The Energy Conservation Center, Japan

Introduction

The first commitment period of Kyoto Protocol started in FY2008, which requires us toachieve a target of reducing greenhouse gas emissions to 6% below the base year (FY1990)
levels by FY2012. Approximately 87% of the greenhouse gas is comprised of carbon
dioxide (CO2) from energy. The CO2 emissions have been significantly growing especially incommercial business sectors and enhancement of drastic measures has become an urgent
need.
Energy conservation must also be promoted in hospitals on condition that the environment
for medical care is ensured.
This brochure is intended for owners of hospitals and persons in charge of energy
conservation promotion or energy facility management, explaining the points, measures andthe case examples of energy conservation based on our investigation data.
We hope that you will find the information taking account of characteristics in energy
consumption particularly seen in hospital operations helpful for your activities toward better
energy conservation practices.

Contents
1. Energy Management and Energy Conservation Promotion in Hospitals ................................... 2
2. Characteristics of Energy Consumption in Hospitals .................................................................. 4
3. Energy Conservation Measures by Hospitals Division ................................................................ 7
4. Major Methods for Energy Conservation Measures in Hospitals ................................................ 13
5. Successful Cases of the Energy Conservation Measures in Hospitals ....................................... 15
6. Effective Tools and Techniques for Promoting Energy Conservation by Improved Operation .... 18

1

Energy Management and Energy
Conservation Promotion in Hospitals■ Establishment of organization and structure
The entire hospital must work together to promote energy conservation. As shown in the pyramid below, it isessential to fulfill one’s role in each position.

Top management’s
responsibility

Management
standard

Structure

Check & Action
ent
m
e
r
u
s
a
Me
Persons in charge
statusof energy
nalysisata
addconservation
anpromotion
Type 1 energy managersgintt
Target seest measur
n
e
m
e
v
o
r
and impsness ofConsciourkers
dical wo

Motivation enhancementme■ Energy conservation by organization activities- It is essential that the management layer should unify the energy conservation
organization- Appoint persons who is responsible for energy conservation from each divisionand display their name at the key points- Follow-ups the energy consumption status at the energy conservation promotion
meetings which are held periodically- Motivate medical workers that "Energy conservation is money conservation"- Conduct periodical patrols by participants from each division, check whether
lightings and air conditioning are left in operation, etc., and notifications to theapplicable divisions- Enlighten employee by in-house magazines, posters, stickers, and etc.
- Raise suggestions for energy conservation and motivate it by commending theresults- Share the sense of accomplishment by making presentations on activity results2

Energy Management and Energy Conservation
Promotion in Hospitals■ Energy conservation promotion by Type 1 energy managers
Facility management of hospitals should be promoted bybalancing the three elements shown in the right figure.
Also, a radar chart in the bottom right indicates the
progress level of energy conservation management by
the current facility item, based on the result of the energy
conservation audit conducted by our center. Assuming
the desired value as 100, the average of the hospital’s
administration by each management item is displayed.
Considering the fact that the scores of the “generalmanagement item” including structure, intensity
management, and PDCA management, etc. of all
hospitals except for university hospitals were below 50,
enhancement of this item is expected.

Medical facility
planning(Installation of medical
equipments)

Medicalenvironment

Energyconservation(Indoor temperature/humidity,
air quality, illuminance)(Operation andmaintenance offacilities/equipments)■ Execution of continuous PDCA
As shown in the below figure, it is essential to promote
continuous PDCA management with the facility’s
operation manager as a leader. The duty of the person in
charge of the facilities operation management is to workout a plan for improving facility operation, to design
installation of high-efficiency systems / equipments, andmaking suggestion to top management. Please refer tothe points and hints for energy conservation.

3

Publichospitals
Privatehospitals

80

Loadequalization

Heat source/heat transfer

60
40
20

Building

Arrangement of
measurement environment
Data analysis

University
hospitals

Generalmanagement item

Air
conditioning/
ventilation
Electricity/
lighting

Hot water supply/
sanitary

Visualization is essential
in convincing top management!

Review

Planning

Review of management standards
Review of the planning program

Setting of objectives and the targets
Preparation of management standards
Program for the planning of improvements

Verification of the effects

Improvement of plans

Progress management
Grasping of improvement effects
Measurement and recording

Elimination/extraction of waste
Execution of the planned program
Communication, education, training

Characteristics of Energy
Consumption in Hospitals
1. Energy intensity is large. (The largest in the type of business)
2. Fuel consumption ratio is large.
(The largest in the type of business: 40%)
3. Energy consumed at night is large.

