A111DS 0371L7

Energy Test Method Development

for Electric Heat Pump Water

C. Andrew Wan

Product Performance Engineering Division

Center for Consumer Product Technology

National Engineering Laboratory

National Bureau of Standards

Washington, D.C. 20234

January 1930

Prepared for United States Department of Energy

and the

Oak Ridge National Laboratory

Oak, Ridge, Tennessee

national bureau

or staxdabds

LIBBABY

NOV 2 4 1980

N8SIR 79-1951 Hoi oux. Qaoi

ENERGY TEST METHOD DEVELOPMENT

FOR ELECTRIC HEAT PUMP WATER

HEATERS

C. Andrew Wan

Product Performance Engineering Division

Center for Consumer Product Technology

National Engineering Laboratory

National Bureau of Standards

Washington, D.C. 20234

January 1980

Prepared for United States Department of Energy

and the

Oak Ridge National Laboratory

Oak Ridge, Tennessee

U.S. DEPARTMENT OF COMMERCE, Philip M. Klutznick, Secretary

Luther H. Hodges, Jr., Deputy Secretary

Jordan J. Baruch, Assistant Secretary for Science and Technology

NATIONAL BUREAU OF STANDARDS, Ernest Ambler, Director

U

!

Table of Contents

Page

Summary i

I . Introduction * 1

II. Proposed Modifications 2

A. Modifications to Part 430.2 2

B. Proposed Modifications for the Test Method 2

1. Definitions 2

2. Test Conditions . 3

3. Test Procedures and Measurements 4

4. Calculation of Derived Results frcm Test Measurements 6

III. Rationale for Modifications to Test Method 8

A. Modifications to Part 430.2 8

B. Modifications for the Test Method 9

1 . Definitions 9

2. Test Conditions 9

3. Test Procedures and Measurements 11

4. Calculation of Derived Results from Test Measurements 12

References 14

Appendix A. Federal Register Notice, Vol. 42, No. 192 A-l

Test Procedures for Water Heaters and all following

amendments in the FR

Appendix B.

I. Introduction B-l

II. Design Review of Electric Heat Pump Water Heaters B-l

A. The Ideal Thermodynamic Cycle B-2

1. Analysis of Heat Punp Cycle Processes B-2

2. Heat Pump Performance Measure B-3

3. Example B-3

3. Analysis of Components B-4

1. Motor Compressor B-4

2. Evaporator Fan Work B-5

3. Heat Pumping Rate B-5

4. Condenser Coil B-6

5. Evaporator Coil B-6

6. Throttling B-7

7. Water Storage Tank B-7

8. Resistance Heater B-7

C. Controls B-7

D. Summary B-8

III. Differences Between Electric Water Heater and Electric Heat

Pump Water Heater B-8

A. Difference in Construction B-9

1. Electric Water Heater B-9

2. Electric Heat Pump Water Heater B-9
Page

B. Differences in Operation B-10

1. Electric Water Heater B-10

2. Electric Heat Pimp Water Heater B-ll

C. Summary B-ll

IV. Confirmatory Laboratory Tests B-ll

A. Purposes of the Tests B-12

B. Laboratory Setup B-12

1. Description of the Laboratory B-12

2. Instrumentation B-12

3. Data Collection B-13

4. Water Supply System B-13

C. Tests B-13

1. Standby Tests B-13

2. Recovery Tests B-14

3. Energy Consumption B-14

4. Power Measurement of the Heat Punp B-14

D. Results and Discussion B-14

1. Standby Tests B-14

2. Recovery Tests B-15

3. Energy Consumption B-16

4. Pcwer Consumption of the Heat Punp B-18

E. Conclusions B-18

V. Validation Tests B-18

A. Purpose of Tests B-18

B. Laboratory Setup B-19

1. Environmental Chamber B-19

2. Instrumentation B-19

3. Data Collection and Reduction B-19

C- Draw Tests B-19

D. Results and Discussions B-20

E. Conclusions B-20

Table 1. Location of the Interior Thermocouples B-22

Table 2. Summary of Draw Tests B-23

Table 3. Standby Loss Tests to Determine Effects of the Ambient

Temperature B-24

Table 4. Standby Loss Tests to Determine Effects of the Cutout

Temperature B-24

Table 5. Recovery Tests to Determine Effects of the Cutout

Temperature B-24

Table 6. Recovery Tests to Determine Effects of the Inlet

Temperature B-25

Table 7. Recovery Tests to Determine Effects of the Ambient

Temperature B-25

Table 3. Confirmatory Tests to Determine the Effects of Floating

Temperature Rises in Daily Energy Consumption B-26

Table 9. Results of Validation Draw Tests for Daily Energy

Consumption B-27
Page

Figure la. Electric Heat Pump Water Heater B-28

Figure lb. Evaporator Coil and Compressor Unit B-28

Figure 2. Electric Heat Pump Water Heater Schematic Diagram ... B-29

Figure 3. Condenser Coil B-30

Figure 4. Pressure-Enthalpy Diagram of the Four Heat Pump Cycles. B-31

Figure 5. Operating Cycles of the Electric Heat Pump at Three

Different Condenser Temperatures (R-12) B-33

Figure 6. A Typical Construction of the Double-Walled Condenser

Coil B-35

Figure 7. Schematics of the Laboratory Setup B-36

Figure 8. Typical Temperatures (Ambient, TCI, TC3, TC5) vs Time

for a Recovery and Standby Test B-37

Figure 9. Typical Temperatures (TC2, TC4 , TC6, and Water Average)

vs Time for a Recovery and Standby Test B-38

Figure 10. Standby Loss vs (T^-T ) ^ B-39

Figure 11. Standby Loss vs Ambient Temperature T

f- 62.8 C (145°F) . B-39

Figure 12. Standby Loss vs Cutout Temperature T - 23.9 C (75°F) . B-39

Figure 13. Cooldcwn Behavior of an Electric Heat Pump Water

Heater Storage Tank B-40

Figure 14. Recovery Efficiency vs Cutout Temperature B-41

Figure 15. Recovery Efficiency vs Inlet Temperature B-41

Figure 16. Recovery Efficiency vs Ambient Temperature B-41

Figure 17. Average Water Temperature, Average Ambient Temperature

,

Heat Pump Energy, and Total Cumulative Energy vs Time

for a Typical Recovery Test B-43

Figure 18. Heat Pump Power vs Mean Water Temperature B-44

Figure 19. Draw Test-Temperature of TCI, TC2, and TC3 vs Time . . B-44

Figure 20. Draw Test-Temperature of Ambient and TC6 vs Time . . . B-45

Figure 21. Water Temperature, Ambient Temperature and Heat Pump

Energy vs Time B-46

Figure 22. Ambient Temperature vs Time B-47

References B-48

Summary

Modifications are proposed for the current U.S. Department of Energy

test procedures for water heaters in order to make them applicable to

electric heat pump water heaters. The modifications are in the areas of

definitions and technical procedures. The latter include the test

conditions, test procedures and measurements, and calculations. Reasons

for making these modifications and laboratory test data are provided to

support the modifications in the technical procedures. The main

modifications include: 1) lowering the water supply temperature from 70

l

’F to 55°F, 2) lowering the tank thermostat setting from 160°F to 145°F to

maintain the same 90°F temperature rise, 3) measuring the power input

instead of using the nameplate rating as in the case for an electric water

heater, 4) measuring the recovery efficiency instead of calculating it by

using the stanaby losses in the case for an electric water heater.

i

I. Introduction

This report is submitted to DOE/ORNL by the Product Performance

Engineering Division, Center for Consumer Product Technology, NBS, under

the Interagency Agreement No. EW-78-I -05-5750, Task A, as revised via

Narrative Report for July 1978. The purpose of this report is to present

proposed modifications to the current test procedure for water heaters to

include electric heat pump water heaters and the rationale for these

modifications. This report presents in section II the proposed

modifications to part 430—Energy Conservation Program for Appliances, Test

Procedures for Water Heaters—of the Code of Federal Regulations. That

document, as published in the Federal Register, Vol. 42, No. 192, Tuesday,

October 4, 1977, is attached as Appendix A for reference. This report

presents in section III the rationale for making these modifications.

In section IIA, the additions to part 430.2—Definitions—are given.

In section IIB, the modifications to the Appendix E (of the same part

430) —Uniform Test Method for Measuring the Energy Consumption of Water

Heaters—(henceforth referred to as Test Method) are discussed. In it each

section of the Test Method requiring changes is referred to specifically,

and the necessary changes are given to include electric heat pump water

heaters.

A final rule in the Test Method for the determination of first hour

rating (FHR) of water heaters has not been published in the Federal

Register. Therefore, FHR is net yet part of the regulations. NBS provided

a test procedure for FHR to DOE and this has been published as a proposed

rule in the Federal Register (Appendix A). As proposed, the FHR test

procedure would require some modifications in order to be applicable to the

electric heat pump water heater.

If a new section must be added, it is included in the format of the

Test Method. Proposed additions to the text are indicated by underlines

and deletions by

In section IIIA the rationale for additions to part 430.2 are given.

In section IIIB, each section of the Test Method requiring change and the

additional sections are again referred to specifically and the rationale

for changes or additions given.

The relevant results of the studies which provided the technical

analysis and experimental data necessary to develop this report are summarized in Appendix B.

1
II. Proposed Modifications

A. Modifications to Part 43C.2

430.2 Definitions

(5) "Heat pump" means an electrically-driven mechanical

refrigeration device designed and made to transfer thermal energy from

a low temperature level to a higher temperature level and includes all

ancillary equipment such as fans, pumps, or controls necessary or the

device to perform its function.'

(5)(d) "Electric heat pump water hearer1 * means a water heater which

utilizes electricity as the energy source to supply the integral heat

pimp and immersed heating element, if any, for heating the water,

which has a manufacturer's specified energy input rating of 1 2

kilowatts or less at a voltage no greater than 250 volts, and which

has a manufacturer's specified storage capacity of not less than 20

gallons nor more than 120 gallons.

B. Proposed Modifications for the Test Method

1. Definitions

1.1 "Cutout” means ZVi<£ jridnterit Zvl ZM& when a water heater

thermostat (s) has acted to reduce the energy or fuel input to

the heating elements or heat pump or burners to a minimum.

1.4 "Recovery efficiency" means the ratio of the heat imparted

to the water to

( c) in the case of an electric heat pump water heater , the combined energy input to the heating element, if any, ana the heat pump during the period that the water

temperature is raised from inlet temperature to the final

temperature with the tank filled to capacity.

1.6 "Condensor coil" means that component of a heat pump whose

function is to transfer thermal energy into the system at the

higher temperature level.

1.7 "Evaporator" means that component of a heat pump whose

function is to transfer thermal energy out of the system at the

lower temperature level .

2
2 . Test 2.3 Conditions

Water Supply. During the entire test maintain the water

supply to the water heater inlet at a tanperature of between

68° and 72°F for al l gas, oil, and electric water heaters and

between 53°F and 57°F for an electric heat pump water heater

and at a gauge pressure of between 40 pounds per square inch and

the maximum pressure specified by the manufacturer for the water

heater under test. If the water supply pressure varies outside

these limits during testing, the heater shall be isolated by use

of a shut-off valve in the supply line with an expansion tank

installed in the supply line downstream of the shut-off valve.

There shall be no shut-off means between the expansion tank and

the water heater inlet.

2.4

Energy Supply.

2.4.1 Electrical Supply. For an electric water heater,

an electric heat pump water heater , and for the auxiliary

electrical system, if any, of an oil or gas water heater,

maintain the electrical supply voltage to within — 1

percent of the center voltage range specified by water

heater manufacturer on the water heater nameplate

throughout the entire operating portion of each test.

2.5

Thermocouple Installation. Install six thermocouples

inside the water heater tank. Position each thermocouple

measuring junction along a vertical line at the level of the

center horizontal plane of each of six nonoverlapping sections

of approximately equal volume from the top to the bottom of the

tank such that each thermocouple is surrounded by water and as far as possible frcm any heating element, anodic protective

device, £ water tank or flue wall, or condenser coil, if any . The anodic protective device may be removed in order to install

the thermocouples and all testing may be carried out with the

device removed. Install thermocouples in both the cold water

inlet pipe and the hot water cutlet pipe net more than six

inches from the connections to the water heater, or, where those

connections are inaccessible, at the closest accessible point to

those connections. Install in the test roan a thermocouple with

the junction shielded against direct radiation from the water

heater or air current due to the evaporator fan, if any, and

positioned at the vertical mid-point of the heater at a perpendicular distance of approximately 24 inches frcm the

surface of the water heater jacket. Provide an associated

temperature measursnent and indicator system to assure that the

temgerature indicated for the thermocouple location is within — 1 F of the actual temperature at that location.

3
2.6 Setting the Tank Thermostat. Starting with a tank of

unheated water, initiate normal operation of the water heater.

After cutout, determine whether the maximum value

Q

of the mean

tank temperature is within the range of 160°F — 5 r for all gas,

oil, or electric water heaters or 145°F — 5 F for an electric

heat pump water heater . If not, turn off the water heater,

adjust the thermostat, empty the tank and refill with unheated

water, then initiate normal operation of the water heater, and

once again determine the maximum mean tank temperature after

cutout. Repeat this sequence until the maximum mean tank

Q temperature after cutout is within the range of 160 F — 5 F for

all gas, oil, or electric water heaters or 145°F — 5°F for an electric heat pump water heater, at which time the thermostat is

properly set. If a water heater has two thermostats, the

thermostat which controls the upper heating element shall be set

first to yield a maximum water temperature of 160

+F — 5 F for

all gas, oil, or electric water heaters or 145 F — 5 F for an electric heat pump water heater as measured by the topmost

thermocouple after cutout. The thermostat which controls the

lower heating element or heat pump shall then be set to yield a maximum tank temperature of IgO F —

q

5 F for all gas, oil, or electric water heaters or 145 F — 5 F for an electric heat pump

water heater after cutout.

2.8 Room Ambient Temperature. Maintain the ambient air

temperature of the test room between 65 F ang 85 F fo^ all gas,

oil, or electric water heaters or between 6Q

C

F and 81 F for an electric heat pump water heater at all times during the test, as measured according to section 3-5. The ambient

Q

air temperature

during these tests shall not vary more than — F for gll gas , oil, or electric water heaters or more than +3 F or -6 F for an electric heat pump water heater from the average ambient air

temperature determined as the arithmetic average of the air

temperatures measured periodically at intervals no greater than

15 minutes throughout the duration of the test.

Test Procedures and Measurements.

3-2 Power Input Determination.

3.2.3 Power input determination for an electric heat pump

water heater. Initiate the recovery operation of the

electric heat pump water heater specified in section 3.3.3

and by using the appropriate instrumentation specified in

section 2.7, determine the quantity of electrical energy

used in the duration of the recovery test. The power

input. P, expressed in kilowatts, is calculated as
z

= t- ’ r

where Z is defined in section 4.1.4 and

rt = duration of the recovery test determined

r in accordance with section 3-4.1.

3.3 Recovery efficiency.

3 . 3.3 Recovery efficiency for an electric heat pump water

heater. With the water heater turned off, fill the tank

with water and eliminate any residual air remaining in the

tank. If the mean tank temperature is constant and within

55°F — 2 F record the mean tank temperature, initiate

normal operation of the water heater, and begin measuring

the energy flow to the heat pump and the heating element,

if any, of the water heater using the appropriate

instrumentation specified in section 2.7. After cutout

determine the maximum mean tank temperature and record the

total electrical energy flow, Z , to the heat pump and the

heating element, if any, of thewater heater, from

initiation to cutout. Record the temperature difference,

At , obtained by subtracting the initial from the final

maximum mean tank temperature.

3.4 Standby Loss.

3.4.3 Standby loss for an electric heat pump water

heaterEstablish normal water heater operation within

the maximum mean tank temperature within the range

specified in section 2.6 and with all air eliminated from

the tank. Begin the standby loss test immediately after

cutout. At the beginning of the standbv loss test record

the time. the mean tank temperature, the ambient air

temperature, and begin measuring energy flow to the heat

pump and the heating element, if any, of the water heater

using the appropriate instrumentation specified in section

2.7. All water heaters to be tested must be equipped with

immersed heating elements that have a design power rating

of 45C0 watts, if the water heaters are equipped wi th

heating elements, unless such a design power rating

exceeds the maximum design power rating specified by the

manufacturer for the water heater to be tested in which

case the standby loss test will be conducted with the

water heater equipped with immersed heating elements of a design power rating equal to the manufacturer's specified

maximum design power rating.
At the end of the first 15 minute interval and at

the end of each subsequent 15 minutes interval following

the beginning of the test, record the mean tank

temperature and the ambient air temperature. Continue

these measurements until the end of a 48-hour period

unless a heating element, if any, or heat pump is on at

that time, in which case continue these measurements until

the first subsequent cutout. When the test is terminated , record the total electrical energy flow. Z . to the

heating element, if any, and heat pump, frSm the beginning

to the end of the test period, the final mean tank

temperature. The final ambient air tanperature, and the

time duration, t, of the standby loss test, in hours

rounded off to the nearest tenth of an hour, which elapsed

from the beginning to the end of the test period.

Calculate the average of the recorded values of the mean

tank temperatures and of the ambient air temperatures

taken at the end of each time interval, including in each

case the initial and final values. Determine the

difference AT between these two averages by

substracting tne latter from the former, and the

difference, AT

^

, between the final and initial mean tank

temperatures by substracting the latter from the former.

4. Calculation of Derived Results from Test Measurements

4.1 Recovery efficiency.

4.1.4 Recovery efficiency for an electric heat pump water

heater. For an electric heat pump water heater, calculate

the recovery efficiency, E

^

, expressed as a dimensionless

quantity and defined as :

k x V x A t

E

r

= Z x 3412 Btu/kWh

r

where k, V, and AT^ are defined in section 4.1.1 .

Z = total electrical energy flow to tne heau pump

and the heating element, if any, in the recovery

test, determined in accoraance with section 3. 3. 3,

expressed in kilowatt-hours.

6
4.2 Standby loss.

4.2.3 Standby loss for an electric heat pump water

heate^. calculate tne standby loss, S, expressed in

hour and defined as:

Z x 3412 Btu/kWh AT.,

_ s - 4

"kxVxAT-xt AT, x t x E*

3 3 r*

where k and V are as defined in section 4.1.1.

Z = total electrical energy flow to the heat pump

a^d heating element, if any, in the standby loss

test, determined in accordance with section 3.4.3.

A T-, = difference between the average value of the

mean tank temperature and the average value of the

ambient air tanperature during the standby loss

test, determined in accordance with section 3.4.3 . expressed in~°F . ATa

= difference between the initial and final mean

tank temperatures, determined in accordance with

section 3.4.3, expressed in F.

t = duration of the standby loss test, determined

in accordance with section 3-4.3, expressed in

hours

E* ~ E as calculated in section 4.1.4 for an electric heat pump water heater .

4.4 Average hourly hot water storage energy consumption.

Calculate the average hourly hot water storage energy

consumption, c , the average energy required per hour to

maintain storeli swater temperature, expressed in Btu per hour and

defined as:

c : S x k x V xAT,,

us 6’

where

k and V are as defined in section 4.1.1.
S is as calculated in section 4.2.1 for gas and oil water

heaters, or section 4.2.2 for electric water heaters, or section 4.2.3 for an electric heat pump water heater.

4.5 Average daily energy consumption.

4.5.4 Average daily energy consumption for electric water

heaters and electric heat pump water heaters. For an electric water heater pr an electric heat pump water

heater , calculate the average daily energy consumption,

C , expressed in kilowatt-hours per day and defined as:

C =

3412 Btu/kWh

24 hrs

+ C x

us

(- day ” P x 3412 Btu/kWh) - J

h-°c]

G,^ is as calculated in section 4.3.

c is as calculated in section 4.4. us

J, and J are as defined in section 4.5.2.

h c

P r input power, determined in accordance with section

3-2.1 for electric water heaters with other than

immersed heating elements or section 3-2.2 for

electric water heaters with immersed heating

elements or section 3-2.3 for electric heat pump

water heaters , expressed in kilowatts.

III. Rationale for Modifications to Test Method

A. Modifications to Part 430.2.

430.2 Definitions

(5) This addition is made in order to define the term "heat pump."

(5)(d) This addition is made in order to define the term "electric

heat pump water heater." The heat pump component, as defined here, is

considered as an integral part of the water heater as manufactured in

the factory. The heat pump is not designed and made as a separate

package to be retrofitted to an existing water heater.

8
B. Modifications for the Test Method

1. Definitions

1.1 This change is made in order to include the heat pump as a source of heat in defining the term "cutout."

1.4 This change is also made in order to include the heat pump

as a source of heat in defining the term "recovery efficiency."

1.6 This section is needed to define the heat pump condensor

which is addressed in later sections of the Test Method.

1.7 This section is needed to define the heat pump evaporator

which is addressed in later sections of the Test Method.

2. Test Conditions.

2.3 Water Supply. The National Bureau of Standards has

determined that the national average water supply temperature is

55°F (Appendix A). The current test method specifies a 70 F

water supply temperature for the reason that a 70 F water supply

temperature is less burdensome to obtain for use in the testing

of water heaters. Furthermore, for the general types of gas,

oil, or electric storage type water heaters, the inlet water

temperature has a negligible effect on the determination of the

water heater's recovery efficiency. For most testing

facilities, climatic conditions or other factors are such that

I'or all or part of the year water supply temperatures exceed

55 F. Therefore, if a 55 F water supply temperature were

specified in the current test method, these facilities would

have an added cost of equipment and time to cool the available

supply water prior to conducting a test.

Using the same 7C°F water supply temperature for testing

of an electric heat pump water heater, however, imposes a penalty on the recovery efficiency for this type of water

heater. Tnis is due to the fact that the heat pump works more

efficiently at a lower condenser temperature (water temperature)

than at a higher condensor temperature for the same evaporator

temperature (room temperature) (Appendix B). A 55°F water

supply temperature, therefore, is specified for the electric

heat pump water heater in order to yield energy use information

comparable to the information for the other types of water

heaters using the 7C°F water supply temperature.

In order to establish the same tolerance for variation as

in the current test method requires the water supply temperature

9
to the electric heat pump water heater inlet to be maintained

between 53°F to 57°F.

2.4.1 Electrical supply. The change in this section is

made to include the electric heat pump water heater.

2.5 Thermocouple Installation. The current test method

requires that the thermocouples installed to measure the mean

water temperature be positioned as far as possible from any

obstructions such as the heating element, anodic protective

device or a water tank or flue wall. In the case where there is

a heat pump condensor coil in the water heater, the

thermocouples should be positioned as far away as possible from

the condensor coil also in order to minimize any direct effects

the condensor coil may have on the accurate measurement of water

temperature using thermocouples.

The current test method requires that the test room

thermocouple be shielded against direct radiation from the water

heater. The electric heat pump water heater also generates

convective air currents around the water heater because of the

evaporator fan, therefore, the test room thermocouple should

also be shielded against this convective air current.

2.6 Setting the Tank Thermostat. Water heater thermostats are normally factory-set at 140°F for gas water heaters and at 150°F

for electric water heaters. DOE uses the average value of the

two common factory settings of water heater thermostats. Since

NBS has determined that the national average water supply

temperature is 5g

uF the difference between these two

temperatures, 90

U

F, is the required water temperature rise in

the current test method. The 55°F water supply temperature is now proposed for the electric heat pump water heater. With a required water temperature rise of 9C°F then, the tank

thermostat setting must be specified at 145°F.

The maximum mean tank temperature after cutout, therefore,

should be 145 F — 5 F to maintain the same temperature

differential and tolerance as in the current test method.

2.8 Room Ambient Temperature. The tests conducted on the

electric heat pump water heater in Ref. 2, indicate that both

the standby loss and the recovery efficiency are affected by the

variation of the room ambient temperature. Therefore, the roan ambient temperature should not be allowed to vary over too wide

a range. However, to maintain the room ambient temperature

within a narrow range may require the use of an environmental

chamber for testing which could become excessively burdensome.

10
The modified range of room ambient temperature, then, should be

the narrowest achievable without the use of an environmental

chamber. Results presented in Appendix B indicate that a range

for the room ambient temperature of 75°F — 6°F can usually be

achieved without the use of an environmental chamber.

The standby tests reported in Appendix B also indicate

that during short periods of heat pump operation, the room ambient temperature may dip momentarily. It is impossible to

avoid the dipping of the room ambient temperature without the

use of a rapid response environmental chamber. Therefore, the

test method is modified to allow for more undershooting than

overshooting. This permits the room ambient temperature to dip

momentarily during short periods of heat pump operation.

3. Test Procedures and Measurements

3.2 Power Input Determination.

3.2.3 Power input determination for an electric heat pump

water heater. One major difference between the electric

water heater with immersed elements and the electric heat

pump water heater is in the manner they consume power.

The former operate at a constant power when energized; the

latter operates at variable power when the heat pump is

energized. Hie amount of energy an electric heat pump

water heater consumes depends strongly on its operating

conditions. This fact is clearly documented in Appendix

B.

