DOE Water Heater Workshop

Summary of Issues and Comments

February 12, 1997

EE-RM-94-230 COMMENT 49C

·. 

DOE Water Heater Workshop . 

Summary of Issues and Comments 

. 

February 12,1997 

1 

·. 

DOE Water Heater Workshop . 

Summary of Issues and Comments 

. 

February 12,1997 

1 
FIRST-HOUR RATING FOR STORAGE-TYPE WATER HEATERS

1DOE 1979 Method: Procedure used from 1979 to 1990

*** Simplified summary of the procedure:

(1) Cut off energy source to the burner/heating element, start draw at 5

g.p.m. from a fully heated tank, stop when outlet temperature

decreased by 20°F. Correct the volume drawn by (Tmean/Tmax).

Record the time at thermostat cut in as Tc.

(2) Calculate the amount of water that can be heated from inlet

temperature to thermostat setting at the rated input rate at the

recovery efficiency over time (1- rc).

(3) Sum the volumes from 1 and 2 as the first-hour rating.

Option to determine first hour rating by calculation:

F = (0.85 x V) + {R x [1 hour - (0.0028 hour/gallon x V)]}

*** Comments: EEI, EPRI - Thermal mass of stored water un-accounted.

: * . : "' * ' ' ~~~~~~~~~~~~~

. .

EE-RM-94-230 COMMENT 49C

FIRST-HOUR RATING FOR STORAGE-TYPE WATER HEATERS 

1. DOE 1979 Method: Procedure used from 1979 to 1990 

***Simplified summary of the procedure: 

(1) Cut off energy source to the burner/heating element, start draw at'5 

g.p.m. from a fully heated tank, stop when outlet temperature 

decreased by 20°F. Correct the volume drawn by (TmeanlTmax). 

Record the time at thermostat cut in as 'tC. 

(2) Calculate the amount of water that can be heated from inlet 

temperature to thermostat setting at the rated input rate at the 

recovery efficiency over time (1- 'tc). 

(3) Sum the volumes from 1 and 2 as the first-hour rating. 

Option to determine first hour rating by calculation: 

F = (0.85 x V) + {R x [1 hour -(0.0028 hour/gallon x V)]} 

*** Comments: EEl, EPRI - Thermal mass of stored water un-accounted. 

2 

FIRST-HOUR RATING FOR STORAGE-TYPE WATER HEATERS 

1. DOE 1979 Method: Procedure used from 1979 to 1990 

***Simplified summary of the procedure: 

(1) Cut off energy source to the burner/heating element, start draw at'5 

g.p.m. from a fully heated tank, stop when outlet temperature 

decreased by 20°F. Correct the volume drawn by (TmeanlTmax). 

Record the time at thermostat cut in as 'tC. 

(2) Calculate the amount of water that can be heated from inlet 

temperature to thermostat setting at the rated input rate at the 

recovery efficiency over time (1- 'tc). 

(3) Sum the volumes from 1 and 2 as the first-hour rating. 

Option to determine first hour rating by calculation: 

F = (0.85 x V) + {R x [1 hour -(0.0028 hour/gallon x V)]} 

*** Comments: EEl, EPRI - Thermal mass of stored water un-accounted. 

2 
First-hour rating - continued

2. DOE 1990 Method: Simplified Summary of Procedure as following:

(1) Start draw at 3 g.p.m. from a fully heated tank, stop when outlet

temperature is 25°F below Tmax. Set Tmin=Tmax-25.

(2) Calculate the mean outlet temperature Tm,1, and DT1=(Tm,1-Tin,1).

(3) Wait for the top thermostat to cut out.

(4) Start a second draw. Stop when outlet water drops to tmin. Calculate

the mean outlet temperature Tm,2, and DT2=(Tm,2-Tin,2).

(5) Continued the sequence until 1 hour has elapsed. At the 1 hr mark:

(6) (A) Draw in progress - Finish draw when Tmin is reached, then

record the time as rf.