Intensity of the facilities corresponding to Type 2 (and above)
designated energy management factories by business type

Fuel ratio of the primary energy in facilities corresponding
to Type 2 (and above) designated energy management factories

Electricity
OfficeOfficeDepartment store

Department store

Supermarket

Supermarket

Shopping mall

Shopping mall

Hotel

Hotel

Hospital

Hospital
0

1,000

2,000

3,000

4,000

0

5,000

20

40

Average intensity (MJ/m 2 per year)

60

Fuel

80

100

Ratio (%)

According to the investigation on energy conservation use in buildings (FY2003)
by the Energy Conservation Center, Japan

According to the investigation on energy conservation use in buildings (FY2003)
by the Energy Conservation Center, JapanThe energy intensity of hospitals is
the largest in the business type!

Fuel ratio of hospitals is the largest
in the business type!

Consumption ratio of nighttime in the daily energy consumption(Primary energy base)

Nighttime (22:00-8:00)

Weekdays in summer

Daytime (8:00-22:00)

Hospital
Hotel
Commercial facility
Office

0

10

20

30

40

50

60

70

80

90

100

According to the investigation on energy conservation use in buildings (FY2003)
by the Energy Conservation Center, Japan

As with hotels, nighttime energy consumption in
hospitals is large!

4Characteristics of Energy Consumption in Hospitals■ Difference in energy consumption depending on scale and type of hospitals
It is necessary to know whether your hospital’s energy consumption is larger or smaller than other hospitals.
The below figure indicates private hospitals’ energy intensity by scale, based on the Project Committee
Investigation organized by the “Japan Medical Association Research Institute” and the correlation of theenergy consumption by hospital type and the total floor space which is based on our survey.

Energy intensity(MJ/m 2 per year)

Private hospitals’ intensity by scale

m2

or

m

or

9m
99
9,
50

,0

00

-4
00
,0
40

e

2

2

9m

2

99
9,

,0
30

00

-3

9,

99

9m

2

9m
,0
20

00

-1
,0

00

-2

9,

99
10

8,

00

0-

9,

7,
000
6,

99

9m

9m

2

2

2

99

99

9m

2

5,
000
4,

000
2,

Be

lo

w

1,

3,

99

99

9m

9m

2

FY2005
FY2006

Scale (Total floor space: m 2 )From the “Operating Procedure of Energy Conservation in Hospitals” (Released by the Ministry of Health, Labor and Welfare in March, 2008)* Project Committee Investigation: Analysis based on the data of 973 hospitals including private hospitals (with more than 300 beds) which correspond to the designated factories
mentioned in the Act on the Rational Use of Energy (Energy Conservation Act), private hospital specific buildings (hospitals with total floor space of 2,000 square meters or more)
based on the Act on the Rational Use of Energy (Energy Conservation Act), and private hospitals with more than 50 beds (which includes specific generator including private
hospitals mentioned in the Act on Promotion of Global Warming Countermeasures).

Types of hospitals and energy consumption

Primary energy (thousand GJ/year)

Large

Total floor space (m 2, parking area excluded)

Total floor space (m 2, parking area excluded)

Mental/children/elderly hospitals etc.
less than 50 thousand square meters

Public/special hospitals etc. less than
50 thousand square meters
Primary energy (thousand GJ/year)

Acute care-oriented

Primary energy (thousand GJ/year)

Recuperation-oriented

Total floor space (m 2, parking area excluded)

5

Medium to large size hospitals
with short term (outpatient/operation) typePrimary energy (thousand GJ/year)

Medium to large size hospitals with long term Size of facility(hospitalization) medical examination type

Small

Total floor space (m 2, parking area excluded)

Based on the survey by the Energy Conservation Center, Japan in FY2004 (Number of answers: 237)

Characteristics of Energy Consumption in Hospitals

As to the hospitals in which we conducted energy conservation diagnosis, the energy consumption intensity
by hospital type is shown in the table below. The following trends are seen in general.

- University hospitals have large scale and intensity, while private
hospitals' intensity is small.
- The younger the building's age, the larger the intensity.
- Recuperation-oriented hospitals' intensity is about 70% of that ofacute care-oriented hospitals.
Total floor space(m2)

Number of beds
(beds)

index(MJ/m2 per year)

University hospital

75,700740

4,000

Public hospital

32,600400

3,100

Private hospital

25,800490

2,800

Less than 5 years

32,700410

3,500

6-24 years

34,500460

3,200More than 25 years

50,900580

2,700

Care-oriented

41,400490

3,300

Recuperation-oriented

16,400

360

2,400

Type

Administration

Building’s age

Charactermore than 0.3
0.275-below 0.3
0.25-below 0.275

Cumulative frequency

CO 2 emission intensity (t/me per year)

0.225-below 0.25
0.2-below 0.225
0.175-below 0.2
0.15-below 0.175
0.125-below 0.15
0.1-below 0.125

By hospital's character

More than 10
9.5-below 10
9-below 9.5
8.5-below 9

Administration
University hospital Public hospital Private hospital
4.93

4.43

4.30

Building’ s age
Less than 5 years
4.93

6-24 years
4.49

More than 25 years
3.81

8-below 8.5

Cumulative frequency

The figure in the right shows the annual energy
expense per unit floor space.
Also, the figure below describes the amount of
CO2 emissions per unit floor space.