The input power is used to determine the average

number of hours the water heater is operating in the

recovery mode as required in the equation to determine the

average daily energy consumption for electric water

heaters. The input power is an average power over the

period of a recovery test. Therefore, the total

electrical energy is measured for a recovery test and the

average power is equal to that total electrical energy

divided by the time elapsed for the test.

3.3 Recovery Efficiency

3-3*3 Recovery efficiency for an electric heat pump water

heater. Because the power consumption of the electric

heat pump water heater is variable, the recovery

efficiency has to be experimentally determined. The test

starts when the mean tank temperature is constant and

within 55 F — 2 F, the same temperature as the water

11
supply. Then the test is done similarly to the recovery

test for gas, oil, and electric water heater with other

than immersed heating elements as specified in the current

test method.

3.4 Standby Loss

3.4.3 Standby loss for an electric heat pump water

heater. This type of water heater may have two different

types of heat sources, the heat pump and the immersed

heating element. The test should be conducted in the same manner as that for an electric water heater with immersed

heating elements. The electric heat pump water heater

under test should be equipped with a standard 4500 watt

heating element unless such a power rating exceeds the

maximum design power rating specified for the units to be

tested. In which case the standby test for the units

should be conducted using heating elements of a design

power rating equal to that specified by the manufacturer

for the units. This latter procedure is to maintain the

same restrictions as those specified in the current test

method for electric water heater with immersed heating

elements.

4. Calculation of Derived Results from Test Measurements

4.1 Recovery Efficiency

4.1.4 Recovery efficiency for an electric heat pump water

heater. The calculation of recovery efficiency for this

type of water heater is the sane as that for the electric

water heaters with other than immersed heating elements.

The inclusion of this section is meant to account for the

different wordings and definitions in the calculation of

the recovery efficiency.

4.2 Standby Loss

4.2.3 Standby loss for an electric heat pump water

heater. The difference between the calculation of the

standby loss for the electric heat pump water heater and

for the electric water heater with immersed elements is

that the recovery efficiency for the former is an experimentally determined value and for the latter is a predetermined value of 0.98.

12
4.4 Average Hourly Hot Water Storage Energy Consumption

The only modification in this section is to include the

electric heat pump water heater.

4.5 Average Daily Energy Consumption

4.5.4 Average daily energy consumption for electric water

heaters and electric heat pump water heaters. The only

modification to the calculation in this section is in the

determination of the water heater input power. In the

case of electric water heaters with immersed heating

elements, the input power is taken as the design power

rating of the heating elements. In the case of electric

water heaters with other than immersed heating elements,

the input power is a measured value. In the case of the

electric heat pump water heater, the input power is an

average derived by dividing the electrical energy input

duing a recovery test by the elapsed time of the test.
References

1. Wan, C.A. Letter Report for Tasks 1, 2, and 3, Energy Test Method

Development for High Efficiency Water Heaters.

2. Wan, C.A. Letter Report for Task 4, Phases 1, 2, and 3, Energy Test

Method Development for High Efficiency Water Heaters.

3- Chaddock, J. B., Feasibility Study of the Heat Pump Water Heater, Final

Report, Purdue University, Lafayette, IN, August 31, 1961.

14
54110

[3128-01 ]

Title 10—Energy

CHAPTER II—FEDERAL ENERGY ADMINISTRATION.

PART 430—ENERGY CONSERVATION

PROGRAM FOR APPLIANCES

Test Procedures for Water Heaters AGENCY: Federal Energy Administration. ACTION: Final rule. SUMMARY: This rule prescribes final

test procedures for water heaters. Appliance test procedures are one element

of the appliance energy efficiency program required by the Energy Policy and

Conservation Act. EFFECTIVE DATE: November 8, 1977. FOR FURTHER INFORMATION CONTACT:

James A. Smith (Office of Conservation) , Room 307 Old Post Office Building, 12th and Pennsylvania Avenue

NW„ Washington, D.C. 20461 (202-

566-4635).

Jim Meraa (Media Relations), Room

3104 Federal Building, 12th and Pennsylvania Avenue NW„ Washington,

D.C. 20461 (202-566-9833)

Robert D. R. de Sugny (Office of the

General Counsel) , Room 5116 Federal

Building, 12th and Pennsylvania Ave- nue NW., Washsington, D.C. 20461

(202-566-9750 or 202-566-9380)

SUPPLEMENTARY INFORMATION:

- A. Background

The Federal Energy Administration

(FEA) hereby amends Part 430, Chapter

n of Title 10, Code of Federal Regulations, in order to prescribe test procedures for water heaters pursuant to section 323 (42 U.S.C. 6293) of the Energy

Policy and Conservation Act (Pub. L. 94-163). Water heater test procedures

were proposed by notice issued April 21, 1977 (42 FR 21576, April 27, 1977) , and a

public hearing on the proposed test procedures was held on June 13, 1977. By notice issued May 24, 1977 (42 FR

27896, June 1, 1977), FEA established

Subparts A and B of Part 430, Chapter

II of Title 10, Code of Federal Regulations. Certain definitions and general

provisions applicable to the energy conservation program for appliances have

been promulgated in Subpart A. Final

test procedures for room air conditioners, dishwashers, television sets, clothes

dryers, electric refrigerators, freezers,

and electric refrigerator-freezers, have

been prescribed in Subpart B and the

final test procedure for clothes washers

has been issued today by separate notice. Several other test procedures have been

proposed for inclusion in Subpart B and

FEA has also proposed a Subpart C for appliance energy efficiency improvement

targets. An outline of the provisions of Part 430 which have so far been established, including provisions in today’s

notice, is as follows:

APPENDIX A

RULES AND REGULATIONS

Subfast A—General Provisions

Sec. 430.1 Purpose and scope.

430.2 Definitions. Subpabt B—Test procedures

Purpose of scope. Test procedures for measures of energy consumption.

(a) Refrigerators and refrig- erator-freezers. (b) Freezers.

(c) Dishwashers.

(d) Clothes dryers.

(e) Water heaters.

(f) Room air conditioners.

• • •

1 •

(h) Television sets. %

• • » •

( j ) Clothes washers. Units to be tested [reserved]. Representations regarding measures

of energy consumption.

(a) Refrigerators and refrigerator-freezers.

. (b) Freezers.

(c) Dishwashers.

(d) Clothes dryers.

( e ) Water heaters.

(f) Room air conditioners.

• • • • •

(h) Television sets. • • • • •

(J) Clothes washers. Appendices to Subpabt B

Appendix A1—Uniform Test Method for Measuring the Energy Consumption of

Electric Refrigerators and Electric Refrigerator-freezers.

Appendix B—Uniform Test Method for Measuring the Energy Consumption of Freezers. Appendix C—Uniform Test Method for Measuring the Energy Consumption of Dishwashers. Appendix D—Uniform Test Method for Measuring the Energy Consumption of Clothes

Dryers. Appendix E—Uniform Test Method for Measuring the Energy Consumption of Water

Heaters. Appendix F—Uniform Test Method for Measuring the Energy Consumption of Room

Air Conditioners.

430.21 430.22

430.23 430.24

• • • • • Appendix H—Uniform Test Method for Measuring the Energy Consumption of Television Sets.

• • • • • Appendix J—Uniform Test Method for Measuring the Energy Consumption of Clothes Washers. B. Discussion of Comments

Comments were received from industry, consumers, and both Federal and

State agencies. Those comments which

were directly concerned with the labeling

program under section 324 of the Act

were forwarded to the Federal Trade

Commission for consideration in devel- oping labeling rules applicable to water

heaters and they are not addressed here. The following is a discussion of the is- sues raised by those comments which

pertained to the technical aspects of the

proposed water heater test procedures.

The comments have been analyzed by

topic, rather than source, since in many

cases the same or similar comments were

received from more than one person.

1. THE BURDEN OF TESTING Both the electric water heater manufacturing Industry and the oil water

heater manufacturing industry commented that the proposed test procedure was unduly burdensome, however, their

objections were based on different grounds.

The basis of the electric water heater

industry’s objection was that testing

costs would be prohibitive due to the ex- tremely large number of basic models

they would be considered to manufacture

under the test procedure’s proposed defi- nition of basic model. That definition categorized units as different basic models not only if they differed in factors such as tank capacity and insulation, but

also if they differed in heater element

wattage or voltage ratings. As a conse- quence, one manufacturer commented

that he theoretically offered 20,000 basic

models. Another manufacturing firm

stated that 144 different electrical input

configurations are available for each of

its electric water heater tank sizes. FEA finds that the test procedure, as proposed, would prove unduly burden- some for manufacturers of electric water

heaters with immersed heating elements

in view of the large number of basic

models that would have to be tested and

the attendant high cost of testing. As a

result, FEA has made changes .to the pro- posed test procedure which are designed

to reduce the burden of testing for manufacturers of electric water heaters with

immersed heating elements. The changes

are based on the fact noted at the hearing and in the comments that the electri- cal characteristics of an electric water

heater with immersed heating elements

have a minimal effect on efficiency for many purposes of the test procedure. It was therefore feasible to eliminate the

distinction between units made on the

basis of electrical characteristics. This

reduces the number of basic models that

most manufacturers would be considered

to produce to twenty according to testi- mony received at the hearing.

As a consequence, several important

changes in the test procedure have been

made. First, the definition of a water

heater basic model was revised to exclude

immersed heating elements from consideration. Second, the standby loss test for electric water heaters with immersed

heating elements was revised to require

the installation of “standardized” heating elements in the water heaters to be

tested. Third, the hot water supply rating

test and the recovery rate calculation were deleted from the test procedure.

Finally, the method for determining the

power input for electric water heaters

with immersed heating elements was

changed. Each of these changes is dis- cussed in detail in other sections of the

preamble.

The oil water heater manufacturing in- dustry also commented that the test pro- cedure was burdensome as applied to them and they requested to be exempted

from testing. They based their request on

the fact that they represent only one

percent of water heater sales and the

FEDERAL REGISTER, VOL 42, NO. 192—TUESDAY, OCTOBER 4, 1977

A- 1
claim that their costs of testing would

be higher than for manufacturers of other types of water heaters. The oil water heater manufacturing industry

presented a cost analysis to demonstrate

how the costs of testing would result In

a much higher per unit cost increase for water heaters produced by a small manufacturer of oil water heaters with small

production runs than for a large manufacturer of electric water heaters with

large production runs. Thus, it was

claimed, the much greater increase in

price due to testing costs of oil water

heaters over gas and electric water

heaters would price the oil water heaters

outside of the water heater market and

lead to the demise of the oil water heater

manufacturing industry.

FEA finds that insufficient evidence

has been produced by the oil water

heater manufacturing industry to establish grounds for excluding oil water

heaters from the water heater test procedure. The cost analysis presented is a comparison of hypothetical cases. No

evidence was presented to indicate that

these hypothetical cases are representative of industry-wide conditions or that

the costs would be any different for a

small electric water heater manufacturer. The sampling plan used in the cost

analysis was not the sampling plan

which appeared in the proposed test pro- cedure and the assumption was made

that each manufacturer would test his own units even though independent test- ing laboratories could be utilized. FEA

rejects the recommendation that oil water heaters be excluded from the water

heater test procedure at this time but

may reconsider its position upon the submission of sufficient evidence that the

test procedure is unduly burdensome or

significantly more burdensome to oil water heater manufacturers as compared to similar sized manufacturers of other types of water heaters.

2. FLUE REQUIREMENTS

A comment made was that a specifica- tion is needed for the attachment of a

flue pipe extension to gas or oil water

heaters having horizontal vent outlets. FEA concurs. The flue requirement

specification in the proposed test proce- dure inadvertently addressed only water

heaters with vertical vent outlets. Section 2.2 of Appendix E has been revised

to incorporate a specification for attaching a flue pipe to a water heater with a

horizontal vent outlet. Another comment made was that the

test procedure should require that a direct vent water heater be set up as specified in the manufacturer's instructions that accompany the water heater. FEA

concurs with this comment with the proviso that the length of vertical flue pipe

attached to the water heater must not

be greater than the specified five foot

length. Section 2.2 of Appendix E has

been revised to incorporate this specifi- cation. A third comment suggested the use of a longer flue pipe extension in the test procedure to better represent actual conditions of gas and oil water heater lnstalRULES AND REGULATIONS

lation in the home. While it would be more representative of field conditions to use a longer length of flue pipe for test- ing water heaters, e.g., 15 feet instead of the specified 5 feet, the physical limitations of the manufacturer’s test laboratories might make such a requirement

unduly burdensome. FEA has therefore not adopted this suggestion.

3. FUEL HEATING VALUE Many comments were directed toward

Section 2.4 of Appendix E, “Energy Supply.” Most of these comments concerned

the heating values assigned to gas and

oil fuels. One such comment was a rec- ommendation that a manufacturer of oil water heaters be permitted to conduct

testing either by using fuel oil with a presumably certified heating value of

138,000 Btu per gallon or by determining

the actual heating value of the fuel oil used in the test. FEA has assumed that

the figure 138,000 cited in the comment

above was a typographical error in the

comment and was supposed to be 138,500,

the heating value of fuel oil in Btu per

gallon cited in the proposed test procedure. Another comment was a recom- mendation that the heating value of natural gas and propane should be designated as approximate net values. A com- ment was also made that specifying a

heating value for natural gas of 1025 Btu per standard cubic foot is unrealistic since the heating value of the natural

gas supplied by local utilities varies with

geographic location. A manufacturing

firm implied that the requirement that

the actual heating value of the natural

gas used in the test be determined with an error no greater than one percent is unduly burdensome. This firm stated that it does not have the instrumentation available at its water heater manufacturing plants to measure the heating

value of the natural gas supplied by the

local utilities. It has been this firm’s practice to rely on the local utility to furnish on an “as needed” basis the

heating value of the natural gas supplied. The firm recommended allowing

the use of the gas supplied by the local

utility for testing on the condition that is identified by the utility as "natural gas.”

The firm also stated that its comments

concerning the determination of the

heating value of natural gas apply to propane gas as well. A comment was made that an ERDA report indicated

that the heating value of fuel oil supplied by utilities may be as low as 120,000

Btu per gallon. It was also pointed out

that FEA did not state what type of test was to be used for determining the heating value of fuel oil. This can have a dramatic impact on the results it was

claimed. Finally, a comment recom- mended that the requirement that natural gas with a heating value of 1025 Btu per standard cubic foot be used in the test be deleted, the reason being that

the manufacturers performing the tests would have no control over the gas supplied by the utilities. The concerns expressed in the comments above fall into two categories:

(1) the proposed test procedures specif!-

54111

cation of exact heating values for gas and oil fuels, and (2) the burden of having to determine the heating value of the fuel used in testing with an error of no greater than one percent. In the proposed test procedure heating

values for gas and oil fuels were inadvertently specified as exact values. The

actual heating value of the fuel used in testing need only approximate the value

specified for that fuel in the proposed

test procedhre. Therefore, section 2.4 of Appendix E has been revised to specify

approximate heating values for gas and ‘ oil fuels. FEA rejects the recommendations that a standard heating value be assumed for each fuel or that local utilities be relied upon to provide the heating value of the

J fuel they supply. Fluctuations in the

heating value of fuels supplied by utili- ties do occur as studies have shown. FEA ? does not have sufficient information on

the capability of local utilities to pro- 1 vide accurate and meaningful heating ; value information on the fuel or fuels they supply to warrant acceptance of ' this means of determining fuel heating

value. On the other hand, FEA accepts < the recommendation made at the public ‘ hearing that water heater manufacj turers be permitted the option of pur- ‘ chasing “bottled” fuel whichTias had its i actual higher heating value determined 3 with an error of no greater than one

percent as certified by the supplier. Thus, a manufacturer would have the choice

of either purchasing a calorimeter, if one

is not already available, to determine

the actual heating value of the fuel or

fuels supplied by the local utility or pur- chasing the necessary quantity- of “bottled” fuel of a certified heating

value. Section 2.4 of Appendix E has

been revised to allow for the use of “bottled” gas or a tested oil of a certified heating value in the test procedure.

4 . WATER TEMPERATURE RISE AND THERMOSTAT SETTING

Several comments were made which

questioned the specification of 90* F. in the test procedure for the temperature

rise through which a water heater under

test must heat the inlet water. One com- ment recommend that values of tern- 1 perature rise be selected on the basis of ’ geographical regions to better reflect actual conditions where water heaters 0 are marketed. In other words, the water

heater test procedure should be regionalized to account for different water in- , let temperatures which result in differ1 I ent temperature rises in various parts of 1 P the country. FEA rejects this recommen- f li dation on the basis that it would require c water heater manufacturers to conduct a many more tests than currently required ' U and it would therefore be unduly burden- h some. « Comments were made that the 90° F. ^ temperature rise figure was too high and f « should be lowered to reflect conditions ® of operation advocated by FEA. i.e., that consumers should lower the thermostat

[ settings on their water heaters to reduce

energy consumption. FEA rejects this recommendation. Water heater thermoI

f FEDERAL REGISTER, VOL. 47, NO. 192—TUESDAY, OCTOBER 4, 1977
54112 RULES AND REGULATIONS

stats are normally factory-set for gas

heaters at 140° F. and at 150* F. for

electric water heaters. The fact that these

settings may be adjusted both up or down by the installer or the homeowner

is irrelevant to the determination of the

cost of operation unless held surveys indicate that water heaters in representative use are normally adjusted to a dif- ferent thermostat setting than at the

time of purchase. No such field survey

data was presented at the public hearing.

Therefore, the test procedure uses the

average value of the two common factory

settings of water heater thermostats,

145* F., as the best approximation of the

typical field water heater thermostat setting. Since, as stated in the proposed

test procedure, NBS has determined that

the national average inlet water temperature is 55° F., the difference between

these two temperatures, 90° F., is used

a the water temperature rise in the test procedure.

Further comments questioned FEA’s

selection of the inlet water temperature

and the water heater thermostat setting for the purposes of the test procedure.

It is true that these values, 70* F. and

160° F., respectively, do not represent

field conditions as described by FEA.

However, for some testing facilities, cli- matic conditions and/or other factors may be such that for all or part of the

year tap water temperatures will exceed

55® F. Therefore, if a 55° F. inlet water

temperature were to be specified in the

test procedure, these facilities would have

to purchase additional equipment to cool the available tap water prior to conducting a test. FEA believes that appropriate

and comparable results can be obtained and the test procedure can be

made less burdensome if water heaters

are tested with an inlet water temperature of 70® F. This inlet water temperature can normally be achieved in laboratories throughout the country at any

time of year without the need for cooling

of the tap water. When the inlet water

temperature of 70® F. is coupled with the

requirement of a 90® F. water temperature rise, it results in a thermostat setting

of 160® F. FEA finds that specifying an

inlet water temperature of 70* F. and a

water heater thermostat setting of 160®

F. makes for a less burdensome test procedure which justifies their use.

5.

OIL WATER HEATER DEFINITION Comments were made that the definition of an oil water heater in the pro- posed test procedure included oil water

heaters predominantly used in commercial and industrial facilities. To exclude

commercial and industrial type units and

thereby make the types of oil water

heaters covered by the test procedures

comparable to the types of gas and electric water heaters covered, it was rec- ommended that the value of the maximum energy input rate, 172,500 But per

hour in the proposed test procedure, be

reduced to 103,875 Btu per hour which

equates to an oil consumption rate of

0.75 gallons per hour. It was further

recommended that the value of the maximum energy input rate, 172,500 Btu per

the proposed definition of an oil water

heater be reduced from 50 gallons to 40

gallons for the same reason. FEA finds that the proposed definition of an oil water heater does cover units

which are not normally purchased by

individuals for household use. FEA has

revised the proposed definition of an oil water heater to specify a maximum

energy input rating of 103,875 Btu per

hour (which equates to an oil consumption rate of 0.75 gallons per hour) but

has not revised the specified maximum

tank capacity value, 50 gallons. With the

reduction of the, maximum specified

energy input rate,' FEA finds that oil water heaters with 50 gallons tank capacities are purchased by individuals for

household use and therefore will be covered by the test procedure.

6.

HOT WATER USE RATE Many comments questioned the daily

hot water usage rate of 64.3 gallons per

day specified in the test procedure to compute annual costs of operation. Most

of these comments stated that this rate

is too high to represent national average

conditions. The reason for the apparent

discrepancy between the hot water usage

rate specified by FEA and the studies

cited in the comments is that FEA’s

usage rate is based upon representative

conditions of use of the types of water

heaters covered by the proposed test procedure. The comments cited national

average use rates based on household

surveys which includes water usage data

from households not serviced by the type

of water heaters covered by the proposed

test procedures such as apartment dwellings serviced by large commercial water

heaters. Including these types of households also lowers the number of persons per household from four, which is used

by FEA to determine the daily hot water

usage rate, to three, further contributing

to a lower usage rate than that used by

FEA.

The hot water usage rate of 64.3 gal- lons per day was arrived at from a survey

of 50 gas and 50 electric utility companies for hot water and energy usage

data for water heaters. Eighteen of these

companies supplied metered data. Data

obtained were normalized to a family of

four and to a 90* F. temperature rise. The family size of four was taken from

Census Bureau data as the average

family size. The types of water heaters

covered by the proposed test procedure

are usually found in the service of single

families. The use of a 90® F. temperature

rise is explained in the previous section. Water Temperature Rise and Thermostat Setting. When the hot water usage

rate of 64.3 gallons per day and the temperature rise of 90° F. are inserted into

the water heater test procedure equations along with typical water heater

performance parameters of • recovery

efficiency and standby loss as determined

by laboratory tests, the result correlates well with typical home energy usage as determined by the field survey. Therefore no changes to the proposed

test procedure are considered necessary with respect to the national average

value of hot water usage rate as used in the calculation of average' daily energy

consumption.

7.

WATER HEATERS NOT COVERED BY THE

TEST PROCEDURES

Comments were made that the pro- posed test procedures do not address

solar water heaters, water heater/boiler

combinations, or recirculating water

heaters. Although the Energy Policy and

Conservation Act empowers the Administrator to include other energy sources, at this time only those appliances powered by electricity- or fossil fuels are subject to testing. Therefore solar water

heater manufacturers are not subject to the Act, however, they may use the pres- ent test procedure to provide the con- sumer with information concerning solar water heater performance if they so

choose.

Boiler/water heater combinations are not considered in this test procedure because it is more appropriate to consider

such combinations as systems rather

than to attempt to consider the water

heater and boiler components separately.

Since the water heater portion of a boil- er/water heater combination is a secondary system of the boiler, FEA finds that

it is more appropriate to include boiler/

water heater combinations with furnaces. Therefore the boiler/water heater

type of appliance will be considered in, and subject to, the test procedure which

is currently under development for fur- naces. The recirculating water heater is generally used in large apartment buildings or for other commercial applications

such as office buildings where long runs

of piping from the water heater to the

point of use would result in a long delay

period before hot water becomes avail- able at the fixture if a recirculating sys- tem were not used. Very few of these

systems are sold to the typical consumer and many are custom designed and cus- tom built. Therefore, the inclusion of recirculating systems in the test procedure

is not recommended at this time.

3. TEMPERATURE DIFFERENCE BETWEEN

STORED WATER AND ROOM TEMPERATURE

AS USED IN THE CALCULATIONS

A comment stated that the mean temperature difference between the stored

water and room temperature is more

likely in the range of 70-80° F. since most

water heaters are located indoors. The

proposed test procedure specifies that a

temperature difference of 90° F. is to be

used as the temperature difference between the stored water and the room

temperature. Unlike all of the other val- ues specified in this test procedure, this value for temperature difference is a derived value rather than a value deter- mined by empirical data. FEA has no

data on typical ambient temperatures

where water heaters are installed, however, the assumed value of 90° F., when

coupled with a hot water usage rate of

64.3 gallons per day heated through a 90°

F. temperature rise, will yield values of calculated energy consumption that agree with actual energy consumption

FEDERAL REGISTER, VOL 42, NO. 192—TUESDAY, OCTOBER 4, 1977 A-3
data ior water heaters* A change in this value would necessitate a change in one

of the other parameters such as hot

water usage rate, water temperature rise,

etc., in order to maintain agreement between the energy consumption calculated by use of the test procedure and actual

energy consumed in representative use. Therefore, no change to the specified

temperature difference between stored water and room temperature is recom- mended.

9. MEASUREMENT AND CALCULATION OF

STANDS? LOSS Concerning the standby loss test, FEA

concurs with the comments that standby

loss for electric water heaters with immersed heating elements is virtually in- dependent of energy input rating.

Standby loss is a measure of the hot water

storage performance of a water heater. This measure is primarily a function

of the type and configuration of the tank

insulation since most of the heat loss during standby is through the water

heater jacket to the air surrounding the water heater. This is particularly true

for electric water heaters which do not have flue losses and therefore their only

other heat loss is through the Inlet and

outlet pipes when no heat traps are present. Because of this and because virtually

all input energy to the heating elements

goes towards heating water by the very nature of their design of having the

heating elements in direct contact with

the water in the water heater tank,

standby loss will be the same for all electric water heaters with immersed heating elements of a given basic model.

