Development and Evaluation of A

Test Method for Shower Heads

U S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Engineering Laboratory

Center for Building Technology

Washington, DC 20234

December 1982

Issued February 1983

Sponsored by:

iQC_^Jfice of Policy Development and Research

IlUO

U56

62-2630

1982

S. Department of Housing and Urban Development

ashington, DC 20410

NBSIR 82-2630

DEVELOPMENT AND EVALUATION OF A

TEST METHOD FOR SHOWER HEADS

RATIONAL OF STANDARDS

LIBRARY MAR ig f9 83

r\oVoxLc_ . - c\ f c. Glc, o

ulSLp

C.'S-'

Paul Kopetka

Lawrence Galowin

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Engineering Laboratory

Center for Building Technology

Washington, DC 20234

December 1 982

Issued February 1983

Sponsored by:

Office of Policy Development and Research

U.S. Department of Housing and Urban Development

Washington, DC 20410

U.S. DEPARTMENT OF COMMERCE, Malcolm Baldrige, Secretary

NATIONAL BUREAU OF STANDARDS, Ernest Ambler. Director
. ' • • • ...
ABSTRACT

A proposed test method for the evaluation of low-flow shower heads or flow-restrictor-modified shower heads was developed. The test method

provides for the measurement of the principal operating characteristics, i.e.,

pressure-flow rate dependency and the shower spray distribution. The requirements for laboratory instrumentation suitable for application to the apparatus

and the procedures for testing were established. A water collection device,

"sector rig", was designed and constructed for the measurement of spray distribution patterns. Experiments were conducted with a small number of shower heads

to determine the suitability of the proposed test method. The experimental

results indicated the applicability of the method for measurement of spray

distribution patterns and other conventional hydraulic performance parameters.

A proposed test method for evaluation of shower heads was prepared based upon

the analysis of the test results. The test method includes the specification

of instrumentation, apparatus, procedures, measurements, and data reduction.

Key words: plumbing; shower heads; water conservation; water supply devices.

iii
PREFACE

This report is one of a group documenting National Bureau of Standards (NBS)

research and analysis efforts in developing water conservation test methods,

models for technical and economic analysis, and strategies for implementation

and acceptance of practices. This work is sponsored by the Department of

Housing and Urban Development, Office of Policy Development and Research,

Energy, Building Technology and Standards Divisions, under Interagency

Agreement H-48-78.

Iv
TABLE OF CONTENTS

Page

ABSTRACT iii

PREFACE iv

LIST OF FIGURES vii

LIST OF TABLES viii

1. INTRODUCTION 1

2. EXPERIMENTAL APPROACH 4

2.1 Laboratory Procedures 4

2.2 Apparatus 6

2.2.1 Water Delivery System 6

2.2.2 Mixing and Conditioning System 7 2.2.3 Shower Head Mounting/Clamping Device 7 2.2.4 Shower Spray Collection Device - Sector Rig 7

2.3 Instrumentation 8

2.4 Test Procedure 9

2.5 Data Reduction 10

3. TEST RESULTS 12

3.1 Water Distribution 12

3.1.1 Radial and Circumferential Water Distribution 12

3.1.2 Measured and Metered Water 13

3.2 Shower Head Orientation 13

3.3 Water Flow Rate vs Pressure 14

4. RECOMMENDATIONS FOR IMPLEMENTATION OF SHOWER HEAD TEST METHOD 15

4.1

Test Method Guides 15

4.1.1 Shower Heat Test Configuration 15

4.1.2 Test Instrumentation 15

4.1.3 Testing and Data Recording 16

4.1.4 Results 18

5. CONCLUSIONS 20

6. REFERENCES 21

v
TABLES OF CONTENTS (Continued)

Page

APPENDIX A. WATER COLLECTION DEVICE CALIBRATION PROCEDURE AND RESULTS .. 36

APPENDIX B. ALTERNATIVE METHODS OF WATER DEPTH MEASUREMENT 38

APPENDIX C. WATER COLLECTION DISTRIBUTIONS 41

vi
LIST OF FIGURE^

Page

Figure 1. Water collection device - "sector rig" - geometry and

dimensions 28

Figure 2. Shower head test configuration 29

Figure 3. Distribution of water collected in sector rig compartments .. 30

Figure 4. Distribution of water collected in sector rig compartments .. 31

Figure 5A. Measured vs metered water - warm water 32

Figure 5B. Measured vs metered water - hot water 32

Figure 6A. Water flow rate vs pressure 33

Figure 6B. Water flow rate vs pressure 34

Figure 7. Water flow rate vs pressure - flow restrictors 35

Figure B-l. Alternative test configuration - manometer bank 39

Figure B-2. Alternative test configuration - pressure transducer bank ... 40

vii
LIST OF TABLES

Page

Table 1. List of Laboratory Instrumentation 22

Table 2. Shower Head/Flow Restrictor Classlf iciations 23

Table 3. Water Distributions In Sector Compartments at 138 kPa 24

Table 4. Water Distributions In Sector Compartments at 344 kPa 25

Table 5. Water Distributions in Sector Compartments at 551 kPa 26

Table 6. Shower Head Orientation Test Results 27

Table A-l. Water Collection Device Calibration Results 37

vlii
1. INTRODUCTION

Requirements for residential water conservation have resulted from a number of

factors, such as limited water resources, shortages during drought conditions,

inadequate processing capacity for supply of potable water and treatment of

wastewater, growth of population in arid areas, and announced national policy

[1].* Potable water consumption in residential usage is distributed as follows

approximately 40 percent of the total for flushing of water closets; bathing

consumes about 30 percent, and all other uses comprise the remaining 30 percent

[2,3,4]. Reduction in hot water usage with low-flow devices results in energy

conservation as indicated in the California drought experience [4,5]. The U.S.

Department of Energy (DoE) Low-Cos t/No-Cost Program included inserting flow

restrictors in showers for energy reduction. Cost benefits due to energy

conservation are usually greater than those directly attributable to water

conservation [5].

Grey water systems (water reuse to reduce potable water consumption) are frequently considered as alternatives for providing water for flushing of water

closets [6] and sometimes partially treated for landscape applications. The

primary single source of grey water is from bathing. If significant reduction

in the use of potable water is achieved through reuse/recycle for water closet

usage, then bathing water becomes a more significant parameter in potable water

consumption and could represent up to 50 percent of total residential usage.

Similarly, if very low-flow water closets (using potable water) gain broader

acceptance, the percentage of residential potable water usage for bathing

increases significantly.

Reduced flow shower heads or flow restrictor modified shower heads have proved

to be effective in reducing water consumption [2, 3, 4, 5]. The basis for selection of a new low-flow or retrofit shower device which provide adequate and

satisfactory performance levels for flow rate pressure dependency or patterns

of water distribution is not well established. There is generally little con- sumer oriented label information provided to describe the performance of new

shower heads, e.g.

,

the flow rates, desired range of supply pressures or the

water spray distribution (cone angle). The need for a method to provide essential performance requirements and rating methods for various plumbing devices was recognized in the "Water Efficiency Labeling Act" introduced in Congress

[7]; although the legislation was not passed, it is indicative of the concerns

for performance requirements through the establishment of test methods for

evaluation and rating information.

Classification of shower bathing activities and equipment was identified in

"Space Requirements for Showers" [8]. The specifications for shower stalls

developed by the investigators related to the functions and space requirements

for space accommodations in which to perform wetting, soaping, rinsing and

drying of the entire body. The scope of that study was limited to only those

four functional elements and did not attempt to establish any linkage between

* Numbers in brackets indicate references.

1
the functions performed within the space to the characteristics of the source

of water and its distribution, i.e. , shower head. The investigators established

a second (hydraulic) classification group that identified the need for research on hydraulic performance for the shower spray, adjustment, water flow rate, and

water temperature as important shower parameters which were beyond the scope of

that study.

The specific shower head performance requirements to provide hygienic sanitary

functions, i.e., the removal of dirt, body oil, sweat, bacteria, and soap film/

suds, do not appear to be established in the literature. Also, under existing

standards [9,10], the impact of shower streams on the body, particularly upon

extremely sensitive areas of the body, do not appear to be characterized or quantified. Measures of comfort parameters that tend to satisfy user needs,

e.g., very hot showers for relaxation and "needle” showers for awakening or following an exercise period, are largely unknown. The disincentives resulting

from user dissatisfaction with reduced flow devices in attaining water conserva- tion program goals have been documented when poor performance occurs [11]. Lowflow shower heads or retrofit add-on restrictors are available for replacement

by the user/consumer with ease and little skill requirements. Consequently,

low-flow showers with nonacceptable performance (i.e., strong variation of flow

rate with pressure, inadequate water distribution over the body, narrow high

intensity streams, excessive amounts of water striking the shower stall wall or shower curtain, etc.) have great potential for discouraging water/energy savings

practices

.

Existing codes and standards, federal specifications, and criteria for

requirements of low-flow shower heads [9,10] emphasize materials and durability

requirements. The performance requirements for hydraulic related parameters

are usually limited to the flow rate dependency on pressure and broadly prescribed tolerances on the cone angle. The requirements for the test measurement

methods, instrumentation, and formats for data recording and evaluation of

results are inadequately described.

