showerhead amenities for reduced energy use and

Showerhead amenities for reduced energy use and standardization of hot water conservation

Masayuki Mae Associate Professor, The University of Tokyo

Akinori Suzuki Tokyo Gas Company, Ltd.

Yuhi Murakami Graduate student, Tokyo University of Science

Yuki Mori Graduate student, Tokyo University of Science

Takashi Inoue Professor, Tokyo University of Science

Shizuo Iwamoto Professor, Kanagawa University

Takashi Kurabuchi Professor, Tokyo University of Science

Masayuki Otsuka Professor, Kanto Gakuin University

Japan Valve Manufacturers’ Association

Nov 3-5, 2013 At ACEEE Hot Water Forum, Atlanta, GA

2

Energy consumption trends in Japan

・Industrial sector: Improved energy savings as a result of oil shock; 0.9 times 1973 level・Civilian sector: Seeking increased convenience and comfort; 2.4 times 1973 level

Revised energy standards, resulting from the Great East Japan Earthquake

Source: Energy Whitepaper 2013, METI

0.0

100.0

200.0

300.0

400.0

500.0

600.0

0

2

4

6

8

10

12

14

16

18

73 75 80 85 90 95 00 05 11

（1018J）

（年度）

(兆円、2005年価格）

42.8%

19.6%

23.3%

x2.4 from increased

GDP, 1973–2011

Business

14.2%

Transport

Residential

Industrial65.5%

9.2%

16.4%

8.9%

x1.9

Increase(Fiscal 1973

→2011)

x2.8

x0.9

x2.1

x2.4

Drastic enhancement of energy-saving and power-saving measures

Fisical year

Trillion yen

3

Source: Energy Whitepaper 2013, Agency for Natural Resources and Energy

Source: Nakahama et al. (2009) “Measurement of bathtub water consumption for bathing (Part 4),” Proceedings of the Air Conditioning and Sanitary Engineers Annual Meeting

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Shower

108L

Non-bathfaucet

100%

90%

80%

70%

60%

50%

40%

30%

20%

10%

0%

120L

149L

Bath

Residential energy consumption in Japan

Residential energy consumption breakdown Hot water consumption, 4-member family (n=47)

Energy-saving measures are needed in the civilian sector

From regulation of only residential insulation to primary energy regulation

Fiscal 201138,358×

106 J/home

Heating28.3%

Kitchen8.1%

Lighting, etc.34.7%

Cooling2.2%

Hot water28.3%

4

Residential energy reduction attempts in Japan

(Old) energy conservation standards

Amended energy conservation standards

1980

Revision

Oil shock

Introduction of (voluntary) standards, based on judgment of home builders・ Definition of hot water equipment (standards A (manual cutoff) / B (low flow spout))・Addition of primary energy consumption standard to insulation standards

Rational use of energy resources1992 New energy-saving standards

Next-generation energy-saving standard

Strengthened residential standards for primary energy consumption in addition to envelope thermal performance Hot water / AC / Ventilation / Lighting / Elevators

・High-efficiency water heaters・High-insulation bathtubs・Solar water heaters・Installation/replacement of low-use hot water equipment

1999

2006 Revision

2009

2013

Meeting standards requires… High energy-saving effects for construction costs; rapid adoption expected

Water-saving standards A1 (manual) / C1 (water priority spout)

Reconsideration of standard B1（low-flow spout)

New consideration of standard B2 (revised low-flow spout)

Currently, best-effort; mandatory in 2020

Low-flow water discharge standards in Japan

Definition Flow rate [L/min] MoreLess

Conditions Test conditions Shower sprayed onto chest areaReason: Spraying on face is likely to result in lower flow than in typical use

Subject conditions At least 10 subjects, approx. equal division of sexesReason: To prevent differences in spray amounts due to sex

Optimal flow Max. satisfactory flowMin. usable flow Max. usable flow

Reason: 1. Taking the mean of optimal flow (1), (4), and (7) considers variation due to measurement conditions. (4) is likely overly large, (7) overly small.