Therefore, FEA has adopted the recom- mendation that standby loss tests for

electric water heaters with immersed

heating elements be performed with the water heaters to be tested equipped with

"standardized” heating elements. The

procedure for determining standby loss for electric water heaters with immersed

heating elements is presented in section

3.4.2 of Appendix E. A suggestion was made that determining standby loss in terms of the fraction

of the heat content of the stored water

lost per hour instead ofIn units of energy

lost per hour hides the actual value of standby loss. FEA finds that the deter- mination of standby loss in terms of units of energy lost per hour can be

accomplished by additional calculations

which utilize the results obtained by the

present test procedure. The determination of standby loss in terms of the fraction j>f the heat content of the stored water above room temperature lost per

hour, however, allows the test for standby loss to be run without maintaining an exact 90° F. temperature difference between the stored water and the ambient laboratory room temperature since

the test procedure compensates for ambient temperature and will yield the same value of standby loss as long as the ambient room temperature is within

the range specified, 65° F. to 85° F. In order to directly determine standby loss

in absolute terms of Btu per hour, the

test would need to be run under condlRULES AND REGULATIONS

tions of a constant room temperature of

70* F. with stored water at 160* F. in

order to obtain an exact 90* F. temperature difference. Alternatively, the stored water temperature would have to be adjusted depending on the laboratory room

temperature at the time of tests. Thus, the determination of standby

loss in terms of the fraction of the heat

content of the stored water lost per hour

makes for a less burdensome test pro- cedure than the one which would have to be developed if the suggestion that

standby loss be determined in terms of

units of energy lost per hour were to be

adopted. In addition, It allows FTC to

label the standby loss In the manner suggested if the FTC deems it appropriate.

Therefore, the suggestion has not been

adopted.

A comment was made that a calcula- tion be Included In the test procedure to determine a cost of operation for a water

heater on standby in terms of dollars per

month. FEA finds such a cost can be determined from the test results of the

current test procedure. Therefore, FTC

can adopt this proposal to determine a

cost of operation of a water heater on

standby as part of their water heater

labeling program, if they so choose. Another comment suggested that a

single test be conducted to determine both standby loss and recovery efficiency.

The test recommended consists of a 12- hour standby period followed by a draw

period repeated enough times to provide

acceptable accuracy. It was stated that

the standby test proposed may not credit the savings to be expected from an electric ignition system and that recovery during dynamic conditions such as a water draw schedule may be different than

recovery from 70° F. to 165° F., as pro- posed in the static test. Although no

testing with intermittent Ignition has

been conducted by NBS to date, preliminary testing with a reduced pilot input

rate has shown energy savings for a 72- hour standby test. The question of accurately predicting an energy savings for

electric ignition alone seems to be a moot

point since that design option is not considered economically practical unless it is accompanied by the use of a flue damper. In any event, NBS considers the test procedure as proposed to be sufficient to detect energy savings for inter- mittent ignition systems. FEA concurs with the NBS position. Therefore, this suggestion has not been adopted.

10. MEASUREMENT AND CALCULATION OF RECOVERY EFFICIENCY A comment noted that a recovery effi- ciency of 100 percent Is assumed for electric water heaters with immersed heating elements in the calculation of standby loss yet a value for the recovery effi- ciency of an electric water heater with

immersed heating elements is calculated

in a previous section. This apparent in- consistency results from the different methods used to calculate recovery effi- ciency and standby loss between the

electric and gas or oil fueled heaters. The recovery efficiency of an electric water heater with immersed heating ele54113

ments is very near to 100 percent since, as explained in the section on standby

loss, an Immersed heating element delivers practically 100 percent of the energy input at the point of use to the \ water. To make a direct measurement

of the recovery efficiency of such a water { heater would be very difficult. The proce- . dure would require that the temperature

of the water in the water heater tank be

determined very accurately. The six c thermocouple array that is required to c be installed in the tank according to sec- £ tion 2.5 for the purpose of measuring

water temperature is not sufficient for > the purpose of such a test. In fact, at- tempts made to measure the recovery

efficiency of an electric water heater with

this thermocouple array could result in values of recovery efficiency greater than

100 percent due to the error introduced ; by variations in water temperature which , exist in the spherical portion at the bot- tom of the tank. An analysis would have ; to be made of the geometry of the tank

} and additional thermocouples would have

to be used in order to achieve the accu- racy requisite to directly measure rej covery efficiency. The requirements of making such a direct measurement would

result in a test procedure which would

be unduly burdensome for a manufacturer to conduct.

Instead of requiring that the recovery

efficiency of an electric water heater with

immersed heating elements be determined directly, the test procedure pro- , vides for calculating the recovery effl- ciency as one minus the standby losses during recovery since standhy loss is the “ only energy loss for such water heaters. This indirect method for determining re1 covery efficiency is more accurate than

any direct method of determination

.which would not be unduly burdensome.

The standby loss measurement pro-

" cedure is the same for each type of

J heater. However, the calculation differs L in that an assignment of 0.98 for the £ recovery effciency, Er *, is made" for the

'

electric water heater with immersed I, heating elements. Since one does not ^

I know the exact recovery efficiency for

t

‘

electric water heaters until the standby . loss is measured and the standby loss C. contains a correction based on recovery

efficiency, there exists two equations with

three unknowns. It therefore becomes

necessary to assign a recovery efficiency ( in the standby loss equation. In the pro- f posed test procedure, an assignment of - 1.00 was made. The actual value of the recovery efficiency is more likely in the , range of 0.97 to 0.99. Therefore, in order ; to reduce the error introduced into the standby loss equation for electric water j, heaters with immersed heating elements, |, FEA has changed the assigned value for recovery efficiency from 1.00 to 0.98. One comment proposed that the water t heater tank should be preheated for the purposes of performing the recovery ef- ficiency test since oil fueled heaters are

affected more by a cold start test than

either gas or electric heaters. Elimination of the tank preheating test reduced

the test time and the cost of testing. NBS

testing has revealed that the cold start

FEDERAL REGISTER, VOL. 42, NO. 192—TUESDAY, OCTOBER 4. 1977

A - 4
54114 RULES AND REGULATIONS

procedure gives test results 2 percent

to 3 percent lower than if the tank were

preheated for oil fueled water heaters. The preheated tank procedure would

credit the recovery tgst with heat re- tained in the tank from the preheating

of the tank. This does not represent actual held conditions since heat input is not obtained free in actual use. However,

the cold start test as proposed also does not represent actual use in the field. In

the interest of reducing the time and the

costs required to include a tank preheating test in the test procedure, the use of a tank preheating test has not been

adopted.

A comment stated that the static tests, without drawing water for measuring

recovery efficiency, are not sufficiently accurate for determining the recovery

efficiency of gas or oil fueled water heaters. Tests at NBS using a typical withdrawal schedule have shown a good

correlation between the static test meas- urements and calculations compared to actual metered energy consumption for a 16-hour withdrawal schedule. Therefore, no change to the static test procedure has been made.

A comment was made that a calculation be included in the test procedure

to determine a cost of operation for a

water heater during the recovery stage

in terms of dollars per 1000 gallons of hot water delivered per month. Such a

cost can be determined from the test

results of the current test procedure.

Therefore, PTC can adopt this proposal

1 to determine a cost of operation of a water heater on recovery as part of their water heater labeling program, if they

so choose.

11. POWER INPUT DETERMINATION

As a result of the change made to the

definition of a basic model of a water

heater, a method for determining the

power input for an electric water heater

with Immersed heating elements had to be developed. Section 3.2.2 of Appendix

E of this subpart presents the method

for making this determination. The

method does not require that power in- put measurements be made. The manufacturer's assigned design energy ratings

for the immersed heating elements that

are installed in a water heater are used

to calculate the power input term. Although this means of determining the

power input for an electric water heater

with immersed heating elements is an

approximation of the actual value, the

error that may be present will have little bearing on the two measures, recovery

efficiency and average daily energy consumption, that use the power input term

in their equations, by the nature of the

equations themselves. The values determined from these equations are sufficiently insensitive to error in the power

input term to justify using an approximation for power input and not requiring

that it be directly measured.

i 12. HOT WATER SUPPLY RATING AND RECOVERY RATE The hot water supply rating test and

the recovery rate determination that

i

were part of the proposed test proce- dure have been deleted from the test procedure on the basis that, in their

present form, they would make the test procedure unduly burdensome for manufacturers of electric water heaters with

Immersed heater elements to conduct,

unlike standby loss, hot water supply

rating and recovery rate determinations

are very dependent on the actual watt- age and location of the immersed heating

elements installed in the water heater,

the number of such elements Installed,

and the configuration of the auxiliary

electrical system of the water heater

which controls the operation of the heating elements. Testing for hot water supply rating and recovery rate would have

to be done for all possible combinations

of these factors which goes back to the

problems associated with the proposed

definition of a basic model of a water

heater. Comments were made that the hot

water supply rating of an electric water

heater with immersed heating elements

could be predicted for all basic models of

electric water heaters in much the same way that standby loss could be predicted.

No hot water supply rating prediction

scheme was presented. Neither was any

data submitted from which a hot water

supply rating prediction scheme might

be developed. Without a hot water supply rating prediction scheme and without test data to verify that a particular

prediction scheme is sufficiently accurate, FEA cannot consider making such

a modification to the hot water supply

rating test at the present time. In the case of recovery rate, the power

input to the water heater must be determined. The current procedure for determining power input for electric water

heaters with immersed heating elements

is to accept the design value assigned by

the manufacturer. Unlike recovery effi- ciency and average daily energy consumption, recovery rate is sensitive to error in the power input term and the

approximations of power input determined in section 3.2.2 would introduce a

potentially significant error into the determination of recovery rate which would

be unacceptable.

FEA finds that in the absence of a hot

water supply rating prediction scheme

and a recovery rate prediction scheme,

the hot water supply rating test and the

recovery rate determination must be deleted from the water heater test proce- dure at the present time. FEA recognizes

that this deletion will eliminate an important measure of water heater per- formance from the test procedure. FEA

also recognizes that without a hot water

supply rating, or some other measure of hot water delivery performance, the test procedure leaves, a consumer with less than the best information to select a

water heater which will satisfy his needs. Therefore, FEA plans to investigate prediction schemes for the determination

of hot water supply rating or for the determination of some other measure of hot water delivery performance for water

heaters. The goal of this investigation

will be to provide consumers with a useful measure of hot water delivery per- formance for water heaters while not imposing unduly burdensome test re- quirements on any segment of the water

heater industry.

FEA hereby invites the water heater

industry and any other interested parties

to provide input to FEA concerning this proposed investigation. This investigation will be completed by December 1, 1977. In its present form, nothing in this

final test procedure prohibts a manufacturer from making representations concerning the hot water supply rating of any of his water heater products.

13.

SYMBOLS USED IN THE TEST PROCEDURE EQUATIONS

Coments were made that the symbols

used in the equations of the proposed

test procedure exhibited inconsistencies

which made interpretation of the equations difficult. Further comments rec- omended that the symbols used be

revised in accordance with standard

.practices. FEA concurs. The equations

of section 4 of Appendix E of this subpart reflect the recommended changes.

14.

TESTING CONDITIONS

Comments on section 2.5 of the pro- posed test procedure pointed out that

the requirement that thermocouples be

installed along the centerline of the* water heater tank may lead to confusion

since for many gas and oil water heaters

the flue is located at the centerline of the tank. Section 2.5 has been revised to eliminate this potential source of confusion. In response to a comment concerning

the hook-up of the water heater inlet and outlet pipe connections to water supply and delivery pipes, the test proce- dure has been revised to require a heat

trap type of configuration for water

heaters with vertical inlet and/or outlet pipe connections.

15.

CALCULATIONS OF THE ENERGY FACTOR

The proposed test procedure did not

clearly state the appropriate section -of Appendix E to be used in the calculation

of the energy factor in section 430.22(e)

.

This resulted in misinterpretation of the

use of the average daily energy consumption. Section 430.22(e) has been cor- rected to properly reference the appropriate section of Appendix E.

16.

INDIRECT ENERGY CONSUMPTION

A comment was made that the test procedure should account for the in- creased operating time and energy con- sumption of a furnace or air conditioner

which is caused by gas and oil water

heaters. The increased energy consumption arises from the fact that most gas and oil water heaters utilize interior air for combustion and draft maintenance

which is then vented out of the house

and replaced by the infiltration of exterior air which must then be heated

by the furnace or cooled by the air conditioner depending on the season. Tl*e

loss of interior conditioned air continues even when the water heater is not in the

combustion state due to the natural draft

of the flue unless the water heater is

FEDERAL REGISTER, VOL. 42, NO. 192—TUESDAY, OCTOBER 4, 1977

A- 5
RULES AND REGULATIONS 54115

equipped with a flue damper which is usually not the case. FEA is sensitive to such hidden costs

of operation and will incorporate them

whenever they are of sufficient magnitude to warrant the burden of additional

testing designed to measure and quantify

such costs. Secondary costs have been included in the final test procedures for dishwashers

and clothes washers, and in the proposed

test procedures for dehumidifiers and

furnaces, however, FEA has decided not

to incorporate these costs in the water

heater test procedure at this time. FEA

bases its decision on data forwarded by

NBS which indicates that the secondary

costs represent only 2 percent of the cost

of operation of a water heater and that

the testing burden to account for such

costs would be large. Furthermore, NBS

has reported to FEA that the potential

dollar savings achieved by the use of a

direct vent system, which utilizes exterior air rather then interior air and

thereby avoids imposing additional costs on furnaces or air conditioners, is not

sufficient to pay for the cost of such devices. Only when direct vent systems are combined with preheating devices do

they become economically viable and the

test procedure, as currently written, will measure most of the increased efficiency of water heaters so equipped. Therefore

there is little justification for modifying

the test procedures at this time. Anyone with information indicating that direct vent systems alone are currently economically justified for water

heaters or that the cost associated with

the loss of interior conditioned air is greater than 2 percent of the cost of operation of a gas or oil water heater is hereby requested by FEA to submit such

information. Should the assumptions on which FEA has based its decision be

shown to be incorrect, FEA will consider

modifying the water heater test proce- dure to incorporate the secondary costs

of operation.

17.

PRIMARY ENERGY LABELING While a comment suggested primary

energy labeling, i.e., taking into consideration the energy consumed by a power

plant to produce the amount of electrical energy consumed by an appliance, the Energy Policy and Conservation Act

specifically requires that the estimated

annual operation co6t of an appliance

be calculated in terms of the retail cost

of energy likely to be consumed in representative use. Therefore, this suggestion

has not been adopted.

18.

NUMBER OP UNITS TO BE TESTED Some comments expressed objections

to the sampling provision for water heaters Proposed section 430.23(e) provided

for sampling of each basic model to be

tested when testing of water heaters is required by the Act or by program regulations of agencies responsible for administering the Act. This provision was

intended both to provide an acceptable

level of assurance that the test results are applicable to all units of a basic model for which testing is required and

to minimize the testing burden on manufacturers. Test procedures prescribed under sec- tion 323 of the Act are intended ulti- mately to be used, for example, for label- ing under section 324, for monitoring the

progress of manufacturers toward ac- complishing the energy efficiency improvement targets under section 325, and

for enforcement testing under section

326. These aspects of the appliance pro- gram have not, however, been implemented. It is quite possible that the objectives of appliance testing under each

of these parts of the program, as well as the instructions as to how a test proce- dure should be applied, e.g., sampling of production units, may differ. FEA, NBS,

and FTC are continuing to evaluate the

appropriate method or methods for sampling the units to be tested in order

to comply with the statute and satisfy

all of the different elements of the appli- ance program.

While the various parts of the appli- ance program identified above are not in

effect at this time, section 323(c) of the

Act provides

:

Effective 90 days after a test procedure rule applicable to a covered product is prescribed

under this section, no manufacturer, distrib- utor. retaUer or private labeler may make any

representation

(1) In writing (including a representation on a label) . or

(2) In any broadcast advertisement,

respecting the energy consumption of such

product or cost of energy consumed by such

product, unless such product has been tested

in accordance with such test procedure and

such representation fairly discloses the re- sults of such testing. In order to eliminate the problem dis- cussed above associated with a general

sampling provision, § 430.23 has been re- served in the final test procedure, and

sampling requirements which apply only

for purposes of advertising have been

reorganized into 5 430.24(e) of the final

test procedures. Section 430.24(e) is similar to proposed § 430.23(e) , but contains

several revisions. Most notably, the units

tested may now be either representative

of production units, or actual production

units. This change is intended to reduce

the burden which might be caused by

requiring post-production rating of basic models in every instance of testing pursu- ant to section 323(c) of the Act. In addition, certain technical changes

have been made in sampling language.

Specifically, there is to be 90 percent confidence that the true mean of any measure of the basic model lies within ±10

percent of the mean of such measure of the sample. Comments pertaining to several proposed test procedures criti- cized the language of the proposed sampling provision. These comments suggested that a sampling provision should

refer to the estimate of the mean rather

than to the true mean. FEA has considered this suggestion and has determined

that the language prescribed today is more technically correct because the statistical measure "estimate of the mean"

and “mean of the sample” are generally

considered to be Identical. The final test procedures for room air conditioners

and dishwashers used both these terms

in a manner that could be confusing,

and the language prescribed today is in- tended to eliminate this possibility.

Until a labeling rule has been implemented pursuant to section 324, manufacturers are not required to test unless they choose to make representations re- garding a measure of energy consumption. It should be emphasized that the

test procedures prescribed today apply

only to the initial rating of a basic model.

19.

MISCELLANEOUS

After careful consideration of all of the comments and further consultation

with NBS and FTC, FEA has incorporated some minor changes in the pro- posed test procedures in the final rule that are not discussed above.

C. Regulations Prescribed

1. TEST PROCEDURES

The test procedures for water heaters

prescribed today are included in Subpart B and are substantially the same as those proposed with the exception of the

elimination of the hot water supply rat- ing test and the recovery rate determination. As with the proposed procedures,

test methods and conditions incorporate

the approach contained in American National Standards Institute standard Z21.- 10.1—1971 and C72.1—1972. The test procedure also uses the definition of the term “oil” contained in the American Society for Testing and Materials (ASTM)

D396-71. Subsequent amendments of either the standard or the supplement

made by the standard setting organization will have no effect on the test proce- dure which can only be amended by FEA.

Under the requirements of section 32

(c) of the Federal Energy Administration Act of 1974 (15 U.S.C. 761 et seq.) as amended by section 9 of the Federal

Energy Administration Authorization Act

of 1977 (Pub. L. 95-70), the Administrator is to consult with the Attorney General and the Chairman of the Federal

Trade Commission concerning the impact on competition of any rules prescribed by FEA which utilize or incorporate any commercial standards.

The Administrator has transmitted

copies of the final test procedures for water heaters, which incorporate the

above mentioned commercial standards,

to the Attorney General and the Chair- man of the Federal Trade Commission

for their comments concerning the impact of such standards on competition in accordance with section 32(c). Neither

individual has any comments nor do they

recommend against the incorporation or use of these commercial standards in the

final test procedures for water heaters.

2. GENERAL PROVISIONS

Prescribed today are certain defini- tions applicable to water heaters which

were previously proposed in Subpart A

(41 FR 19977. May 14, 1976; 42 FR 15423,

March 22, 1977). Comments were re- ceived regarding these definitions and

the issues and changes have been dis- cussed earlier in this notice. All defini- tions appearing in section 321 of the Act were Incorporated by reference into SubFEDERAL REGISTER, VOl. 42, NO. 192—TUESDAY, OCTOBER 4, 1977 A- 6
54116 RULES AND REGULATIONS

part A of Part 430 in the final test procedures for room air conditioners issued

May 24, 1977 (42 PR 27896, June 1, 1977)

.

Definitions of the terms “Administrator”, “Btu” and “PEA" were also incorporated into Subpart A by the final room

air conditioner test procedures. The defi- nition of the term “basic model” for water heaters has been changed, as dis- cussed above. Definitions of the terms

“cutout” and “design power rating” have

been added.

It should be noted that some of the

definitions prescribed today may be applicable to test procedures for other

appliances. While these definitions are

final, comments to the effect that any of these definitions are inapplicable to a

particular appliance will be evaluated to determine whether amendment or modification is appropriate.

3. APPLICATION OF TEST PROCEDURES

As discussed previously, the final water

heater test procedures prescribed today

must be applied before representations

regarding a measure of energy consumption can be made. Because the purposes and needs of the different elements of the appliance program, such as labeling

or targets, vary, application of the standard test methodology prescribed today

may differ in some respects for each pro- gram element. Instructions on how to apply the standard test methodology will be proposed for comment as these other

element of the appliance program are

developed.

The requirements of § 430.24(e) of the

final regulations apply until such time as

final labeling requirements for a particular measure of energy consumption

and the associated test procedure application provision are prescribed. After

that time, all representations regarding a measure of energy consumption covered

by a labeling rule must be the same as represented on the label. D. Unit Costs of Energy

Under section 323(b)(2) of the Act, PEA is to provide manufacturers in- formation as to the representative aver- age unit costs of energy. This information was provided by notice issued

July 11, 1977 (42 PR 36549, July 15. 1977).

E. Preemption

Today’s rulemaking prescribing final

test procedures for water heaters supersedes any State regulation to the extent

required by section 327 of the Act. Pursuant to section 327, all State regulations

which provide for the disclosure of in- formation with respect to any measure

of energy consumption of water heaters

or which provide for any energy effi- ciency standard or similar requirement

with respect to energy efficiency or energy

use of water heaters must now employ

test procedures identical to those specified in today’s final rule. In consideration of the foregoing.

Chapter n of Title 10, Code of Federal

Regulations is amended as set forth

below, effective November 8. 1977.

(Energy PoUcy and Conservation Act, Pub. L.

94-163, as amended by Pub. L. 94-385; Federal Energy administration Act at 1974, Pub.

L. 93-275, as amended by Pub. L. 94-386;

E.O. 11790, 39 FR 23185.) Issued in Washington, D.C., September 27, 1977. Eric J. Fygi,

Acting General Counsel,

Federal Energy Administration.

1.

Section 430.2 is amended by adding

paragraph (5) as part of the definition of “basic model” and by adding in appropriate alphabetical order the defini- tion of “immersed heating element” and

“water heater” to read as follows:

§ 430.2 Definitions.

• * * * * “Basic model” means all units of a given type of covered product, or class thereof, manufactured by one manufacturer and

:

(5)*****with respect to water heaters,

which have the same primary energy

source and which, with the exception of

immersed heating elements, do not have

any differing electrical, physical, or functional characteristics that affect energy

consumption.

“Immersed

*****

heating element” means

an electrically powered heating device

which is designed to operate while totally

immersed in water in such a manner

that the heat generated by the device is imparted ***** directly to the water.

“Water heater” means an automatically controlled thermally insulated

vessel designed for heating water and

storing heated water, which utilizes either oil, gas, or electricity as the fuel or energy source for heating the water,

which is designed to produce hot water

at a temperature of less than 180°P., and

which includes the following products:

(a) “Electric water heater” means a water heater which utilizes electricity as the energy source for heating the water,

which has a manufacturer’s specified

energy input rating of 12 kilowatts or

less at a voltage no greater than 250

volts, and which has a manufacturer’s

specified storage capacity of not less than 20 gallons nor more than 120 gallons.

(b) “Gas water heater” means a water heater which utilizes gas as the energy source for heating the water, which

has a manufacturer’s specified energy

input rating of 75,000 Btu per hour or

less, and which has a manufacturer’s

specified storage capacity of not less than

20 gallons nor more than 100 gallons.

(c) “Oil water heater” means a water

heater which utilizes oil as the energy

source for heating the water, which has

a manufacturer’s specified energy input

rating of 103,875 Btu per hour or less, and which has a manufacturer’s specified storage capacity of 50 gallons or

less.

2. Section 430.22 Is amended by adding a paragraph (e), to read as follows:

§ 430.22 Test procedures for measures

of energy consumption.

• * • » * (e) Water Heaters. (1) The estimated

annual operating cost for water heaters

shall be

(1) For a gas or oil water heater, the

product of the representative average

use cycle of 365 days per year times the sum of (A) The product of the average

daily auxiliary electrical energy con- sumption in kilowatt-hours per day, determined according to section 4.5.1 of Appendix E of this subpart, times the

representative average unit cost of electricity in dollars per kilowatt-hour as provided by the Administrator plus (B)

The product of the average daily gas or

oil energy consumption in Btu per day,

determined according to section 4.5.2 of Appendix E of this subpart, times the

representative average unit cost of gas

or oil, as appropriate, in dollars per Btu

as provided by the Administrator, the

resulting product then being rounded

off to the nearest dollar per year.

(ii) For an electric water heater, the

product of the following three factors: (A) The representative average use cycle of 365 days per year, (B) Hie average

daily energy consumption in kilowatthours per day, determined according to section 4.5.4 of Appendix E of this subpart, and (C) The representative aver- age unit cost of electricity in dollars per kilowatt-hour as provided by the Administrator, the resulting product then

being rounded off to the nearest dollar per year.

(2) The energy factor for water heaters shall be

(i) For a gas or oil water heater, the

quotient of .the daily water heating energy consumption determined according

to section 4.3 of Appendix E of this subpart divided by the product of the

average daily energy consumption as determined according to section 4.5.4 of Appendix E of this subpart times 3,412

Btu per kilowatt-hours, the resulting

quotient then being rounded off to the nearest 0.01.