(B) Draw not in progress - Wait for the top thermostat to cut out,

then start a final draw. Record the time tf.

(7) For each draw No. I, correct the volume drawn by the factor (DTi/77).

(8) The first hour rating is the sum of the temperature corrected draws

times the factor (60/rf), where Of is in minute.

*** Comments: GAMA - Method under-estimate water heaters with large

tank/low recovery rate.

3

EE-RM-94-230 COMMENT 49C

" 

~~ 

First-hour rating - continued 

2. DOE 1990 Method: Simplified Summary of Procedure as following: 

(1) Start draw at 3 g.p.m. from a fully heated tank, stop when outlet 

temperature is 25°F below Tmax. Set Tmin=Tmax-25. 

(2) Calculate the mean outlet temperature Tm,1, and DT1=(Tm, 1-Tin, 1). 

(3) Wait for the top thermostat to cut out. 

(4) Start a second draw. Stop when outlet water drops to tmin. Calculate 

the mean outlet temperature Tm,2, and DT2=(Tm,2-Tin,2). 

(5) Continued the sequence until 1 hour has elapsed. At the 1 hr mark: 

(6) (A) Draw in progress - Finish draw when Tmin is reached, then 

record the time as ,;f. . 

(8) Draw not in progress - Wait for the top thermostat to cut out, 

then start a final draw. Record the time ,;f. 

(7) For each draw No. I, correct the volume drawn by the factor (DTil77). 

(8) The first hour rating is the sum of the temperature corrected draws 

times the factor (60/,;f), where ,;f is in minute. 

*** Comments: GAMA - Method under-estimate water heaters with large 

tank/low recovery rate. 

3 

" 

~~ 

First-hour rating - continued 

2. DOE 1990 Method: Simplified Summary of Procedure as following: 

(1) Start draw at 3 g.p.m. from a fully heated tank, stop when outlet 

temperature is 25°F below Tmax. Set Tmin=Tmax-25. 

(2) Calculate the mean outlet temperature Tm,1, and DT1=(Tm, 1-Tin, 1). 

(3) Wait for the top thermostat to cut out. 

(4) Start a second draw. Stop when outlet water drops to tmin. Calculate 

the mean outlet temperature Tm,2, and DT2=(Tm,2-Tin,2). 

(5) Continued the sequence until 1 hour has elapsed. At the 1 hr mark: 

(6) (A) Draw in progress - Finish draw when Tmin is reached, then 

record the time as ,;f. . 

(8) Draw not in progress - Wait for the top thermostat to cut out, 

then start a final draw. Record the time ,;f. 

(7) For each draw No. I, correct the volume drawn by the factor (DTil77). 

(8) The first hour rating is the sum of the temperature corrected draws 

times the factor (60/,;f), where ,;f is in minute. 

*** Comments: GAMA - Method under-estimate water heaters with large 

tank/low recovery rate. 

3 
First hour rating - continued

3. DOE 1995 Proposed Method: Simplified Summary of Procedure as:

(1) Start 3 g.p.m. draw from a fully heated tank at 135°F. Record Tmax,1.

(2) End draw when Tmin,1 = (Tmax,1-25). Determine mean temp Tm,1.

(3) Wait for uppermost thermostat to cut out. Then start draw again. (4) Continued sequence for 1 hr. Cut off fuel/electricity supply at 1 hr.

(5) (A) At 1 hr, if drawing - continued until 25°F below Tmax,n.

(B) If not drawing - impose a draw until outlet drops to Tmin,n-1.

Correct this last draw, n, by (Tm,n - Tmin,n-1)/(Tm,n-1 - Tmin,n-1). (6) Sum up all draws (1 through 5A or 5B) as the first-hour rating.

*** Comments:

GAMA - In general support procedure. Tests showed

no repeatability problem. May need minor change.