The objectives of the research on low-flow shower heads were: (a) development

of a laboratory-based hydraulic performance test evaluation method; (b) establishment of recommendations for test evaluation guidelines and criteria with

potential rating applications suitable for standards and codes; (c) limited

validation of laboratory selection criteria in a pilot field demonstration based

upon user acceptance tests. Selected aspects of acceptability of low-flow rate

showers by users are to be determined in the HUD demonstration program and to

establish whether changes in patterns of usage occur, particularly if the time

period and temperature setting are altered with reduced flows.

The shower head is a device which converts the pressure available at the fixture

into a spray (or fine streams) as a results of the pressure drop across an assembly of orifices. The design of the spray nozzle is usually axisymmetric

and in simpler designs uniformly distributed discharge orifices are provided to

develop an essentially conical spray. Selectively, attempts are made to vary

the spray pattern through the geometrical distribution of the orifices and the

flow rate controlled by the orifice size. In some designs, a variable control

is provided for the user to manually change the spray distribution pattern and

2
the flow rate. The current trend in low-flow showerhead designs is to reduce

the cone angle in order to focus the spray onto the body thereby reducing the

water which would have been directed to the shower enclosure. The requirement

for removal of soap suds from shampooed hair can be achieved more satisfactorily

by a narrower spray at low flow rates.

For water conservation the flow rate is of particular importance since the total

water consumption is dependent on the time period in use; therefore, the flow

rate is an indicator of the water conserving potential. Measurement methods for

determination of flow rate are relatively simple, e.g. , in-line flow meters or volumetric collection in calibrated tanks over given time periods. The specification of a limiting cone angle, prescribed in standards, only represents the

extent of wetted surface area at a prescribed distance from the shower head.

The measurement method for the hydraulic effectiveness of the conversion of

water supply flow energy (or total head) into a distributed spray pattern,

over a representative wetted area, has not been developed. With reduced

water usage the distribution patterns provide a parameter that could of

greater significance than the cone angle. Body surface wetting patterns and

the shearing away of suds from the body may in the future be included by

behavioral researchers as a parameter of the "quality of a shower" related to

removal of dirt and body oils or bacteria.

A water spray collection device, subsequently referred to as the sector test

rig, was developed as a measurement method to determine the shower distribution

characteristics

.

The development of the laboratory test procedures, equipment, instrumentation,

and results obtained in the experiments with the sector test rig are discussed

in the following sections of the report. The equipment installation and test

requirements were based upon the premise that any conventional hydraulic test

facility or plumbing manufacturer quality control laboratory, with existing

equipment and instrumentation, should be able to readily duplicate the

evaluation procedure if adopted through the voluntary consensus standards

process.

3
2 . EXPERIMENTAL APPROACH

2.1 LABORATORY PROCEDURES

The laboratory test plan was developed to fulfill the following goals:

(i) establish the basis for measurement methods(s) to provide quantifiable

levels of performance for low-flow shower heads; (ii) conduct experiments to

evaluate the suitability of the instrumenation and measurement technique(s)

;

(iii) determine the applicability of the compartmented sector test rig to provide test results for evaluation of the performance parameters. The study of

the utility of the test methods for evaluation of the shower spray distribution

characteristic(s) was to establish the basis for a standard evaluation procedure. The methods would be applicable for federal guidelines and become a reference source to voluntary consensus standards organizations considering

requirements for water conserving devices.

The measurement techniques and water spray collection device were required to

provide data on the following shower head operating characteristics:

(a) Water flow rate as a function of supply line pressure,

(b) Radial and circumferential water distribution characteristics at a reference distance from the shower head,

(c) A volumetric distribution function to represent the flow quantity

delivered over the wetted area at a reference distance from the

shower head,

(d) Water temperature effects on variability of flow rate, spray

distribution, and cone angle (or its improvement), and

(e) Variability of water flow rate, distribution and cone angle as a function of representative water supply pressures for adjustable and

nonadjustable shower sprays and angular orientation (tilt) head

positions.

Other shower spray characteristics, such as droplet size and water stream

velocity, were not considered in the test procedures. The hydraulic flow

parameters in (a), and elements of (d) and (e) were measurable with commercially

available instrumentation; the water collection device - sector rig illustrated

in figure 1 - was developed to provide the shower spray distribution characteristics of (b), (c), (d)

,

and (e) with limited application to (a). In addition, a mounting/ clamping device to maintain alignment of the shower head assembly was required for the shower head test apparatus. A schematic of this configuration

is shown in figure 2.

The customary basis for evaluating the performance of low-flow shower heads has

been the determination of the water flow rate and cone angle as a function of

the pressure measured at the shower head. The test pressure range should be

representative of water supply systems across the country. In some communities,

water is delivered to residential dwellings without pressure regulators, at

4
pressures as high as 689 kPa (100 psi) ; in other places, particularly in

hilly terrain, line pressures may drop to as low as 68.9 kPa (10 psi). The

range from 68.9 to 689 kPa (10 to 100 psi) was adopted for the test program.

The water flow rate can be obtained by: (1) a water flow meter in the supply

line, or (2) summing the individual volumes of water collected in each sector

compartment of the water collection device over the total time period. The

use of a flow meter also provides a supplementary measurement useful in determining the overall accuracy of the data collection procedures, i.e. , the

measurement of the total quantity of water collected during the time interval

in the sector rig. Both flow measurement procedures were utilized in the

laboratory testing and are included in the recommendations for the proposed

shower head test method. The water pressure can be measured with either a dial pressure gauge or transducer located at a point close to the shower head;

both measurements were used in the laboratory, but that redundancy in the

measurement procedure is not required for the proposed shower head test method.

To obtain data on shower spray patterns, items (b), (c), (d) , and (e), above,

and establish a basis for a standardized test method, it was necessary to

provide a simple means of measurement for the distributed volumes of water.

The configuration for the test water collection apparatus was selected to be

circular annular cylinders divided into sectors, since shower heads are generally designed to produce axisymmetrical spray distribution patterns; however,

offsets in new shower head assemblies or retrofit flow restrictors may not

maintain the original circular distribution patterns. Other grid arrays for

collectors comprised of squares, triangles, or diamond shaped cross sectional

areas were rejected because generally a large number of "cells" would be

required or the simplicity of the test collection device could not be maintained. Division of the annular rings into 60° (pie shaped) sectors provides

for collection of the distributed spray in the circumferential as well as radial directions.

Measurements in the radial direction provides a means of estimating the spray

cone angle; measurement of the circumferential shower spray distribution provides information about the uniformity within the circular bands. The capability of the water collection device to indicate the shower spray cone angle was desired since the cone angle has conventionally been a measure for shower head

requirements [10]. Improvement in accuracy of determination of the geometric

cone angle would require a greater number of radial collector rings than shown

in figure 1 (smaller radial intervals are necessary). For greater accuracy in

determining circumferential variations sector angles less than 60° are required.

To account for the effects of water supply temperature on shower head

performance (as indicated by previous studies [4]), all the shower heads were

tested at two temperatures, 29.4° and 40.6°C (85° and 105°F) with a tolerance

of 2.5°C (+ 5°F). These two temperatures were selected as representative levels

5
for "warm" and "hot" showers*. Flow rate regulation in many shower devices

depends upon pressure sensitive deformable rings or perforated discs (formulated

from elastomers) to regulate the flow rate. The flow rate changes will depend

upon the specific type of shower head, the design of the rate control element,

and the construction and composition of its components. The temperature affects

the viscosity of the water as well as the dimensions of the flow restricting

orifices through expansion or contraction of the material. The temperature

change can alter the elastic deformation response of the pliable orifice materials (of volume rate controllers) to the applied water pressure. The effects

of temperature changes may result in different flow rate-pressure relationships.

Previously conducted water-saving shower head tests [4] which incorporated an integral ball-joint flow restrictor indicated that a noticeable deviation of

the flow rate-pressure relationship occurred when the shower head was tilted

with respect to the mounting pipe. Consequently, provision was made for shower

head tests with an angle offset with respect to the mounting pipe, (tilted) as well as vertically aligned (plumb line), included in the study of the test

method for the determination of the flow effects, i.e., both the flow ratepressure relationship and shower spray distribution characteristics. The

maximum offset position is governed by the stop limits due to the physical

construction of the shower head (see figure 2). The apparatus should permit

duplication of any offset that could be experienced in actual installations.

Additional test method developments were required for shower heads with

manually operated control mechanisms (integral to the shower head but adjustable externally) for variable shower spray since a large number of such shower

heads are commercially available. Since the flow rate-pressure relationship

and the shower spray characteristics may vary depending on the wide range of

adjustments possible in the spray control mechanisms, the simplified test

procedure was limited to: (i) the extreme settings physically allowable; these

control positions generally represent the two operating extremes for the shower

head (i.e., minimum or maximum flow, fine or coarse spray, small or large cone

angle, etc.); and (ii) additional settings, arbitrarily selected, between the

two extreme limits.

2 . 2 APPARATUS

The installation of the apparatus, as shown in figure 2, consists of a controllable water delivery system, mixing and flow control system, shower head

mounting/ clamping device, and the water collection components.