(ii) For an electric water heater, the

quotient of the daily water heating en- ergy consumption determined according

to section 4.3 of Appendix E of this subpart divided by the product of the aver- age daily energy consumption as deter- mined according to section 4.5.4 of Appendix E of this subpart times 3,412 Btu

per kilowatt-hours, the resulting quotient then being rounded off to the nearest 0.01.

(3) Other useful measures of energy

consumption for water heaters shall be

those measures of energy consumption

for water heaters which the Administrator determines are likely to assist con- sumers in making purchasing decisions

and which are derived from the application of Appendix E of this subpart.

• • • • *

3. Section 430.24 is amended by adding

a paragraph (e) , to read as follows

:

m>ERAL REGISTER, VOL 42, NO. 192—TUESDAY, OCTOBER 4, 1977

A- 7
RULES AND REGULATIONS 54117

§ 430.24 Representations regarding

measures of energy consumption.

• • » • • (e) Water heaters. (1) Except as provided in paragraph (e) (3) of this section, no manufacturer, distributor, retailer. or private labeler of water heaters

may make any representation with re- spect to or based upon a measure or measures of energy consumption described in § 430.22(e) unless a sample

of sufficient size of each basic model for which such representation is made has

been tested in accordance with applicable provisions of this subpart such that, for each such measure of energy consumption, there is at least 90 percent

confidence that the true mean of such measures of the basic model is within ±10

percent of the mean of such measures of the sample.

(2) The sample selection for paragraph

(e) (1) of this section shall be comprised

of units which are production units, or which are representative of production

units, of the basic model being tested.

(3) Whenever a rule applicable to water heaters has been prescribed under

section 324 of the Act, this paragraph

shall not apply to any label covered by

such rule, and all representations of any

measure of energy consumption covered

by such rule shall be identical to the measure of energy consumption on the

label.

> • • • • *

4. Subpart B of Part 430 is amended to add an Appendix E, to read as follows: Appendix E

Uniform Test Method for Measuring the Enerct Consumption of Water Heaters

1. Definitions.

1.1 "Cutout” means the moment In time when a water heater thermostat has acted to reduce the energy or fuel Input to the heating elements or burners to a minimum.

1.2 "Design Power Rating" means the nominal power rating that a water heater manufacturer assigns to a particular design

of water heater heating element, expressed In kilowatts.

1.3 "Heat Trap" means a device which can

be Integrally connected, or Independently at- tached. to the hot of cold water pipe connections of a water heater such that the device

will develop a thermal or mechanical seal to minimize the recirculation of water due to natural thermal convection between the water heater tank and Its water supply pipes

and thereby reduce the heat loss to the en- vironment from the hot water stored In the water heater.

1.4 "Recovery Efficiency” means the ratio of the heat Imparted to the water to—

(a» in the case of an electric water heater, the energy Input to the heating elements during the period that tl^ water temperature is raised from the Inlet temperature to the final temperature with the tank filled to capacity.

(b) In the case of a gas or oil water heater. the heat content of the fuel consumed

by the burners during the period that the water temperature Is raised from the inlet temperature to the final temperature with

the tank filled to capacity.

1.5 “Standby loss" means the ratio of the heat lose per hour to the heat content of the

stored water above room temperature.

e. Test conditions.

2.1 Installation. Install the water heater according to the manufacturer’s directions on a 34-lnoh-thlck plywood platform supported by three 2 x 4-lnch runners. For water

heaters without Integral heat traps and with

vertical inlet and outlet pipe connections.

Install the inlet and outlet piping with heat

traps at the inlet and outlet ports. Such heat

traps may be made using pipe fittings such

as elbows connected In such a fashion that

the Inlet and outlet piping make vertically

upward runs Just before turning downward

to connect to the inlet and outlet ports. For water heaters with Integral heat traps or with horizontal Inlet and outlet pipe connections, install the inlet and outlet piping

in pny convenient fashion.

Sufficient clearance shall be allowed be- tween the water heater surface and the piping t including heat traps, if any) so that when the piping is Insulated as specified below, the Insulation does not contact any water heater surface except at the location where the pipe connections penetrate the water heater Jacket. Insulate the water heater inlet and outlet piping (including heat

traps, if any) for a length of four feet from

the connection at the water heater with a material having a thermal resistance (R) value of not less than

op

^ Btu/'ft^hr

2.2 Flue requirements /or gas and oil water heaters.

2.2.1 Flue requirements for gas water

heaters. For a gas water heater having a vertically discharging draft hood outlet, a 5 foot vertical flue pipe extension having a diameter equal to the largest flue collar size of the draft hood shall be connected to the

draft hood outlet. For a gas water "heater having a horizontally discharging draft hood

outlet, a 90 degree elbow having a diameter

equal to the largest flue collar size of the

draft hood shall be connected to the draft hood outlet. A 5 foot length of flue pipe shall be connected to the elbow and oriented to discharge vertically upward. Perform all tests with the natural draft established by

this length of flue pipe. Direct vent gas water heaters should be Installed with venting equipment as specified In the manufacturer's Instructions: however, the vertical length of the flue pipe shall be no greater than 5 feet.

2.2.2 Flue requirements /or oil water heaters. For an oil fueled water heater, establish

a draft at the flue collar equivalent to at least

0.02 Inch of water column during periods of burner firing. For an oil- water heater having

a vertically discharging draft hood outlet, establish the draft by using a sufficient length

of flue pipe connected to the water heater

flue outlet and directed vertically upward.

For an oil water heater having a horizontally

discharging draft hood outlet, a 90 degree elbow having a diameter equal to the largest

flue collar size of the draft hood shall be connected to the draft hood outlet. A length

of flue pipe sufficient to establish the draft

shall be connected to the elbow fitting and

oriented to discharge vertically upward. Direct vent oil water heaters should be installed with venting equipment as specified In the manufacturer's instructions. When celling

height limits the use of a sufficient length of

vertical flue pipe for an oil water heater, a mechanical draft Inducer may be used during

periods of burner firing to establish the specified draft at the flue collar.

2.3 Water supply. During the entire test maintain the water supply to the water

heater inlet at a temperature of between

68 and 72* F., and at a gauge pressure of between 40 pounds per square inch and the

maximum pressure specified by the manufacturer for the water heater under test. If the water supply pressure varies outside of these limits during testing, the heater shall be isolated by use of a shut-off valve In the supply line with an expansion tank installed

In the supply line downstream of the shut-off

valve. There shall be no shut-off means be- tween the expansion tank and the water

heater inlet. 2.4 Energy Supply.

2.4.1 Electrical supply. For an electric water heater and for the auxiliary electrical system, if any, of an oil or gas water heater, maintain the electrical supply voltage to within ±1 percent of the center of the voltage range specified by the .water heater manufacturer on the water heater nameplate throughout the entire operating portion of each test. 2.4.2 Gas supply.

2. 4.2.2 Natural gas. For a gas water heater

utilizing natural gas. maintain the gas supply at a normal inlet test pressure Immediately ahead of all controls at 7 to 10 Inches

of water column. If the water heater is equipped with a gas appliance pressure regulator, the regulator outlet pressure at the normal test pressure shall be approximately

that recommended by the manufacturer. All burners shall be adjusted to achieve an

hourly Btu rating that Is within ±2 percent

of the hourly Btu rating specified by the manufacturer. Use natural gas with a higher

heating value of approximately 1,025 Btu per standard cubic foot. Determine the actual higher heating value, Hn, In Btu per standard cubic foot, for the natural gas to be used In the test, with an error no greater than ±1 percent, and use that value for all calculations included herein. Alternatively, the test can be conducted using “bottled" natural gas of a higher heating value of approximately 1,025 Btu per standard cubic

foot as long as the actual higher heating

value of the bottled natural gas has been determined with an error no greater than d:l percent as certified by the supplier.

2. 4.

2.2

Propane gas. For a gas water

heater utilizing propane, maintain the gas supply at a normal Inlet test pressure Immediately ahead of all controls at 11 to 13 Inches of water column. If the water heater

Is equipped with a gas appliance pressure

regulator, the regulator outlet pressure at normal test pressure shall be approximately

that recommended by the manufacturer. All burners shall be adjusted to achieve an hourly Btu rating that Is within ±2 percent of the hourly Btu rating specified by the manufacturer. Use propane with a higher heating

value of approximately 2,500 Btu per standard cubic foot. Determine the actual higher

heating value. HP , in Btu per standard cubic

foot, for the propane to be used In the test, with an error no greater than ±1 percent, and use that value for all calculations In- cluded herein. Alternatively, the test can

be conducted using “bottled” propane of a higher heating value of approximately 2.500 Btu per standard cubic foot as long as the

actual higher heating value of the bottled propane has been determined with an error no greater than ± 1 percent as certified by

the supplier.

2.4.3 Oil supply. For an oil water heater

utilizing fuel oil, maintain an uninterrupted

supply of fuel oil to the water heater during

the entire operating portion of the test cycle. Use fuel oil with a heating value of approximately 138,500 Btu per gallon. Determine

the actual heating value. Ho, In Btu per

gallon for the fuel oil to be used In the

test, with an error no greater than ± 1 percent, and use that value for all calculations

I

i

KDERAl REGISTER, VOL. 42, NO. 192 —TUESDAY, OCTOBER 4, 1977
54118 RULES AND REGULATIONS

1

1

i

|

!

I

i

i

Included herein. Alternatively, the tests can

be conducted using a tested fuel oil with a

certified higher heating value of approximately 138,500 Btu per gallon as long as the

actual higher heating value of the test fuel

oil has been determined with an error of no

greater than ±1 percent as certified by the

supplier.

2.5 Thermocouple installation. Install six thermocouples Inside the water heater tank.

Position each thermocouple measuring junction along a vertical line at the level of the

center horizontal plane of each of six nonoverlapping sections of approximately equal

volume from the top to the bottom of the

tank, such that each thermocouple Is sur- rounded by water and as far as possible from

any heating element, anodic protective device, or a water tank or flue wall. The anodic

protective device may be removed in order

to Install the thermocouples and all testing

may be carried out with the device removed.

Install thermocouples In both the cold- water Inlet pipe and the hot-water outlet

pipe not more than six Inches from the connections to the water heater, or, where those

connections are Inaccessible, at the closest

accessible point to those connections. Install

in the test room a thermocouple with Junction shielded against direct radiation from

the water heater and positioned at the vertical mid-point of the heater at a perpendicular distance of approximately 24 Inches from the surface of the water heater Jacket. Provide an associated temperature measure- ment and Indicator system to assure that the

temperature Indicated for the thermocouple location Is within ±1* P. of the actual temperature at that location.

2.6 Setting the tank thermostat. Starting

with a tank of unheated water. Initiate nor- mal operation of the water heater. After

cutout, determine whether the maximum

value of the mean tank temperature Is within

the range of 160° P. ±5* P. If not, turn off the water heater, adjust the thermostat,

empty the tank and refill with unheated

water, then Initiate normal operation of the

water heater, and once again determine the maximum mean tank temperature after cutout. Repeat this sequence until the maximum

mean tank temperature after cutout Is within the range of 160° P. ±5“ F., at which time

the thermostat is properly set. If a water

heater has two thermostats, the thermostat

which controls the upper heating element

shall be set first to yield a maximum water

temperature of 160° P. ±5* P. as measured

by the topmost tank thermocouple after cutout. The thermostat which controls the

lower heating element shall then be set to

yield a maximum mean tank temperature of

160° P. ±5°F. after cutout.

2.7 Fuel or energy consumption measurement. Install one or more Instruments which

measure, as appropriate, and with an error no greater than ±1 percent, the quantity

of electrical energy, natural gas, propane or

fuel oil consumed by a water heater. Electrical energy consumption Is to be expressed

in units of kilowatt-hours. Natural gas and

propane consumption shall be expressed In units of standard cubic feet, l.e., measured

cubic feet corrected to standard conditions

of 60° P. temperature and 30 Inches of mercury column pressure. Fuel oil consumption is to be expressed in units of gallons. Also install one or more instruments which

measure, as appropriate, and with an error no greater than ±1 percent, the rate of

electrical energy, natural gas, propane or fuel

oil consumption by a water heater. The rate

of electrical energy consumption shall be expressed in units of kilowatts. The rate of natural gas and propane consumption shall

be expressed In units of standard cubic feet per hour. The rate of fuel oil consumption

shall be expressed in units of gallons per

hour.

2.8

Room ambient temperature. Maintain

the ambient air temperature of the test room

between 66* P. and 85' P. at all times during

the test, as measured according to section

3.5. The ambient air temperature during

these tests shall not vary more than ±7* P. from the average ambient air temperature

determined as the arithmetic average of the

air temperatures measured periodically at

Intervals no greater than 15 minutes

throughout the duration of the test.

3. Test procedures and measurements.

3.1 Tank storage capacity. Determine the

storage capacity, V, of the water heater under

test, in gallons, according to the method specified In section 2.26 of the American National Standard for Gas Water Heaters, Volume I, designated ANS Z21. 10. 1-1975.

3.2 Power input determination.

3.2.1 Power input determination for gas and oil water heaters and electric water heaters with other than immersed heating ele- ments. Initiate normal operation of the water

heater, and by using the appropriate instru- mentation specified in section 2.7 and the

appropriate fuel heating values of sec- tion 2.4, determine the power Input,

P, to the main burners (Including pilot

light power. If any) or heating ele- ments of the water heater under test. In Btu per hour or kilowatts, as aproprlate. In

addition, determine the power Input, pr to any auxiliary electrical system of a gas or

oil water heater when the main burners are

in operation, In kilowatts; and the power

input, p», to any auxiliary electrical system

of a gas or oil water heater when the main

burners are not in operation, in kilowatts.

3.2.2 Power input determination for electric water heaters with immersed heating

elements. The power input, P, to the heating element of an electric water heater with one immersed heating element shall be taken to be the design power rating of the

heating element. For an electric water

heater with dual immersed heating elements, the power input, P, to the heating elements

shall be taken to be the arithmetic mean

of the design power ratings of the heating

elements, if. In characteristic operation of the water heater, only one heating element

will be energized at any time; otherwise, P

shall be taken to be the sum of the design power ratings of the heating elements.

3.3

Recovery efficiency.

3.3.1 Recovery efficiency for gas and oil water heaters and electric water heaters with other than immersed heating elements. With the water heater turned off, fill the tank with water and eliminate any residual

air remaining in the tank. If the mean

tank temperature is constant and within

70* F.±2° F., record the mean tank temperature. initiate normal operation of the water

heater, and begin measuring the fuel or energy flow to the burners (including pilot

light fuel if any) or heating elements of the water heater using the appropriate in- strumentation specified in section 2.7. After cutout determine the maximum mean tank

temperature and record the total fuel flow, Qr, for a gas or oil water heater, or the total

electrical energy flow, Zr, to the heating ele- ments of an electric water heater, from initi- ation to cutout. Record the temperature dif- ference, AT,, obtained by subtracting the

initial from the final maximum mean tank

temperature.

3.3.2 Recovery efficiency for electric water

heaters with immersed heating elements. The

recovery efficiency for electric water heaters with immersed heating elements is derived

from the results of the standby loss tests of section 3.4.3. 3.4 Standby loss. 3.4.1 Standby loss for gas and oil water

heaters and electric water heaters with other than immersed heating elements. Establish normal water heater operation within the maximum mean tank temperature within the range specified In section 2.8 and with all air eliminated from the tank. Begin the standby loss test immediately alter cutout. At the beginning of the standby loss test record the time, the mean tank temperature, the ambient air temperature, and begin

measuring the fuel or energy flow to the burners (including pilot light fuel If any)

or heating elements of the water heater using the appropriate instrumentation specified In section 2.7. At the end of the first 15 minute interval and at the end of each subsequent 15 minute

interval following the beginning of the test, record the mean tank temperature and the ambient air temperature. Continue these measurements until the end of a 48 hour

period unless a main heating element or burner Is on at that time, in which case, continue these measurements until the first subsequent cutout. When the test is terminated, record the total fuel flow, Q,. for a

or oil water heater, or the total electrical energy flow, Zr, to the heating elements of an electric water heater, from the beginning

to the end of the test period, the final mean

tank temperature, the final ambient air temperature, and the time duration, t, of the standby loss test, in hours rounded off to the

nearest tenth of an hour, which elapsed

from the beginning to the end of the test period. Calculate the average of the recorded

values of the mean tank temperatures and

of the ambient air temperatures taken at the end of each time interval, including in each

case the Initial and final values. Determine

the difference, AT,, between these two aver- ages by subtracting the latter from the for- mer, and the difference, A T„ between the

final and initial mean tank temperatures

by subtracting the latter from the former.

3.4.2 Standby loss for electric water heaters with immersed heating elements. All water heaters to be tested must be equipped

with immersed heating elements that have a design power rating of 4,500 watts unless such a design power rating exceeds the maximum design power rating specified by the manufacturer for the water heater to be

tested, in which, case the standby loss test

will be conducted with the water heater equipped with Immersed heating elements of a design power rating equal to the manufacturer’s specified maximum design power

rating. All water heaters capable of operating

with dual immersed heating elements will be equipped and tested with dual immersed

heating elements of equal design power rat- ing in accordance with the provisions specified above. Tests shall be conducted in ac- cordance with the same procedures as those

specified in section 3.4.1. 3.5 Room temperature measurement. Room temperature wherever specified shall be the temperature determined by using the

test room thermocouple described in section

2.5.3.6 Mean tank temperature measurement. Mean tank temperature, the average temperature of the water in a water heater tank,

wherever specified shall be the mean of the temperatures determined by using the six water heater tank thermocouples described

in section 2.5.

4. Calculation of derived results from test measurements.

4.1

Recovery efficiency.

FEDERAL REGISTER, VOL. 42, NO. 192—TUESDAY, OCTOBER 4, 1977 A- 9
RULES AND REGULATIONS 54119

4.1.1 Recovery efficiency for gaa and oil water heaters. For a gas or oil water heater, calculate the recovery efficiency, Er, expressed

as a dimensionless quantity and defined as: kXVXAT,

r ~ QrXH ’ where

t = 3.25 Bta per gallon °F., the nominal specific heat

ol water. l'=tank capacity, determined in accordance with

section 3.1. expressed in gallons. A 7\= difference between the initial and final mean tank

temperatures, determined in accordance with

section 3.3.1, expressed in °F. Q,= total fuel flow in the recovery test, determined in accordance with section 3.3.1, expressed in appropriate units. //= higher heating value for the appropriate fuel type, H-. H„ or as determined in accordance with

section 2.4, expressed in appropriate units.

4.1.2 Recovery efficiency for electric water

heaters with other than immersed heating

elements. For an electric water heater with

other than immersed heating elements, cal- culate the recovery efficiency, Er , expressed

as a dimensionless quantity and defined as: kXVXATt

T ZrX 3,412 Btu/kWh’

where k, V, and A7\ are as defined in section 4.1.1. Z,= total electrical energy flow to the heating elements in the recovery test, determined in accordance with

section 3.3.1, expressed in kilowatt-hours.

4.1.3 Recovery efficiency for electric water

heaters with immersed heating elements. For an electric water heater with immersed heating elements, calculate the recovery efficiency,

Er, expressed as a dimensionless quantity and

defined as: „ SXkXVXATj

P X 3,412 Btu/kWh’

where k and V arc as defined in section 4.1.1 S= standby loss, as calculated in section 4.4.2. aT;= 45° F., the nominal average difference between the mean tank temperature and the ambient air temperature during recovery. P= water heater input power, determined in accord- ance with section 3.2.2, expressed in kilowatts.

4.2

Standby loss.

4.2.1 Standby loss for gas and oil water

heaters. For a gas or oil water heater, calculate the standby loss, expressed in hour-1 and defined as:Q.XH AT,

kxVXAT} Xt ATiXlXEr'

4.2.2 Standby loss for electric water heaters. For an electric water heater, calculate the standby loss, S, expressed in hour —1 and

defined as:

S _Z.X 3,412 Btu/kWh AT,

kXVXAT,Xt AT3 XtXEr *

where k and V are as defined in section 4.1.1. Z,= total electrical energy flow to the heating elements

in the standby loss test, determined in accordance with section 3.4.1 for electric water heaters with

other than immersed heating elements, or section

3.4.2

for electric water heaters with immersed

heating elements, expressed in kilowatt-hours. A Ti = difference between the average value of the mean

tank temperature and the average value of the ambient air temperature during the standby loss

test, determined in accordance with section 3.4.1 for electric water heaters with other than immersed

heating elements, or section 3.4.2 for electric water

heaters with immersed heating elements, ex- pressed in kilowatt-hours. ATi=ditTerence between the initial and final mean tank

temperatures, determined in accordance with sec- tion 3.4.1 for electric water heaters with other than immersed heating elements, or section 3.4.2 for electric water heaters with immersed heating ele- ments, expressed in kilowatt-hours. f=duration of the standby loss test, determined in accordance with section 3.4.1 for electric water

heaters with other than immersed heating ele- ments, or section 3.4.2 for electric water heaters with immersed heating elements, expressed in

hours. E,’ = Er as calculated in section 4.1.2 for electric water

heaters with other than immersed heating ele- ments, or 0.98 for electric water heaters with im- mersed heating elements.

4.3

Daily water heating energy consumption. Calculate the dally water heating energy consumption, C.», the energy required

to heat the nominal amount of hot water used daily, expressed In Btu per day and

defined as: „ kXUXAT,

t- w h — 1

where fc is as defined in section 4.1.1. Er is as calculated in section 4.1.1 for gas and oil water

heaters, section 4.1 2 for electric water heaters with other than immersed heating elements, or section 4.1.3 for electric water heaters with immersed heating elements. Arj=90° F., the nominal difference between the water

heater inlet and outlet water temperatures.

C'=(M.3 gallons per day, the nominal daily hot water

usage.

4.4

Average hourly hot water storage energy consumption. Calculate the average hourly hot water storage energy consumption, c«„ the average energy required per hour to maintain stored water temperature,

expressed in Btu per hour and defined as:

ca .= SXkXVXATs, where k and V are as defined in section 4.1.1. S Is as calculated in section 4.2.1 for gas and oil water

heaters, or section 4.2.2 for electric water heaters.

AT»=90“F., the nominal difference between the mean

tank temperature and the ambient air temperature.

4.5

Average daily energy consumption.

4.5.1. Average daily auxiliary electric energy consumption for gas and oil water

heaters. For a gas or oil water heater, calculate the average dally auxiliary electrical energy consumption, C«ui, expressed kilo- watt-hours per day and defined as:

C. UI = pr X^+p,x(24 hours Cu,a\

day P )

'

where C„* is as calculated in section 4.3. P=power input to the burner, determined in accordance with section 3.2.1, expressed in Btu per hour. pr =power input to any auxiliary electrical system during

periods of main burner operation, determined in accordance with section 3.2.1, expressed in kilowatts. p.= power input to any auxiliary electrical system during

periods when the main burner is not in operation, determined in accordance with section 3.2.1, expressed in kilowatts.

4.5.2

Average daily gas or oil energy con- sumption for gas and oil water heaters. For

a gas or oil water heater, calculate the aver- age dally gas or oil energy consumption, Cr, as appropriate, expressed in Btu per day and

defined as: C

f

— C f~ C ut

C.» is as calculated in section 4.3. c.. is as calculated in section 4.4. P is as defined in section 4.5.1. J\=daily energy credit for a heat trap installed in the

outlet water connection of a water heater = l, 311 Btu

per day for water heaters that have such a heat trap

as an integral part of the water heater, or zero for water heaters that do not. Jc =daily energy credit for a heat trap installed in the

inlet water connection of a water heater=983 Btu

per day for water heaters that have such a heat trap

as an integral part of the water heater, or zero for water heaters that do not.

4.5.3

Average daily energy consumption

for gas and oil water heaters. For a gas or oil water heater, calculate the average dally energy consumption. C*, expressed in Btu per day and defined as: C*=C7 + C» ui X 3,412 Btu/kWh,

where

Ct is as calculated In section 4.5.2. C.ui is as calculated in section 4.5.1.

4.5.4

Average daily energy consumption

for electric water heaters. For an electric water heater, calculate the average dally energy consumption, C», expressed In kilo- watt-hours per day and defined as:

where k, V, and H are as defined In section 4.1.1 E. is as calculated In section 4.1.1 «.= total fuel flow in the standby loss test, determined

in accordance with section 3.4.1, expressed in appropriate units. A7";=dinerence between the average value of the mean

tank temperature and the average value of the ambient air temperature during the standby

loss test, determined in accordance with section

3.4.1, expressed In °F. A 7', = 'inference between the initial and final mean

tank temperatures, determined In accordance with section 3.4.1, expressed In °F. (-duration of the standby loss test, determined

in accordance with section 3.4.1, expressed in

hours.