2. (2)(3)(5)(6) not needed for water reduction devices, but measured to compensate for variation in perceived optimal flow rate.

Optimum flow rate is the average of (1), (4), and (7)

Flow

Reduction

Flowmeasurement

method

Avg. optimal flow as measured by monitorCurrent typical flow rate (10 L/min)

Voluntary amenity standards by the Japanese Valve Manufacturers' AssociationQuantitative metrics under consideration for standardization

5

(1) Optimal flow (initial)(2) Max. satisfactory flow(3) Max. usable flow(4) Optimal flow(5) Min. satisfactory flow(6) Min. usable flow(7) Optimal flow

Source: Japan Valve Manufacturers' Association http://www.j-valve.or.jp/

Reduction ratio = (1 – ) x 100

Min. satisfactory flow

(2009 measurement method)

StandardStandard of Judgment for Residential

Construction Clients （2009）

Low-energy standards for homes and buildings

Energy code 2013

DefinitionItems fulfilling reduction standards according to the monitoring method established by the Japan Valve Manufacturers Association

Items meeting standards for low-water construction

Certification Manufacturer measurement and evaluation JIS measurement and certification

Typ

e an

d e

ffec

t

Manualstoppage

(Type A)

Low-flowfaucet

(Type B)

Combined

Japanese shower standards

Low-flow faucet standardscurrently being established

Water is easily stopped by manual operation 20% reduction

Optimal flow of 8.5L/min or less

Push button faucet

Switch shower

Switch

32% reduction


Currently being established

6

15% reduction Spray shower(Low-Flow)

International shower standards

FLOW RATE OTHER REQUIREMENTS STANDARD

Japan Mandatory

Voluntary Common: 10L/min(Optimal flow rate)Hot water saving: Type A ⇒ Quick-stop Function

Type B ⇒ 8.5L/min(Optimal flow rate)Type A B ⇒ Type A and Type B

Effectiveness and comfortOptimum pressure calculated

Japan ValveManufacturers’ Association

USA Mandatory Common: Max. 9.5 L/min(2.5 gpm) at 550 kPaHigh efficiency: Max. 7.6 L/min (2.0 gpm)

Min. 75% of max. at 550 kPa75% of max. at 410 kPa60% of max. at 140 kPa

Spray force: Min. 0.56 N (2.0 oz) @ 140 kPaSpray coverage: ≤75% (φ50～100 mm)

≥25% (φ50～150 mm)

ANSI/ASMEA112.18.1

Voluntary Max. 7.6 L/min (2.0 gpm)Min. 75% of max. at 550 kPa

75% of max. at 310 kPa60% of max. at 140 kPa

EPAWaterSense

High efficiency (prerequisite): 7.6 L/min (2.0 gpm)Very high efficiency (2pt): 6.6L/min (1.75 gpm)

LEED (2009 v3)

EU Mandatory Water run through apparatus and flow rate calculated Type 1: (0,3 + 0,02) MPa (3 + 0,2) barType 2: (0,01 + 0,005) MPa (0,1 + 0,05) barRecord flow rate Q after stabilization

Thermal shock testLeakage testMechanical strength test Rotary connection test

EN1112(2008)

Voluntary Min. flow rate: 6 L/min; max. flow rate: 12 L/min. A and B Rating two criteria: volume and temperaturetwo stars for each evaluation criterion is the best possible.A= Maximum efficiency at approx. 6L/min <9L B=>9L<12L

WELL (2011)

US, EU, etc.: Regulations and restrictions based on physical quantity measurements

Japan: Evaluation of optimal flow based on industry standards (enacted 2009, voluntary)

Highly reproducible water discharge force standards that preserve amenity are needed (2013)

7

2013 Currently, best-effort; mandatory in 2020

2009

Problems in previous cases

• Most showers in Japan are handheld– Distance between showerhead and body is not fixed

• Excluding load of water droplets on plate

8

0.0

1.0

2.0

3.0

4.0

5.0

6.0

Z905S

Z905SMC

S3950-

82X

S3950-

80X

S31B-80X

S329GB-

80X

TH770C

THC24C

THC10

THY475G

通販A社

通販B社

通販C社

［°］

TO TO

KVK

三栄水栓

13 retail market showerheads (sample)

Pla

te r

evo

luti

on

[d

eg.]