EEI/EPRI - Disagree with the procedure. Major comments are:

1. Low draw rate limits reheat time available for large tank.

2. Time longer than one hour and variable.

3. Cumbersome correction factor to last imposed draw (in 5B).

4. Variable heat content of water drawn. Mixing valve not covered.

' ' ' ' ~~~~~~~~~~

EE-RM-94-230 COMMENT 49C

First hour rating - continued 

3. DOE 1995 Proposed Method: Simplified Summary of Procedure as: 

(1) Start 3 g.p.m. draw from a fully heated tank at 135°F. Record Tm~x,1. 

(2) End draw when Tmin,1 = (Tmax,1-25). Determine mean temp Tm,1. 

(3) Wait for uppermost thermostat to cut out. Then start draw again. 

(4) Continued sequence for 1 hr. Cut off fuel/electricity supply at 1 hr. 

(5) (A) At 1 hr, if drawing ~ continued until 25 ° F below Tmax,n. 

(8) If nO.t drawing -. impose a draw until outlet drops to Tmin,n-1. 

Correct this last draw, n, by (Tm,n - Tmin,n-1 )/(Tm,n-1 - Tmin,n-1). 

(6) Sum up all draws (1 through 5A or 58) as the first-hour rating. 

*** Comments: 

GAMA - In general support procedure. Tests showed. 

no repeatability problem. May. need minor change. 

EEIIEPRI - Disagree with the procedure. Major comments are: 

1. Low draw rate limits reheattime available for large tank. 

2. Time longer than one hour and variable. 

3. Cumbersome correction factor to last imposed draw (in 58). 

4. Variable heat content of water drawn. Mixing valve not covered. 

4 

First hour rating - continued 

3. DOE 1995 Proposed Method: Simplified Summary of Procedure as: 

(1) Start 3 g.p.m. draw from a fully heated tank at 135°F. Record Tm~x,1. 

(2) End draw when Tmin,1 = (Tmax,1-25). Determine mean temp Tm,1. 

(3) Wait for uppermost thermostat to cut out. Then start draw again. 

(4) Continued sequence for 1 hr. Cut off fuel/electricity supply at 1 hr. 

(5) (A) At 1 hr, if drawing ~ continued until 25 ° F below Tmax,n. 

(8) If nO.t drawing -. impose a draw until outlet drops to Tmin,n-1. 

Correct this last draw, n, by (Tm,n - Tmin,n-1 )/(Tm,n-1 - Tmin,n-1). 

(6) Sum up all draws (1 through 5A or 58) as the first-hour rating. 

*** Comments: 

GAMA - In general support procedure. Tests showed. 

no repeatability problem. May. need minor change. 

EEIIEPRI - Disagree with the procedure. Major comments are: 

1. Low draw rate limits reheattime available for large tank. 

2. Time longer than one hour and variable. 

3. Cumbersome correction factor to last imposed draw (in 58). 

4. Variable heat content of water drawn. Mixing valve not covered. 

4 
First hour rating - continued

4. EPRI/EEI Proposed Method:

*** Simple Summary of the Procedure:

(1) Draw from a fully heated tank at 135°F until Tout = 110 0F. Stop draw.

(2) Correct the volume drawn by a temperature ratio to 110°F water.

(3) Start clock. Measure time T to reheat to 110°F at top thermocouple.

(4) Calculate time remaining from one hour mark as (1 - =).

(5) Calculate amount of heated water (from 58°F to 110°F) at rated input

over the remaining time of (1 - T).

(6) add to the temperature corrected first draw in 2 as the first-hour

rating.

*** Suggested advantage of the method:

1. Uniform hot water temperature (110°F).

2. No waiting for thermostat to cut out before hot water can be

drawn. More realistic to actual user action.

*** Comments: GAMA - Do not support the Procedure.

. -cedur 5

EE-RM-94-230 COMMENT 49C

.' 