C„=7

3,412 Btu/kWh X £c,ra + c u ,X^

24 hours Cwl

|

day PX3.412 Btu/kWh

is as calculated in section 4.3. c.. is as calculated in section 4.4. J\ and J. are as defined in section 4.5.2. P- input power, determined in accordance with sec- tion 3.2.1 for electric water heaters with other than immersed heating elements or section 3.2.2 for oleotrio water heatere with immersed heating elements, ex- pressed in kilowatts. [FR Doc.77-29000 Filed 10-3-77:8:45 ami

FEDERAL REGISTER, VOL 42, NO. 192—TUESDAY, OCTOBER 4, 1977

A - 1 0
13865

rules and regulations

Thii section of tho FEDERAL REGISTER contains regulatory documents having general applicability and legal effect most of which are keyed to and

codified' in the Code of Federal Regulations, which is published under SO titles pursuant to 44 U.S.C 1510.

The Code of Federal Regulations is sold by the Superintendent of Documents. Prices of new books are listed in the first FEDERAL REGISTER issue of each

month.

[1505-01]

Title 1 —General Provisions

CHAPTER I—ADMINISTRATIVE

COMMITTEE OF THE FEDERAL

REGISTER

CFR CHECKLIST

1977 Issuances

This checklist, prepared by the

Office of the Federal Register, is published in the first issue of each month.

It is arranged in the order of CFR

titles, and shows the revision date and

price of the volumes of the Code of

Federal regulations issued to date for

1977. New units issued during the

month are announced on the back

cover of the daily Federal Register as

they become available.

For a Checklist of current CFR vol- umes comprising a complete CFR set,

see the latest issue of the Cumulative

List of CFR Sections Affected, which

is revised monthly.

The rate for subscription service to

all revised volumes issued for 1977 is $350 domestic, $75 additional for foreign mailing. Order from Superintendent of Documents, Government Printing Office,

Washington, D.C. 20402.

CFR Unit (Rev. as of Jan. 1, 1977):

Title

2 [Reserved]

3

7Parts: <M5_

48-51.

52. 53-209.. 210-699 700-749

750-699

900-944 945-980

981-999

1000-1059., 1080-1119 1120-1199

1200-1499

1500-end..

9lOP&rte; 0-199

200-end.

11 <Rev. 5/1/77).

12 Pert*

1-299 _

„ — 14 Part*;

Price

51.65

3.00

3.25 4.70

5.30

4.20

5.20 5.80

6.10 4.10

1.80 4.25

2.40

2.50

4.25 4.40

3.20 4.20

7.25

2.60 6.80

4.40

4.60 2.30

7.40

, 7.30

4.20

Title

1-59.... Price

6.00 Title

60-199 . 50^50 200-1199 . ...... 6.20 fin_QQ 1200-end - r - 2.20 100-300 - - 16 Parts: 0-149 400-end

41 Chapters:

150-999 ... 4.25 1-^ 1000-end 3

_ 6 CFR Unit (Rev. as of April 1, 1977):

7 .

Price

4.25

5.75 5.00

4.25

4.75

5.75

5.25

5.50

2.75 2.30 Title Price

18 Parte

1-149 4.25 150-end. 4.00

20 Parte

01-399 3.25 400-499 5.00 500-end. 4.00 21 Parte

100-199 [ZZZZZIZZZZ.'TM!! 4.75 200-299 2.10 300-499 5.00 500-599 4.00 600-1299 3.50 1300-end. 4.25

24 Parte

0-499 5.00 500-end. 5.25

26 Parte

1 (55 1.0-1.169) 4.75

1 <H 1.170-1.300) 4.00

1 (§5 1.301-1.400) 3.75

1 (55 1.401-1.500) 4.00

1 (55 1.501-1.640) 4.00

1 (551 841-1.850) 4.35

1 (55 1.851-1.1200) - 5.25

1 (55 1.1201-end) ... 6.75 40-299”"ZZZZZZI 4.50 300-499 4.35 800-end — — 2.40 CFR Unit (Rev. as of July 1, 1977):

Title Price

29 Parts:

0-

499 5.75 1900-1919 8.00 1020-end 4J50

32 Parte

1-

39 (V. I) (Rev. 7/1/78) 4.75

(V. H) (Rev. 7/1/78) 7.50

(V. Ill) (Rev. 7/1/76) 5.25 400-589 5.00 590-899 4.00 700-799 8.25 1000-1399 2.75 1400-1569 4.25 1600-end. 2.75

33 Parte

1-199 7.00 200-end 5.30

34

1.70

40 Parte

9 (Rev. 9/26/77) 8.00

19-100 ZZ..ZIZIZZ!! 4.50 101-end ——„—— 5.7S CFR Unit (Rev. as of Oct. 1, 1877):

Title 43 Parte

1-999 46 Parte

70-89.... 90-109.. 110-139

49 Parte

1-99

Price

4.00

3.2S

3.00 3.00

3.00

[3128-01]

Title 10—Energy

CHAPTER II—FEDERAL ENERGY

ADMINISTRATION 1

PART 430—ENERGY CONSERVATION

PROGRAM FOR APPLIANCES

Indefinite Suspension of Final Test Procedures for Water Heaters

AGENCY: Department of Energy.

ACTION: Suspension of final rule. SUMMARY: The Department of

Energy, by separate notice issued

today, is proposing an amendment to

its test procedures for water heaters,

10 CFR Part 430, Subpart B. Pending

the hearing on this proposal and pre- scription of the final rule, the provisions of 10 CFR 430.22(e)(2) are hereby suspended.

EFFECTIVE DATE: March 29, 1978. FOR FURTHER INFORMATION

CONTACT:

James A. Smith, (Office of Conservation and Solar Applications), Old

Post Office Building, Room 307,

'Editorial Note It is contemplated that Chapter II will be renamed at a future date

to reflect the fact that it contains regulations administered by the Department of Energy, including regulations administered

by the Office of Conservation and Solar Applications.

FEDERAL REGISTER, VOL 43, NO. 64—MONDAY, APRIL 3, 1978
13888

proposed rules

ThU section of the FEDERAL REGISTER contain! notices to the public of the proposed issuance of rules and regulations. The purpose of these notices is to give interested persons an opportunity to participate in the rule making prior to the adoption of the final rules.

[ 3128-01 ]

DEPARTMENT OF ENERGY

Office of Conservation and Solar Applications

[10 CFR Part 430]

ENERGY CONSERVATION PROGRAM

FOR APPLIANCES

Proposed Rulemaking and Public Hearing

Regarding Test Procedures for Water Heaters AGENCY: Department of Energy.

ACTION: Proposed rule. SUMMARY: The Department of

Energy hereby proposes to amend its test procedures for water heaters.

These test procedures are a part of Che

appliance energy efficiency program

established pursuant to the Energy

Policy and Conservation Act, which re- quires that standard methods of test- ing be prescribed for covered appli- ances. DATES: Comments by May 22, 1978; requests to speak by May 3. 1978: statements by May 15, 1978: hearing

to be held on May 16, 1978. ADDRESSES: Comments and requests

to speak at the hearing to: Office of Public Hearing Management, Box SA,

Department of Energy. Room 2313,

2000 M Street NW., Washington. D.C.

20461; statements to: Office of Public

Hearing Management, Box SA, De- partment of Energy, Room 2313, 2000 M Street NW., Washington, D.C.

20461; hearing to be held at: Room

2105, 2000 M Street NW., Washington,

D.C. FOR FURTHER INFORMATION

CONTACT:

James A. Smith (Office of Conservation and Solar Applications), Old

Post Office Building, Room 307,

12th and Pennsylvania Avenue NW.,

Washington, D.C. 20461, 202-566-

4635. Robert C. Gillette (Hearing Procedures) 2000 M Street NW., Room

2222A, Washington, D.C. 20461, 202-

254-5201.

Jim Mema (Media Relations), 12th

and Pennsylvania Avenue NW.,

Room 3104, Washington, D.C. 20461,

202-566-9833.

William J. Dennison (Office of the

General Counsel), 12th and Pennsylvania Avenue NW., Room 7148,

Washington, D.C. 20461, 202-566-

9750. SUPPLEMENTARY INFORMATION:

A. Background

On October 1, 1977, the Department

of Energy (DOE) assumed the authority of the Federal Energy Administration (FEA) for the energy conservation program for appliances, pursuant

to section 301 of the Department of

Energy Organization Act (DOE Act)

(Pub. L. 95-91). The energy conservation program for appliances was estab- lished by FEA pursuant to title HI,

part B of the Energy Policy and Conservation Act (Act) (Pub. L. 94-163).

Section 323 (42 U.S.C. 6293) of the Act

requires that standard methods of

testing be prescribed for covered appli- ances. FEA proposed test procedures for water heaters by notice issued April

21, 1977 (42 FR 21576, April 27, 1977),

and a public hearing on the proposed

test procedures was held on June 13, 1977. Final test procedures for water

heaters were prescribed by FEA on

September 27, 1977 (42 FR 54110, October 4. 1977).

DOE is today proposing to amend

section 430.22(e)(2) of the final test procedures for water heaters and Appendix E to subpart B of part 430 in order to specify a different method of

determining the energy factor for water heaters.

B. Discussion

A review of the final test procedures

for water heaters revealed an error in the derivation of the energy factor. In both the proposed and final test procedures, the energy factor was computed

by dividing the daily water heating

energy consumption by the average

daily energy consumption. The energy

factor was intended to relate a water

heater’s useful output of services to its energy consumption. As currently for- mulated, the numerator of the equation used to determine the energy

factor actually reflects a portion of

the water heater’s energy consumption rather than the water heater's

useful output of services. One approach to determining the

useful output of a water heater is to determine the energy Imparted by a water heater to the volume of water

delivered by the water heater. The

final water heater test procedures are

based upon an average daily hot water

usage of 64.3 gallons and an average

temperature difference between the

water heater inlet temperature and

water heater outlet temperature of 90* F. Under these conditions, the useful

output of a water heater would be the

product of (a) 64.3 gallons per day, (b) a 90° F. temperature rise, and (c) the

specific heat of water. The energy

factor could be determined by dividing

this measure of the useful output of a water heater by the energy consumption of the water heater.

Because of the importance of the

energy factor to the efficiency target

program and to any future energy effi- ciency standard program for appli- ances, DOE has decided to propose the

methodology for determining the

energy factor discussed above as an amendment to the final test procedures, As an ancillary matter, by separate notice also published today, DOE

is suspending section 430.22(e)(2) of

Title 10, Code of Federal Regulations,

until the amendments proposed today

are either adopted or withdrawn. No

other provisions of Title 10 are affect- ed by this suspension.

C. Comment Procedure

1. Written comment Interested per- sons are invited to participate in this rulemaking by submitting data, views

or arguments with respect to the pro- posed amendments set forth in this notice to Office of Public Hearing

Management, Box SA, Washington,

D.C. 20461. Comments may suggest al- ternative methods of determining the

energy factor for water heaters, but

any suggestions should discuss how

they relate the useful output of ser- vices to the energy consumption of a j water heater.

Comments should be identified on j, the outside of the envelope and on

documents submitted to DOE with the

designation “Water Heaters-Proposed

Amendments.’’ Fifteen copies should

be submitted. All comments received

by May 22, 1978, before 4:30 p.m.,

1

e.d.t., and all other relevant information, will be considered by DOE before

final action is taken on the proposed ; regulation.

Any information or data considered 1 by the person furnishing it to be confi- dential must be so identified and sub- 1 mitted in writing, one copy only. DOE

reserves the right to determine the

confidential status of the information

or data and treat it according to its de- 1 termination.

FEDERAL REGISTER, VOL 43, NO. 64—MONDAY, APRIL 3, 1978
PROPOSED RULES 13889

2. Public hearings—a*. Request procedures. The time and place of the

public hearing are indicated at the be- ginning of this preamble. The hearing

will be continued, if necessary, on May

17, 1978. DOE invites any person who has an

interest in the proposed amendment

issued today, or who is a representative of a group or class of persons that

has an interest in today’s proposed

amendment, to make a written request

for an opportunity to make an oral presentation. Such a request may be

hand delivered to Office of Public

Hearing Management, Box SA, Department of Energy, Room 2313, 2000

M Street NW„ Washington, D.C.

20461, between the hours of 8 am. and

4:30 p.m., Monday through Friday. A

request should be labeled both on the

document and on the envelope “Water

Heaters — Proposed Amendments.

The person making the request

should briefly describe the interest

concerned; if appropriate, state why

she or he is a proper representative of a group or class of persons that has

such an -interest; and give a concise

summary of the proposed oral presentation and a telephone number where

she or he may be contacted through

May 15, 1978. DOE will notify, before 4:30 p.m.,

e.d.t.. May 9, 1978, each person select- ed to appear at a hearing. Each person

selected to be heard must submit 100

copies of her or his statement to the

address and by the date given in the

beginning of this preamble. In the

event any person wishing to testify

cannot meet the 100-copy requirement, alternative arrangements can be

made with the Economic Regulatory

Administration (ERA) in advance of

the hearing by so indicating in the

letter requesting an oral presentation

or by calling the ERA at 202-254-3345.

b. Conduct of hearings. DOE re- serves the right to select the persons

to be heard at this hearing, to schedule their respective presentations and

to establish the procedures governing

the conduct of the hearing. The

length of each presentation may be

limited, based on the number of per- sons requesting to be heard.

A DOE official will be designated to preside at the hearing. This will not be

a judicial or evidentiary-type hearing.

Questions may be asked only by those

conducting the hearing, and there will be no cross-examination of the persons

presenting statements. Any decision

made by DOE with respect to the subject matter of the hearing will be

based on all information available to DOE. At the conclusion of all initial oral statements, each person who has

made an oral statement will be given

the opportunity, if she or he so desires, to make a rebuttal statement. The rebuttal statements will be given

in the order in which the initial statements were made and will be subject

to time limitations.

Any interested person may submit

questions to be asked of any person

making a statement at the hearing to Public Hearing Management, Box SA,

DOE, 2000 M Street NW„ Washington,

D.C., before 4:30 p.m., e.d.t.. May 9, 1978. DOE will determine whether the

question is relevant, and whether the

time limitations permit it to be pre- sented for answer. Any person who makes an oral state- ment and who wishes to ask a question

at the hearing may submit the question, in writing, to the presiding offi- cer. The presiding officer, will deter- mine whether the question is relevant,

and whether the time limitations

permit it to be presented for answer. Any further procedural rules needed

for the proper conduct of the hearing

will be announced by the presiding officer. A transcript of the hearing will be

made and the entire record of the

hearing, including the transcript, will be retained by DOE and made avail- able for inspection at the DOE Free- dom of Information Office, Room

2107, Federal Building. 12th and Pennsylvania Avenue NW., Washington,

D.C., between the hours of 8 a.m. and

4:30 p.m., Monday through Friday.

Any person may purchase a copy of

the transcript from the reporter. D. Environmental and Inflationary

Review

Pursuant to section 7(c)(2) of the

FEA Act, a copy of this notice has

been submitted to the Administrator

of the Environmental Protection

Agency for his comments concerning

the impact of this proposal on the

quality of the environment. The Administrator has no comments.

The National Environmental Policy

Act of 1969 requires DOE to assess the

environmental impacts of any proposal issued by the Department for

“major Federal actions significantly

affecting the quality of the human en- vironment.’’ Since test procedures

under the energy conservation pro- gram for appliances will be used only

to standardize the measurement of energy usage and will not affect the

quality or distribution of energy

usage, DOE has determined that the

action of prescribing test procedures,

by itself, will not result in any environmental impacts. On this basis, DOE

has determined that, with respect to prescribing test procedures under the

energy conservation program for appliances, no environmental impact

statement is required.

The proposed rule has been reviewed

in accordance with Executive Order

11821 as amended by Executive Order

11949, and OMB Circular No. A-1Q7

and has been determined not to be a major proposal requiring evaluation of

its economic impact as provided for

therein.

(Energy Policy and Conservation Act, Pub.

L. 94-163, as amended by Pub. L. 94-385; Federal Energy Administration Act of 1974, Pub. L. 93-275, as amended by Pub. L. 94-

385; Department of Energy Organization

Act. Pub. L. 95-91; E.O. 11790, 39 FR 23185.) In consideration of the foregoing, it

is proposed to amend Part 430 of

Chapter II of Title 10, Code of Federal

Regulations, as set forth below.

Issued in Washington, D.C., March

27, 1978. William S. Heffelfinger,

Director ofAdministration.

1. Section 430.22 is amended by re- vising paragraph (e)(2) to read as fol- lows:

(e) • • • (2) The energy factor for water heaters shall be—

(i) For a gas or oil water heater, the

quotient of the daily hot water energy

consumption determined according to section 4.6 of Appendix E of this subpart divided by the average daily

energy consumption as determined ac- cording to section 4.5.3 of Appendix E

of this subpart, the resulting quotient

then being rounded off to the nearest

0.01; and

(ii) For an electric water heater, the

quotient of the daily hot water energy

consumption determined according to section 4.6 of Appendix E of this subpart divided by the product of the

average daily energy consumption as determined according to section 4.5.4 of Appendix E of this subpart times

3,412 Btu per kilowatt-hour, the re- sulting quotient then being rounded

off to the nearest 0.01.

2. Appendix E to Subpart B of Part

430 is amended by adding a new sec- tion^. 6, to read as follows:

4.6 Daily hot water energy consumption.

Calculate the daily hot water energy con- sumption, C„ the energy content of the nominal daily hot water usage, expressed in Btu per day and defined as: Ct =JcxUxbT.,

Where:

fc is as defined in section 4.1.1; and

A 7*i and U are as defined in section 4.3. [FR Doc. 78-8591 Filed 3-31-78; 8:45 am]

[ 4810-33 ] DEPARTMENT OF THE TREASURY

Comptroller of the Currency

[12 CFR Port 9] FIDUCIARY POWERS OF NATIONAL BANKS

AND COLLECTIVE INVESTMENT FUNDS

Extension of Comment Period AGENCY: Comptroller of the Currency, Treasury.

ACTION: Extension of comment

period.

FEDERAL REGISTER, VOL. 43, NO. 64—MONDAY, APRIL 3, 1978 A- 1 3
48986 RULES AND REGULATIONS

[3128—01-M]

Title 10—Energy

CHAPTER II—FEDERAL ENERGY

ADMINISTRATION 1

PART 430—ENERGY CONSERVATION

PROGRAM FOR CONSUMER PRODUCTS

Test Procedures for Water Heaters

AGENCY: Department of Energy.

ACTION: Final rule. SUMMARY: The Department, of Energy hereby amends its test proce- dures for water heaters as they relate

to determining the energy factor for water heaters. These test procedures

are a part of the consumer product

energy efficiency program established

pursuant to the Energy Policy and

Conservation Act. which requires that

standard methods of testing be pre- scribed for covered consumer products.

EFFECTIVE DATE: November 20, 1978. FOR FURTHER INFORMATION

CONTACT:

James A. Smith, Office of Conservation and Solar Applications, Room

2248. 20 Massachusetts Avenue NW„

Washington, D.C. 20545, 202-376-

4815. Jim Meraa, Media Relations. Federal Building, Room 3104, 12th and

Pennsylvania Avenue NW„ Washington, D.C. 20461, 202-566-9833.

William J. Dennison, Office of the

General Counsel, Federal Building,

Room 7148, 12th and Pennsylvania

Avenue NW.. Washington, D.C.

20461, 202-566-9750.

SUPPLEMENTARY INFORMATION:

A. Background

On October 1, 1977, the Department

of Energy (DOE) assumed the authority of the Federal Energy Administration (FEA) for the energy conservation program for consumer products,

pursuant to section 301 of the Department of Energy Organization Act (DOE Act) (Pub. L. 95-91). The energy

conservation program for consumer

products was established by FEA pur- suant to title III, part B of the Energy

Policy and Conservation Act (Act)

(Pub. L. 94-163). Section 323 (42 U.S.C. 6293) of the Act requires that standard methods of testing be prescribed

for covered consumer products.

1 Editorial Note.— It is contemplated that

ch. II will be renamed at a future date to re- flect the fact that It contains regulations ad- ministered by the Department of Energy,

including regulations administered by the

Office of Conservation and Solar Applications.

FEA proposed test procedures for water heaters by notice issued April

21. 1977 (42 FR 21576. Apr. 27, 1977),

and a public hearing on the proposed

test procedures was held on June 13, 1977. Final test .procedures for water

heaters were prescribed by PEA on September 27, 1977 (42 FR 541 1G. Oct.

4. 1977).

A subsequent revit \v of the final test procedures for water heaters revealed an error in the derivation of the

energy factor. The energy factor is in- tended to be a measure of efficiency

equal to the ratio of the useful output

of a water heater to the energy input

of the water heater, i.e., the total energy consumed to provide the useful

output. The useful output of a water

heater is the energy content of the water actually delivered by the water

heater on a daily basis. The energy

input to a water heater is the total energy consumed by the water heater on a daily basis. In the promulgated

test procedures, the useful output of a water heater (the numerator of the

energy factor ratio) was erroneously

expressed as a water heater’s "daily water heating energy consumption.”

This term, which is correctly utilized

in other parts of the test procedures,

includes both the energy content of the water actually delivered by the

water heater on a daily basis (the

useful output) and any additional

energy which is dissipated as a result

of any inefficiency in the heat transfer process, and which does not contribute to the useful output. The

result was that the water heater effi- ciency was overstated since part of the

term in the numerator of the energy

factor was not attributable to useful

output.

Today’s amendment specifies that

the useful output (the numerator of the energy factor) shall be the "daily

hot water energy consumption,” a term defined by new section 4.6 of ap- pendix E to include only the energy

content of the water actually delivered

by the water heater on a daily basis. By notice issued March 27, 1978 (43

FR 13888, Apr. 3, 1978), DOE proposed

to amend § 430.22(e)(2) and appendix

E to subpart B of part 430. The intent

of the proposed amendments was to specify the proper method of deter- mining the energy factor for water

hearers. Pending a resolution of this matter, DOE suspended the provisions

of the final water heater test proce- dures dealing with the determination

of the energy fsfctor, by notice issued

March 29, 1978 (FR 13865, Apr. 3. 1978). A public hearing on the pro- posed amendment was scheduled for May 16, 1978, but no requests for the

presentation of oral statements were

received.

B. Discussion of Comments

One written comment was received

from an engineering consulting firm,

which contended that despite the pro- posed changes, the DOE test proce- dures would still substantially overstate the energy consumption of water

heaters. In support of this contention,

the commenter referred to data previously submitted to DOE. This issue was reviewed at the time the notice

prescribing final test procedures for water heaters (42 FR 54110, Oct. 4. 1977) was promulgated.

Based on available data, FEA deter- mined that the test procedures did not

overstate the energy consumption of water heaters. In connection with

today's amendment, DOE has again

revieu’ed this issue and finds no basis’ for changing the original FEA deter- mination.

C. Regulations Prescribed

The effect of today's rulemaking is to amend the test procedures for water heaters by substituting in 10 CFR 430.22 a new paragraph (e)(2) for determination of the energy factor for water heaters and by adding to appendix E a new section 4.6 for calculation

of the daily hot water energy con- sumption of water heaters. DOE’S suspension of 10 CFR

430.22(e)(2) (43 FR 13865, Apr. 3,

1978)

, terminates when today’s amendments become effective. As part of today's rulemaking DOE

is also changing the name of 10 CFR

Part 430 to “Energy Conservation Pro- gram for Consumer Products.” DOE

believes that this change will elimi- nate any possible confusion regarding

the contents of 10 CFR Part 430. In accordance with the proposed

DOE plan for implementing Executive

Order 12044. “Improving Government

Regulations,” DOE has determined

that this final rule to amend the test procedures for water heaters is not a

significant regulation. In consideration of the foregoing,

part 430 of chapter II of Title 10, Code

of Federal Regulations, is amended as

set forth below, effective November

20, 1978. Issued ir> Washington. D.C.. October

13. 1978. William P. Davis,

Deputy Director

ofAdministration.

1. Section 430.22 is amended by re- vising paragraph (e)(2) to read as fol- lows:

(e) • * • (2) The energy factor for water heaters shall be—

(i) For a gas or oil water heater, the

quotient of the daily hot water energy

consumption determined according to section 4.6 of appendix E of this subFEDERAl REGISTER, VOL 43, NO. 203—THURSDAY, OCTOBER 19, 1978

A - 1 4
RULES AND REGULATIONS

part divided by the average daily energy consumption as determined ac- cording to section 4.5.3 of appendix E of this subpart, the resulting quotient

OOVznT5 rounded off to the nearest

(ii) For an electric water heater, the quotient of the daily hot water energy consumption determined according to section 4.6 of appendix E of this subpart divided by the product of the

average daily energy consumption as determined according to section 4 5 4

of appendix E of this subpart times

<3,412 Btu per kilowatt-hour, the re- nting quotient then being rounded

off to the nearest 0.01.

2- Appendix E to subpart B of part 430 is amended by adding a new sec- tion 4.6, to read as follows: w

?

ter energy consumption.

daily hot water energy con- 2n

‘,n

rt n"Jhe energy content of the hot water usage, expressed in otu per day and defined as: C,=kx Ux\Ts. Where:

A: is as defined in section 4.1.1; and A71, and > are as defined in section 4.3.

. 3

;, .Jhe name of Part 430 is changed

to Energy Conservation Program For Consumer Products," as set forth above.