U.S. EPA evaluation testing #1（Watersense）

Water receiving plate

6.0

5.0

4.0

3.0

2.0

1.0

0.0


K Co. S Co.

Sho

wer

A -B

T Co.

-C

-D -E -F

-G

-H -I -J

-K

-L

-M

Testing Maker

9

Studies on physical properties of showers (Japan)

“Experimental Study on the Usability of Residential Hot Water Supply System : Part 2-Showering and Bathing” (Kamata et al.)

“Study on methods of designing shower heads” (Kondo et al.)

“A Study on the Design Requirements of Equipment for Taking a Shower”(Murakawa et al.)

Measurement perpendicular to spray force

Measurement 45° to spray force

Optimal shower flow rate is proportional to the nth power of the total hole area

Need to analyze low-water showerheads implementing various mechanisms

Need to exclude factors affecting load other than shower spray

𝑄𝑇…Optimum flow 𝐴…Total hole area𝐶，𝑛 …Experimental constants

𝑄𝑇 = 𝐶𝐴𝑛

10

Spray force test conditions (current draft)

Receiving plate

Spray distance (to receiving plate)

Spray force measurement device

150±15mm

Horizontal directionSuppress influence of water load

Spray

Spray adhesion point (central)

Dimensions: 200×200 mm, t = 3 mmMaterial: Acrylic

Rated capacity: 20 NResolution: 0.01NPrecision: ±2% FSSampling period: 50ms

Spray angle

Permissible range (a): 0±20mm

Permissible range (b): 0±15°

Spray adhesion point(central)

(a)(b)

Spray angle

Flow rate

7.0, 8.5, 10L/min Permissible range: ±0.2L/min

12.2 26.112.9

25

1829.6

34

18.0 26.62

7.0

18.9 26.5 18.0 19.5

⑦ ⑧ ⑨ ⑩ ⑪ ⑫

6.5 6.5 6.2 5.8 6.0 不明

シャワー番号

散水板外観

メーカー表示最適流量[L/m in]

① ② ③ ④ ⑤ ⑥

10.5 8.5 8.3 7.8 7.0 6.8

シャワー番号

散水板外観

メーカー表示最適流量[L/m in]

Showerheads used in the experiment

Air added to hot water, increasing volumeBuilt-in impeller releases water intermittently

11

Manufacturer-stated optimal flow: Optimal flow results based on Standard of Judgment for ResidentialConstruction Clients in 2009(mean of 3 companies).

Showerhead

Showerhead

Manufacturer-statedoptimal flow

Showerhead

Manufacturer-statedoptimal flow

Waterdispersion

plate

Waterdispersion

plate

Unknown

No water-saving mechanism (Typical example of showerheads currently in use)①：

②～⑫：Commercially available water-saving showerheads⑧，⑨:

⑩ :

Relation between spray force and flow

– Spray force proportional to square of flow rate

– Proportionality constant C is proportional to the inverse of the total hole area

→By knowing proportionality constant C, the spray force at a given flow can be calculated

12

R2=0.933

Total hole area “A” [㎟]

① ② ③ ④ ⑤ ⑥ ⑦ ⑧ ⑨ ⑩ ⑪ ⑫

Pro

po

rtio

nal

ity

con

stan

t “

C”