Energy expense intensity (thousand yen/m 2 per year)

From the results of the Energy Conservation Diagnosis (FY2005-FY2007)

7.5-below 8
7-below 7.5
6.5-below 7
6-below 6.5
5.5-below 6
5-below 5.5
4.5-below 5
4-below 4.5
3.5-below 4
3-below 3.5
2.5-below 3
2-below 2.5
Below 2

Emergence frequency (number)

0.075-below 0.1
0.05-below 0.075
Below 0.05

Emergence frequency (number)

6

Energy Conservation Measures
by Hospitals Division■ Energy conservation depending on the characteristic of the division
Hospitals consist of multiple divisions. The following table indicates the average value of each divisionaccording to our investigation. As shown below, there is a unique characteristic in energy consumption ofeach division. It is essential to grasp the characteristic of the energy consumption by each division and to
take adequate measures.

Division structure and energy consumption
Division

Area ratio

Operationhour

Energyconsumption
rationWard

35%24hours34%

Outpatient13%9hours11%

Central consultation
division

22%

10hours29%

Supply division

8%

10hours

8%

Management
division

10%9hours8%

Kitchen2%

18hours5%

Common-use space

10%

24hours

5%This data is based on the data of 54 hospitals (Type 1 designated factories) according to the investigation on energy
consumption conducted by the Energy Conservation Center, Japan in 2003-2004.

7

Energy Conservation Measures
by Hospitals Division
Characteristic of the wards
Though this is a division with small energy density, 24 hours operated and large area ratio cause
the largest energy consumption among the divisions.
Energy consumption can be significantly changed by switching on/off the air conditioning of thegeneral patients rooms in the night-time. Also, due to personnel and their working hours, water
consumption is the largest.

Points for measures(1) Be careful not to cause excessive cooling or
heating.
(2) Turn off the air conditioning and open thewindow when the outside air is comfortable.
(3) Consider installing a four-tube system withzero-energy band control.
(4) Attach a water-saving top in a faucet used forwashing.
(5) Check and adjust the water supply pressure asneeded to prevent excessive pressure.
(6) Check whether the shower's water temperature
is adjustable. -> If not, consider a replacement.

Characteristic of the outpatient division
Though this is a division with a regular energy density, the energy consumption is about 10% of theoverall divisions due to short operation time.
With many comings and goings of people, outside air be brought to inside through the door way
leads to large air conditioning load.
Also, there is a significant difference in a number of people depending on the time.

Points for measures(1) Adopt a windbreak room at door way. (Offset
flow line is preferable.)(2) Consider shorter operation hours of the air
conditioning.
(3) Consider to increase/decrease the outside air
intake according to the number of patients byschedule control etc.
(4) Enable to switch the illuminance of the lighting
equipments, about three stages according to theconsultation hours.

8Energy Conservation Measures
by Hospitals Division
Characteristic of the central consultation division
With large area ratio and energy density, the energy consumption ratio is the second largest to
the ward, and also with the largest steam consumption due to sterilization purposes, this divisionconsumes the largest heat consumption in the hospital. Also, use of city water and hot watersupply mainly used for cleaning are large as well.
In addition, with many high-tech medical equipments operating even at night such as MRI,
standby power requirement is large, resulting in large electricity consumption at night.
Number of operations and steam consumption for autoclave(Scale which corresponds to a general hospital in Tokyo with 600 beds: 6 operating rooms)

1400
20

1200
1000

15

800
10

600
400

5

200
0

Fri

Sat

Sun Mon Tue Wed Thu Fri Sat
Day of the week

Sun Mon Tue Wed Thu

Number of operations and child-birth25

0From the investigation on energy status (FY2004) by the Energy Conservation Center, Japan

Time trend of MRI/CT electricity consumption(Scale which corresponds to a general hospital in the Koshinetsu district with 600 beds)
Weekdays

Saturdays

Sundays

The entire week

0.30
0.25
0.20
0.15
0.10

6:

4:
00

2:
00

0.00

00
8:
00
10
:0
0
12
:0
0
14
:0
0
16
:0
0
18
:0
0
20
:0
0
22
:0
0
24
:0
0

0.05
0:
00

(1) Conduct washing work efficiently.
-> Compile the same kinds,eliminate waste of water, and etc.
(2) Objects to be sterilized should be
washed well in advance.
(3) Be careful not to pack the
autoclave in too much.
(4) Preheat the outer tube of the
autoclave sufficiently.
(5) Conduct periodical cleaning andinspection of the autoclave.
(6) Consider minimizing the air
volume (to the extent that positive
pressure is maintained) of theoperating rooms when they are notused.
(7) Switch off the medical equipments
as possible during the nighttime
and holidays.