. First hour rating .. continued 

4. EPRI/EEI Proposed Method: 

*** Simple Summary of the Procedure: 

(1) Draw from a fully heated tank at 135°F until Tout = 110°f. Stop draw. 

(2) Correct the ,volume drawn by a temperature ratio to 110°F water . 

. (3) Start clock. Measure time 't to reheat to 110 ° F at top thermocouple . 

. (4) Calculate time remaining from one hour mark as (1 - 't). 

(5) Calculate amount of heated water (from 58°F to 110°F) at rated input 

. over the relllaining time of (1 - 't)'. 

(6) add to the temperature corrected first draw in 2 as the first-hour 

rating. 

*** Suggested advantage of the method: 

1. Uniform hot water temperature (110°F). 

2. No waiting for thermostat to cut out before hot water can be 

drawn. More realistic to actual user action. 

*** Comments: GAMA - Do not support the Procedure. 

5 

.' 

. First hour rating .. continued 

4. EPRI/EEI Proposed Method: 

*** Simple Summary of the Procedure: 

(1) Draw from a fully heated tank at 135°F until Tout = 110°f. Stop draw. 

(2) Correct the ,volume drawn by a temperature ratio to 110°F water . 

. (3) Start clock. Measure time 't to reheat to 110 ° F at top thermocouple . 

. (4) Calculate time remaining from one hour mark as (1 - 't). 

(5) Calculate amount of heated water (from 58°F to 110°F) at rated input 

. over the relllaining time of (1 - 't)'. 

(6) add to the temperature corrected first draw in 2 as the first-hour 

rating. 

*** Suggested advantage of the method: 

1. Uniform hot water temperature (110°F). 

2. No waiting for thermostat to cut out before hot water can be 

drawn. More realistic to actual user action. 

*** Comments: GAMA - Do not support the Procedure. 

5 
First hour rating - continued

*** DOEINIST evaluation on the EEI/EPRI proposed procedure:

1. Variable test time - variable time needed for first draw.

2. Heating (recovery) involved during part of the first draw.

3. Correction to 110°F significantly increases rating value.

4. If water is drawn after reheat time T, since the max temperature

in tank is 110°F, the draw rate has to match the heat input rate

to maintain the 110°F outlet after the stored 110°F water is

exhausted (for dual heating element units, the time can be short).

- At a heat input rate of 4.5 kW, the ability to heat water from

58°F to 1100F is (4.5x3413160)/(8.34x1x52) = 0.59 g.p.m.

6

EE-RM-94-230 COMMENT 49C

First hour rating - continued 

*** DOE/NIST evaluation on the EEI/EPRI proposed procedure: 

1. Variable test time - variable time needed for first draw. 

2. Heating (recovery) involved during part of the first draw. 

3. Correction to 110 ° F significantly increases rating value. 

4. If water is drawn after reheat time 't, since the max temperature 

in tank is 110°F, the draw rate has to match the heat input rate 

to maintain the 110°F outlet after the stored 110°F water is 

exhausted (for dual heating element units, the time can be short). 

- At a heat input rate of 4.5 'kW, the ability to heat water from 

58 ° F to 110 ° F is (4.5x3413/60)/(8.34x1 x52) = O.59g.p.m. 

6 

First hour rating - continued 

*** DOE/NIST evaluation on the EEI/EPRI proposed procedure: 

1. Variable test time - variable time needed for first draw. 

2. Heating (recovery) involved during part of the first draw. 

3. Correction to 110 ° F significantly increases rating value. 

4. If water is drawn after reheat time 't, since the max temperature 

in tank is 110°F, the draw rate has to match the heat input rate 

to maintain the 110°F outlet after the stored 110°F water is 

exhausted (for dual heating element units, the time can be short). 

- At a heat input rate of 4.5 'kW, the ability to heat water from 

58 ° F to 110 ° F is (4.5x3413/60)/(8.34x1 x52) = O.59g.p.m. 