Measuring spray force at 3.0, 5.0, 6.5, 8.5, 10, 14 L/min

F=CQ2

F: 全吐水力(N) Q=流量(L/min)

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

0 5 10 15 20

No water-saving mechanism(①)

Water flow rate “Q”[L/min]

𝐹 = 𝐶𝑄2

Tota

l spr

ay forc

e “F

”[N

]

0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

0 5 10 15 200.000

0.005

0.010

0.015

0.020

0.025

0 10 20 30 40 50 600.000

0.010

0.005

0.015

0.020

0.025

10 20 30 40 50 600

𝐶 =𝜌

2𝐴𝜌…water densityWater temp: 40℃

No water-saving mechanism(①)

Finding optimal flow (subject experiment)

13

4 showerheads

Flow adjustment valve

Temp. adjustment valve

-3 -2 -1 0 +1 +2 +3

Veryuncomfortable

UncomfortableSlightly

uncomfortableNeutral

Slightlycomfortable

ComfortableVery

comfortable

DressingRoom

BathingRoom

Instantaneous gas water heaters

(60℃)

Hot waterpipe

18

48

140017003100

Showerhead×4

Valve

Data logger

Data logger

(25℃)

Test period

Test location

Subjects

Men and women (20s): Nos. ①–⑫

Men (50s): Nos. ①, ②, ⑥, ⑩

Temp. Laboratory temp: 25 °C ; Water temp: Freely set by subject

Posture Sitting with showerhead handheld

Oct–Nov 2012

Univ. of Tokyo, School of Engineering, Bldg. artificial environment laboratory bath unit

10 men (20s), 10 women (20s), 10 men (50s); 30 people in total

Showerhead

Conditions

Artificial environment lab. bath unit (25℃)

Body part Parameter Item Definition

Max. satisfactory flow Upper limit of flow allowing comfortable use

Optimal flow Ideal flow level

Min. satisfactory flow Lower limit of flow allowing comfortable useChest

Head

Combined

Flow

SatisfactionEntire body

10

.5

8.8

10

.3

7.8

7.5

6.1

7.2

7.8

7.7

7.3

7.3

5.5

10

.1

8.4

10

.2

8.3

7.4

5.9

7.9

7.6

7.6

7.2

6.4

5.4

12

.1

10

.6

8.3

8.4

10

.3

8.6

10

.2

8.1

7.4

6.0

7.5

7.7

7.7

7.2

6.9

5.5

02468

101214161820

① ② ③ ④ ⑤ ⑥ ⑦ ⑧ ⑨ ⑩ ⑪ ⑫

20代男性平均(N=10) 20代女性平均(N=10) 50代男性平均(N=10) 20代男女平均

Optimal flow results by showerhead

14

Chest

Op

tim

al f

low

[L/m

in]

Showerhead

1820

1416

1012

68

24

0① ② ③ ④ ⑤ ⑥ ⑦ ⑧ ⑨ ⑩ ⑪ ⑫

Showerhead

12

.9

10

.2

11

.9

10

.2

9.4

7.7

9.3

9.6

9.4

8.6

8.1

7.3

11

.8

10

.1

11

.7

9.6

8.8

6.9

8.4

9.0

8.5

8.0

6.9

6.8

14

.3

11

.5

9.5

9.9

12

.3

10

.2

11

.8

9.9

9.1

7.3

8.9

9.3

8.9

8.3

7.5

7.0

02468

101214161820

① ② ③ ④ ⑤ ⑥ ⑦ ⑧ ⑨ ⑩ ⑪ ⑫

20代男性平均(N=10) 20代女性平均(N=10) 50代男性平均(N=10) 20代男女平均

① ② ③ ④ ⑤ ⑥ ⑦ ⑧ ⑨ ⑩ ⑪ ⑫

Op

tim

al f

low

[L/

min

]