Electricity consumption (Wh/m2)

Points for measures

Steam consumption (kg)

1600

Time
From the investigation on energy status (FY2004) by the Energy Conservation Center, Japan

Electricity consumption during non-operating hours(standby power requirement) is large.
-> Wish to switch to weekend mode also at nighttime of weekdays, if possible.
Time trend of X-ray electricity consumption

9

Weekdays

Saturdays

Sundays

The entire week

1.20
1.00
0.80
0.60
0.40
0.20
:0
0
18
:0
0
20
:0
0
22
:0
0
24
:0
0

:0
0

16

:0
0

14

:0
0

12

00
8:

10

6:
00

00
4:

00
2:

00

0.00
0:

Electricity consumption (Wh/m2)(Scale which corresponds to a general hospital in the Koshinetsu district with 600 beds)

Time
From the investigation on energy status (FY2004) by the Energy Conservation Center, Japan

Electricity consumption during non-operating hours(standby power requirement) is large.
-> Wish to cut down power, except for emergency use.

Energy Conservation Measures
by Hospitals Division
Characteristic of the supply division
Time trend of steam/water (water/hot water supply) consumption in laundry room
(Scale which corresponds to a general hospital in the Koshinetsu district with 600 beds)

90
70
60

6
5

50

4

40

3

30

2

20
10

1

0

0

Water (water/hot water supply)
consumption (m3)7
Total of the daily consumption
Steam: 516kg
Water: 21m3 (including 6m3
hot water supply)

80

4:
00
5:
00
6:
00
7:
00
8:
00
9:
0
10 0
:0
11 0
:0
12 0
:0
13 0
:0
14 0
:0
15 0
:0
16 0
:0
17 0
:0
18 0
:0
19 0
:0
20 0
:0
21 0
:0
22 0
:0
23 0
:0
24 0
:0
0

Steam consumption (kg)Though with an average energy density,
the operation time of the overall division
corresponds to general business hours,
resulting in small energy consumption
ratio.
However, steam and water/hot watersupply are largely consumed forlaundry, cleaning/sterilization of beds
etc.
Also, electricity consumption arisingfrom the air conditioning(cooling)/ventilation system for
deodorizing the waste storage is large.

Time
From the investigation on energy status (FY2004) by the Energy Conservation Center, Japan

Points for measures(1) Review the temperature of washing water.
(2) Consider effective drying since it is no use thedryness above the indoor humidity.
(3) Conduct periodical cleaning of the lint screenand exhaust duct.
(4) Consider heat recovery from the laundry room.
(5) Air-tight doors should be employed to the waste
storage, and try to shorten the operation time of
the cooling/ventilation equipments.

Characteristic of the management division
Along with a small energy density inthe entire hospital, the energy
consumption ratio is also small due tothe division’s operation time, whichcorresponds to general businesshours. It has a similar characteristic asthat of a general office building. Dueto the evolution of OA and IT,
electricity consumption by computers
accounts for a large ratio.
In contrast, though the kitchen
attached to the dining room/coffee
shop has a similar characteristic as
the kitchen already mentioned, it isdifferent in a way that the loaddecreases significantly in theweekdays and the holidays.

Points for measures(1) Ensure thorough management of the OA
equipments.
Switch to stand-by mode during lunch break or
when leaving your desk for a long time.
The last one to leave the office should confirm
whether all the powers are turned OFF.
(2) Ensure thorough management of the window
shades.
During the winter, the last one to leave the officeshould close all the shades.
During the summer, the last one to leave theoffice should close the shades of the east and thewest windows.
(3) Ensure that the air-conditioning and lightings inunused meeting rooms etc. are turned OFF.

10

Energy Conservation Measures
by Hospitals Division
Characteristic of the kitchenThis is a division in which energy density is the largest
within a hospital. Since gas consumption for cooking
is large, plenty of outside air-intake is necessary for
combustion, as well as a large amount of energy isnecessary to treat them.
Also the refrigerators/freezers for food storage areoperating 24 hours, the energy consumption of them
can not be disregarded.
Thus, consumptions of steam and water/hot watersupply are large as well.

Gas/water consumption(Scale which corresponds to a general hospital in the Koshinetsu district with 600 beds)

Amount of
hot water supply

Amount of gas

Amount of water /hot water supply

14

Amount of consumption (m3)

Points for measures

Amount ofwater supply

12
10
8
6
4
2

00

00

21

00

20

00

19

18

00

00

17

00

16

15

00

00

Time

14

00

13

00

12

11

00
9

00

00
8

10

00

00
7

00
5

6

00
4

0

From the investigation on energy status (FY2004) by the Energy Conservation Center, Japan

Both gas and water are linked to the working hours.
-> Reduction of working hours is the point.