6 
First Hour Rating for Instantaneous Water Heaters

Current DOE Method:

Continuous draw at the rated input and at the draw g.p.m. that will give a

nominal temperature rise of DT=77°F, for one hour.

Comments: GAMA, EEI, EPRI, TVA, Virginia Power - The DOE procedure can

mislead consumers to compare the instantaneous water heater with a storage

type water heater. It masks the fact that the heater can deliver hot water at the

77°F DT only at the specific g.p.m. flow rate. A greater draw rate will deliver

hot water at a lower temperature.

Proposed Alternative Method by Comments: Specify the maximum draw rate

in g.p.m. to give a specific temperature rise as the rating criterion.

GAMA: Suggested a DT of 77 F to agree with the requirement for storage

type water heaters.

EEI, EPRI, TVA, and Virginia Power: Suggested a DT of 50°F.

7

EE-RM-94-230 COMMENT 49C

First Hour Rating for Instantaneous Water Heaters 

Current DOE Method: 

Continuous draw at the rated input and at the draw g.p.m. that will give a 

nominal temperature rise of DT=77°F, for one hour. 

Comments: GAMA, EEl, EPRI, TVA, Virginia Power - The DOE procedure can 

mislead consumers to compare the instantaneous water heater with a storage 

type water heater. It masks the fact thaf the heater can deliver hot water at the 

77°F DT only at the specific g.p.m. flow rate. A greater draw rate will deliver 

hot water at a lower temperature. 

Proposed Alternative Method by Comments: Specify the maximum draw rate 

in g.p.m. to give a specific temperature rise as the rating criterion. 

GAMA: Suggested a DT of 77°F to agree with the requirement for storage 

type water heaters. 

EEl, EPRI, TVA, and Virginia Power: Suggested a DT of 50°F. 

7 

First Hour Rating for Instantaneous Water Heaters 

Current DOE Method: 

Continuous draw at the rated input and at the draw g.p.m. that will give a 

nominal temperature rise of DT=77°F, for one hour. 

Comments: GAMA, EEl, EPRI, TVA, Virginia Power - The DOE procedure can 

mislead consumers to compare the instantaneous water heater with a storage 

type water heater. It masks the fact thaf the heater can deliver hot water at the 

77°F DT only at the specific g.p.m. flow rate. A greater draw rate will deliver 

hot water at a lower temperature. 

Proposed Alternative Method by Comments: Specify the maximum draw rate 

in g.p.m. to give a specific temperature rise as the rating criterion. 

GAMA: Suggested a DT of 77°F to agree with the requirement for storage 

type water heaters. 

EEl, EPRI, TVA, and Virginia Power: Suggested a DT of 50°F. 

7 
Instantaneous Water Heaters - Other Issues

Comments: GAMA, Paloma, CEC.

GAMA:

No oil-fired instantaneous water heater on the market.

Distinction between models of single- and multi-point of use.

Paloma, CEC:

For gas-fired heaters, two ratings values for EF - one with and one

without pilot light when heater is off.

CEC:

(1) For heaters with capability to vary input rate, DOE specifies that 50%

of the 6 draws in the 24-hr use test be at the minimum input rate. The

minimum flow rate is used less and a less efficient use of the heater.

Suggestion: Change the 50% to 25%.

(2) The 135°F outlet temperature setting should not apply to

instantaneous water heaters. The temperature is too hot for use and there

is no advantage (in the availability of additional hot water) at the high setting as for storage-type water heaters. Suggestion: Change the

setting to a field use value.

' ~~~~~~~~~~8

EE-RM-94-230 COMMENT 49C

Instantaneous Water Heaters - Other Issues . 

Comments: GAMA, Paloma, CEC. 

GAMA: 

No oil-fired instantaneous water heater on the market. 

Distinction between models of single- and multi-point of use. 

