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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
Source: Japan Valve Manufacturers' Association http://www.j-valve.or.jp/
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
Source: Japan Valve Manufacturers' Association http://www.j-valve.or.jp/
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
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
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 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
Standard B2(Being standardized)
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
Standard B2(Being standardized)
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
24
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