Time trend of the main kitchen’s electricity consumption(Scale which corresponds to a general hospital in the Tohoku district with 600 beds: Winter)

100
90
80
70
60
50
40
30
20
10
00
22
:

00
20
:

18
:0
0

16
:0
0

00
14
:

12
:

00

00
10
:

00
8:

00
6:

4:
00

00
2:

00

0
0:

Electricity consumption (kWh)(1) Frequently extinguish the pilot
flame of the gas appliance forcooking.
(2) Adjust the gas appliance to theadequate heating power for perfectcombustion.
(3) Increase/decrease the air flow ofthe exhaust fan and the outside airprocessing air-conditioning
according to gas consumption tominimize electricity consumption.
(4) Remove food leftovers before
washing to reduce water/hot watersupply consumption.
(5) Be careful not to pack in the
refrigerators/freezers for foodstorage excessively, and control
the number/time of openings.
(6) Check the installation status of theoutdoor condensing units ofrefrigerators/freezers to eliminate
short path or cross path.
(7) Conduct periodical maintenanceto check the air-tightness of therefrigerators/freezers doors, stains
on the condenser, and etc.
(8) Review the steps and thesequence of the work to minimize
the operation time in the kitchen.
(9) Consider installing IH cooking
equipments which are effective on
saving HVAC loads.

Time
Air conditioning

Exhaust air fan

Refrigerator

Hot/cold serving wagon

Lighting outlet
Kitchen equipment

From the investigation on energy status (FY2004) by the Energy Conservation Center, JapanThe air flow from the air conditioning (all fresh air) fans increases/
decreases in conjunction with the operation of the combustion appliances.

11

Major Methods for Energy
Conservation Measures in Hospitals■ Fuel-air ratio management of the boiler
Ensure thorough management of the air ratio of the combustion
equipments including boilers, etc. to save fuels
Energy conservation result by improving air ratio(A heavy oil, gas 13A, exhaust gas 450°C)

8
A heavy oil

7
Fuel reduction ratio (%)

The air ratio of the boilers in the business division isoften set to be high. With high air ratio, fuels are
consumed excessively.
According to the standards of judgment in the Act
on the Rational Use of Energy (Energy Conservation
Act), the target air ratio of the boiler with amount ofsteam less than 30t/hour is from 1.15 to 1.25.
Measurement of air ratio can be simply derived
from the oxygen concentration within the exhaustgas.
As shown in the right figure, when oxygen
concentration within the exhaust gas: 6% (air ratio
1.35) is adjusted to 3% (air ratio 1.2), fuels can besaved by about 4%.

Gas 13A

6
5
4
3
2
1
0

0

2

4

6

Oxygen concentration within exhaust gas (%)■ Measures for steam-related heat loss
Heat loss ofsteam isabout 20-30%!!

Trap inspection/
maintenancePrevent steam
loss by conducting
inspection/maintenanceon the steam traps.

Enforcement of
piping-related
heat insulation
Prevent heat loss
by employing
heat insulation to
the raw part ofsteam valves,
extension joints,
flanges, and etc.

Stop the supply
when unnecessary

Steam (for hot water supply)
consumption intensity(kJ/m2 per hour)

It is said that steam-related heat loss isabout 20-30% of the total loss.
The right figure indicates the time trend of
the hot water supply consumption and thesteam consumption for hot water supply,
based on our investigation on energy
consumption. Note that steam for hot watersupply is consumed even at midnight, when
there is no hot water supply demand. The
following measures are to be taken.

Hot water supply consumption intensity(L/m2 per hour)

Reduce steam-related heat lossTime
From the investigation on energy status (FY2004) by the Energy Conservation Center, Japan

As to systems inwhich steam is notnecessary duringholidays andnighttime, close
the valves at theheader’s outlet.

12

Major Methods for Energy Conservation
Measures in Hospitals■ Outside air cooling
As shown in the right figure, this is a method to take in a large amount of outside air when theoutside temperature is lower than the indoor temperature, and exhaust return air to outside
instead of return them to the AHU(Air handling Unit) .

Period in which outdoor air coolingis possible in each area

End

MiddleEnd

Nov.

Beginning

MiddleEnd

Oct.

Beginning

MiddleEnd

Sept.

BeginningEnd

MiddleMiddle

Aug.

Osaka

BeginningEnd

MiddleJul.

Tokyo

BeginningEnd

MiddleJun.

Sendai

Beginning

End

May

SapporoBeginning

MiddleEnd

Apr.

BeginningEnd

MiddleEnd

MiddleMar.

Beginning

Feb.

BeginningEnd

MiddleMiddleJan.

Beginning

AHU

Beginning

Specific enthalpy (KJ/kg)

Conventional method

Dec.