2.2.1 Water Delivery System

Water for the shower head tests was supplied from a high pressure water system

(from pneumatic boost storage tanks in the laboratory facility) to provide the

test conditions up to 689 kPa (100 psi) required for the test program. Hot

water was delivered to the mixing system from a conventional 454 Si (120 gallon))

*Cold water temperatures in storage tanks may vary due to the source of supply

and heated/air conditioned environments.

6
residential water heater maintained at 82°C (180°F) located adjacent to the

test area. 2.2.2

Mixing and Conditioning System

The water mixing and flow control system blended the cold and hot water to

establish the test water temperature and regulate the quantity of flow to the

shower head. The system consisted of a thermostatically controlled mixing

valve, a throttling valve, water flow indicating meter, and measuring components. The water flow temperature was set and regulated by the mixing valve.

The throttling valve, connected to the output of the mixing valve, was used

to establish the water flow rate. A solenoid valve was used to quickly start

and stop the water flow to the shower head. 2.2.3

Shower Head Mounting/ Clamping Device

The shower head mounting/ clamping device securely held the shower head in the

desired vertical orientation (above the sector rig). The water supply pipe

could be displaced to a "tilted" position; the configuration and the test

positions for the mounting pipe are also shown in figure 2. The shower head

was connected to the water supply pipe 0.6 m (24 in.) length, 1/2 in. diameter

schedule 40 brass pipe. A 1/8 in. pressure tap located 51 mm (2 in.) from the

shower attachment end of the mounting pipe was provided to mount a water

pressure gauge.

2.2.4

Shower Spray Collection Device - Sector Rig

The water spray from the shower was collected in the sector rig, figure 1*

located 1.9 m (6.5 ft) below the shower head; the sector rig was leveled on the test stand platform. The collection device with three annular channels

each divided into six 60° (pie shaped) sectors, was fabricated from (12.5 mm

and 6.2 mm thickness) plexiglass sheets. The outer diameter of 76.2 cm (30

in.) for the third annular ring was based upon the shower head cone angle specification in Federal Performance Specification WW-S-1913A [10]. The diameter

of the innermost section, the 10.2 cm (4 in.) cylinder, was arbitrarily selected;

it provides added attachment support for the radial divider pieces. Each

annular channel was divided into sectors, 60° apart, to obtain circumferential

distribution data on the angular variability of the spray. The 60° divisions

were considered to be a reasonable value for peripheral measurement purposes,

e.g. , the use of 90° elements was rejected since the quadrants would provide

averaged collection data over too large a peripheral distance. Ultimately, a decision for 60° or smaller divisions should be determined within a committee

of a consensus standard group. Plastic graduated scales, 15.2 cm (6 in.) were

* A plastic pool was placed under the collector to collect and prevent

excessively wide sprays and overflows from wetting the laboratory test area.

7
permanently attached by a waterproof adhesive to a vertical side within each

of the 19 compartments. The scales provided the depth level measurement by

observation of the miniscus at the water surface on the scale for the water

collected in each of the compartments. Alternative methods of measuring the

depth of water and hence the volume in the water collection device are discussed in appendix B. In each sector, a drain hole was provided to remove the

water after each test; stoppers were provided to plug the holes during testing.

2 . 3 INSTRUMENTATION

The shower head test instrumentation system was designed to monitor and record

the important fluid flow parameters. The instruments and their location were

also noted in figure 2. A list of equipment and their respective accuracies

is presented in table 1.

Data were recorded by means of an electronic data acquisition system (DAS)

consisting of a multichannel data logger, eight bit microcomputer with asso- ciated floppy disk file storage, video terminal and impact printer. Signals

from the turbine flow meter, flow switch, pressure transducer, and thermocouple

were inputs to the data logger. The control interface of the data logger unit

provided for transfer of data to the microcomputer. The computer was programmed

to collect the raw data from the data logger, reduce the data, store the data

on the floppy disks, and display the results on the system printer.

The water consumption and flow rate were measured by a residential type water

meter and also by a separate turbine meter. The water meter provided an accurate means of determining the quantity of water used during each test.

The turbine flow meter was installed in addition to provide direct digital

display of the water flow rate. The unit also provided an analog output voltage

directly proportional to the measured water flow rate and recorded by the data

acquisition system.

The water temperature was monitored with a thermocouple inserted into the

shower head water supply line, in contact with the water. The transducer

values were displayed on a digital temperature indicator. The thermocouple

was also connected to the DAS for automatic recording of the water temperature.

The temperature indicator was primarily used to set the desired water temperature before a test, while the data logger recorded the temperature during a test. The water pressure at the shower head was measured by a mechanical gauge

and a strain gauge type transducer connected to the pressure tap located on

the mounting pipe. Both instruments had a pressure range of 0 to 689 kPa

(0 to 100 psi). The mechanical indicator gauge was used to set a nominal

operating test pressure while the more accurate pressure transducer provided a more precise recorded measurement. Other methods of instrumentation are described in appendix B.

8
2.4 TEST PROCEDURE

The tests were conducted as follows:

1. The shower head was attached to the water supply mounting pipe and

tested for leakage.

2. The mounting pipe and shower head assembly were carefully centered and

aligned with a plumb line over the inner central zone of the water

collection device to provide discharge in the vertical direction.

3. The water flow through the system was initiated by energizing the

electrically operated solenoid valve.

4. Adjustment was made to the mixing valve to obtain the proper water

temperature and then the needle valve was adjusted for the correct

pressure.

5. The solenoid valve was closed to stop the water flow but retain the

valve settings for the next test step. The water collected in the

sector rig was drained. After draining, the holes were plugged with

stoppers.

6. The numerical display on the water meter was recorded on the data

sheet as the initial value. The toggle switch was closed to allow the

computer to accept input from the flow meter, pressure transducer, and

thermocouple.

7. The test was initiated. The solenoid control valve was opened to

start the water flowing again and simultaneously start a laboratory

type stop watch. The flow of water was continued until either one of

the sectors reached a 75 percent fill level or at preselected time

periods of 20, 30, or 60 seconds.

8. The flow rate and actual water temperature in the time interval were

recorded on the data sheet. After the flow was terminated, the water

meter reading was recorded as the final value. The total time (in

seconds) of water flow was entered on the data sheet.

9. The total volume of water discharged through the shower head was obtained as the difference between the final and initial values on

the water meter. The volume divided by the time of the test run provides an average flow rate value. The flow rate, indicated by

the turbine meter, when multiplied by the time also provides the

total water volume used.

10.

The water level for each of the compartments of the water collection

device were then recorded on the data sheet. The total quantity of

water in all the sectors, determined by using the conversion factor

from a calibration (volume curve vs scale reading) graph for each

9
sector*, should equal the amount indicated by the water meter. For

these tests, the accuracy of the total water used and calculated by

summing the sector should agree within + 5 percent. The test should

be repeated and observations carefully made to reduce errors and/or

determine overspray if outside + 5 percent agreement.

To determine the effect of changing the alignment between the shower head and

the mounting pipe, an additional test was carried out. Two pressures of

340 kPa and 550 kPa (50 and 80 psig) and only one temperature of 29.4°C

+ 2.5°C (85 + 5°F) were selected. With the temperature conditions and one of

the preselected pressures established and the mounting pipe and shower head

aligned, the flow rate data and angular position of mounting pipe were obtained

and were stored in the computer. The data input to the computer was then

interrupted, the supply pipe position displaced to the limited or prescribed

tilt and the water flow then reestablished. After a 30 second stabilization

period, the pressure, flow rate, and temperature values were again stored in

the computer for subsequent analysis.

On shower heads equipped with a manual spray adjustment, it was recognized that

tests may be required to include determination of the effect of the adjustment

setting over the range of pressures on the shower head flow rate and the distributions in the sectors. The recommended test procedure for measurement at

various settings of the manual spray adjustment are presented in section 4.I.3.C.

Classification of shower heads into two groups is necessary; convenient

designations are: (1) manufactured assemblies, and (2) modified retrofits.

Subcategory designations were also necessary to distinguish the technique for

controlling or regulating the flow rate as either a fixed orifice or deformable

orifice. A fixed orifice shower head is essentially a rigid flow control

element (restrictor) with one or more orifices which restricts the flow. A

deformable orifice is fabricated from a pliable substance which alters the

orifice dimensions as a result of variations in line pressure, thereby controlling the rate of flow. In addition, it is necessary to distinguish between

nonadjustable and manually adjustable shower heads. Manually adjustable refers

to the type of shower head construction where the spray stream (intensity,

flow rate or cone angle) may be altered in use with a control device which is

external (not requiring disassembly) and located within or outside the shower

spray cone. Nonadjustable heads do not have external control capability.

Table 2 indicates the seven types of shower heads selected for the laboratory

tests and also indicates category designations for restrictors.

2.5 DATA REDUCTION

The data derived from the vertically aligned water distribution tests are listed in appendix C for each shower head. Each data record contains three

groups of tabulated results for one shower head; they are the sector compartment, water depth, and water volume for each temperature, pressure, and

orientation of the shower head. The actual water volumes collected are shown;

* See appendix A for a method of calibration of the sector rig compartments.

