## DOE Water Heater Workshop Summary of Issues and Comments February 12, 1997 ·. 

## DOE Water HeaterWorkshop
. Summary of Issues and Comments

. 

## February 12,1997

1 ·. 

## DOE Water HeaterWorkshop
. 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 ofthe 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 overtime (1-rc). (3) Sum the volumes from 1and 2as the first-hour rating. Option to determine first hour rating by calculation: F= (0.85 x V) + {Rx [1 hour - (0.0028 hour/gallon x V)]} *** Comments: EEI, EPRI - Thermal mass ofstored water un-accounted.

: *
. : "' * ' ' ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~2

. . FIRST-HOUR RATING FOR STORAGE-TYPE WATER HEATERS 1. DOE 1979 Method: Procedure used from 1979to 1990 ***Simplified summary ofthe procedure: (1) Cut offenergy source to the burner/heating element, startdraw 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 atthermostat 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 overtime (1- 'tc). (3) Sum thevolumes 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 ofstored water un-accounted.

2 FIRST-HOUR RATING FOR STORAGE-TYPE WATER HEATERS 1. DOE 1979 Method: Procedure used from 1979to 1990 ***Simplified summary ofthe procedure: (1) Cut offenergy source to the burner/heating element, startdraw 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 atthermostat 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 overtime (1- 'tc). (3) Sum thevolumes 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 ofstored 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) Startasecond draw. Stop when outlet water drops to tmin. Calculate the mean outlettemperature Tm,2, and DT2=(Tm,2-Tin,2). (5) Continued the sequence until 1hour has elapsed. At the 1hr 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 thevolume drawn bythe 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 "**~~** 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. SetTmin=Tmax-25. (2) Calculate the mean outlettemperature Tm,1, and DT1=(Tm,1-Tin,1). (3) Waitforthe top thermostatto cut out. (4) Starta second draw. Stopwhen outletwaterdropstotmin. Calculate the mean outlettemperature Tm,2, and DT2=(Tm,2-Tin,2). (5) Continued the sequence until 1 hour has elapsed. Atthe 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 thetime ,;f. (7) Foreach draw No. I, correctthevolume drawn by the factor (DTil77). (8) The first hour rating is the sum ofthe temperature corrected draws times the factor (60/,;f), where ,;f is in minute. *** Comments: GAMA - Method under-estimatewater 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. SetTmin=Tmax-25. (2) Calculate the mean outlettemperature Tm,1, and DT1=(Tm,1-Tin,1). (3) Waitforthe top thermostatto cut out. (4) Starta second draw. Stopwhen outletwaterdropstotmin. Calculate the mean outlettemperature Tm,2, and DT2=(Tm,2-Tin,2). (5) Continued the sequence until 1 hour has elapsed. Atthe 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 thetime ,;f. (7) Foreach draw No. I, correctthevolume drawn by the factor (DTil77). (8) The first hour rating is the sum ofthe temperature corrected draws times the factor (60/,;f), where ,;f is in minute. *** Comments: GAMA - Method under-estimatewater heaters with large tank/low recovery rate.

3

### First hour rating - continued 

### 3. DOE 1995 Proposed Method: Simplified Summary of Procedure as: (1) Start 3g.p.m. draw from afully heated tank at 135°F. Record Tmax,1. (2) End draw when Tmin,1 = (Tmax,1-25). Determine mean temp Tm,1. (3) Waitfor uppermost thermostat to cut out. Then start draw again. (4) Continued sequence for 1hr. Cut offfuel/electricity supply at 1hr. (5) (A) At 1hr, 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 (1through 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 factorto last imposed draw (in 5B). 4. Variable heat content ofwater drawn. Mixing valve not covered.

' ' ' ' ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~4 First hour rating - continued 3. DOE 1995 Proposed Method: Simplified Summary of Procedure as: (1) Start3 g.p.m. drawfrom a fully heated tank at 135°F. Record**Tm~x,1.** (2) End drawwhen Tmin,1 

# = (Tmax,1-25). Determine mean temp Tm,1. (3) Waitfor uppermostthermostatto cut out. Then startdraw again. (4) Continued sequencefor 1 hr. Cut offfuel/electricity supply at 1 hr. (5) (A) At 1 hr, ifdrawing**~** continued until 25° F belowTmax,n. (8) IfnO.t drawing -. impose a draw until outlet drops to Tmin,n-1. Correctthis lastdraw, n, by (Tm,n - Tmin,n-1)/(Tm,n-1 - Tmin,n-1). (6) Sum up all draws (1 through 5A or58) 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. Majorcomments are: 1. Low draw rate limits reheattime available for largetank. 2. Time longerthan one hourand variable. 3. Cumbersome correction factorto last imposed draw (in 58). 4. Variable heat content ofwater drawn. Mixing valve not covered.

4 First hour rating - continued 3. DOE 1995 Proposed Method: Simplified Summary of Procedure as: (1) Start3 g.p.m. drawfrom a fully heated tank at 135°F. Record**Tm~x,1.** (2) End drawwhen Tmin,1 

# = (Tmax,1-25). Determine mean temp Tm,1. (3) Waitfor uppermostthermostatto cut out. Then startdraw again. (4) Continued sequencefor 1 hr. Cut offfuel/electricity supply at 1 hr. (5) (A) At 1 hr, ifdrawing**~** continued until 25° F belowTmax,n. (8) IfnO.t drawing -. impose a draw until outlet drops to Tmin,n-1. Correctthis lastdraw, n, by (Tm,n - Tmin,n-1)/(Tm,n-1 - Tmin,n-1). (6) Sum up all draws (1 through 5A or58) 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. Majorcomments are: 1. Low draw rate limits reheattime available for largetank. 2. Time longerthan one hourand variable. 3. Cumbersome correction factorto last imposed draw (in 58). 4. Variable heat content ofwater drawn. Mixing valve not covered.

4

### First hour rating - continued 4. EPRI/EEI Proposed Method: *** Simple Summary ofthe Procedure: (1) Draw from afully heated tank at 135°F until Tout = 110 0

### F.Stop draw. (2) Correct the volume drawn by a temperature ratio to 110°F water. (3) Start clock. Measure time Tto 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 overthe remaining time of (1- T). 

### (6) add to the temperature corrected first draw in 2 as the first-hour rating. *** Suggested advantage ofthe 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 

### .'

. First hour rating
.. continued

4. EPRI/EEI Proposed Method: *** Simple Summary ofthe Procedure: (1) Drawfrom a fully heated tank at 135°F until Tout

### = 110°f. Stop draw. (2) Correctthe,volume drawn by a temperature ratio to 110°F water.

.(3) Start clock. Measure time 't to reheatto 110° F attop thermocouple
.

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

(5) Calculate amountofheated water (from 58°F to 110°F) at rated input

.overthe relllaining time of (1 - 't)'. (6) add to the temperature corrected first draw in 2 as the first-hour rating. *** Suggested advantage ofthe method: 1. Uniform hotwatertemperature (110°F). 2. No waiting for thermostat to cut out before hot water can be drawn. More realistic to actual useraction. *** Comments: GAMA - Do notsupportthe Procedure.
5 

### .'

. First hour rating
.. continued

4. EPRI/EEI Proposed Method: *** Simple Summary ofthe Procedure: (1) Drawfrom a fully heated tank at 135°F until Tout

### = 110°f. Stop draw. (2) Correctthe,volume drawn by a temperature ratio to 110°F water.

.(3) Start clock. Measure time 't to reheatto 110° F attop thermocouple
.

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

(5) Calculate amountofheated water (from 58°F to 110°F) at rated input

.overthe relllaining time of (1 - 't)'. (6) add to the temperature corrected first draw in 2 as the first-hour rating. *** Suggested advantage ofthe method: 1. Uniform hotwatertemperature (110°F). 2. No waiting for thermostat to cut out before hot water can be drawn. More realistic to actual useraction. *** Comments: GAMA - Do notsupportthe Procedure.
5

### First hour rating - continued 

### *** DOEINIST evaluation on the EEI/EPRI proposed procedure: 1. Variable testtime - variable time needed for first draw. 