Fukuoka

Outdoor air cooling

Calculated from the average of the maximum value in the data of the Japan Meteorological Agency (FY2007)

A period in which outdoor air cooling is possible isdetermined by the indoor and outside air enthalpies. The
above figure is created based on the average of the
maximum value in the data of the Japan Meteorological
Agency (FY2007). Outdoor air cooling is enabled in Tokyo
from the middle of October to the middle of May.

AHU
From the website of Hitachi Plant Technologies, Ltd.

■ Night-purge
When airconditioned

Night

Morning

Stop

Conventional
Carries over to the next
day with the internallygenerated heat storedindoor.

Operation time forpre-cooling gets longer
due to the load of theheat stored indoor.

Replaces the indoor
stored heat withoutside air anddischarges to outdoor.

With no operation time
for pre-cooling since
there is no stored heatload.

Night-purge

Without ventilation

With nighttime ventilation

Case example of effective use of night-purge
According to Kajima Corporation

13

As shown in the above left figure, this is amethod for cooling the heat stored in concretebuilding frames or indoors at night (while theair conditioning is not operated) when theoutside temperature is low, in order to reduce
air conditioning load required for start-up.
The figure in the bottom left indicates thecomparison of the indoor temperatures of abuilding; with or without (standard) employing
night-purge. This method will be effective in a
management division, where heavily equippedwith OA equipments for clerical works and in
examination rooms, and a zone where heat isstored in internally installed equipments orbuilding frames, and air conditioning is turned
off at night. Consider employing this method
during the season or a day in which there is alarge difference between the “indoor
temperature of start-up air conditioning” andthe “outdoor temperature (from the point air
conditioning is turned off on the previous day
to the next day’s activation)”.

Successful Cases of the Energy
Conservation Measures in Hospitals■ Free cooling using outdoorair conditioning
A system to cool with outside air by using outdoor air processing
air conditioning to resemble a cooling tower.
In the right figure, stop the (1)refrigerator, (2) chilled water primary
pump, (3) cooling tower, and (4) coolingwater pump depending on the outside
air requirements, and open the (5)chilled water control valve is opened
and water is cooled with the (6) outdoor
air conditioner’s coiling coil. The chilledwater cooled by the outdoor air
conditioner is supplied to the (7) fan coilunit, etc. to be used for the air
conditioning. At the same time, since
the outside air is preheated by thechilled water coil, load of the (8) hot
water becomes small. In this example, arefrigerator of 600RT can be stopped,
resulting in an annual reduction of 170
thousand m3 of city gas, 220 thousand
kWh of electricity, and about 12 million
yen in energy cost.

Air conditioning for outdoor air processing

Chilledwater coil

Outside airHotwater coil

About 22°C

Transfers air toeach roomFan
Hot water
Cold water adjustment damper

Controller for
air conditioning
Controls

Fan coil unit, etc.

Chilledwater coilIndoor air

Hotwater coil

Returns
to indoor

Fan
Computer room,
meeting room, etc.

Chilled water primary header (return)

Chilled water secondary header (inlet)

Flow meter

Cold water secondary pump

Chilled water secondary header (return)

Chilled water primary header (inlet)
Bypass valve

From here under is
unnecessary whenusing zero-energy
cooling control.

Steam
Refrigerator
9.3 kW

Chilled water
primary pump
30 kW

Capacity with 600RT

Cooling
tower
45 kW x 2

Cooling water pump
Refrigerator
76 kW
9.3 kW

From the presentation of Energy Conservation Outstanding Case Examples (FY2004)

Wet-bulb temperature (°C)

A period in which free cooling is possible is determined by the outdoor wet-bulb temperature.
The below figure is created from the average of the wet-bulb temperature in the data of theJapan Meteorological Agency. In the previous example, the outdoor temperature is 9°C and thewet-bulb temperature is 6.5°C. Thus, the period in which free cooling is possible is assumed to
be a little longer. It should be worthful to consider employing this method if the outdoor air
conditioner has two coils and with cooling demands even in the winter.

SapporoSendai

Tokyo

Osaka

End

MiddleEnd

Nov.

Beginning

MiddleEnd

Oct.

Beginning

MiddleEnd

MiddleEnd

Sept.

Beginning

Aug.

Beginning

MiddleEnd

Jul.

Beginning

MiddleEnd

MiddleJun.

Beginning

End

May

Beginning

MiddleEnd

Apr.

BeginningEnd

MiddleEnd

MiddleMar.

Beginning

Feb.

Beginning

MiddleEnd

MiddleJan.

Beginning

Beginning

Period in which free coolingis possible in each area

Dec.