CPR Doc. 78-29535 Piled 10-18-78: 8:45 am]

48987

FEDERAL REGISTER, VOL. 43, NO. 203-THURSDAY, OCTOBER 19, 1978

A - 1 5
Federal Register / Vol. 44, No. 91 / Wednesday, May 9, 1979 / Proposed Rules 27191

DEPARTMENT OF ENERGY

Office of Energy Conservation and

Solar Applications

[10CFR Part 4301

Energy Conservation Program for Consumer Products; Test Procedures

for Water Heaters; Public Hearing

agency: Department of Energy.

action: Proposed rule. summary: The Department of Energy

hereby proposes to amend its test procedures for water heaters. These test procedures are a part of the energy

conservation program for consumer

products established pursuant to the Energy Policy and Conservation Act as amended by the National Energy

Conservation Policy Act which requires

that standard methods of testing be

prescribed for covered products.

dates: Written comments in response to

this notice by July 9. 1979; requests to speak at the public hearing by June 14, 1979; statements by June 22, 1979; public

hearing to be held on June 27, 1979, 9:30 a.m. addresses: Written comments, requests

to speak at the public hearing, and

statements to: Margaret W. Sibley, U.S. Department of Energy, Office of Conservation and Solar Applications,

Docket -CAS-rm-79-105, Mail Stop

2221C, 20 Massachusetts Avenue, NW.,

Washington, D.C. 20585. PUBLIC HEARING TO BE HELD AT: Department of Energy, Room 3000A,

Federal Building. 12th Street and

Pennsylvania Avenue. NW.,

Washington, D.C. 20585. FOR FURTHER INFORMATION CONTACT.

James A. Smith, U.S. Department of Energy,

Office of Conservation and Solar

Applications, Division of Buildings and

Community Systems. Consumer Products

Efficiency Branch. Room 2248. 20 Massachusetts Avenue. NW.. Washington.

D.C. 20585. (202) 370-4814. Margaret W. Sibley (Hearing Procedures),

U.S. Department of Energy. Office of Conservation and Solar Applications. 20 Massachusetts Avenue. NW., Mail Stop

2221 C, Washington. D C. 20585. (202) 370-

1651. Robert M. Mussler. U.S. Department of Energy, Office of Ceneral Counsel. 20 Massachusetts Avenue. NW.. Room 3224. Washington. D.C. 20585. (202) 376-4100. SUPPLEMENTARY INFORMATION:

A. Background

Title III, Part B of the Energy Policy

and Conservation Act (Act) (Pub. L 94-

163) established an energy conservation

program for consumer products. As part

of this program, section 323 (42 U.S.C.

6293) of the Act requires that standard

methods of testing to determine

estimated annual operating cost and at least one other useful measure of energy

consumption be prescribed for certain products, including water heaters. Test procedures for water heaters were proposed by notice issued April 21, 1977 (42 FR 21576, April 27, 1977). Final

test procedures for water heaters were

prescribed on September 27, 1977 (42 FR

54110, October 4, 1977). DOE amended

the test procedures for water heaters by

notice issued October 13, 1978 (43 FR

48986, October 19, 1978) in order to specify a new method of determining the measure of efficiency of water heaters. DOE is today proposing to amend the

test procedures for water heaters,

specifically Appendix E to Subpart B of Part 430, Code of Federal Regulations, in order to specify two new measures, first hour rating and recovery rate.

B. Discussion

When originally proposed on April 21. 1977, the test procedures for water

heaters included the measures of hot

water supply rating and recovery rate. Hot water supply rating was a measure

of the maximum amount of hot water

that a water heater could provide in one

hour. Recovery rate was a measure of the rate at which a water heater could

heat water. Both of these measures were

included in the original proposed test procedures because they were likely to assist consumers in making purchasing

decisions. At the public hearing on the original

proposed water heater test procedures,

members of the water heater industry

argued that the test procedures as proposed were unduly burdensome for the testing of electric water heaters with

immersed heating elements due to the

large number of models that would have

to be tested and the attendant high cost

of testing. After reviewing those comments, a decision was made to revise the definition of a water heater basic model

for the final test procedures to exclude

immersed heating elements from

consideration as a distinguishing feature

of a basic model. This change was made

only after a very careful evaluation led

to acceptance of the commenters’ claim

that, for the purposes of the test procedures, the electrical characteristics

of an electric water heater with

immersed heating elements have only a minimal effect on its efficiency and

hence its energy consumption. Since

these characteristics did, however, have

a significant effect on the proposed

measures, hot water supply rating and

recovery rate for electric water heaters,

this revision of the definition of a water

heater basic model made the proposed

method for the determination of these measures unworkable. _

Since hot water supply rating was a

useful measure of the capacity of a water heater, members of the water

heater industry expressed concern over

the possible loss of this measure. They

commented that the hot water supply

rating of an electric water heater with

immersed heating elements could be

predicted by calculation; however, they

had no such prediction scheme to present at the time. Neither did they

submit any data from which a hot water

supply rating prediction scheme might

be developed. > While the development of a scheme i? for predicting the hot water supply

rating of such a water heater was

considered feasible, it was found that, « lacking a proven hot water supply rating d prediction scheme and lacking test data t from which to attempt to develop such a scheme, the proposed measure, hot |i water supply rating, had to be deleted * from the final test procedures for water > heaters. However, a statement was

included in the notice of the final rule on

test procedures to the effect that further investigations into schemes for the prediction of hot water supply rating or

for the determination of some other measure of hot water delivery

performance for water heaters would be J made. It was further stated that the water heater industry and other

interested parties were invited to provide input concerning these

investigations.

No comments on the original proposed

test procedures for water heaters addressed the measure of recovery rate. This measure, sometimes referred to as “recovery capacity," accounted for the combined effect of a water heater’s power input and recovery efficiency on

the rate at which the water heater could

heat water. In the proposed test procedures, recovery rate was to be • determined independently of hot water

supply rating and was intended to serve

as a useful measure of the rate at which

a water heater could recover from a

large hot water draw. The higher the recovery rate, the more quickly the water heater could replenish its stored volume of hot water subsequent to a large water draw.

Revising the definition of a water

heater basic model also made the proposed method for the determination

of recovery rate unworkable. Again,

lacking a proven recovery rate prediction scheme and the test data

from which to attempt to develop such a

A- 1 6

m

r<B

mw

J)

«B
27192 Federal Register / Vol. 44, No. 91 / Wednesday, May 9, 1979 / Proposed Rules

scheme, this proposed measure, like hot water supply rating, had to be deleted

from the final test procedures.

The investigation into schemes for the

prediction of hot water supply rating or

. for the determination of some other measure of hot water delivery

performance for water heaters was

concluded by DOE at about the same

time that two events occurred which

reaffirmed the need for such measures

i to be included in the test procedures for water heaters. The first of these events was the release of the Federal Trade

Commission’s (FTC) final staff report on

FTC's proposed rule concerning

disclosure of energy cost and

consumption information in labeling and

advertising of consumer products. This

j report was released on February 12, 1979. In it, FTC made the following statement in the section dealing with the

j determination of the capacity of consumer products covered by the proposed rule:

"Historically, gas and oil water heater

sales are based on recovery capacity, while

i electric water heater comparisons are based

on storage capacity. Some participants [in the

public hearing and written comments

j process] argued that the traditional methods

of comparing water heaters are

unsatisfactory. A system that reflects the energy needed both to store and to replace

consumed hot water is more informative than

| one that measures only storage or recovery.

I The Recommended Rule reservedly bases

j capacity on tank storage, in accordance with

j current DOE test procedures. If the

| Department of Energy prescribes methods of

i measuring first hour recovery rates or hot

J water supply ratings before the Commission

| issues the final labeling rule, staff

| recommends that the final rule reflect the

j DOE procedure for measuring capacity in

t effect at that time."

I The second event was the series of six

I public meetings held on DOE’s

j advanced notice of proposed rulemaking

' regarding energy efficiency standards

! for nine types of consumer products.

I These public meetings were held over

the period January 26 to February 8, 1979. Four of the participants in these

public meetings, all representatives of

the water heater industry, made

statements to the effect that DOE should

use the measure, first hour rating, as the measure of the capacity of a water

heater and issue minimum energy

efficiency standards which are a

function of this capacity measure. (As it

is used here, first hour rating can be

considered to be equivalent to hot water

supply rating.) These commenters

claimed that the establishment of minimum energy efficiency standards as

a function of tank volume, the present measure of the capacity of a water

heater, would impose a more stringent

requirement on water heaters with large

tank volumes than those with small tank

volumes. Such an approach would

discriminate against water heaters with

large tank volumes. It was pointed out

that water heaters with large tank

volumes provide a utility which cannot always be matched by those with

smaller tank volumes, particularly in the case of electric water heaters. Commenters argued that consumers need water heaters with large tank

volumes to satisfy their hot water needs

in order to take advantage of off-peak or time-of-day electric utility rates to reduce their water heating energy bill. In an effort to develop a more useful measure of water heater capacity', DOE

is proposing to amend the test procedures for water heaters to incorporate two new measures, recovery

rate and first hour rating.

Recovery rate as proposed in this notice is the same as it appeared in the

original proposed test procedures except

that a new method of determining the power input of an electric water heater

with immersed heating elements is specified. Also, as proposed in this notice, recovery rate is used in the determination of first hour rating. After

reviewing the rationale behind the decision to delete this measure from the

original proposed test procedures for water heaters, DOE has determined That

the measure should now be

reconsidered. DOE finds that while the method for the determination of power

input for electric water heaters with

immersed heating elements may

introduce some error into the determination of recovery rate, such

error may not be of such a magnitude as

to be unacceptable. The benefits of this measure, both with regard to its usefulness to consumers, discussed

earlier, and its contribution toward the determination of first hour rating, may

outweight concerns over any slight

inaccuracy in the measure. While first hour rating as herein

proposed is equivalent to hot water

supply rating as it appeared in the

original proposed test procedures for water heaters, the different name for the measure has been chosen for two

reasons: to eliminate possible confusion

between the two versions of the measure since the methods for their determination differ and to eliminate the subjective term "hot" from the title. Consumers of differing sensibilities are

likely to differ in their interpretation of what constitutes "hot" water. Since it is not DOE’s intent to define “hot" water,

the use of this term could be misleading

to consumers. The new title “first hour

rating” is a more appropriate title since

it both identifies the time base of the measure, and hour, and, by use of the term "first", implies that the measure is only indicative of the performance of the water heater during its “first" hour of operation. While the consumer will not know the conditions for the determination of this measure, it is sufficient that the term will discourage

the interpretation of the measure as a

rate of hot water delivery performance

which the water heater can maintain

hour after hour. The test for first hour rating proposed

here is significantly less burdensome

than the test for hot water supply rating

previously proposed. Not only are fewer

tests required for electric water heaters

with immersed heating elements, but the

test itself is a simpler, less timeconsuming one than the hot water

supply rating test previously proposed.

Just as with the hot water supply rating

test, the first hour rating test can be

conducted right before or after a standby loss test. The only additional

test instruments required will be a weighing container and a scale for weighing the water drawn from the water heater during the test or a water

flow meter for determining directly the amount of water drawn from the water

heater during the test. The determination of the measure,

first hour rating, is based partly on test results and partly on calculation. The

test portion is intended to account for the influence of tank capacity, tank

geometry, and water inlet/dip tube

design. The calculation portion is intended to account for the influence of input power and recovery efficiency.

This method of determining first hour

rating overcomes the problem

associated with the determination of hot

water supply rating in that the influence

of the electrical characteristics of an

electric water heater with immersed

heating elements on the first hour rating

is determined by calculation rather than

by test.

C. Comment Procedure

1. Written Comment

Interested persons are invited to participate in this rulemaking by

submitting data, views or arguments

with respect to the proposed

amendments set forth in this notice to Margaret Sibley at the address indicated

at the beginning of this preamble.

Comments should be identified on the outside of the envelope and on documents submitted to DOE with the designation “Water Heaters—Proposed

Amendments (Docket No. CAS-RM-79-

A-17
Federal Register / Vol: 44. No. 91 / Wednesday, May 9, 1979 / Proposed Rules 27193

105).” If possible, fifteen copies should

be submitted. All comments received by

July 9, 1979 and all other relevant

information, will be considered by DOE

before final action is taken on the proposed regulation. Late comments will be considered to the extent that time

permits. Pursuant to the provisions of 10 GFR

1004.11. any person submitting

information which he or she believes to be confidential and exempt by law from

public disclosure should submit one

complete copy, and fifteen copies from

which information claimed to be

confidential has been deleted. In accordance with the procedures

established at 10 CFR 1004.11, DOE shall make its own determination with regard

to any claim that information submitted

be exempt from public disclosure.

2. Public Hearing

a. Request procedures. The time and

place of the public hearing are indicated

at the beginning of this preamble. The

hearing will be continued, if necessary, on June 28. 1979. DOE invites any person who has an

interest in the proposed amendment

issued today, or who is a representative

of a group or class of persons that has

an interest in today's proposed

amendment, to make a written request

for an opportunity to make an oral presentation. Such a request should be

directed to the address indicated at the beginning of this preamble and must be

received before June 14. 1979. A request

may be hand delivered to such address,

between the hours of 8:00 a.m. and 4:30

p.m., Monday through Friday. A request

should be labeled both on the document

and on the envelope "Water Heaters

Proposed Amendments (Docket No. CAS-RM-79-105). ” The person making the request should

briefly describe the interest concerned:

if appropriate, state why he or she is a proper representative of a group or class

of persons that has such an interest, and

give a concise summary of the proposed

oral presentation and a telephone

number where he or she may be

contacted. DOE will notify, before 4:30 p.m., June

18, 1979, each person selected to appear

at the hearing. Each person selected to be heard must submit 15 copies of his or her statement to the address and by the date given in the beginning of this preamble. In the event any person

wishing to testify cannot meet the 15 copy requirement, alternative arrangements can be made with

Margaret W. Sibley in advance of the hearing by so indicating in the letter

requesting an oral presentation or by

calling (202) 375-1651.

b. Conduct of hearings. DOE reserves

the right to select the persons to be

heard at this hearing, to schedule their respective presentations and to establish the procedures governing the conduct of the hearing. The length of each presentation may be limited, based on the number of persons requesting to be heard.

A DOE official will be designated to preside at the hearing. This will not be a

judical or evidentiary-type hearing.

Questions may be asked only by those

conducting the hearing, and there will be no cross-examination of the persons

presenting statements. Any decision

made by DOE with respect to the subject matter of the hearing will be

based on all information available to DOE. At the conclusion of all initial oral statements, each person who has made

an oral statement will be given the opportunity if he or she so desires, to make a rebuttal statement. The rebuttal statements will be given in the order in which the initial statements were made

and will be subject to time limitations. Any person who wishes to ask a

question at the hearing may submit the question, in writing, to the presiding

officer. The presiding officer will determine whether the quesstion is relevant and whether the time

limitations permit it to be presented for answer. Any further procedural rules needed

for the proper conduct of the hearing

will be announced by the presiding

officer. A transcript of the hearing will be

made and the entire record of the hearing, including the transcript, will be

retained by DOE and made available for inspection at the DOE Freedom of Information Reading Room. Room

GA152, Forrestal Building, 1000

Independence Avenue, S.W.. Washington, D.C., between the hours of

8:00 a.m. and 4:30 p.m., Monday through

Friday. For information concerning the

availability of records at the Freedom of Information Reading Room, call 202-

252-5969. In addition, any person may

purchase a copy of the transcript from

the reporter.

D. Environmental and Inflationary

Review

Pursuant to section 7(c)(2) of the Federal Energy Administration Act of

1974, a copy of this notice has been

submitted to the Administrator of the Environmental Protection Agency for his comments concerning the impact of this proposal on the quality of the

environment. The Administrator has no comments.

The National Environmental Policy

Act of 1969 requires DOE to assess the environmental impacts of any proposal

issued by the Department for “major

Federal actions significantly affecting

the quality of the human environment.”

Since test procedures under the energy

conservation program for consumer

products will be used only to standardize the measurement of energy usage and will not affect the quality or

distribution of energy usage, DOE has

determined that the action of prescribing

test procedures, by itself, will not result

in any environmental impacts. On this basis, DOE has determined that, with

respect to prescribing test procedures

under the energy conservation program

for appliances, no environmental impact

statement is required.

The proposed rule has been reviewed

in accordance with Executive Order

12044 and DOE Order 2030. From the regulatory analysis performed, it was

determined that the proposal was

significant in nature but did not have

major impacts to manufacturers and

consumers (imposing annual economic

costs of $100 million or more).

(Energy Policy and Conservation Act. Pub. L

94-163, 89 StaL 871, 42 U.S.C. 6201 as amended by Pub. L. 95-619, 92 Stat. 3281; Department of Energy Organization Act. Pub.

L. 95-91, 91 Stat. 565, 42 U.S.C. 7101).

In consideration of the foregoing, it is proposed to amend Part 430 of Chapter

II of Title 10, Code of Federal

Regulations, as set forth below.

Issued in Washington, D.C., May 3. 1979. Maxine Savitz, Deputy Assistant Secretory. Conservation ar.ti Solo.- Applications. Appendix E to Subpart E—(Amended]

1. Appendix E to Subpart B of Part 430

is amended by adding a new section 3.7

to read as follows:

3.7 First hour rating test. 3.7.1 First hour rating test for gas

and oil water heaters and electric water

heaters with other than immersed

heating elements. Establish normal water heater operation with the maximum mean tank temperature within

the range specified in section 2.6 and

with all air eliminated from the tank. Begin the first hour rating test immediately after a cutout by recording

the time and withdrawing water from

the water heater at a rate of 5.0 ± 0.25 gallons per minute. All water withdrawn

from the water heater during this test shall be collected in a weighing

container for the purpose of determining ,1

A- 1 8
27194 Federal Register / Vol. 44, No. 91 / Wednesday, May 9, 1979 / Proposed Rules

its weight. Alternatively, a water flow

meter may be used to measure the

volume of water withdrawn from the

water heater directly. Continuously

monitor the outlet water temperature

from the start of the waterdraw and

record the maximum value measured.

For the purposes of this test, this

recorded temperature shall be referred

to as the initial outlet water

temperature. Continue the withdrawal of

water until the outlet water temperature

drops to a value 40* F below the initial

outlet water temperature, at which time

terminate the withdrawal, record the

time duration, tf, of the test in hours

measured with an error no greater than

2 percent, and record the weight of the

water withdrawn, W, in pounds,

measured with an error no greater than

2 percent or the volume of the water

withdrawn. G, in gallons, measured with

an error no greater than 2 percent. If the

outlet water temperature does not drop

40* F after one hour, the test is to be

terminated and the first hour rating

expressed as greater than 300 gallons.

3. 7.2 First hour rating test for

electric water heaters with immersed

heating elements. Except as provided in

this section, ail electric water heaters

with an immersed heating element shall

be tested with an immersed heating

element that has a design power rating

of 4.5 kilowatts. If 4.5 kilowatts exceeds

the maximum design power rating

specified by the manufacturer for the

water heater to be tested, the first hour

rating test shall be conducted with the

water heater equipped with an

immersed heating element of a design

power rating equal to the manufacturer’s

specified maximum design power rating.

All water heaters designed to operate

with dual immersed heating elements

shall be tested with dual immersed

heating elements of equal design power

rating in accordance with the provisions

specified in this section. Tests shall be

conducted in accordance with the same

procedures as those specified in section

3.7.1.

2. Appendix E to Subpart B of Part 430

is amended by adding a new section 4.7

to***** read as follows:

4-7 Recovery rate.

4.7.1 Recovery rate for gas and oil

water heaters. For a gas or oil water

heater, calculate the recovery rate, R.

expressed in gallons per hour and

defined as:

R = P x Er

k X AT,

Where:

k is as defined in section 4.1.1.

* is as defined in section 4.3

Er is as calculated in section 4.1.1. P = power input to the burner, determined in accordance with section 3.2.1, expressed

in Btu per hour.

4.7.2 Recovery rate for electric water heaters. For an electric water

heater, calculate the recovery rate, R, expressed in gallons per hour defined

as: R = P' X E, x 3,412 Btu /kWh

k x AT,

Where:

k is as defined in section 4.1.1. AT, is as defined in section 4.3. Er is as calculated in section 4.1.2 for electric water heaters with other than immersed

heating elements, or section 4.1.3 for electric water heaters with immersed

heating elements.

P* = P (power input to the heating elements,

expressed in kilowatts, as determined in accordance with section 3.2.1 for electric water heaters with other than immersed

heating elements or section 3^2 for

electric water heaters with immersed

heating elements) with the following

exception: For electric water heaters with dual immersed heating elements

which, in characteristic operation of the water heater, are not energized

simultaneously at any time. P* shall be

taken as the design power rating of the heating element in closest proximity to the hot water outlet of the water heater, expressed in kilowatts. Appendix E to Subpart B [Amended]

3. Appendix E to Subpart B of Part 430

is amended by adding a new section 4.8

to read as follows:

4.8 First hour rating. Calculate the

first hour rating. F. expressed in gallons

and defined as:

F = W + [R X (1 - t

f

)]. Or

d

F = G + [R x ( 1 - tf )]

Where

R is as calculated in section 4.7.1 for gas and oil water heaters, or section 4.7.2 for

electric water heaters. W= weight of the water withdrawn from

the water heater during the first hour

rating test, determined in accordance

with section 3.7.1 for gas and oil water

heaters and electric water heaters with

other than immersed heating elements, or

section 3.7.2 for electric water heaters

with immersed heating elements,

expressed in pounds.

d = 8.25 pounds per gallon, the nominal

density of water. G = volume of water withdrawn from the water heater during the first hour rating

test, determined in accordance with

section 3.7.1 for gas and oil water heaters and electric water heaters with other

than immersed heating elements, or

section 3.7.2 for electric water heaters with immersed heating elements,

expressed in gallons. t,= duration of the water draw in the first hour rating test, determined in accordance with section 3.7.1 for gas and

oil water heaters and electric water

heaters with other than immersed

heating elements, or section 3.7.2 for

electric water heaters with immersed

heating elements, expressed in hours.

(Docket No. CAS-RM-79-105|

[FR Doc. 79-14489 Filed 5-4-79: 4:38 pm| BILLING CODE 6450-01-M

[10 CFR Part 436]

Federal Photovoltaic Utilization Program; Public Hearing

agency: Department of Energy

action: Proposed rule. summary: The Department of Energy

today proposes rules for the monitoring

and assessment requirements of the Federal Photovoltaic Utilization Act

Title V, Part 4 of the National Energy

Conservation Policy Act. The.program

implementing this legislation is referred

to as the Federal Photovoltaic

Utilization Program, and is summarized

in the following preamble. Under this program, Federal agencies will receive

funds from the Department of Energy for the installation of photovoltaic solar

electric systems at Federal facilities. Today’s proposed rules relate only to requirements for monitoring and

assessing the performance and

operation of systems installed as a part of the program. dates: Written comments must be

submitted by July 9. 1979. Public

hearings will be held on June 14. 1979. beginning at 9:30 a.m. Requests to testify at the hearing must be submitted by

June 4, 1979. ADDRESSES: Send written comments and

requests to speak to Margaret W. Sibley.

Office of Conservation and Solar

Applications, Room 2221C, 20 Massachusetts Avenue. N.W.,

Washington, D.C. 20545. Hearing will be

held at Room 3000A, 12th and

Pennsylvania Avenue, Washington. D.C. Documents for public inspection or copying may be found at the DOE

Reading Room, GA-152, Forrestal

Building, 1000 Independence Avenue.

S.W.. Washington. D.C. 20585.

A-l 9

APPENDIX B

I. Introduction

This appendix summarizes the results of work done by the Product

Performance Engineering Division, Center for Consumer Product Technology,

National Bureau of Standards, in support of the DOE/ORNL Energy

Conservation Program for Appliances. These results have been reported to

DOE/ORNL in the form of memorandum reports. Specifically, this appendix

presents the results of the analytical and laboratory studies leading to

the proposals for modification of the Water Heater Test Procedures to cover

electric heat pump water heaters. It is divided into four general

sections. Hie first section reviews a typical design of an electric heat

pump water heater. The second section discusses the differences in design

between the common type electric water heaters and electric heat pump water

heaters. The third section discusses the labor aory tests performed on an electric heat pump water heater for confirmatory purposes. The fourth

section discusses a second series of laboratory tests performed by NBS

under the more stringent conditions of a draw schedule to check the

validity of the proposed modified test procedures.

II. Design Review of Electric Heat Fump Water Heaters

This review is mainly based on the information provided to NBS by

manufacturers, which includes

1) Drawings, sketches, photographs, and laboratory test data;

2) Discussions with manufacturer's personnel; and

3) Inspection of typical electric heat pump water heaters.

This design review does not purport to review the validity of any

particular engineering design of an electric heat pump water heater; it

merely reviews those aspects of the design that may significantly conflict

with the current DOE water heater test procedures as would be applied to

the electric heat pump water heater.