### 2. Heating (recovery) involved during part ofthe first draw. 3. Correction to 110°F significantly increases rating value. 4. Ifwater 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 (fordual heating element units, thetime 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 First hour rating - continued *** DOE/NIST evaluation on the EEI/EPRI proposed procedure: 1. Variable testtime - variable time needed forfirst draw. 2. Heating (recovery) involved during partofthe first draw. 3. Correctionto 110° F significantly increases rating value. 4. Ifwater is drawn after reheattime 't, since the maxtemperature 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 (fordual heating element units, thetime can be short).

- At a heat input rate of4.5 'kW, the ability to heat waterfrom 58° F to 110° F is (4.5x3413/60)/(8.34x1x52)

# = O.59g.p.m.

6 First hour rating - continued *** DOE/NIST evaluation on the EEI/EPRI proposed procedure: 1. Variable testtime - variable time needed forfirst draw. 2. Heating (recovery) involved during partofthe first draw. 3. Correctionto 110° F significantly increases rating value. 4. Ifwater is drawn after reheattime 't, since the maxtemperature 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 (fordual heating element units, thetime can be short).

- At a heat input rate of4.5 'kW, the ability to heat waterfrom 58° F to 110° F is (4.5x3413/60)/(8.34x1x52)

# = 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 heaterwith a storage type water heater. It masks the factthatthe heater can deliver hotwater atthe 77°F DT only atthe specific g.p.m. flow rate. A greater draw rate will deliver hotwater 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 of77 Fto agree with the requirement forstorage type water heaters. EEI, 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 comparethe instantaneouswater heaterwith a storage type water heater. Itmasksthe factthafthe heater can deliver hotwateratthe 77°F DT only atthe specific g.p.m. flow rate. A greaterdraw rate will deliver hotwaterat a lowertemperature. Proposed Alternative Method by Comments: Specifythe maximum draw rate in g.p.m. to give a specific temperature rise as the rating criterion. GAMA: Suggested a DT of77°F to agree with the requirementforstorage type water heaters. EEl, EPRI, TVA, and Virginia Power: Suggested a DT of50°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 comparethe instantaneouswater heaterwith a storage type water heater. Itmasksthe factthafthe heater can deliver hotwateratthe 77°F DT only atthe specific g.p.m. flow rate. A greaterdraw rate will deliver hotwaterat a lowertemperature. Proposed Alternative Method by Comments: Specifythe maximum draw rate in g.p.m. to give a specific temperature rise as the rating criterion. GAMA: Suggested a DT of77°F to agree with the requirementforstorage type water heaters. EEl, EPRI, TVA, and Virginia Power: Suggested a DT of50°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 capabilitytovary 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 ofthe heater. Suggestion: Change the 50% to 25%. (2) The 135°F outlet temperature setting should not apply to instantaneous water heaters. Thetemperature istoo hotfor 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 afield 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 ofsingle- and multi-point of use. Paloma, CEC: For gas-fired heaters, two ratings values for EF - one with and one without pilot lightwhen heater is off. CEC: (1) For heaters with capabilitytovary input rate, DOE specifies that 50% ofthe 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 ofthe heater. Suggestion: Change the 50% to 25%. (2) The 135°F outlet temperature setting should not apply to instantaneouswaterheaters. The temperature istoo hot'foruse and there is no advantage (in the availability of additional hot water) at the high setting as forstorage-type water heaters. Suggestion: Change the. setting to a field usevalue.
8 Instantaneous Water Heaters - Other Issues
. Comments: GAMA, Paloma, CEC. GAMA: No oil-fired instantaneous water heater on the market. Distinction between models ofsingle- and multi-point of use. Paloma, CEC: For gas-fired heaters, two ratings values for EF - one with and one without pilot lightwhen heater is off. CEC: (1) For heaters with capabilitytovary input rate, DOE specifies that 50% ofthe 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 ofthe heater. Suggestion: Change the 50% to 25%. (2) The 135°F outlet temperature setting should not apply to instantaneouswaterheaters. The temperature istoo hot'foruse and there is no advantage (in the availability of additional hot water) at the high setting as forstorage-type water heaters. Suggestion: Change the. setting to a field usevalue.
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 fortankwith small volume - heat loss through fittings are the same (not a function oftank size) for all tank size. (2) Most small storage volume heaters are electric type. (3) Draw rate (1g.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 dailyvolume: 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 appropriatefortankwithsmall volume - heat lossthrough fittings are the same (not a 'function oftank size) for all tank size. (2) Mostsmall storage volume heaters are electric type. (3) Draw rate (1 g.p.m.) too large for tank less than 10 gallons during Energy Factortest in determining average temperature perdraw. (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 dailyvolume: 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 appropriatefortankwithsmall volume - heat lossthrough fittings are the same (not a 'function oftank size) for all tank size. (2) Mostsmall storage volume heaters are electric type. (3) Draw rate (1 g.p.m.) too large for tank less than 10 gallons during Energy Factortest in determining average temperature perdraw. (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 ofsmall 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 lessthan 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 ofsmall storage heaters are differentfrom regular