10
for comparisons the data have been normalized to a common 2 minute test

period to provide a common base to facilitate comparisons for all tests.

Generally, testing was completed within 1 minute and never extended beyond

2 minutes to avoid overflow. The equation utilized for determining the amount

of water collected in individual compartment, adjusted for the 2 minute test

period, is:

Q

= (B-C) (X) (Y) liters

where: X = 120

t

and: Q

= water collected per compartment (liters)

X = normalization factor

t = actual test duration (seconds)

C = initial water level reading (mm)

B = final water level reading (mm)

Y = calibration factor, appendix B (liters per mm of water depth)

From this detailed set of data, the radial and circumferential water

distribution patterns by compartments may be examined.

The second data group presents the quantity of water collected in each annular

channel for the selected test conditions. These results were obtained from the

first data group by summing the individual sector water volumes for each ring.

This group of data essentially represents the radial distribution of water

(independent of peripheral distribution) and can be used to determine the

shower spray cone angle (upper limit values only since the radial distribution

variation is averaged over each radial increment).

The total quantity of water for each test condition is tabulated in the third

group of data. Listed separately in this group are the water volumes

collected, based on the sum of the sectors and water volume based upon the

time interval and flow rate from the meter reading. The accuracy is indicated

by the percent difference based upon the difference of the metered value and

the sector sum value.

11
3. RESULTS AND DISCUSSION

3.1 WATER DISTRIBUTION

3.1.1 Radial and Circumferential Water Distribution

The tabulations of the spray distribution pattern results for the seven shower heads tested are listed in tables 3, 4, and 5. These tables present the

data collected from the distribution tests at three pressures, 140, 340, and

550 kPa (20, 50, and 80 psig) and two temperatures 29.4° + 2.5°C and 40.5°C +

2.5°C (85°F + 5°F and 105°F + 5°F). Examination of the results, presented in

the tables as liters of water collected in each sector (normalizing all results

to a common 2 minute flow period), illustrates the wide variation in spray

distribution patterns among the sampled low-flow shower heads. Figures 3 and

4 present the distribution patterns for the seven shower heads obtained from

distribution patterns among the sampled low-flow shower heads. Figures 3 and

4 presents the distribution patterns for the seven shower heads obtained from

the sector rig for two pressures at one temperature. Within the same ring "a"

in figure 3, the mean values in the sectors vary by 3:2, whereas at the higher

pressure in figure 4 the mean of the "a" sectors vary by 2:1 around the

periphery. In ring "b", except for sector 6, the mean is nearly constant. At

the higher pressure a greater quantity of water is collected in ring "a" as compared with the low pressure case; that indicates a reduction in cone angle

with increased pressure. AJ.so, the greater total volume of water can be

noted at the higher pressure. Ring "c", with diameter greater than 75 cm,

collects very little water, while the central cylinder, 7.5 cm, has a mean

value either greater than or comparable to the values in the "a" and "b" rings.

The values shown from this limited test sample indicate that a reference

average basis for establishing relative comparisons between shower heads can

be developed from a large enough sample of shower head tests. The test method

primarily indicates whether excessive concentration in one sector occurs (compared with others) and if considerable wetting of the shower stall (or

walls) may occur. A broader based statistically averaged data set, from a very

large number of sample shower heads, would indicate the variability of water

distribution deliverable from currently manufactured shower heads. The distribution pattern would establish a common basis for comparisons (leading to

ratings based upon departure from the mean including a tolerance on the

performance) for all types of shower heads.

The amount of water collected in each compartment provides for the derivation

of another measure of shower head performance, an intensity distribution. The

intensity distribution term provides an indication of the distribution of water

flow volume per unit area per unit time. From the volumetric rate of water

collected in any compartment, the value of volumetric rate per unit area

(across the surface area of the collector) may be computed; it is an indicator

(on the average, over the area of the specific compartment) of the rate at

which the water spray (across the horizontal plane above the sector rig) enters

that region. Low values indicate a "soft” shower and larger values imply a "hard" shower. Intensity distribution mapping over the wetted areas may be

useful in establishing "effectiveness" ratings since it is an improved measure

of distribution as compared to the direct measurement of the collected volume

12
in each compartment. Since the surface area of sector compartments increase

from "a" to "b" to ”c” rings, the values of intensity distribution derived from

the collected volumes in figures 3 and 4 would decrease in inverse proportion

to the increased areas. This measure may also become a useful parameter in

further research for subjective response on comfort characteristics, or associated with a method for determining the effectiveness of the removal of surface

(soap or oil) films.

3.1.2 Measured and Metered Water

Figures 5A and 5B present comparisons of the total measured water based upon the

collection device (summed) values vs metered water used in three separate tests.

Measured water is the total quantity of water collected in all the compartments

of the sector rig. Metered water is the total quantity of water obtained from

the turbine meter rate over the test time interval. Figure 5A presents data

from tests conducted with warm water on three different shower heads, and

figure 5B from tests conducted with hot water. The ideal relationship between

the two quantities is indicated by the straight line. Although there is some scatter of data in these representative comparisons, the agreement shown is

good. The two quantities are not necessarily equal; a discrepancy between the

two quantities could be attributed to the shower spray water falling outside

the collection device. The metered water readings should always be more exact

(with a calibrated meter) than the sum of the measured compartmental water

volumes. Discrepancies in reading the individual scales for the depth of the

water in a compartment contributes to the error in the summation; the calibration procedure of appendix A will reduce errors. Water outside the outer ring

cannot be measured by the distribution device but may be observed and noted

during the test (and could be collected). Differences in values greater than

+ 5 percent between the rig collection and meter readings should be repeated

and observations carefully made to reduce errors and/or determine over spray.

Figure 5A, illustrates data for volume collected by summation beyond 5 percent

limits. To reduce or eliminate the error in measuring the water depth in

individual sector compartments by physically reading the scales, other instrumentation, such as pressure transducers or water manometers, as indicated in

appendix B, can be substituted. Such instruments would improve measurement

accuracy, reduce the time needed to run the tests, and provide a method by

which the tests could be computerized.

3.2 SHOWER HEAD ORIENTATION

The effect of shower head orientation on the shower head flow rate-pressure

relationship is shown in table 6. The results were obtained from tests where

the angular displacement of the shower head mounting pipe was set to the

maximum obtainable offset determined by the physical limits of the shower

head. An examination of these data reveals that there appears to be little or no significant change in the water flow rate or pressure drop between the

aligned and offset conditions. In this test series, the large changes cited

in the California study [4] (test series of a very large variety of shower

heads) were not found. The California study revealed that with some shower

13
heads (ball type) the flow rate changed significantly when the shower heads

were swiveled. The number of shower heads in the NBS tests was small, since

the subject of the investigation was the method of testing and was not intended

to be a test program for evaluation of shower heads.

3.3 WATER FLOW RATE VS PRESSURE

Appendix C includes the data on the volume of water collected at the three

test pressures, 140, 340, and 550 kPa (20, 50, and 80 psi). These data are average values calculated from the total quantity of water used during the

test time period and normalized to the common basis of a 2 minute test

duration. The data for the total collected volumes can then be converted into

flow rates for the adjusted time period and compared. Since the distribution

pattern tests are primarily intended to provide data at a limited number of

selected pressures, the data for the the flow rate pressure dependency over

the entire range of possible pressures should be determined separately. A

supplementary series of tests was performed with the turbine meter in the

water supply line to obtain data points for determination of the dependence of

flow rate on pressure.

The water flow rate vs pressure data at the two test temperatures are shown in

figures 6A and 6B for six of the seven tested shower heads. Although these

tests indicate little shower head water flow rate dependency on temperature,

the results of the larger study [4] indicated significant changes for several

shower heads.

The flow rate pressure dependency in some cases shows undesirable variations

of flow rate with changes in pressure. An ideal shower head would be one with very flat response curve to changes in pressure. For two shower heads,

after a rise in flow rate with pressure, the curves are flat (figures 6A-1

and 6B-2); a trending downward after a peak flow rate occurs with two others

(figures 6A-2 and 3). The other shower heads display a continuing rise in flow

rate with pressure, a characteristic usually associated with a nonwater saving

device where flow rate is proportional to the square root of pressure drop.

However the highest flow rate in those tests were close to 14 liters/min (3.5

to 4 gpm) and may be regarded as a watersaving shower head. The lower flow

rates at lower pressure can result in an unsatisfactory shower based upon user requirements [4].

The flow rate variations with pressure for three restrictor inserts in a conventional shower head are shown in figure 7. The data indicate that the

modified performance with reduced flow restrictors may not provide sufficient

reductions in water consumption. The hydraulic discharge characteristics are dependent upon other parameters (e.g., geometrical distribution of orifices,

internal flow channels) as well as the design of the restrictor.

14
4.

RECOMMENDATIONS FOR IMPLEMENTATION OF SHOWER HEAD TEST METHOD

4.1

TEST METHOD GUIDES

The requirements for shower head tests to determine the hydraulic

characteristics should include the following proposed elements:

4.1.1 Shower Head Test Configuration

An instrumented shower head test configuration, similar in design to that

illustrated in figure 2, should be utilized. The minimum test configuration

will consist of:

1. A straight shower head mounting arm (pipe) consisting of 1/2 in.

schedule 40 brass pipe at least 1 ft long.