Paloma, CEC: 

For gas-fired heaters, two ratings values for EF - one with and one 

without pilot light when heater is off. 

CEC: 

(1) For heaters with capability to vary input rate, DOE specifies that 50% 

of the 6 draws in the 24-hr use test be at the minimum input rate. The 

minimum flow rate is used less and a less efficient use of the heater. 

Suggestion: Change the 50% to 25%. 

(2) The 135°F outlet temperature setting should not apply to 

instantaneous water heaters. The temperature is too hot'for use and there 

is no advantage (in the availability of additional hot water) at the high 

setting as for storage-type water heaters. Suggestion: Change the. 

setting to a field use value. 

8 

Instantaneous Water Heaters - Other Issues . 

Comments: GAMA, Paloma, CEC. 

GAMA: 

No oil-fired instantaneous water heater on the market. 

Distinction between models of single- and multi-point of use. 

Paloma, CEC: 

For gas-fired heaters, two ratings values for EF - one with and one 

without pilot light when heater is off. 

CEC: 

(1) For heaters with capability to vary input rate, DOE specifies that 50% 

of the 6 draws in the 24-hr use test be at the minimum input rate. The 

minimum flow rate is used less and a less efficient use of the heater. 

Suggestion: Change the 50% to 25%. 

(2) The 135°F outlet temperature setting should not apply to 

instantaneous water heaters. The temperature is too hot'for use and there 

is no advantage (in the availability of additional hot water) at the high 

setting as for storage-type water heaters. Suggestion: Change the. 

setting to a field use value. 

8 
Storage-Type Water Heaters With Less Than 20 Gallons Capacity

DOE Proposed Test Procedure:

First-hour rating and 24-hr simulated use test as specified in ASHRAE

Std. 118.2 for draw rate and daily volume:

Storage tank at 10 to 20 gallons: 1 ±0.25 g.p.m., 24 gallday.

Storage tank below 10 gallons: 1 ±0.25 g.p.m., 9 gal/day.

*** Comments: GAMA, EEI, EPRI, Vaughn, Southern Co. Services Inc.

GAMA:

(1) Proposed formula for determining minimum efficiency not

appropriate for tank with small volume - heat loss through fittings are

the same (not a function of tank size) for all tank size.

(2) Most small storage volume heaters are electric type.

(3) Draw rate (1 g.p.m.) too large for tank less than 10 gallons during

Energy Factor test in determining average temperature per draw.

(4) First hour rating not appropriate for small storage heater.

Suggestion: Classify by volume only.

9

EE-RM-94-230 COMMENT 49C

Storage-Type Water Heaters With Less Than 20 Gallons Capacity - ' 

DOE Proposed Test Procedure: 

First-hour rating and 24-hr simulated use test as spe,cified in ASHRAE 

Std. 118.2 for draw rate and daily volume: 

Storage tank at 10 to 20 gallons: 1 ±0.25 g.p.m., 24 gal/day. 

Storage tank below 10 gallons: 1 ±0.25 g.p.m., 9 gal/day. 

*** Comments: GAMA, EEl, EPRI, Vaughn, Southern Co. Services Inc. 

GAMA: 

(1) Proposed formula for determining minimum efficiency not 

appropriate for tank with small volume - heat loss through fittings are 

the same (not a 'function of tank size) for all tank size. 

(2) Most small storage volume heaters are electric type. 

(3) Draw rate (1 g.p.m.) too large for tank less than 10 gallons during 

Energy Factor test in determining average temperature per draw. 

(4) First hour rating not appropriate for small storage heater. 

Suggestion: Classify by volume only. 

9 

Storage-Type Water Heaters With Less Than 20 Gallons Capacity - ' 

DOE Proposed Test Procedure: 

First-hour rating and 24-hr simulated use test as spe,cified in ASHRAE 

Std. 118.2 for draw rate and daily volume: 

Storage tank at 10 to 20 gallons: 1 ±0.25 g.p.m., 24 gal/day. 