The electric heat pump water heater, as shown in Figure l.a., consists

of a storage water tank, similar to that of an electric water heater, and a heat pump atop the storage tank, as shown in Figure l.b. The heat pump

operates as a heating mode only heat pump. Schematically, the electric

heat pump water heater is shown in Figure 2, where the storage water tank

is located beneath the heat pump which has the condensing coil entering

through a "chimney" in the storage tank. The coil design shown in Figure 3

is typical of current designs.

5-1
A. The Ideal Thermodynamic Cycle

The analysis of the thermodynamic cycle of the heat pump

determines the ratio of the amount of heat transferred to the stored

water to the amount of energy to the heat pump; coefficient of

performance, COP. The electric water heater always has a COP of 1.0;

i.e., the heat generated by the resistance elements and the amount of

energy transferred to the stored water are the same. The heat pump in

its usual use environment, however, has a COP greater than 1.0.

1. Analysis of Heat Pump Cycle Processes

The ideal thermodynamic heat pump cycle is illustrated in

Figure 4. The coordinates of this plot are pressure and

enthalpy. The refrigerant in most cases is R-12. The ideal

cycle follows the paths labeled l-2s-3-4-l. This consists of

four processes as follows:

l-2s Compression of the refrigerant gas from a superheated

state 1, at pressure p, , to a more highly superheated state 2s . at pressure, p ^. This ideal compression process is reversible

and adiabatic^and , thereby, follows an isentropic path. Thus,

state 2s is fixed by the pressure ratio p„/p^ and by the entropy

of the gas at the compressor suction stat£ IT The ideal work

input to the compressor, VL, per pound of refrigerant pumped is

equal to the the enthalpy change, = (h^

s - h

n

)

.

2s-3 Condensation of the refrigerant at the constant pressure

£p. This process is more accurately described as desuperheating

Tran "2s" to "a", condensation from "a" to "b" and subcooling

from "b" to "3." The heat rejected, q

R

, per pound of

refrigerant circulated during this process is the "pumped" heat

of the cycle, and is determined by the enthalpy change, q^ =

3-

4 Expansion of the refrigerant from the condensing pressure

p to the evaporating pressure p. . This is an irreversible

adiabatic throttling process accomplished by either an expansion

valve or a capillary tube. In either case, the result is that

the enthalpy of the refrigerant leaving the condenser is

identical with the enthalpy entering the evaporator, h-, = h^.

4-

1 Evaporation and superheating of the refrigerant at pressure

The heat absorbed, q , per pound of refrigerant pumped

during this process is furnished by a low grade energy source in

this case by the ambient air, and is equal to the enthalpy

change, qA

= (i^ - h

4

).

6-2
2 . Heat Pump Performance Measure

For a heat pump the useful effect desired is the maximum

heat rejection rate from the condenser, q

R

, with a minimum

power input to drive the compressor, W^.

nThe ratio of q

R

to

both expressed in the same units is the COP,

COP

Theoretically, this number is always greater than 1.0 since

W,

COP = W, W,

and q^ is always greater than zero.

What is wanted of the heat pump is a COP as large as possible so that its the multiplicative effect on W„ gives the

largest possible q

R

for the least W^. This can be seen readily

since

q

R

= (C0P)W

c from the definition of COP above.

3. Example

Calculate COP at three different condensing temperatures

of 100

U

F, 120 F, and 140U

F and a constant evaporator temperature

of 80°F (Figure 5). Assumptions:

a. the compression process is isentropic;

b. the state of compressor suction is that of the

saturated vapor;

c. the state of condenser outlet is that of the

saturated liquid; and

d. the refrigerant is R-12.

Condition 1 . The evaporator is maintained at 80°F and the

condenser is maintained at 100C

F.

COP 87.5 - 31.0

87.5 - 85.0

= 22,6
Condition 2. The evaporator is maintained at 80°F and the

condenser is maintained at 120°F.

Condition 3- The evaporator is maintained at 80°F and the

condenser is maintained at 140 F.

Although the actual heat pump water heater does not

operate with ideal processes, the underlining fact is that as the temperature of the stored water (i.e. , condenser) increases,

the COP decreases drastically.

B. Analysis of Components

The COP of a heat pump is influenced primarily by the designs of

its various components—the efficiency of the motor-compressor, the

design and sizing of the evaporator and condenser, the choice of

refrigerant, and the sizing of the refrigerant lines which

interconnect all the components. Some of these effects will be

discussed later. The important operational factors which affect COP

are the temperatures of the surroundings in which the heat pump must

function (i.e., ambient air and stored water temperatures).

The heat absorbed at the evaporator, q^, is heat absorbed from

somewhere in the surroundings—the basement, closet , etc., —where the

heat pump water heater is located. The pumped heat, q R

, is rejected

to the stored water. The COP is maximized by having tne highest

possible heat source temperature in the surroundings for a given

temperature within the stored water.

The temperature of the surroundings if large enough is usually

constant. The stored water is at its coldest at cold startup or at

the beginning of the heat pump operation. As the stored water is

heated the COP decreases. The impact of decreasing COP as the stored

water temperature increased was illustrated in the preceeding example.

1. Motor Compressor

In a heat pump compressor there are two kinds of losses

which ada to the required work input. First there are the

irreversibilties in the gas compression process within the

B-4

il
cylinder and in the flow through the valves. These losses are accounted for by the so-called compression efficiency which is

the ratio of the ideal work to the actual work input to the gas

during compression. This efficiency is a function of the type

of compressor and the pressure ratio across which it pumps. For

the small hermetic compressors used in electric heat pump water

heaters, the compression efficiency varies between 50% to 80%.

The second kind of losses in the compressor is the

mechanical friction losses between the moving parts. These

losses are accounted for by the mechanical efficiency of the

compressor. The overall efficiency of the compressor,

accounting for both compression and mechanical efficiency, is

nearly a constant over a range of 50% to full load due to the

compensating effect of the two efficiencies.

There is an additional less due to the compressor motor

which is accounted for by the motor efficiency. The motor

efficiency of a hermetic compressor motor is a broad flat curve

over the operating range of the compressor. The overall

efficiency of the motor-compressor may therefore be taken as a constant for the 50 percent to full load range.

2. Evaporator Fan Work

The power input to the evaporator fan is a function of the

air flow rate and pressure loss across the evaporator. This

power input is indepencent of changing load on the compressor.

3. Heat Fumping Rate

dS

In the ideal cycle the heat pumping rate, q R

, per pound of

refrigerant circulated is determined by the enthalpy change (h

- h, ) . In the actual cycle, state 2 at compressor discharge

will depart somewhat from the isentropic state 2s due to the

irreversibilities associated with the compression process (see

Figure 4 )

.

The product of the compression, mechanical, and motor

efficiencies is very nearly 50% for most small hermetic motorcompressors. This means that approximately one-half of the

energy input to the motor-compressor will be dissipated as heat

losses. If these losses can be recovered as heat input to the

storage tank, the heat pumping rate of the cycle can be

increased by a much as 20% according to Reference Bl.*

The electric heat pump water heater system has insulation

between the storage tank and the compressor to reduce heat loss

»References are on page B-51.

E-5
during standby. Some of the dissipatd heat from by the

compressor is recovered by the air which is drawn over the

compressor before passing across the evaporator coil

.

In order to recover directly the heat loss from the

compressor and to minimize heat losses during standby, the

compressor could be installed in close thermal contact with the

stored water and the entire storage tank and compressor system

be insulated. The resulting design would then be similar to

that of a Harvey-Whipple design in which the motor-compressor

unit is sunken into the storage tank (Reference Bl). On the

other hand, however, the manufacturing cost would be

significantly higher and the compressor operated in a higher

temperature environment—a condition detrimental to the durable

operation of the compressor.

4. Condenser Coil

The installation of the condenser coil in the storage tank

is shown in Figure 2. A typical detail coil design is shown in

Figure 3- The double wall construction as shown in Figure 6 is

used to satisfy local code requirements that potable water be

separated from the refrigerant with two barriers. For heat

transfer enhancement, the cavity between the two walls is filled

with water.

5. Evaporator Coil

The evaporator coil for one design is shown in Figure l.b.

It is installed atop the storage tank jacket. The evaporator

coil is a single tube, single row heat exchanger. The main

consideration in designing the physical size and configuration

of the coil, in this case, was aesthetic. To conform to the

shape of the storage tank jacket (i.e., cylindrical shape) the

tube bank has been formed with an arc.

As shown in Figure 2, The motor-compressor unit is

installed atop the storage tank jacket. The evaporator fan is on top of the unit . The evaporator coil and a cover , a shown

partially in Figure 2, surrounds the unit. The fan operation

accomplishes two functions at the same time: 1) it draws

ambient air into the coil cavity to cool the motor-compressor

,

thus recovering some of the heat resulting from motor-compressor

inefficiency, and 2) then circulates the heated air across the

evaporator coil which allows it to operate at a temperature

higher than that of the ambient.

E-6
6 . Throttling

For the throttling or expansion process, a thermal

expansion valve is used. This valve has a superheat bulb which

adjusts the valve to give a designed amount of superheat at

compressor suction.

7. Water Storage Tank

The water storage tank used in the electric heat pump

water heater is similar to that used in a standard electric

water heater. Essentially, it consists of a cylindrical tank

and a concentric cylindrical jacket, the gaps between the tank

and jacket are filled with insulation. There are supply water

inlet, hot water outlet, drain and pressure relief valves as used with the water storage tank of an electric water heater.

8. Resistance Heater

During a cold startup or for a fast recovery after a heavy

water draw, or for periods when the ambient temperature is so low as to cause evaporator frosting, there is a resistance

heater which operates. The resistance heater’s function is

similar to the upper heating element in an electric water

heater; it heats water only in the upper portion of the tank.

C . Controls

There are two thermostats that regulate the water temperature.

Similar to an electric water heater, both of the thermostats are installed on the side walls of the storage tank. One of the

thermostats regulates the resistance heater;, the other one regulates

the heat pump. The resistance heater is designed to heat the upper 12

to 15 inches of water; the condenser coil of the heat pump is designed

to input heat to the water at the lower level of the storage tank.

In the case of a cold start or after a heavy water draw, the

resistance heater and the heat pump operate simultaneously. The

simultaneity of operation of two separate heating components is one of

the differences in operation of the electric heat pump water heater

from that of an electric water heater having two high wattage

resistance heating elements.

An over temperature safety thermostat limits the operation of

either the backup heating element or the heat pump such that the water

temperature never exceeds 173°F.

B-7
Another thermostat prevents the heat pump from operating when

ambient temperature drops below 47°F to prevent frosting of the

evaporator coil

.

A thermal overload is provided to prevent overloading of the

electric motor

.

D. Summary

1. Figuratively speaking, the electric heat pump water heater

is an electric water heater with its bottom heating element

replaced by the condenser coil of a heat pump.

2. The heating capacity of the heat pump is a function of the

operating conditions. These are the ambient air temperature

which affects the evaporator performance and the stored and

supply water temperature which affects the condenser

performance.

3. Under favorable conditions, given one unit of energy

input, the heat pump delivers more than one unit of energy to

the stored water; while for the same one unit of energy input,

the electric water heater delivers only one unit of energy in

terms of hot water.

4. Under unfavorable conditions, the stored water in an electric heat pump water heater is heated by a resistance

heating element operating as in an electric water heater.

III. Differences between Electric Water Heater and Electric Heat Pump Water

Heater

The DCE test procedure for water heaters covers two types of electric

water heaters: 1) electric water heaters with immersed heating elements,

and 2) electric water heaters with other than immersed heating elements.

The former is much more important than the latter in terms of unit in use

and units shipped annually. Only the design differences between the

electric water heater with immersed heating elements and the electric heat

pump water heater will be discussed.

The differences between the electric water heater and the electric

heat pump water heater may be classified into two categories: construction

and operation. Both types of water heaters fulfill a basic requirement

converting of electrical energy into water thermal energy and subsequently

delivering hot water on demand.

B-8
A. Differences in Construction

1. Electric Water Heater

The construction of an electric water heater with immersed

heating elements is relatively simple. It consists of a water

storage tank, electric heating elements, thermostats and some miscellaneous items. The water storage tank is a cylindrical

tank with an external jacket concentric with the water tank.

Insulating material fills the gap between the two. In the case

of the residential water heaters, there are normally two

resistance electric heating elements which penetrate the side

walls of the water tank, and are totally immersed in the water.

The thermostats, one for each heating element, control the on- off operation of the heating elements depending on local

temperature and thermostat settings. The miscellaneous items

include the water inlet (and dip tube) the water outlet, the

anodic rod, the pressure relief valve, the drain valve and the

electrical connecting terminal block.

2. Electric Heat Pump Water Heater

The electric heat pump water heater consists of a water

storage tank, thermostats, a heat pump, a resistance electric

heating element similar to the ones used in an electric water

and some miscellaneous items also similar to those of the

electric water heater, and a heat pump.

The heat pump system, however, is a relatively complicated

machine. It consists of four basic components with connecting

pipes and an air circulating fan. The pipes connect the four

components: hermetic motor-compressor, condenser coil, thermal

expansion valve, evaporator coil, and back to the motor

compressor forming a closed loop. The air circulating fan,

which is driven by a fractional horsepower motor, blows ambient

air across the evaporator coil transferring thermal energy from

the ambient air to the refrigerant. The detailed thermodynamic

processes were described in the Design Review section.

The most important link between the heat pump and the

water storage tank is the condenser coil. The condenser coil in

the electric heat pump water heater is effectively replacing the

bottom heating element of a two element electric water heater.

The heat pump is essentially packaged into two units with

connecting pipes. One unit consists of the hermetic-motcrcompressor, the evaporator coil, the thermal expansion valve and

the air circulating fan. This unit, having the appearance of a stub cylinder with the same diameter as the water storage tank,

B-9
is installed atop the water storage tank. The second unit—the

condenser coil —is installed in the middle of the water storage

tank. For detailed component descriptions refer to the Design

Review.

B. Differences in Operation

1. Electric Water Heater

Residential electric water heaters operate in two

different modes: standby and recovery. The two heating

elements normally do not operate at the same time. During the

standby mode, the upper heating element is off. As the water

temperature in the water storage tank reduces to a level lower

than the setting of the bottom thermostat—the bottom heating

element is turned on. As the water temperature rises above the

setting of the lower thermostat, the heater is turned off.

During a cold start or after a heavy water draw when the water

temperature in the upper portion of the water tank is also low,

the water heater goes into its recovery operation. The upper

heating element will be turned on when the water temperature in

the upper portion of the water tank drops below the setting of

the upper thermostat. As the water tonperature rises above the

setting of the upper thermostat, the upper heating element will

be turned off. Immediately, the lower heating element will be

turned on to continue heating the water in the lower portion of

the tank, until it rises above the setting of the lower

thermostat. Thus, the upper element operates only during the

recovery mode while the lower element may operate during the

standby mocie as well as the recovery mode.

The heated water is supplied on demand. This is

accomplished by the fact that the water tank and the hot water

line are pressurized by the water supply line and that the

opening of a hot water fixture causes hot water to exit through

the outlet of the water tank, located at the top of the water

tank. Thermal stratification causes the warmest portion of the

water to locate at the top of the tank and the coldest water at

the bottom. The tank inlet with its dip tube supplies cold

water to the tank frcm the bottom. As a result, the warmer

portion of the water is always supplied to the hot water

fixture.

The electric heating elements supply thermal energy to the

stored water through resistance heating virtually at a fixed

rate.

B-10
2 . Electric Heat Pump Water Heater

The electric heat pump water heater also operates in two

modes: standby and recovery. In the recovery mode, the

resistance heater and the heat pump operate simultaneously.

This usually occurs with a cold start or after a heavy water

draw. The resistance heater is turned off by its thermostat

when the upper portion of the water reaches the set temperature;

the heat pump continues to operate until its thermostat, which

controls the lower portion of the water temperature, reaches its

set point. Only the heat pump normally operates during the

standby mode and is controlled by its thermostat.

The resistance heater produces thermal energy at a fixed

rate. The heat pump delivers thermal energy at a rate which is

dependent on the temperatures of the stored water and the

ambient air conditions from which the heat pump is extracting

energy. If the ambient temperature is too low, the evaporator

may start to form frost when operating. A thermostat is used to

turn the heat pump off at that temperature. Below this

temperature the resistance heating element will operate to heat

the upper portion of the stored water.

C . Summary

1. The two-element electric water heater produces thermal

energy at a virtually constant rate. Only one element operates

at a time.

2. The electric heat pump water heater produces thermal

energy at a variable rate. The resistance element and the heat

pump may operate simultaneously or independently.

IV. Confirmatory Laboratory Tests

A series of tests were conducted in the laboratory of the Product

Performance Engineering Division and included standby tests, and recovery

tests. They were conducted at different combinations of water supply

temperature, thermostat settings, and room ambient temperatures. The

instantaneous thermal energy content of the stored water, room ambient

temperature and electrical energy inputs were monitored continuously.

Thermocouple temperature readings were sanpled and recorded by a minicomputer. The watt-hour meter readings, however, were recorded

manually.

B-li
A. Purposes cf the Tests

In general, the tests were conducted to assist in developing the

test procedure modification. Specifically, the purposes of the tests

were: first, to subject the propose Test Method to actual use to find

out hew realistic are the specifications; second, to find out the

degree of burdensomeness of testing; and third, to determine the

effects of water supply temperature, thermostat setting, and room ambient tonperature on the recovery efficiency, and the effects of

thermostat setting and room ambient temperature on the standby loss.

The results of these tests were then used to pinpoint any necessary

changes to the proposed test procedure modifications.

B. Laboratory Setup

1. Description of the Laboratory

The water heater laboratory measures approximately 3-7 m

(12 ft) high, 3*7 m (12 ft) wide, and 4.9 m (16 ft) deep. It’s

environment is controlled via the building's central HVAC system

and therefore cannot be independently controlled. To change the

room ambient temperature, however, a few provisions were made,

among them: blocking of the air register, addition of room

heaters, and blocking of the entrance door. Even with these

provisions, the room ambient temperature could not be controlled

to a predetermined value. One reason is that the heat removal

rate is not known a priori without at least a moderate test

program. Therefore, even though many of tests were designed to

be conducted at some given room ambient temperature, it was not

always achieved. Notwithstanding the above fact, the objectives

of finding the effects on the standby less and the recovery

efficiency of room ambient temperature were achieved.

2. Instrumentation

In accordance with the DOE water heater test procedure

with the proposed modifications, six thermocouples were

instailea within the storage tank of an electric heat pump water

heater (121.9 cm (48 in) tall, 289*5 L (76.5 gal) in capacity), one at the level of the center point of each of six sections of

equal volume from top to bottom of the tank. (See Figure 7 for

a schematics of the setup.) They were usea to determine the

thermal energy content of the stored water. The actual location

of the thermocouples is given in Table 1.

One thermocouple was carefully located in a part of the

labortory shielded from any radiant or convective heat sources

for the rneasursnent of the room ambient tenperature. Type K

B-12
(chromel-alumel) thermocouples were used with a minicomputer

data collection system, which sampled temperatures at any

predetermined rate. An additional thermocouple was used to

monitor the air temperature at the evaporator coil outlet. This

thermocouple, a Type T (copper-constantan) , was connected to a strip chart recorder for continuous monitoring of the air

temperature.

A regulated power source of 240 VAC was used to supply the

electric heat pump water heater. Three separate watt-hour

meters were used to measure the energy consumed by the heat pump

the backup heating element and the sum of the two.

3. Data Collection

The minicomputer used in the data sampling and collection

system is an Interdata 7/32 Multi-Task computer.

4. Water Supply System

The water supply system consists of a reservoir, heat

exchanger in a freezer, pump, mixing tank, and piping system. A

schematic of the system is shown in Figure 7.

C . Tests

The Confirmatory Tests included a series of standby and recovery

tests. Some of the tests were exploratory in nature and were

conducted to gain experience and to find any probable pitfalls. The

tests were planned to be conducted at given temperature combinations.

The controlling temperatures were the water inlet, T. , the average

tank water temperature at thermostat cutout, T^, and

x the ambient

temperature, T

g

. The inlet water temperature was conveniently

controlled using the water supply system. The cutout temperature was

not easily controlled because the thermostats did not always cutout at

a fixed temperature for a given thermostat setting. The ambient

temperature was not completely controlled due to the laboratory HVAC

system and because operation of the heat pump affected the laboratory

environment. Therefore, the temperature combinations of the actual

tests were not exactly the same as those of the planned tests.

1. Standby Tests

The standby loss for an electric heat pump water heater

was anticipated to be a function of two temperatures—the

cutout temperature, T

f

, and the ambient temperature, T . The

tests were designed to find the effects of these two

temperatures on the standby loss. Standby tests were conducted

B-13
at different ambient temperatures while keeping the cutout

temperature at a fixed value.

Similarly, standby tests were conducted at different

cutout temperatures while keeping the ambient temperature at a fixed value.

2.

’ Recovery Tests

The same approach was used to determine the individual

effect of varying the water inlet temperature, T^, the cutout

temperature, T~, and the ambient temperature, T , on the

recovery efficiency.

3. Energy Consumption

To determine the effects of the floating temperature rises

on the daily energy consumption, other recovery and standby

tests were conducted

.

These tests involved keeping A T, at approximately 5C°C

(90°F) and A T^ at approximately 38*9°S (70°F) while changing

the absolute temperature levels between which the temperature

rise is derived. The AT- is defined as the temperature

difference between the otitlet and the inlet, (T

q

-T^ )

,

in tests

with draw anG between the cutout and the inlet , (Tt-T^) , in

tests without draw. The AT^ is defined as the difference

between the cutout and the room ambient temperature, (T—T ).

4. Power Measurement of the Heat Pump

The power consumption of the heat pump was anticipated to

be a function of the stored water temperature for a fixed

ambient temperature. To determine the relationship and the

average power rating for the calculation of the daily energy

consumption, the instantaneous power consumption was measured as

a function of the average stored water temperature.

This measurement was accomplished through the measurement

of the cumulative watt-hour and the simultaneous reading of

average water temperature.

D. Results and Discussions

1 . Standby Tests

The temperature recordings of a typical recovery/standby

test are shown in Figures 8 and 9 . For clarity of presentation,

e-iij
the temperature recording of thermocouples #1, #3, #5 and the

ambient thermocouple are given in Figure 8 and those of

thermocouples #2, #4, #6, and the average of the six

thermocouples are given in Figure 9. The standby test lasts

from the 21.7 hour mark till the 104.6 hour mark.

In Figure 10, the standby loss, S, is plotted as a function of the temperature difference between the mean cutout

tank temperature and the average ambient air temperature (T^-

T ). The standby loss increases as the temperature difference

increases.

The standby loss results plotted in Figure 11 as a function of ambient temperature indicate that the standby loss

decreases as the ambient temperature is increased when the

cutout mean tank temperature is held approximately constant.

The results are also tabulated in Table 3-

The standby loss plotted in Figure 12 as a function of the

cutout mean tank temperature for an approximately constant

ambient air temperature. The standby loss increases as the

cutout temperature increases for the fixed ambient temperature.

The results are also tabulated in Table

The standby less also indicates how well the storage tank

is designed for storing the water thermal energy as well as how

efficiently the heat pump can replace the dissipated thermal

energy. The factor which indicates the effectiveness of a design is the characteristic time for cooldown (section IV).

The thermal energy of the water in a storage tank dissipates in an approximately exponential fashion. The characteristic time

is the time required for the thermal energy of the water to

reach 36.3 percent (1/e = 0.368) of that at the start of the

cooldown experiment. To illustrate this fact, the cooldown of

the heat pump water heater is shown in Figure 13, where, as can

be seen, the thermal energy of the stored water reduces to 36.8%

of that at the start of the cooldown experiment in 88.0 hours.

This is the characteristic time cf this storage tank and

indicates an energy loss of 1.13%/h.

2. Recovery Tests

The temperature data from a typical recovery test are shown in Figures 8 and 9, where, as described previously, the

temperature recording of the six interior thermocouples, one

ambient thermocouple, and the average tonperature of the six

thermocouples are plotted against time. The recovery test lasts

B-15
from the 16.6 hour mark till the 21.7 hour mark, when the

standby test was initiated.

The recovery efficiency is plotted in Figure 14 as a function of mean cutout temperature. T^. Efforts were made to

keep the inlet temperature, T . , and the ambient temperature, T , fixed. These results are also shown in Table 5 along with the3

three temperatur es

.

The recovery efficiency is plotted in Figure 15 as a function of inlet temperature, T^, while the mean cutout tank

temperature, T~, and the ambient air temperature, T , were kept

approximately constant. The recovery efficiency an§ the three

temperatures are summarized in Table 6.

The recovery efficiency is plotted in Figure 16 as a function of the ambient air temperature while the initial tank

temperature and the mean cutout tank temperature were kept at

constant values. The recovery efficiency and the three

temperatures are summarized in Table 7.

Data from a typical recovery test are shown in Figure 17

where the average water temperature, average ambient

temperature, cumulative energy consumption, ana the heat pump

energy consumption. Eoth the average water tanperature and the

cumulative energy consumption increase rapidly in the initial

period of the test when both the heating element and the heat

pump are operating. When the temperature of the water in the

top portion of the storage tank reaches a preset level, the

heating element cycles off. After the heating element cycles

off, only the heat pump is operating Thus, both the average

water temperature and the cumulative energy consumption increase

at a slower rate. The heat pump energy consumption curve is

almost linear and is parallel to the cumulative energy line.