2. A pressure tap 2-4 mm (1/16 in. - 1/8 in.) in diameter positioned

25-50 mm (1-2 in.) from the bottom of the mounting arm (pipe).

3. A means of providing rigid support for the shower head to maintain it

in a vertical position.

4. A method of changing the angular orientation of the centerline of the

mounting arm (pipe) with respect to the shower head (to simulate tilt

of the shower head)

.

5. A water collection device located 1.9 m (6.5 ft) below the water

exit plane of the water supply connecting pipe (or to the test shower

head). In addition, the collection device provided is to be comparable

in size and configuration to figure 1. The centerline of the collection device is to be located directly below the centerline of the test

shower head.

6. A water supply system capable of delivering 30 £pm (8 gpm) of water

at 690 kPa (100 psig) over a range of temperatures from the cold

supply to 29.5°C + 2.5°C (105°F + 5°F).

4.1.2 Test Instrumentation

Suitable instrumentation is required to set, monitor, and measure the water

flow rate, temperature, and pressure before and during shower head tests. The

following is a description of the instrumentation required for a minimum

acceptable test configuration.

1. Water consumption will be monitored by a low range (typical)

0-60 £pm (0-15 gpm) water meter.

2. Water flow rate will be measured by a direct indicating instrument,

such as the turbine meter-signal conditioner used in this study, with

a minimum accuracy of + 1 percent full scale and resolution of 0.4 ipm

(0.1 gpm) or better.

15
3. Water temperature is to be measured to within + 0.6°C (+ 1°F) of

specified test temperature.

4. Water pressure, to be measured at the location specified in

section 4.1.1, is to be measured by a pressure gauge or transducer

with a minimum accuracy of + 5 percent full scale and a resolution

of 7 kPa (1.0 psi).

5. Water level measurements in the water collection device will be

made by graduated scales, pressure transducers, or manometers.

Accuracy of the transducers or manometers may not be less than the

graduated scales (1 percent of full scale).

6. A timer, accurate to 0.1 second or better, will be required to

record the test duration.

4.1.3 Testing and Data Recording

Utilizing a test apparatus configuration with instrumentation which meets the

specifications outlined in the previous two sections, two types of tests, water

distribution and pressure-flow rate, will be performed on each shower head.

Shower heads with no mechanical provisions for adjustment of the spray stream

are to be examined using test procedures described in A and B below. The

shower heads with adjustable spray streams are to be tested using procedures A,

B, and C.

A. 1 Water Distribution

This procedure is designed to provide data for radial and circumferential

water distribution of the shower head spray pattern. Appendix C illustrates

typical test data requirements. The hot water range of temperature should be

29.5°C + 2.5°C ( 105°F + 5°F) and warm 40.6°C + 2.5°C (85°F + 5°F). The tests

will be run at three pressures, 140, 340, and 550 kPa (20, 50, 80 psig). The

two positions for the mounting pipe, vertical and offset, are illustrated in

figure 2. The vertical position is defined as that arrangement where the head

is always vertical and the mounting pipe is aligned with the vertical position

of the shower head. The offset position is where the pipe is placed to the

maximum swiveled position relative to the shower head.

A. 2 Test Procedure

1. Level the water collection device. Mount the shower head to the mounting

pipe and secure the pipe in the vertical position. Check for water leakage

by pressurizing. Use a plumb line to center the water collection device

beneath the shower head.

2. Run water through the system and shower head by opening the solenoid, or quick opening valves, and adjust the pressure and temperature to their

preselected values. Orient the shower head so that the resultant spray

pattern on the water collection device is also visually centered (and

16
check again with plumbline) . This can be accomplished by viewing the

shower from two locations 90° apart and then making the required position

corrections. Clamp the shower head in position to prevent any further

movement.

3. Turn the water off and empty the water collection device.

4. Plug the drain holes in the water collection device. For each compartment,

record the water level if not completely drained (tare correction).

5. Record the water meter reading.

6. Open the solenoid or quick opening valve, simultaneously start the timer.

7. Stop the water flow and timer when any of the following occurs:

a. 120 seconds have elapsed,

b. any one sector is approximately 75 percent full.

8. Record the following data:

a. water meter reading,

b. elapsed time,

c. water levels in each sector compartment,

d. notation if overspray occurs.

9. Repeat the procedure for other pressure, temperatures, and mounting pipe

positions.

The above description outlines the procedure proposed for use with the test

configuration similar in design to that presented in this report. The basic

principles underlying this procedure would be applicable to other configurations

such as those discussed as alternative methods and illustrated in appendix B

with appropriate changes in the data collection and recording procedures.

B. Shower Head Flow Rate - Pressure Test

This section deals with the method to be used to collect data on the flow

rate-pressure relationship of any type of shower head independent of the collection device. Each shower head will be tested at two temperatures, 29.5°C

+ 2.5°C (85°F + 5°F) and 40.6°C + 2.5°C (105°F + 5°F) , and over a pressure range

of 70 to 690 kPa (10 to 100 psig). Starting at 10 psig repeat the tests in

increments of 10 psi until 100 psig is attained, then repeat downscale to

10 psig. That provides 19 data points for an individual shower head. The

procedure required is outlined below:

17
1. Mount the shower head and position the mounting pipe in the vertical

position.

2. Run water and set the initial pressure point; adjust to the required

temperature.

3. Record the pressure and flow rate.

4. Repeat procedure for the other pressures and temperatures.

C. Manually Adjustable Spray Head Test

The test method outlined in this section applies to those types of shower heads

which employ a mechanism for manual adjustment of the spray stream without

device disassembly. Each shower head is to be tested at two temperatures,

29.5°C + 5°C (85°F + 5°F) and 40.6°C + 2.5°C (105°F + 5°F) over a pressure

range of 70 to 690 kPa (10 to 100 psig) in 70 kPa (10 psi) increments. At

each pressure point, three and up to six data points are to be collected cor- responding to a different setting of the spray adjustment mechanism. Of these

(three to six points) two will be end points for maximum fine and coarse spray

and the others shall be intermediate settings. A brief description of the

test procedure is given below:

1. Mount shower head and secure mounting pipe in vertical position.

2. Adjust the shower spray with water running for maximum fine or coarse.

3. Set water pressure and adjust temperature.

4. Record pressure and flow rate.

5. While maintaining selected pressure, adjust spray mechanism and record

the corresponding flow rate.

6. Repeat step 5 for at least three and up to six shower head spray

adjustment settings as indicated above.

7. Repeat entire procedure for the other required pressures and

temperatures.

4.1.4 Results

The test results for each shower head are derived from the data collected

utilizing the procedures A, B, and C outlined in the previous section. The

scheme for reducing the data is outlined in sections 2 and 3 of this report.

The results of the tests are recorded in a form similar to that illustrated

in appendix C, and should include the radial and angular water distribution

patterns. These tables provide information so that additional shower head

spray characteristics, such as flow rate (cone angle, over spray and intensity

18
distribution) may be calculated. The flow rate data obtained by this procedure

is supplementary to the detail from procedure B. The cone angle may be established by examining the shower head spray radial distribution results. The

value represents only an approximation because the radial resolution of the

water collection device is very low (radially spaced inserts placed into the

sectors are required for finer resolution). The cone angle can alternatively

be obtained for the shower spray based upon observations or photographic means

,

or measuring the maximum wetted diameter at a fixed location below the shower

head. Guidelines for determining the acceptable values for cone angles are unknown in terms of user spray pattern requirements. Overspray water that

falls outside the prescribed cone angle or water collection matrix may be

determined from the reduced test data, appendix C. The cone angle measurement

provides an indication of the size of wetted surface area covered by the

shower spray.

The average water intensity distribution can be defined as the quantity of water

per unit of time and area entering an individual compartment, sector ring or other zone. The intensity distribution can be useful in describing the spray

symmetry and could imply a measure of the stream strength (or force) as a comfort indicator or possibly as an average velocity to shear away the soap

suds film.

The results from test procedure B contain information to adequately describe

the shower head variability for the flow rate-pressure relationship. A maximum

flow rate can be specified for water saving requirements and the variability

of the flow rate with pressure may be prescribed, within some limit value, for

evaluating or rating the performance of the shower head. Caution must be exercised to prevent an undesirable flow rate requirement which is not acceptable

for the user and intended functions.

The results from the test procedure C are collected only from shower heads

with user adjustable spray patterns. From the data collected and curves plotted the maximum flow rate for any test pressure may be found. Analysis

from the additional data for the various setting is required to determine the

maximum flow rate-pressure relationship for the shower head. Further evaluation

of the performance of a shower head at any given set of pressure-temperature

conditions over the control range may be required.

19
5. CONCLUSIONS

The test equipment and evaluation method for low-flow shower head water spray,

distribution and flow rate was developed to provide performance requirements

not previously considered. The recommended shower head test method was performed with relative ease in the laboratory; the test configuration requires

the usual instrumentation and measurement methods available in hydraulic laboratories. The use of the word "shower head" in all cases is intended to include

flow-restrictor-shower head retrofit combinations. The water collection device

(sector rig) utilized in this study is required for the additional performance

evaluation of water distribution from shower heads which effectively quantifies

the amount of water distributed across the surface of the collection device.