1820

1416

1012

68

24

0

Head AVE＋σ

AVE－σ

σ:標準偏差

Men (20s, N=10) Women (20s, N=10) Men (50s, N=10) Mean

Ave.+σ

Ave.-σσ: Standard deviation

Optimal flow: Averages by type

Men(20s)＜Men(50s) Chest＜Head

15

8.7 8.5

0

5

10

15

20

男性20代女性20代

最適流量

[L/m

in]

9.1 10.9

男性20代男性50代

ShowerMean of ①–⑫

7.7 9.2 8.9

0

5

10

15

20

胸頭全身

15

20

5

10

0

15

20

5

10

0

Op

tim

al f

low

[L/

min

]

Op

tim

al f

low

[L/

min

]

*Finding optimal flow for washing the entire body

Men and Women (20s)

15

20

5

10

0

Op

tim

al f

low

[L/

min

]

8.7 8.5

0

5

10

15

20


最適流量

[L/m

in]

9.1 10.9


8.7 8.5

0

5

10

15

20


最適流量

[L/m

in]

9.1 10.9


ShowerMean of ①②⑥⑩

Men in 20s and 50s By body part (head/chest/entire body)

Little difference

※Men (20s) Women (20s) Men (20s) Men (50s) Chest Head *Entire Body

Free bathing experiment and comparison

6

7

8

9

10

11

12

13

14

6 7 8 9 10 11 12 13 14Mean flow in free bathing experiment [L/min]

Op

tim

al f

low

[L/

min

]

Chest

13

14

11

12

9

10

7

8

676 98 1110 1312 14

For men and women in their 20s, showerhead usage appraisal can be determined from optimal flow at chest area and level of satisfaction

16

Mean flow in free bathing experiment: Near optimal chest flow

① ② ⑩

10.5 8.8 7.7

10.5 8.8 7.3

12.9 10.2 8.6

12.0 10.1 7.6

Optimal flow for chest

Optimal flow for head

Showerhead

Optimal flow for full body

Mean flow

in free bathing experiment

Test period

Test location

Subjects

Showerhead Nos. ①, ②, ⑩Temp Laboratory temp.: 25 °C; Water temp.: Freely set by subject

Order of actions As per subject's normal showering behavior

Nov 2012

Univ. of Tokyo, School of Engineering, Bldg. artificial environment laboratory bath unit10 men (20s; same subjects as in optimal flow tests)

Conditions

0.67 0.66 0.72 0.70 0.69 0.59

0.80

0.48 0.48 0.64

0.94

0.57

0.00.20.40.60.81.01.2

① ② ③ ④ ⑤ ⑥ ⑦ ⑧ ⑨ ⑩ ⑪ ⑫

10.3 8.6

10.2 8.1 7.4

6.0 7.5 7.7 7.7 7.2 6.9

5.5

0

5

10

15

Spray force at optimal flowSpray force can be used as an index for determining optimal flow

Spray force around 0.7 N at optimal flow

For showerheads like ⑧ and ⑨ that add air, optimal flow is below 0.5 N

0.67 0.66 0.72 0.70 0.69 0.59

0.80

0.48 0.48 0.64

0.94

0.57

0.00.20.40.60.81.01.2

① ② ③ ④ ⑤ ⑥ ⑦ ⑧ ⑨ ⑩ ⑪ ⑫

10.3 8.6

10.2 8.1 7.4

6.0 7.5 7.7 7.7 7.2 6.9

5.5

0

5

10

15

Flo

w [

L/m

in]

0

5

10

15

① ② ③ ④ ⑤ ⑥ ⑦ ⑧ ⑨ ⑩ ⑪ ⑫

Tota

l sp

ray

forc

e [N

]

*Mean flow values for men and women in their 20s at chest area

0.7 N

Total spray force at optimal flow

Optimal flow & Range of satisfactory flow

1.0

1.2

0.6

0.8

0.2

0.4

017

Max. satisfactory flow (mean)

Min. satisfactory flow (mean)

Optimal Flow (mean)