. sized storagewater 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) Similarconcerns by GAMA. (2) Tanksize lessthan two and halfgallons 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 ofsmall storage heaters are differentfrom regular

. sized storagewater 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) Similarconcerns by GAMA. (2) Tanksize lessthan two and halfgallons 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 recentsurvey 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 HotWater UsageVolume and Thermostat Setting
Current DOE Requirements: Daily HotWater 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 recentsurvey and metered data and manufacturers' practice (thermostat setting). Effects ofchange: (1) Will change EF on existing models. (2) Lower temperature setting may not meet requirements of clothes washers and dish washers.

11 Daily HotWater UsageVolume and Thermostat Setting
Current DOE Requirements: Daily HotWater 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 recentsurvey and metered data and manufacturers' practice (thermostat setting). Effects ofchange: (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 testappropriate. 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 ofthe test (among the six draws) should be at a greater draw volume per draw. Note: No test data on specific draw volumes atthe 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 theywill cause confusion to users. There is no tank made specificallyfor heat pump water heaters.

12 Heat PumpWater Heaters and Related Definitions 1. DOE: Is the current drawschedule forthe 24-hr usetest 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 higherefficiency rating. Actual field use may have draw greater than. 10.7 gallons, activating the resistance element. Therefore, part ofthe test (among the six draws) should be at a greater drawvolume per draw. Note: No test data on specific drawvolumes atthe presenttime
.

. 2. DOE Proposed Heat PumpWater Heater Related Definitions: integral heat pump, add-on heat pump, heat pump storage tank, and solarwater heaters. Comments: GAMA, EEl, EPRI, Vaughn. Definitions for solar water heater and heat pump water heater storage tank are notappropriate sincethey will cause confusion to users. There is notank made specificallyfor heat pump water heaters.

12 Heat PumpWater Heaters and Related Definitions 1. DOE: Is the current drawschedule forthe 24-hr usetest 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 higherefficiency rating. Actual field use may have draw greater than. 10.7 gallons, activating the resistance element. Therefore, part ofthe test (among the six draws) should be at a greater drawvolume per draw. Note: No test data on specific drawvolumes atthe presenttime
.

. 2. DOE Proposed Heat PumpWater Heater Related Definitions: integral heat pump, add-on heat pump, heat pump storage tank, and solarwater heaters. Comments: GAMA, EEl, EPRI, Vaughn. Definitions for solar water heater and heat pump water heater storage tank are notappropriate sincethey will cause confusion to users. There is notank made specificallyfor heat pump water heaters.

12