The qualification noted is that the configuration adopted appears to be minimally acceptable; alternate designs for the collection device should be

considered in developing a consensus standard.

20
6 REFERENCES

1. President Carter, "Water Conservation Policy," July 1978.

2. Miller, J. , The Potential for Energy Savings Through Reductions in Hot

Water Consumption, Proceedings of Conference on Water Conservation and

Sewage Flow Reduction with Water Saving Devices, Pennsylvania State

University Office of Water Research and Technology, July 1975.

3. Fulton, N. R. , "Elmhurst, Illinois," Division of Water Resource, Illinois

Department of Transportation, Presentation at Plenary Session II, EPA

National Conference on Water Conservation and Municipal Wastewater Flow

Reduction, November 1978.

4. A Pilot Water Conservation Program, Final Report, March 1978,

Bulletin 191, State of California, Department of Water Resources.

5. Water Conservation in California, State of California, Department of

Water Resources, Bulletin 198, May 1976.

6. Milne, M. , Residential Water Reuse, California Water Resources Center,

University of California/Davis, Report No. 46, September 1979.

7. HR 9363 Water Efficiency Labeling Act, Introduced by Congressman

L. Panetta (CA)

8. Englund, M., Hallberg, G. , Space Requirements for Showers, The Swedish

Council for Building Research, Stockholm, Sweden, December 11, 1979,

ISBN 91-540-3105-2.

9. FS-WW-S-1913A Shower Head, Ball Joint Integral Flow Control, October 1977,

Federal Specification, Commanding Officer (Code 512), the Naval Publications

and Forms Center, 5801 Tabor Avenue, Philadelphia, PA.

10. Plumbing Fittings, Canadian Standards Association, GSA Standard B1 25-1975,

October 1975.

11. Elder, J. , State of the Art Summary of Incentives for Residential Water

Conservation, NBSIR 80-2119, October 1980.

21
Table 1. List of Laboratory Instrumentation

Instrument

Figure 2

Reference

Nominal

% Accuracy

Thermostatic Mixing Value 1 -

Throttling Valve 2 -

Water Meter 3 1% F.S.

Temperature Indicator 4

O + H

Turbine (Transducer) Flow Meter 5 1% F.S.

Flow Indicator (Signal Conditioner) 6 -

Flow Switch 7 -

Solenoid Valve 8 -

Pressure Gauge 9 5% F.S.

Pressure Transducer 10 1% F.S.

Data Logger 11 -

Computer (Micro) 12 -

22
Table 2. Shower Head/Flow Restrictor Classifications

Shower Heads

Type NBS

Code

Rated

(flow rate)

Type NBS

Code

Rated

Fixed Orifice Deformable Orifice (flow rate)

Non-Adjustable

Head

FI N/A* Non-Adj us table

Head

El 11.4 (£/m)

(3.0 gpm)

HI N/A* OA 11.4 (&/m)

(3.0 gpm)

Manually

Adjustable

Head A3

9.5 (j^/m)

(2.5 gpm)

Manually Adjustable

Head

Cl N/A*

G3 11.4 (jt/m)

(3.0 gpm)

* Not applicable

Insert Flow Restrictors**

Rigid Deformable

Shower Head Rated Shower Head Rated

Non-Adjustable Head N/A1 Non-Adjustable Head N/A2 Manually Adjustable Head Manually Adjustable Head

** Not included in distribution pattern tests

^ Varies with pressure

2 Flow rate variations with pressure may occur
Table 3. Water Distributions in Sector Compartments at 138 kPa

WARM WATER TEST RESULTS ( 7 TESTS) PRESSURE > 138 . kPa

VOLUHN OF WATER CAUGHT (liters)

SECTOR HIN1HUH HE AN HAXIHUH STD. DEV.

40 .000 1.520 3.744 1.555

la .224 1.412 3.005 1.341

lb .075 .737 1.230 .343

lc .000 .173 1.071 .370

2a .121 1.430 2.740 .772

2b .074 .077 1.533 .544

2c .000 .010 .073 .025

3a .271 1.104 2.232 .705

3b .000 .700 1.403 .457

3c .000 .000 .000 .000

4a .373 .770 1.747 .525

4b .000 .701 1.474 .501

4c .000 .020 .143 .050

Sa .373 1.502 2.453 .700

Sb .000 .077 2.032 .777

5c .000 .020 .143 .050

4a .025 1.444 4.714 1.470

4b .000 2.002 4.542 1.511

4c .000 .010 .071 025

HOT WATER TEST RESULTS ( 4 TESTS) PRESSURE 131. kPa

VOLUHN OF WATER CAUGHT (liters)

SECTOR HINIKUM MEAN HA XI HUH STD. DEV.

00

la

lb

lc2a

2b

2c3a

3b

3c(a

4b

4c

3a5b

5c4a

4b

4c

000 1.257

000 1.470

107 .733 000 .071 174 1.440

172 .727 000 .085

.073 1.147

000 .584

.000 .000

.317 1.077

.000 .447

.000 .012

.025 1.572

.000 .837

.000 .048

.000 1.537

.000 2.078

.000 .107

3.415 1.47? 2.88? 1.125

1.751 .543

.357 .130 2.475 .881 1.342 .442

.437 .140 2.135 .773 1.717 .484 .214 .000 2.142 .471 1.543 .474

.214 .027 3.044 1.042 2.078 .757

.214 .07? 3.734 1.282 4.143 1.545

.42? .144

24
Table 4. Water Distributions in Sector Compartments at 344 kPa

VARH WATER TEST RESULTS ( 7 TESTS) PRESSURE = 344. kFa

VOLUMN OF WATER CAUGHT (liters)

SECTOR MINIMUM MEAN MAXIMUM STD. DEV.

10 .000 2.188 4.244 1.896

la .27? 2.380 5.778 1.598

lb .000 .784 1.514 .539

1c .000 .071 .357 .127

2a .121 2.277 4.638 1.216

2b .000 .752 2.300 .657

2c .000 .042 .218 .076

3a .313 1.761 2.426 .656

3b .000 .708 1.496 .67?

3c .000 .000 .000 .000

4a .31? 1.467 2.948 .863

4b .000 .821 1.870 .655 4c .000 .020 .143 .050

3a .177 1.944 3.243 .961

3b .000 .844 1.755 .688

3c .000 .041 .286 .100

6a .000 1.873 3.537 1.313

4b .000 2.190 5.678 1.935

Ac .000 .243 1.500 .518

HOT WATER TEST RESULTS ( 7 TESTS) PRESSURE * 344. kPa

VOLUMN OF WATER CAUGHT (liters)

SECTOR MINIMUM MEAN MAXIMUM STD. DEV.

00 .000 2.487 6.678 2.381

la .374 2.491 5.778 1.67?

lb .000 .588 1.41? .468

ic .000 .102 .500 .178

2a .364 2.125 4.561 1.241

2b .000 .685 1.533 .538

2c .000 .094 .291 .127

3a .412 1.771 2.523 .688

3b .000 .581 1.309 .589

3c .000 .051 .286 .079

4a .177 1.428 2.751 .962

4b .000 .721 1.776 .661

4c .000 .031 .214 .075

5a .000 1.916 3.734 1.277

5b .000 .877 1.893 .75?

Sc .000 .071 .286 .115

6a .000 1.853 3.636 1.25?

6b .000 1.593 4.163 1.507

6c .000 .255 1.571 542

25
Table 5. Water Distributions in Sector Compartments at 551 kPa

WARM VATER TEST RESULTS ( 7 TESTS) PRESSURE « 551. kPa

VOLUMN OF VATER CAUGHT (literal

SECTOR MINIMUM

00 .000

la .277

lb .000

le .000

2a .121

2b .000

2c .000

3a .315

3b .000

3c .000

4a .373

4b .000

4c .000

5a .244

Sb .000

5c .000

4a .000 4b .000

4e .000

MEAN HAIIHUH

1.322 3.700 3.244 7.372

.771 1.514

.104 .704 2.433 4.017

.724 1.533

.031 .144 1.714 2.523

.441 1.402

.000 .000 1.447 3.044

.741 1.543

.010 .143 1.874 4.418

.005 1.755

.010 .143 2.447 4.287

2.731 8.327

.245 1.284

HOT VATER TEST RESULTS < 7 TESTS) PRESSURE r 551. kPa

VOLUHN OF VATER CAUGHT (liters)

SECTOR MINIMUM MEAN MAXIMUM

00 .000 2.41? 4.830

la .374 2.700 7.571

lb .000 .435 1.325

lc .000 .071 .357

2a .344 2.381 4.114

2b .000 .774 1.533

2c .000 .074 .271

3a .507 1.885 3.408

3b .000 .541 1.215

3c .000 .071 .284

4a .172 1.484 3.537

4b .000 .788 1.823

4c .000 .031 .214

Sa .047 1.730 3.734

5b .000 .484 1.755

5c .000 .051 .357

4a .000 2.211 4.520

4b .000 1.575 4.721

4e .000 .275 1.571

. OEV.