Storage tank below 10 gallons: 1 ±0.25 g.p.m., 9 gal/day. 

*** Comments: GAMA, EEl, EPRI, Vaughn, Southern Co. Services Inc. 

GAMA: 

(1) Proposed formula for determining minimum efficiency not 

appropriate for tank with small volume - heat loss through fittings are 

the same (not a 'function of tank size) for all tank size. 

(2) Most small storage volume heaters are electric type. 

(3) Draw rate (1 g.p.m.) too large for tank less than 10 gallons during 

Energy Factor test in determining average temperature per draw. 

(4) First hour rating not appropriate for small storage heater. 

Suggestion: Classify by volume only. 

9 
Storaqe water heater less than 20 gallons - continued

(5) 24-hr simulated use test may not be supported by actual field use

pattern. Functions of small storage heaters are different from regular

sized storage water heaters.

Suggestion: Base rating on a maximum hourly standby loss value

rather than EF until actual field use data on draw rate and daily

volume are available to develop a proper 24-hr simulated use test.

EEI, EPRI:

(1) Similar concerns by GAMA.

(2) Tank size less than two and half gallons be excluded from coverage.

Vaughn and Southern Co. Services, Inc.:

(1) Small volume heaters occupy a niche market.

(2) Energy usage small. Consumers do not base purchase on the EF.

(3) Suggestion: Exclude from coverage.

10

EE-RM-94-230 COMMENT 49C

. Storage water heater less than 20 gallons - continued 

(5) 24-hr simulated use test may not be supported by actual field use 

pattern. Functions of small storage heaters are different from regular 

. sized storage water heaters. 

Suggestion: Base rating on a maximum hourly standby loss value 

rather than EF until actual field use data on draw rate and daily 

volume are available to develop a proper 24~hr simulated use test. 

EEl, EPRI: 

(1) Similar concerns by GAMA. 

(2) Tank size less than two and half gallons be excluded from coverage . 

. Vaughn and Southern Co. Services, Inc.: 

(1) Small volume heaters occupy a niche market. . 

(2) Energy usage ·small. Consumers do not base/purchase on the EF. 

(3) Suggestion: Exclude from coverage. 

10 

. Storage water heater less than 20 gallons - continued 

(5) 24-hr simulated use test may not be supported by actual field use 

pattern. Functions of small storage heaters are different from regular 

. sized storage water heaters. 

Suggestion: Base rating on a maximum hourly standby loss value 

rather than EF until actual field use data on draw rate and daily 

volume are available to develop a proper 24~hr simulated use test. 

EEl, EPRI: 

(1) Similar concerns by GAMA. 

(2) Tank size less than two and half gallons be excluded from coverage . 

. Vaughn and Southern Co. Services, Inc.: 

(1) Small volume heaters occupy a niche market. . 

(2) Energy usage ·small. Consumers do not base/purchase on the EF. 

(3) Suggestion: Exclude from coverage. 

10 
Daily Hot Water Usage Volume and Thermostat Settinq

Current DOE Requirements:

Daily Hot Water Usage Volume: 64.3 gal/day.

Thermostat Setting: 135°F.

Comments: AGA, Battelle Columbus:

(1) Current DOE requirements are too high.

(2) Suggestion: Change to 54 gallday and 1200F setting based on more

recent survey and metered data and manufacturers' practice (thermostat

setting).

Effects of change:

(1) Will change EF on existing models.

(2) Lower temperature setting may not meet requirements of clothes

washers and dish washers.

'* .~~~~~~~~~~~~~~~~~~~~~~~~11

EE-RM-94-230 COMMENT 49C

Daily Hot Water Usage Volume and Thermostat Setting 

Current DOE Requirements: 

Daily Hot Water Usage Volume: 64.3 gal/day. 