𝐹 = 𝐶𝑄2

0.46

0.64 0.50

0.77 0.90

1.18

1.01

0.59 0.59

0.88

1.45 1.37

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

① ② ③ ④ ⑤ ⑥ ⑦ ⑧ ⑨ ⑩ ⑪ ⑫

8.5

L/分の全吐水力

(計算値

)（N）

0.455

0.643

0.499

0.773

0.903

1.185

1.012

0.585 0.592

0.881

1.445 1.366

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

① ② ③ ④ ⑤ ⑥ ⑦ ⑧ ⑨ ⑩ ⑪ ⑫

8.5L

/ 分における全吐水力

[N]

シャワーヘッド①～⑫

No water-savingmechanism （①）

18

Total spray force at 8.5 L/min (15% reduction)Standard B1

Air included in water (⑧⑨)

Standardized using total spray force at flow of 8.5 L/min

B-1 specifies spray force of 0.6 N or higher at 8.5 L/min

B-2 will add supplementary items

Spray force at 8.5 L/min flow

Tota

l sp

ray

forc

e at

8.5

L/m

in [

N]

-1.0

-0.5

0.0

0.5

1.0

1.5

2.0

-1.0 -0.5 0.0 0.5 1.0 1.5 2.0

Overall and by-part satisfactionSatisfaction: Chest < Head

Total satisfaction: Similar to chest satisfaction

19

-1.0

-0.5

0.0

0.5

1.0

1.5

2.0

-1.0 -0.5 0.0 0.5 1.0 1.5 2.0

Sati

sfac

tio

n (

ches

t)

Total satisfaction

Sati

sfac

tio

n (

Hea

d)

Total satisfaction

+1.5

+2.0

+0.5

+1.0

-0.5

0.0

-1.0-0.5-1.0 +0.50.0 +1.5+1.0 +2.0

No water-savingmechanism （①）

No water-savingmechanisms （①）

+1.5

+2.0

+0.5

+1.0

-0.5

0.0

-1.0-0.5-1.0 +0.50.0 +1.5+1.0 +2.0

① ② ③ ④ ⑤ ⑥ ⑦ ⑧ ⑨ ⑩ ⑪ ⑫

Standard B2(Being standardized)

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

0

5

10

15

20

① ② ③ ④ ⑤ ⑥ ⑦ ⑧ ⑨ ⑩ ⑪ ⑫

32.521.510.50-0.5-1-1.5-2-2.5-3平均値

05

101520

① ② ③ ④ ⑤ ⑥ ⑦ ⑧ ⑨ ⑩ ⑪ ⑫

-3 -2.5 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 2.5 3

Chest satisfaction, appraisers, and mean values

Head satisfaction is overall high, due to be less sensitive by hair.

Water-saving showerheads show possibility for lowering water use while maintaining satisfaction

① ② ③ ④ ⑤ ⑥ ⑦ ⑧ ⑨ ⑩ ⑪ ⑫

Num

. re

sponde

nts

Mean

sat

isfa

ctio

n (

chest

)

-2.00

-1.50

-1.00

-0.50

0.00

0.50

1.00

1.50

2.00

0

5

10

15

20

1 2 3 4 5 6 7 8 9 10 11 12

-2.00

-1.50

-1.00

-0.50

0.00

0.50

1.00

1.50

2.00

0

5

10

15

20

1 2 3 4 5 6 7 8 9 10 11 120

5

10

15

200

5

10

15

20

Num

. re

sponde

nts

+2.0+1.5+1.0+0.5

-1.0-1.5-2.0

0.0-0.5

+2.0+1.5+1.0+0.5

-1.0-1.5-2.0

0.0-0.5

Mean

sat

isfa

ctio

n (

head

)

Chest

Head

Low HighSatisfaction

20


Mean

-1.0

-0.5

0.0

0.5

1.0

1.5

2.0

(10)

(5)