1.475

2.405

.404

.270 1.474

.470 .053

.707

.425

.000 .014

.573

.025 1.347

.47?

.025 2.232

2.551

.435

DEV.

.321 1.272 .402 .127

.735 .540

.115 .770

.554

.115

.054 .710

.075 .102

.727 .125

.404

.750

.543

26
Table 6. Shower Head Orientation Tests Results

Shower Head

Normal Position (Aligned) Extreme Shower Head Adjustment

Pressure

(psi)

Flow

(gpm)

Pressure

(psi)

Flow

(gpm)

A3 78.5 1.29 78.4 1.32

50.0 0.97 49.0 0.94

Cl 79.9 1.95 79.1 1.90

49.8 1.81 50.1 1.83

El 79.9 2.46 82.4 2.36

50.5 2.33 51.1 2.34

FI 77.9 2.65 77.2 2.61

49.4 2.09 48.7 2.08

G1 79.0 2.75 80.3 2.71

49.1 2.98 49.7 2.97

HI 78.7 3.58 74.7 3.55

50.0 2.79 48.2 2.83

OA 79.6 2.83 81.0 2.78

50.3 2.97 50.7 2.96

Conversions:

! psi x 6.89 = kPa

gpm x 0.063 = fc/sec

27
Figure 1. Water collection device - "sector rig” - geometry and dimensions

28
6 FLOW INDICATOR

7 FLOW SWITCH

8 SOLENOID VALVE

9 PRESSURE GAUGE

10 PRESSURE TRANSDUCER

11 DATA LOGGER

12 COMPUTER

Sector Rig Collection

Device

Figure 2. Shower head test configuration

29
C5z

peS O

H

a

w

c/i

(saaaTX) awmoA

30

Figure

3.

Distribution

of

water

collected

in

sector

rig

compartments
Warm

water,

551

kPa

(80

psi)

K\\\\\\\\\\\K?^y7^

"i 1 1 1 1 1 —i 1 1 00 i^vD u“i «3- r-> esi i

OO

(*«3Ti) awmoA

31

Figure

4.

Distribution

of

water

collected

in

sector

rig

compartments
(«*I)

(md8) jotjoag-nms

Oe S3 03 SI 01 so

(radg) .10:100 g-ang

32

Figure

5A.

Measured

vs

metered

water

-

Figure

5B.

Measured

vs.

metered

water

warm

water

hot

water
Flow

Rate

Flow

Rate

Flow

Rate

Shower Heod Test Results

16

14

12

10

8

6

4

2

0

0 100 200 300 400 500 600 700 800

16

14

12

10

8

6

4

2

0

0. 100 200 300 400 500 600 700 800

Water Pressure (kPa)

16

14

12

10

8

6

4

2

0

0 100 200 300 400 500 600 700 800

Water Pressure (kPa)

' —v- «a *

5

i

: a xQ

£

*

0

D Hot K

_ X Warm

ater

water

Water Pressure (kPa)

1— 8

1 *

\ ' «r

£

O

O Hot «

X. Warm

ater

water

a

X x° 8 * 4k «*

ft"

G

G Hot « X Warm

ater

water

Figure 6A. Water flow rate vs pressure

33
Flow

Rate

$pnO

Flow

Rate

(£pm>

Flow

Rate

(J?pTT>

Shower Htoa Test Results

«

°

X o* sh c »* a*'

©

a a

X

Hot %

Warn

ater

water

r i 30 20 0 30 0 400 5 30 600 70te si

Water Pressure (kPa)

16

14

12

10

8

6

4

2

n

0 100 200 300 400 500 600 700 800

Water Pressure (kPa)

m *

R * *

n * © r 0

X

Hot wj

Warn i ter

ater

16

14

12

10

8

6

4

2

0

. d

C

c *

#

*

X

©

fir (Hot w< * jWarm i ter

rater

Water Pressure (kPa)

Figure 6B. Water flow rate vs pressure

34
(kpa)

1

60

0) 4-1 2

o

0 100 200 300 400 500

35

30

25

20

15

10

5

0

Figure 7. Water flow rate vs pressure - flow restrictors

35

(flpm)
APPENDIX A. WATER COLLECTION DEVICE CALIBRATION PROCEDURE AND RESULTS

The raw test data obtained from the water collection device consist of water

level measurements for each of 19 compartments. These values (in centimeters

of water height) multiplied by the calibration constants provide the volumes

of water in liters or gallons.* The constants or calibration factors may be

theoretically calculated, assuming zero wall thickness, from an equation for

volume based upon equal angular sectors and radial rings. Actual calibrations

are based upon the procedure below for the as-built inaccuracies in the sector

geometry and physical material thicknesses (table A-l indicates very small

differences between actual and assumed volumes). The calibration factors should

not be significantly different from the theoretical values.

The calibration procedure (performed with the water collection device installed

and leveled in the test location) is listed below (refer to figure 1 for the

nomenclature)

:

a. Each compartment of the water collection device was drained of water

completely and the holes plugged.

b. Initial volumes of measured water were added to the water collection

device compartments as follows:*

1. 120 ml ( 4 oz) to "00"

2. 240 ml ( 8 oz) to "a" compartments

3. 480 ml (16 oz) to "b" compartments

4. 600 ml (20 oz) to "c" compartments

c. The water levels for each of the compartments were read from the

graduated scales and recorded.

d. Incremental amounts of measured volumes of water were then added to

each compartment:*

1. 960 ml ( 32 oz) to "00"

2. 1920 ml ( 64 oz) to "a" compartments

3. 3840 ml (128 oz) to "b" compartments

4. 3840 ml (128 oz) to "c" compartments

e. The water level in each compartment was read and recorded.

f. The calibration constants (factors) for each compartment were computed

from the difference between the water level measurements and the two

known volumes. These calibration values are tabulated in table A-l.

* Any conveniently graduated cylinder(s) may be used.

36
Table A-l. Water Collection Device Calibration Results

Total volumes in each sector (gallons)

Compartment Calibration Factor

Theoretical

(predicted)

Actual

(measured)

00 .0214 .0219

la .0644 .0658

lb .1235 .1250

lc .1864 .1887

2a .0644 .0641

2b .1235 .1266

2c .1864 .1923

3a .0644 .0641

3b .1235 .1235

3c .1864 .1887

4a .0644 .0649

4b .1235 .1235

4c .1864 .1887

5a .0644 .0649

5b .1235 .1220

5c .1864 .1887

6a .0644 .0649

6b .1235 .1250

6c .1864 .1887

37
APPENDIX B. ALTERNATIVE METHODS OF WATER DEPTH MEASUREMENT

This section briefly describes alternatives for depth measurement methods in the

water collection device. The techniques discussed here provide improved resolution and reduce time required to make the depth measurements. The method

described earlier with small plastic scales, requires reading the level of the

miniscus for individual depths, which is not exact and may be cumbersome.

Figures B-l and B-2 are schematic diagrams which illustrate two alternative

test apparatus configurations for determining the sector water depth. These

methods require either a manometer bank and or installed pressure transducers.

The test configuration shown in figure B-l shows a method to determine the

depth of water collected in the test by substituting water manometers in place

of the graduated scales. In this arrangement each compartment of the water

collection device would have the water depth measured by attaching a pressure

tap to a tube connected to a graduated and calibrated vertical or inclined

manometer. The depth of the water in the compartment would be observed on the

manometer and indicates the level of water in the corresponding sector. For

the configuration adopted in these tests, a bank of 19 manometers would be

required to completely determine the water levels of all the compartments of

the water collection device. Additional fittings and components, such as a solenoid or manual valve and tee connection to facilitate draining of the

collector device would be installed at each pressure tap or bottom of the

compartment. Residual water in a compartment could be accommodated by

recording the initial and final values and the difference represents the

collected water. The manometer bank would simplify recording of the water

depth measurements and eliminate the awkward and tedious data gathering

procedure inherent in the method utilizing the graduated scales. The addition

of a calibration conversion scale would indicate the volume directly and save another computational step.

The schematic of the apparatus illustrated in figure B-2 is similar to the

instrumentation outlined in the above description of figure B-l. Here,

however, the difference is the substitution of pressure transducers for the

manometers. This technique requires costly transducers and signal conditioning

equipment, which may be difficult to install and use, but provides a means of

accurately automating the data collection to acquire data rapidly and efficiently. For extended series of tests this method may be cost-effective since

it completely eliminates the need to read the sector water levels manually.

38
V

O

in

39

Figure

B-l.

Alternative

test

configuration

-

manometer

bank
Figure B-2. Alternative test configuration - pressure transducer bank.

40
APPENDIX C

WATER COLLECTION DISTRIBUTIONS

41
Shower

Head

Aligment .

VERTICAL

Shower

Head

Alignaent *

VERTICAL

Shower

Head

Alignaent *

VERTICAL

42

Total

VOIU1W

of

VATER

CAUGHT »

10.7

liters

Total

VOLUHN

of

WATER

CAUGHT

1.4

liters

Total

VOLUMM

of

WATER

CAUGHT .57

liters

Total

VOLUHN

of

WATER

HETERED «

10.2

liters

Total

VOLUHN

of

VATER

HETERED »

7.»

liters

Total

VOLUMf

of

WATER

HETERED .53

litersI

DIFFERENCE =

-4.5 %

DIFFERENCE .