Thermostat Setting: 135°F~ 

Comments: AGA, Battelle Columbus: 

(1) Current DOE requirements are too high. 

(2) Suggestion: Change to 54 gal/day and ,120°F setting based on more 

recent survey and metered data and manufacturers' practice (thermostat 

setting). 

Effects of change: 

(1) Will change EF on existing models. 

(2) Lower temperature setting may not meet requirements of clothes 

washers and dish washers. 

11 

Daily Hot Water Usage Volume and Thermostat Setting 

Current DOE Requirements: 

Daily Hot Water Usage Volume: 64.3 gal/day. 

Thermostat Setting: 135°F~ 

Comments: AGA, Battelle Columbus: 

(1) Current DOE requirements are too high. 

(2) Suggestion: Change to 54 gal/day and ,120°F setting based on more 

recent survey and metered data and manufacturers' practice (thermostat 

setting). 

Effects of change: 

(1) Will change EF on existing models. 

(2) Lower temperature setting may not meet requirements of clothes 

washers and dish washers. 

11 
Heat Pump Water Heaters and Related Definitions

1. DOE: Is the current draw schedule for the 24-hr use test appropriate.

Comments: GAMA, Vaughn, Southern Co. Services, Inc.

Current 10.7 gallons per draw in the 24-hr simulated use test may not

activate the resistance heating element, resulting in a higher efficiency

rating. Actual field use may have draw greater than 10.7 gallons,

activating the resistance element. Therefore, part of the test (among the

six draws) should be at a greater draw volume per draw.

Note: No test data on specific draw volumes at the present time.

2. DOE Proposed Heat Pump Water Heater Related Definitions: integral heat

pump, add-on heat pump, heat pump storage tank, and solar water heaters.

Comments: GAMA, EEI, EPRI, Vaughn.

Definitions for solar water heater and heat pump water heater storage

tank are not appropriate since they will cause confusion to users. There

is no tank made specifically for heat pump water heaters.

12

EE-RM-94-230 COMMENT 49C

Heat Pump Water Heaters and Related Definitions 

1. DOE: Is the current draw schedule for the 24-hr use test appropriate. 

Comments: GAMA, Vaughn, Southern Co. Services, Inc. 

Current 10.7 gallons per draw in the 24-hr simulate~use test may not 

activate the resistance heating element, resulting in a higher efficiency 

rating. Actual field use may have draw greater than. 10.7 gallons, 

activating the resistance element. Therefore, part of the test (among the 

six draws) should be at a greater draw volume per draw. 

Note: No test data on specific draw volumes at the present time . 

. 

2. DOE Proposed Heat Pump Water Heater Related Definitions: integral heat 

pump, add-on heat pump, heat pump storage tank, and solar water heaters. 

Comments: GAMA, EEl, EPRI, Vaughn. 

Definitions for solar water heater and heat pump water heater storage 

tank are not appropriate since they will cause confusion to users. There 

is no tank made specifically for heat pump water heaters. 

12 

Heat Pump Water Heaters and Related Definitions 

1. DOE: Is the current draw schedule for the 24-hr use test appropriate. 

Comments: GAMA, Vaughn, Southern Co. Services, Inc. 

Current 10.7 gallons per draw in the 24-hr simulate~use test may not 

activate the resistance heating element, resulting in a higher efficiency 

rating. Actual field use may have draw greater than. 10.7 gallons, 

activating the resistance element. Therefore, part of the test (among the 

six draws) should be at a greater draw volume per draw. 

Note: No test data on specific draw volumes at the present time . 

. 

2. DOE Proposed Heat Pump Water Heater Related Definitions: integral heat 

pump, add-on heat pump, heat pump storage tank, and solar water heaters. 

Comments: GAMA, EEl, EPRI, Vaughn. 

Definitions for solar water heater and heat pump water heater storage 

tank are not appropriate since they will cause confusion to users. There 

is no tank made specifically for heat pump water heaters. 

12