The difference between the two curves represents energy which was consumed by the electric heating element.

3. Energy Consumption

The results of the confirmation energy consumption tests

are presented in Table 3. It contains the results of three

tests. Each test consists of one recovery and one standby test.

As mentioned previously, the purpose of the tests was to

determine the daily energy consumption, , for two fixed

temperature differences , A T^ andAT^. Te^t 3, having a different A T^, will be discussed later.) Trie inlet water and

ambient temperatures were allcwed to float. A

T

? in both tests was 50°C (90°F). A T^ was 38.9°C (70°F) for the baseline case

6-16
(Test 1) and 37.8°C (68.1°F) for the floated case (Test 2). The

experimentally determined recovery efficiencies and standby

losses were used to calculate the daily energy consumption. The

baseline case has a lower recovery efficiency, 1.61, ,ana a higher standby loss, 0.64%/hours, when compared with the case

for the floated temperatures which was 1.66 and 0.54%/hcur,

respectively. The daily energy consumptions, however, of 10.8

kWh/day and 10.2 kWh/day, differ by less than 6%.

The implication of this finding is that if 'the daily

energy consumption, C , remains essentially the same for the same temperature differences regardless of the absolute

temperature levels, then an electric heat pump water heater may

be tested with controlled temperature differences only without

specifications on the absolute temperature levels. The

burdensomeness of testing will be significantly lessened. For

example, a manufacturer of electric heat pump water heaters may

conduct tests on the unit at any ambient temperature level of

the laboratory by adjusting the inlet water temperature to

produce a given AT, with a simple cold water supply system along

with the water heater thermostat to produce a given A T^. The

lessening of the burdensomeness of testing is in the fact that

adjustment of the laboratory ambient temperature—a substantial

task—may be eliminated altogether.

Modifying the Test Method to take advantage of , these

findings would reduce the burdensomeness of testing. The

modified Test Method would specify only the temperature

differences for testing rather than the absolute temperature

levels as currently required in the proposed test procedure.

Eefore modifying the Test Method, however, more laboratory tests

should be conducted in order to establish the repeatability of

the conclusion and the limits of the absolute temperatures to

which it would apply.

The daily energy consumption shown for Test 3 are the

results from one standby test and one recovery test of the

validation tests. The AT, and A T^ were maintained at 50°C

(90°F) and the calculated daily energy consumption, C

T , is 12.2

kWh/day. Test 3 and Test 1 have the same cutout and Inlet

temperatures but different ambient temperatures. From a comparison of these tests it is seen that when the unit is

tested with a aT,. of 50°C (9C

c

F) the low recovery efficiency and

high standby loss

consumption.

result is too high a calculated daily energy

B-17
4. Power Consumption of the Heat Pump

The power consumption of the electric heat pump alone is

plotted against mean water temperature in Figure 18. At a fixed ambient temperature of 17.8°C (64.0°F), as anticipated,

it increases as the water tanperature increases. The power

consumption is 720 watts at a water tanperature of 18.3°C (65°F)

and increases to 920 watts at 60°C (140°F).

E. Conclusions

1. The standby loss increases as the cutout water tanperature

is increased and decreases as the ambient temperature is

increased

.

2. The recovery efficiency depends on the ambient and the

supply water tanperatures. Hie recovery efficiency is not

particularly sensitive to the cutout temperature in the range of

the cutout temperatures tested.

3. Changes in absolute tanperature levels have little effect

on energy consumption provided the temperature differences

between the cutout and the inlet water tanperature, and the

cutout and the room ambient remain constant.

4. The power consumption of the heat pump depends strongly on the tank mean water tanperature when the room ambient remains

constant.

V. Validation Tests

Additional validation tests were conducted on the electric heat pump

water heater in an environmental chamber and consisted of standby,

recovery and draw tests.

A. Purpose of Tests

The tests were conducted to establish the validity of the

modified Test Method. Energy use and hot water delivery were measured.

The tests were conducted under conditions which were different from those

required by the modified test procedures, in that the tolerances of the

test conditions were more stringent than these required by the modified

Test Method and a draw schedule was imposed. The results are compared with

those of the confirmatory tests conducted under the modified Test Method.

B-18
B. Laboratory Setup

A crucial component for this testing of the electric heat pump

water heater was the environmental chamber. The ambient conditions

in the regular laboratory were not easily adjusted to the desired

conditions. Even when the ambient temperature of the laboratory was

adjusted to a desired level, tolerances frequently could not be

maintained to specifications more stringent than those in the proposed

Test Method. Therefore, an environmental chamber was used.

1. Environmental Chamber . The environmental chamber measures

2.4 rn high, 2.7 m wide, and 1.9 m deep. A refrigeration unit,

electric heaters, and the associated controls are used to

maintain the chanber temperature within narrow ranges at a given

temperature level. The ambient temperature record of a typical

standby test of the electric heat pump water heater is given in

Figure 20. The average ambient temperature of this test was

12.8°C for more than 48 hours with a range of 11.3°C to 13.7°C

and thus maintained a tolerance narrower than that of the

proposed Test Method of l.?°C below and 3. 3 C above the

average.

2. Instrumentation . Six T-type thermocouples were used to

measure water temperature in a manner described in section IV.

Two T-type thermocouples were used to measure ambient

temperature. Three watt-hour meters were used to monitor the

electric energy use by the heat pump, the heating element, and,

as a check, the sum of the two.

A water supply system similar to the one described in

section II was used to supply water at the desired inlet water

temperature.

3. Data Collection and Reduction. A 100 channel data lGgger

was used to sample the thermocouples and the watt-hour meters at

a predetermined sampling rate of one data point every four

minutes. 1116 data logger converted analog data into digital

data which were recorded on a digital recorder. The recorded

data then were processed using the MBS Univac 1108 computer.

C. Draw Tests

Draw tests were conducted by extensive use of the minicomputer

and a microprocessor flow control. Delivery flow rates were

controlled by the microprocessor which programmed three flow control

valves. Choices of any single valve or any combination of the three

valves gives seven different flow-rates. The draw schedule described

in section IV for a 24-hour period is given in Table 2. The first

3-19
column gives the time at the beginning and the end of a single

individual draw, the second column gives the fraction of the total

draw of the 24-hour period. For example, the first draw lasts 24

seconds and consimes 0.935$ of the total draw. The total draw for the

24-hour period was planned for 243.4 L (64.3 gal). The fourth and the

fifth columns are the supply and delivered water temperatures,

resgectively . The weighted average supply water temperature is 8.3°C

(47 F) while the weighted average delivered water tonperature is

Y^rC (165. 6°F).

The temperature measurements of a typical draw test are shown in

Figures 19 and 20. In Figure 19 the temperature recordings of the

first three thermocouples are given versus the time. In Figure 20,

the temperature recordings of the sixth thermocouple and the ambient

thermocouple are shown versus time.

D. Results and Discussions

Data from a typical standby test prior to a draw test are shown

in Figure 21 where the average water temperature, average amDient

temperature, and cumulative energy consumption are plotted against

time. The cumulative energy consumption follows a staircase curve.

It can be seen in Figure 21 that the average water temperature

follows a regular, periodic pattern of heat pump off (cooldown) and on (recovery) . The average water tanperature stays with a 3°C band

controlled by the thermostat.

The ambient temperature shown in Figure 21 is also plotted in

Figure 22 only with a larger degree of resolution and as mentioned

previously, the tolerance was narrower than that of the proposed Test

Method

.

The results from all draw schedule tests are summarized in Table

9- As can be seen for each test the measured daily energy

consumption, 0. , and the calculated daily energy condition, 0 , based on actual1^ T^ and AT^ temperature differences, agree wi£h one

another to within 6%. The calculated daily energy consumption, C , based on the nominal tanperature aifferences, (AT,- = AT,. = 90°F),'

/r is

insensitive to the actual temperature differences^maintained during

the tests (aT, and AT^) as found in the confirmatory tests.

E. Conclusions

1. The daily energy consumptions, calculated from the standby

loss and recovery efficiency measured under closely controlled

environmental conditions, compare well with the confirmatory

B-20
test results which were calculated from the standby losses and

recovery efficiencies measured according to the modified Test

Method

.

2. The calculated daily energy consumption, based on the

actual temperature differences for tests under draw conditions,

agrees with the actual measured energy consumptions. The

average daily energy consumption, C , is sensitive to the

temperature differences maintained during the tests, A T^ andAT^.

3. The modified Test Method determines energy consumption

accurately under both draw and non-draw conditions.

B-21
Table 1 location of the Interior Thermocouples

Distance frcm Thermocouple

Bottom of Tank No.

cm in

10.2 4 1

30.5 12 2

50.8 20 3

71.1 28 4

91.4 36 5

111.8 44 6

B-22
Table 2. Summary of Draw Tests

Fractional

Time Draw

T. T

/ ; jl: u 7: 1:24

.00935 5.3 C (41.5 F) 72.0 C (161.6 F)

7: 5: 0

7:10: 0

.234 6.9 C (44.4 F) 71.5 C (160.7 F)

7:25: 0

7:25:24 .00935 8.1 C (46.6 F) 70.5 C (158.9 F)

8: 0: 0

8: 0:24 .00935 12.3 C (54.1 F) 70.9 C (159.6 F)

10: 0: 0

10: 2: 0

.125 8.3 C (46.9 F) 74.1 C (165.4 F)

10:22: 0

10:23: 0

.0623 8.6 C (47.5 F) 73.3 C (163.9 F)

10:30: 0

10:30:24

.00935 8.7 C (47.7 F) 72.0 C (161.6 F)

12: 0: 0

12: 0:24

.00935 9.9 C (49.8 F) 74.4 C (165.9 F)

12:45: 0

12:45:24 .00935 8.6 C (47.5 F) 75.8 C (168.4 F)

16: 0: 0

16: 0:24

.00935 10.0 C (50 F) 76.2 C (169.2 F)

17:20: 0

17:20:24 .00935 8.1 C (46.6 F) 75.7 C (168.3 F)

18: 0: 0

18: 0:24 .00935 8.2 C (46.8 F) 76.0 C (168.8 F)

18:20: 0

18:22: 0

.0467 11.4 C (52.5 F) 76.0 C (168.8 F)

18:28: 0

18:30: 0

.0467 8.6 C (47.5 F) 75.4 C (167.7 F)

18:36: 0

18:38: 0

.0467 9.1 C (48.4 F) 74.9 C (166.8 F)

18:44: 0

18:46: 0

.0467 8.8 C (47.8 F) 74.4 C (165.9 F)

18:52: 0

18:54: 0

.0467 8.4 C (47.1 F) 73.9 C (165.0 F)

22: 0: 0

22: 0:24

.00935 7.9 C (46.2 F) 76.2 C (169.2 F)

22: 5: 0

22:10: 0

.234 8.5 C (47.3 F) 76.0 C (168.8 F)

22:25: 0

22:25:24 .00935 8.4 C (47.1 F) 74.6 C (166.3 F)

23:30:0

23:30:24 .00935 11.0 c (51.8 F) 75.1 C (167.2 F)

WEIGHTED AVERAGE = 8.3 c (47.0 F) 74.2 C (165.6 F)

B-23
Table 3

Standby Loss Tests to Determine Effects of the

Ambient Temperature

Standby Loss

S

Cutout

Temperature, T^

Ambient

Temperature, T

g

AT

4 ‘W

0.74 63 . 1°C (145. 6°F) 18 . 7°C ( 65 . 7°F

)

44 . 4°C (79 . 9°F)

0.68 6 1 . 7°C (143. 1°F) 22 . 0°C ( 71 . 6°F

)

39 . 7°C (71. 4°F)

0.64 62 . 4°C (144. 3°F) 23 . 6°C ( 74 . 5°F

)

38 . 8°C (69.8°F)

Table 4

Standby Loss Tests to Determine Effects of the

Cutout Temperature

Standby Loss

S

Cutout

Temperature, T^

Ambient

Temperature, T

g

AT 4

(T f -T ) i a 0.57 55 . 6°C (132. 1°F) 2 3 . 2°C ( 73 . 8°F

)

32 . 4°C ( 5 8 . 3°F)

0.64 62 . 4°C (144. 3°F) 2 3 • 6°C (7 4 . 5°F

)

3 8 . 8°C (69 . 8°F) 1 0.71 62 . 6°C (144. 7°F) 23. 8°C (74.8°F) 3 8 . 8°C ( 69 . 8°F)

0.73 68 . 8°C (155. 8°F) 23 - 5°C (74.3°F) 4 5 . 3°C ( 8 1 . 5°F)

j

Table 5

Recovery Tests to Determine Effects of the

Cutout Temperature

Recovery

Ef f iciency

E

r

Inlet Water

Temperature

T

i

Cutout

Temperature

Tx f

Ambient

Temperature

T

a

at

3

(Tf-T_

)

I 3

at,,

1.61 12 . 7°C

(54 . 9°F

)

57 . 3°C

(135. 1°F)

23. 7°C

( 7 4 . 7°F

)

44. 6°C

(80. 3°F)

33. 6°C

(60.5 FI 1.62 12 . 8°C

(55. 0°F

)

62.8 °C

(145. 0°F ) 21 .7°C

( 7 1 . 1°F

)

50. 0°C

( 90 . 0°F

)

41.1°C

(74.0 FI 1.63 12 . 6°C

(54 . 7°F

)

71 . 1°C

( 160. OF)

23.5°C

(74. 3 F)

53.5°g

(10 5.3 F ) 1.61 13 • 2°C

(55 . 8°F

)

65 . 7°C

(150. 3°F)

23. 7°C

(74 . 7°F

)

52.5°C

( 94 . 5°F)

42 . 0°C

(7.5, 6£a

B-24
Table 6

Recovery Tests to Determine Effects of the

Inlet Temperature

Recovery

Ef f iciency

E

r

Inlet Water!

Temperature ' T

i

!

Cutout

Temperature

T

f

Ambient

Temperature

T

a

at

3

(Tf"T i

)

*t 4

(T f-T

a

) 1.64 15 .4°C

(59 • 7°F

)

62. 9°C

(145. 2°F)

23 • 7°C

(74 . 7°F

)

47 . 5°C

( 85 . 5°F

)

39 . 2°C

(70. 6°F)

1.62 18 . 2°C

( 64 . 8°F

)

62 . 8°C

(145. 0°F)

23 • 7°C

(74.7°F)

44. 6°C

(80. 3°F)

39 . 1°C

(70. 4°F)

1.56 27 . 7°C

(81. 9°F

)

64. 4°C

( 147. 6°F)

17.9°C

(64. 2°F

)

36.7°C

( 66 . 1°F

)

46 . 5°F

(83- 7°F

)

1.60 21 . 6°C

(70 . 9°F

)

62. 8°C

(145. 0°F)

i

23. 6°C

(74.5°F)

41 . 2°C

(74. 2°F)

39 . 2°C

(70. 6°F)

Table 7

Recovery Tests to Determine Effects of the

Ambient Temperature

Recovery

Efficiency

E

r

Inlet Water

Temperature

T.

l

Cutout

Temperature

' T

f

Ambient

Temperature

T

a

iT

3

(T

f -T.)

A i ^

( t,-t )

i a 1.61 11 . 5°C

(52 . 7°F

)

60 . 7°C

(141. 3°F)

17 . 8°C

( 64 . 0°F

)

49 . 2°C

( 38 . 6°F

)

42. 9°C

( 77 . 2°F

)

1.66 12 . 2°C

( 5 4 . 0°F

)

69°C

(147. 2°F)

21 . 2°C

(70 . 2°F)

56 . 8°C

(102. 2°F)

47. 8°C

(86. 0°F)

1.62 12 . 3°C

( 5 5 . 0°F

)

62 . 8°C

(144. 0°F)

21 . 7°C

(71 . 1°F

)

50. 0°C

(90. G°F)

41 . 1°C

(74. 0°F)

1.64 15 . 4°C

( 5 9 . 7°F

)

62. 9°C

(145 ,2°F)

23 . 7°C

(74.7°F)

47. 5°C

(85.5 %)

39. 2°C

(70.6 °F)

B-25
B-26

Definitions

and

units

of

these

symbols

are

given

in

the

Test

Method,

Appendix
Table

9.

Results

of

Validation

Draw

Tests

for

Daily

Energy

Consumption

•K j3 k a 3

O' rii

12.3 10.4 10.7 o o tH 3 -3 • • •

-Jc i—l 2 CO o o

O' ^ rH rH rH

CM ON r^> So -3 • • • O S o o o

rH tH rH

<r ON ON • • • Pm 3 rH rH rH o in o

cn ON NO

rH NO NO

00 1 • • • J3 o o o m CM CO M NO NO W • • • rH rH tH

"N /^V /-N O Pm U fa

U fa 3 O O o o o o H ON O fa o ON NO

<r I CO ON rH

m <r

<r ro p*** CO nO

'w'

V

/-V /"N O fa O fa

U /-N •H o o o o O fa

H ON M3 CNJ NO <0

cO> 1 • • • • • rH

Eh ° in CO ON 00 cO • NO r—1

<r oo

m no

rH ON

'w' 'w'

~N /-N

O faU faO fa

O 0 O 0 o o m co NO CO <r on

fa • • • • • • H oo m <r oo ON 00 no in no <r m co iH rH v/ 'w' L /-s /—V U fa O fa u fa o o O 0 o o

NO CO in co

mm 3 • • • • • H NO co <r CO MT

CM O' cm cm

V-/ 'w'V

/—S /—\

/^N / > U fa U fa U fa o o o o o o O CM m3 m r-l fa M3

E-t <r

m ON O' oo <r

r^. no nom no

m

rH rH rH

'w'V N-^

CJ

O fa CJ o o o o o o

fa co <r- com r"»m

H

CO NO o 00 <r co <r CM M3 fa m

4J • 3 O 3 z: rH ~ CM CO H

<r %

3333

co 3

fa3

•H

4-1 33U

<U

M-l

T33

V43

4J33a 3o

fa

4-J aa3

CO3oa

4-1 toa)3O

333

CO3

rQ3O

fa

4-1 aa3

CO3Oa

So

6033

<U

So

60

Sm3s TJ

aj a) 03 3 3 i—I M 3 3 U 3 fa 3 cd 3 O 6 *

•K -X

B-27
Figure

la.

Electric

Heat

PumpFigure

lb.

Evaporator

Coil

Water

Heater

and

Compressor

Unit
Figure 2 . Electric Heat Pump Water HeaterSchematic Diagram

B-29
0.6cm

Figure 3. Condenser Coil

B - 3 0
<1r

"

(^2S

- ^3

)

O

Q_

CD

5-X

Q-

<

B - 31

Figure

4.

Pres

s

u

reEnt

ha

1

py

Diagram

of

the

Four

Heat

Pump

Cycles.
1000

en

01si

to 11

**

I

01

co

co CO

cou

CO

CM

CQ>-

O.

—l<X

CM

CO

I

( z

«>/qi) 3anss3«d 3imosav

c

<D

i-ai

<4-

cu

ats~

+j

ca

3

Q_

4-> ra<u

s_

4-5 u

<U La

a>

<4-o

m

<ua

>i o

cne

03

t-aia. o

in

a>

s.

B- 32

Condenser

Temperatures

(

R

- 1

2)

.
OUTER

INNER WALL WALL CAVITY FILLED WITH WATER

Figure 6. A Typical Construction of the DoubleWalled Condenser Coil

B-33
TO

DRAIN

CL

<u 3

UJ x: +-> a.

4-> <u 3 • CO o 4— o O >» o a) s- S s- a o

ac =3 4-> UJ Ol +-> IT3 ZH» •r— <a S_ 1 U_ E o X <U JC

-SC ca u —i

to

UJ

CJ3 Z<

C-5 XUJ

cc

UJ

h-<£oo

CJ

V.

B- 34

RELAY
TEMPERATURE

(°C)

82.00

Figure 8. Typical Temperatures (Ambient, TCI, TC3, TC5)

vs Time for a Recovery and Standby Test.

B- 35

TEMPERATURE

(°F)
TEMPERATURE

(°C)

Figure 9. Typical Temperatures (TC2, TC4, TC6, and Water Average) vs Time for a Recovery and Standby Test.

B - 3 6

TEMPERATURE

(°F)
,’F)

50 70 90

0.8 1 —!

0.7 • — •

•

0.6 • •

0.5 _l 1

Figure 10

Standby Loss vs. ( T

T

a

)

20 30 40 50

(Tf -Ta )

C/3

Figure 11

Standby Loss vs. Ambient

Temperature, =" 62.8°C (145°F'

Figure 12

Standby Loss vs. Cutout

Temperature, T = 23.9°C (75°F)

d

B - 37
lUVlS IV A3H3N3

A3H3N3 lN3UHfl3

B- 38

Figure

13.

Cooldown

Behavior

of

an

Electric

Heat

Pump

Water

Heater

Storage

Tank
1.7 130

(°F)

140 150

T”

1.6 -

1.5 -

1.450

• • •

60 70

Tf (°C)

Figure 14

Recovery Efficiency vs

Cutout Temperature

T . = 12 . 8°C ( 55 0 F) , i

T = 2 3 . 9

0 C ( 75 0 F)

a

80

Figure 15

Recovery Efficiency vs Inlet Temperature,

T

f

= 62 .

8

0 C ( 1 45 ° F)

T = 2 3 . 9

° C ( 75 0 F

)

d

Figure 16

Recovery Efficiency vs Ambient Temperature,

T. = 1 2 . 8

0 C ( 5 5

° F)

T

f

= 62 . 8

° C ( 1 4 5

0 F

)

20 30

TQ(°C)

B - 39
NOIldlAlflSNOO A9U3N3

O O O O O

OO (O ^ CM

(Go) 3UniVU3dl/\l31

B-40

Figure

17.

Average

Water

Temperature,

Average

Ambient

Temperature,

Heat

Pump

Energy,

and

Total

Cumulative

Energy

vs

Time

for

a

Typical

Recovery

Test.
B -41
Figure 19. Draw Test-Temperature of TCI, TC2 and TC3

vs. Time.

B - 4 2

TEMPERATURE

(°F)
TEMPERATURE

(°C)

Figure 20. Draw Test-Temperatures of Ambient and

TC6 vs. Time.

B-43

TEMPERATURE

(°F)
0009

0NiaV3H UnOHllVM

B -44

Water

Temperature,

Ambient

Temperature,

and

Heat

Pump

Energy

vs

.

Time

.
(3o) 3UlllVU3dl/m 1N3I9IAIV

8-45

Figure

22.

Ambient

Temperature

vs.

Time
References

Bl. Chaddock, J. B. Feasbility Study of the Heat Pump

Water Heater, Final Report, Purdue University,

Lafayette, IN, August 31, 1961.

B2. Wan, C.A., Conputer Simulation of Vfeter Heater Standby

Loss, Heat Transfer in Energy Conservation, Goldstein,

R.J. , et al. , editors, 1977 WAM, ASME.

B-46
NBS-114A (REV. 9-78)

U.S. DEPT. OF COMM.

BIBLIOGRAPHIC DATA

SHEET

1. PUBLICATION OR REPORT NO. NBSIR 79-1951

m

4. TITLE AND SUBTITLE

Energy Test Method Development for Electric Heat Pump

Water Heaters

5. Publication Date

7. AUTHOR(S) 8. Performing Organ. Report No. C. Andrew Wan

9. PERFORMING ORGANIZATION NAME AND ADDRESS

NATIONAL BUREAU OF STANDARDS

DEPARTMENT OF COMMERCE

WASHINGTON, DC 20234

12. SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street, City, state, ZIP)

Oak Ridge National Laboratory

Oak Ridge, TN 37830

1$ tkitNo*

11. Contract/Grant No. DOE EW-78 -1-05-57 50

13. Type of Report & Period Covered Final

March 1978 - May 1979

15. SUPPLEMENTARY NOTES

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

16. ABSTRACT (A 200-word or less factual summary of moat significant information. If document includes a significant bibliography or

literature survey, mention it here.) Modifications are proposed for the current U,S. Department of Energy test

procedures for water heaters in order to make them applicable to electric heat

pump water heaters. The modifications are in the areas of definitions and technical

procedures. The latter includes the test conditions, test procedures and

measurements, and calculations. Reasons for making these modifications and

laboratory test data are provided to support the modifications in the technical

procedures

.

17, KEY WORDS (six to twelve entries; alphabetical order; capitalize only the first letter of the first key word unless a proper name;

separated by semicolons)

Energy consumption; energy measurements; heat pump; laboratory tests; modifications

test procedures; water heaters

18. AVAILABILITY jXl Unlimited

| ! For Official Distribution. Do Not Release to NTIS

I

1

1 Order From Sup. of Doc., U.S. Government Printing Office, Washington, DC

20402, SD Stock No. SN003-003-

I 1 Order From National Technical Information Service (NTIS), Springfield, V A. 22161

19. SECURITY CLASS

(THIS REPORT)

21. NO. OF

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