FukuokaCalculated from the average of the data of the Japan Meteorological Agency (FY2007)14

Successful Cases of the Energy Conservation Measures in
Hospitals■ Energy Efficiency Improvement of Refrigerator by Temperature Setting Change of Cold Water
There are some areas where the air conditioning is necessary through the year, such as medical
equipment room of MRI, CT, etc. or a laboratory room. Outside air cooling is effective for the air
conditioning of the winter season, but there are many running cases to use freezers for reasonsof the structure and the control. It is expected the refrigerator to run efficiently in the winterseason when the load becomes smaller than the summer season. This is the sample to set
coolant temperature low while cold water temperature high for inspection of improvement of COP
at a certain hospital.
A refrigerator shown in the right photograph was run with thefollowing mode, and the input (electricity) and the output (quantity of
production coldness) were measured. A direct wattmeter was
installed in a board as shown in the lower right photograph, and theelectric energy was recorded in a data logger. And the amount of coldheat was calculated from the outlet temperature of cold water
recorded on a central monitor board and the flow quantity measured
by the supersonic type flow meter temporary installed. wave
360RT Screw Chiller(3 aspect 400V/70kW/4 machines)
flowmeter.

NormalOperation

EnergySavingOperation

Temperature of Cold Water Outlet

7℃

12℃

Temperature of Coolant Inlet

25℃

18℃

Operation Mode
Temperature Conditions

Average
Electric
Runningof Heat
Power
Consumption
Time
Quantity Consumption/ Time

2006
2008

MJ
kW
Hr
795 115,859 1,791
767 72,659 2,015

57
34

Measuring Equipment

Coolant Temperature2007 16th Dec. (Sun.) 17th Dec. (Mon.) 18th Dec. (Tue.) 19th Dec. (Wed.) 20th Dec. (Thu.) 21th Dec. (Fri.)

C.O.P

3.86
6.20

Cold
Water

Coolant

℃
7.2
12.2

℃
25.0
17.8

22th Dec. (Sat.)Time

Coolant water supply temperature2007 16th Dec. (Sun.) 17th Dec. (Mon.) 18th Dec. (Tue.) 19th Dec. (Wed.) 20th Dec. (Thu.) 21th Dec. (Fri.) 22th Dec. (Sat.)2006 in the chart above means Dec.2005 to Feb.2006
2008 in the chart above means Dec.2007 to Feb.2008

Time

The chart below is a graph of the comparison of data of 2006 by the standard driving as a resultof energy saving driving carried out in 2008.
The Electric Power Consumption of the Refrigerator in December

2008

The Electric Power Consumption (kWh)

2006

5th

10th

15th

Comparison Between 2006 and 2008

15

20th

25th

30th

Successful Cases of the Energy Conservation Measures in
Hospitals■ The Driving Control of the Second Pump
Air-conditioning Load

Plural second pumps for cold water are installed at the large-scale
hospital, and various flow quantity controls are performed including
number control. The right figure showing the case of a certain
large-scale hospital is the case of which introduces the inverter
system to all pump from number control system + one inverter
system. The device characteristics was calculated by driving actual
survey data of (1) constant pressure force control and the (2)transformation force control with all inverter system, and simulation
was performed based on the driving results of last year. The bottom
chart shows the calculation results of four cases, that is bypass
dialect control system, one inverter + number control system,
constant pressure force control with all inverter and thetransformation force control system. It was recognized that 56%(about 70,000kWh/ year) reduction of power consumption from theoriginal system might be possible by performing the transformation
force control system.

Flow Rate - Connection with Header Pressure 9th May 2008 - 31st May 2008
PressureCalculation Value of Resistanceof the Device
Header Pressure for Cold Source

Air-conditioning Load

Flow Rate

Flow Rate - Connection with INV Input
Input

Header Pressure Setting forCold Source

9th May 2008 - 31st May 2008

Calculation Value of Powerby RateOperation Power for 2 Units(Power)Calculation Value of Pressure by Rate

Operation Power for 1 Unit
Operation Power for 3 Units

Calculation Value of Transformation
and Input

Flow Rate m3/h

Flow Rate m3/h

Upper figure shows the actual survey value and the theory values ofboth water supply pressure and the power consumption. They are
extremely correspondent to each other. The right chart shows device
characteristics provided from these data. In the case of large-scale
hospital which has plural second pumps, the most effective case isestimated when the system adopts the inverter system to all pumps
and run them with pressure control by flow rate.

Device Characteristic
The Number of Pumps CMH
The Number of Pumps
Resistance Coefficient 1
Resistance Coefficient 2
Control Pressure
Minimum Pressure
Hydrostatic Head
Power

kW

Minimum PowerkW

Power Coefficient
Pa -> m Conversion Coefficient

The Electric Consumption of
the Second Pump

Jan.

Feb.

Mar.

Apr.

Bypass Dialect

May.

Jun.

Jul.

One INV

Aug.

Sep.

Constant Pressure Power

Oct.

Nov.

Transformation Power

Dec.