0

5

10

15

20

① ② ③ ④ ⑤ ⑥ ⑦ ⑧ ⑨ ⑩ ⑪ ⑫

21

Single-hole spray force at optimal flow

① ② ③ ④ ⑤ ⑥ ⑦ ⑧ ⑨ ⑩ ⑪ ⑫

Sin

gle-

ho

le s

pra

y fo

rce

at 7

.0L/

min

[N

/ho

le]

0.015

0.020

0.005

0.010

0


1.5

2.0

0.5

1.0

0

-1.0

-0.5

Single-hole spray force at 7.0L/min

Mea

n s

atis

fact

ion

(C

hes

t)

Single-hole spray forceat 7.0L/min

Mean satisfaction (chest)at optimal flow

Single-hole spray force [N/hole] ＝Total spray force [N]

Number of holes

Use the total spray force at 7.0L/min

Single-hole spray force of unsatisfied Showerhead (⑥,⑫) tends to be strong

•

•

•

•

22

Summary

・Spray force is proportional to square of flowProportionality constant C is proportional to the reciprocal of the

total hole area・Spray force at optimal flow is approx. 0.7 N・ Flow and satisfaction in actual use can be obtained from chest results

Subject testing

Standard B1 (low-flow spray) conditions

・Total spray force is at least 0.6 N at 8.5 L/min (15% reduction)

Standard B2 (revised low-flow spray) conditions

・Revision expected to use single-hole spray force (under consideration)

23

Future directions

Energy code 2013(Low-flow spray

standards)

201310/1

20144/1

Repealed

Enacted Full enactment

201410/1

20154/1

[Residential]

Pre-revision low energy standards

Revised low energy standards

Standard B-18.5 L/min (15% reduction) or less

(Transitional measures)

Standard B-2 7.0 L/min (30% reduction) or less

Begin operation

Present

Acknowledgements: This study is the result of the activities of the Better Living Foundation's committee for research on further improvements to energy efficiency in residential hot water supply systems. We express our deepest thanks to the committee members and other who helped us with this research.

Use fixed-flow valves

Begin operation

Under Planning

Announced

Announced

Announced

20141/1

吐水力試験各規定の理由

項目規定（案）理由

吐水方向横向き（受水板と散水板が平行になるようにする。）

下向きにすると、受水板に水が溜まるため、荷重に影響が出る恐れがある。また上向きにすると、受水板にあたった水が散水板に滴下してシャワーの勢いに影響を与える恐れがある。

吐水距離150mm（受水板から散水板まで）

吐水距離100ｍｍを超えたあたりから荷重値が安定するため。

受水板 □200mm、t=3 材質：アクリル板

シャワーの流線を全て受けることができる大きさ（吐水距離150mm位置でのシャワー範囲を想定）

プッシュプルゲージ

最大20N、±0.2%F.S. 測定器の精度によるバラツキをなくすため。

測定のタイミング安定範囲のピーク値

25

26

【距離と荷重の関係(流量別)】

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

50 100 150 200 250 300

距離[mm]

荷重[N]

10.0ℓ/分

8.5ℓ/分

6.5ℓ/分

【流量と荷重の関係(距離別)】

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

6 7 8 9 10 11流量[ℓ/分]

荷重[N]

50mm

100mm

200mm

300mm

【着水点ズレと荷重の関係(流量別)】

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

6.5ℓ/分 8.5ℓ/分 10.0ℓ/分

荷重[N]

中心(±0) オフセット(+40mm)

①距離と荷重の関係

②流量と荷重の関係

③着水点のズレと荷重の関係

【吐水角度のズレと荷重の関係(流量別)】

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

6.5ℓ/分 8.5ℓ/分 10.0ℓ/分

荷重[N]

中心(±0) 15度 30度

④吐水角度のズレと荷重の関係

吐水力測定時の誤差要因検証結果

showerhead amenities for reduced energy use and

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