-5.4 I

DIFFERENCE

.-12 1
w«<

41S

(V>H H

mh •

««

>

.d

tfl

in

H at oi«AQr«AOf«xia«i4aa*«^Qo^joo U A o<H^-NWNWwww»rf»irtin-««««

a iu

o

sDCS

&19

M II M An u

•* ©» w 13 03 IS as ctf ««

6-* sa cm

vc un m

p cw »

fr* OS Mtoswi _ « ^ 03 &m

s*s ns •»* J— c*

a* JH > jg

H ©

as

t-4 411

1

U 4

•• II 41 4i M U

O O

ns

MEM hau •<uh > o —

Iu

SEh 03 04A04A04A04Ja04A04J30

C9

m 4*

II It II 40au

d w u A I-* B U Ct3 St SC t* 03 *

ua o3 —

ir* B*x G < h _ © «M©

H ©

Iwi ia

u

43
To

til

VOLUHN

of

VATER

CAUGHT

«

11.1

litors

Total

VOLUHN

of

WATER

CAUGHT

«

IS. 8

titan

Total

VOLUHN

of

WATER

CAUGHT

>

IS7

liters

Total

VOLUHN

of

WATER

HETERED

«

10.2

liters

Total

VOLUHN

of

WATER

HETE1ED

>

1S.1

liters

Total

VOLUHN

of

WATER

NETERED

>

144

liters

%

DIFFERENCE

>

-1.5

1

DIFFERENCE

«

-4.0

I

DIFFERENCE

>

-M
Te>t

Mealier

22

Shower

Head

Cl

Test

Naabar

21

Shower

Head

Cl

Test

Neaber

20

Shower

Hoad

Cl

Water

Teaperatare

*

00

deq.

C

Water

Toaparatore

»

01

dcq.

C

Vater

Teaperatare

=

3?

deo

C

Water

Pressere

«

137.8

kPa

Water

Pressare

»

300.5

kPa

Vater

Pressore

«

551 2

kPa

Shower

Head

Alignaent

«

VEHTICAL

Shower

Head

Aliqnaent

s

VERTICAL

Shower

Head

Alignaent

=

VERTICAL

Spray

Adjastaent

»

HAZIHUH

Spray

Adjustment

a

MAI I

HUM

Spray

Adjastaent

a

MAXIMUM

45
Showtr

Hiad

Alignaant

*

VERTICAL

Show«r

Head

Alignaant

«

VERTICAL

5ho«r

Ht

ad

AI

igamsnt

«

VERTICAL

Spray

Adjnitment

«

MAXIMUM

Spray

Adjostaent

*

MAXIMUM

S

p

riy

Adjiataant

r

MAXIMUM

H

CX

u

o

o

n M N <OB U

M M N £u

Q M Ul u at M U) Ul

£

s

I > a

«n *: O J3 V d A O KldD u KAOXAUxfXl O

o

o>•

« » M

—• I N N It ho w

OstX D w Ul 4 h a UmUI _ a: «~

«< l-i >

o

46 -
47
Shower

Hetd

Alignment

a

VERTICAL

Shower

Head

Alignment

a

VERTICAL

Shower

Head

Alignment

*

VERTICAL

Spray

Adjustment

«

MAXIMUM

Spray

Adjustment

e

MAXIMUM

Spray

Adjustment

a

MAXIMUM

Test

Duration

a

40

seconds

Test

Duration

a

30

seconds

T

Cf t

Duration

a

30

seconds

48
49
Shower

Heed

Alignment *

VERTICAL

Shower

Head

Alignaent *

VERTICAL

Shower

Head

Aligaaent *

VERTICAL

50

Total

VOLVHH

of

WATER

CAUGHT «

5.7

liter*

Total

VOIUHN

of

WATER

CAUGHT *

4.7

liters

Total

VOLUHN

of

WATER

CAUGHT «

5.1

liter*

Total

VOIUHN

of

WATER

HETERED =

5.7

liters

Total

VOLUHN

of

WATER

NETERED »

4.4

liters

Total

VOLUHN

of

WATER

HETERED a

5.7

liters1

DIFFERENCE «

-3.2 1

DIFFERENCE a

-4.3 %

DIFFERENCE *

-2J
Shower

Head

Alignaent

«

VERTICAL

Shower

Head

Aliguent

=

VERTICAL

Shower

Head

Alignaent

=

VERTICAL >

••inooerrioinNOvinoyioowio

U < M Ow

tn ac onzio««jaodACfd4aortfX)On)x)0 o*4*4^Mf4eomnr) <w< v<r lninin'o^>«

o

nun

<nu

O D> Qt

fl (3 0

in I

It H It

H n

M

Iiho wiQOinnei

s

3

N N II »Oi «h n d c

O* 03 OS

An o(3

ro i in n e *o i

B>XJ0ndJa0rdJ30nJJ30

0303

Eeo

II H II <»U

a o a

03 OS 03

51

Total

VOLUMN

ol

VATER

CAUCHT

=

5.3

liters

Total

VOLUMN

of

WATER

CAUGHT

=

4.6

liters

Total

VOLUNN

of

WATER

CAUGHT

Total

VQLUHN

of

WATER

METERED

«

5.3

liters

Total

VOLUMN

of

WATER

METERED

*

4.1

liters

Total

VOLUMN

of

WATER

METERED

1

DIFFERENCE

=

-.»

*

DIFFERENCE

«

-l.f

t

DIFFERENCE
Show*r

Held

Alignaent

«

VERTICAL

Shower

Head

Alignaent

«

VERTICAL

Shower

Head

Alignment

«

VERTICAL

Spray

Adjoitment

=

MAXIMUM

Spray

Adjmtaent

«

MAXIMUM

S

prty

Adjaetaent

«

MAXIMUM

H*

I— ad

S>o

o

E

t-m

ejis*< u «d A o i a a «f a u

£o HUM

^ 03 U

52
53
Shower

Head

llignaent

VERTICAL

54
Shower

Head

Alignment =

VERTICAL

Shower

Head

Alignment *

VERTICAL

Shower

Head

Aiignaent

VERTICAL

55

Total

VOLUMN

of

VATER

CAUGHT «

7.2

liters

Total

VOLUMN

of

WATER

CAUGHT »

4.0

liters

Total

VOLUHN

of

WATER

CAUGHT *

7.3

liters

Total

VOLUMt

of

WATER

RETRIED

4.4

liters

Total

VOLUHN

of

WATE1

RETRIED «

5.3

liters

Total

VOLUMN

of

WATER

RETIRED *i\

masft

DIFFERENCE

-12.3

ft

DIFFERENCE

-13.3

ft

DIFFERENCE

-It 9
I NBS-1T4A (rev. 2 -ec) U.S. DEPT. OF COMM. 1. PUBLICATION OR 2. Performing Organ. Report No. 3. Publication Date BIBLIOGRAPHIC DATA

REPORT NO.

SHEET (See instructions) NBSIR 82-2630 February 1983

4. TITLE AND SUBTITLE

DEVELOPMENT AND EVALUATION OF A TEST METHOD FOR SHOWER HEADS

5. AUTHOR(S)

Paul Kopetka and Lawrence Galowin

6. PERFORMING ORGANIZATION (If joint or other than NBS. see instructions)

national bureau of standards

DEPARTMENT OF COMMERCE

WASHINGTON, D.C. 20234

7. Contract/Grant No.

8 . Type of Report & Period Covered

9. SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street. City. State. ZIP)

U.S. Department of Housing and Urban Development

451 7th Street, SW

Washington, D.C. 20410

10. SUPPLEMENTARY NOTES

2) Document describes a computer program; SF-185, FIPS Software Summary, is attached.

11. ABSTRACT (A 200-word or less factual summary of most significant information. If document includes a significant

bibliography or literature survey, mention it here) A proposed test method for the evaluation of low-flow shower heads or flow-restrictormodified shower heads was developed. The test method provides for the measurement of

the principal operating characteristics, i.e., pressure-flow rate dependency and the

shower spray distribution. The requirements for laboratory instrumentation suitable

for application to the apparatus and the procedures for testing were established. A

water collection device, "sector rig," was designed and constructed for the measurement of spray distribution patterns. Experiments were conducted with a small number

of shower heads to determine the suitability of the proposed test method. The

experimental results indicated the applicability of the method for measurement of

spray distribution patterns and other conventional hydraulic performance parameters.

A proposed test method for evaluation of shower heads was prepared based upon the

analysis of the test results. The test method includes the specification of

instrumentation, apparatus, procedures, measurements, and data reduction.

12. KEY WORDS (Six to twelve entries; alphabetical order; capitalize only proper names; and separate key words by semicolon s) plumbing; showerheads; water supply devices jwater conservation

13. AVAILABILITY

[O] Unlimited

| 1 For Official Distribution. Do Not Release to NTIS

| | Order From Superintendent of Documents, U.S. Government Printing Office, Washington, D.C.

20402.

j^j Order From National Technical Information Service (NTIS), Springfield, VA. 22161

14. NO. OF

PRINTED PAGES

64

15. Price

$ 10.00

USCOMM-DC 6043-P80