16

Successful Cases of the Energy Conservation Measures in
Hospitals■ Intermittent operation of the outside air conditioning
There are numbers of patients in hospitals with weak resistance to infection. As to the air
conditioning, not only temperature and humidity but also air quality should be taken into
consideration. Thus, it may result in excessive operation with equipments large in scale.
It is essential to ensure safe and comfortable air environment while reviewing excessive operationof the equipments in order to prevent energy loss. As to the air conditioning/ventilation systems
that assure the air environment, there is a “Design and Management of Hospital Air-conditioning
Guideline (HEAS-02-2004)", set up by the Healthcare Engineering Association of Japan.
According to the guideline, requirements of the air quality should be as follows: the outside air
volume of the general clean area shall be 2 times/h (at minimum) against the indoor air volume,and the CO2 condensation of the indoor environment shall be less than 1,000 ppm, which is
mentioned in the Management Standard of Environmental Sanitation for Buildings. By complying
with the standard, it is essential to rationalize operation management of the air
conditioning/ventilation systems to promote energy conservation.
The following is an example of improving the outside air conditioning of a hospital and the energy
conservation results.
The two figures below show the result of measuring the time trend of the CO2 condensation after
shortening the operation time of the outside air conditioning of the internal medicine outpatient
waiting room in the first floor and the patients’ room in the third floor by four hours a day.
Environment degradation caused by intermittent operation of the air conditioning cannot be seenin either of the results.
2008
12/17 (Wed.)

Temperature in the internal medicine waiting room in the 1st floor of C ward
12/18 (Thu.)

12/19 (Fri.)

12/20 (Sat.)

12/21 (Sun.)

12/21 (Mon.)2008

CO2 condensation in the patients’ room 301 in the third floor of A ward
12/30 (Tue.)

12/23 (Tue.)

12/31 (Wed.)

1/1(Thu.)

1/2(Fri.)

1/3(Sat.)

1/4(Sun.)

1/5(Mon.)Outer air conditioning of 1st floor of C ward

Time

Time

The total rating and the total shaft power of the fan capacity of the 13 outside air conditioning
units in the general clean area-related excluding the operating room-related is 42.75 kW and 36
kW, respectively. By delaying the operation start time by an hour in the winter and by performingintermittent operation throughout the year, operation time is shortened by three hours a day,resulting in reduced fan power as calculated in the following:
36 kW x 1h/day x 120 days/year≒4,320 kWh/year
36ｋW×3ｈ/day×365days/year≒39,420ｋWh/year

43,740ｋWh/year

Thus, assuming that the electricity cost is 15 yen/kWh (flat rate), 43,740 kWh/year x 0.015
thousand yen/kWh ≒ 656 thousand yen reduction.
In addition, since heat quantity required for temperature/humidity processing of the outer air canbe reduced as well, the reduced amount will be larger. However, this is excluded becauseverification by actual measurement could not be conducted at this time.

17Effective Tools and Techniques for Promoting
Energy Conservation by Improved Operation
ECCJ provides tools and techniques for further energy conservation
useful for improving operations of large-scale buildings for business
use without charge.
The three tools and techniques are:(1)ESUM：Energy Speciﬁc Unit Management Tool
ESUM is computer software which estimates energy consumptions of a building and compares
the consumptions before and after implementing an energy conservation measure todemonstrate the energy reduction effect.

(2)TuBE：Tuning of Building Systems for Energy Conservation
TuBE is a document which defines how to select and carry out operational improvement actions
among various energy conservation measures.

(3)EAST：Energy Analysis Support Tool
EAST is computer software which compiles operation process data of air-conditioning units and heatsource equipment and make a graphic presentation of the trends to help you analyze their operation
conditions.

Combined use of the above three tools helps your making smoother energy conservation
activities throughout the necessary steps for the activities; analysis on operation status andconditions, selection of improvement method, estimation of its effectiveness, andimplementation of the measure.

How to obtain more detailed information onenergy conservation of buildings for business use
ECCJ has a website to provide various kind of information on energy
conservation of buildings.
The site includes:
inputs from actual users of tools (e.g. ESUM and EAST) useful for enhancing your energy
conservation activities for buildings;
various forums for different types of facilities (e.g. office buildings, commercial facilities, hotels,
and hospitals), which serve as an information exchange forum among members; andinvitations to seminars and lecture classes which provides information on successful cases ofimproved energy conservation of buildings for business use and examples of effective use ofvarious tools as well as materials for those seminars and lectures

Owners of buildings for business use
Persons in charge of energy conservation promotion
Persons in charge of energy facility management
Energy conservation business operators

Open spacefor energy
conservationin buildings

18

The Energy Conservation Center, Japan

Head Office: 3-19-9, Hatchobori, Chuo-ku, Tokyo,
104-0032 Japan
Tel: 81-3-5543-3018 Fax: 81-3-5543-3022

This is translated from the original Japanese document.
For precise information and nuances, please refer to the original.
Copyright (C) The Energy Conservation Center, Japan 2010 All rights reserved

2010.03