sales Price

In order to actualize the efficiency of an energy saving model for the next generation, it is essential toincrease size of a heat exchanger, which leads to cost increase for material input.

Hence, it isconcerned that it will not be possible to offset a difference in the initial cost between energy saving
models and others even with a difference in running cost for 10 years between them.

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