WATER HEATER COMPANY

April 26, 2001

Assistant Secretary for Conservation and Renewable Energy United States Department of Energy 1000 Independence Avenue, SW Washington, DC 20585

To Whom It May Concern:
Subject: Application for Interim Waiver

American Water Heater Company seeks a waiver in the application ofthe "Uniform Test Method for Measuring the Energy Consumption ofWater Heaters" contained in 10 CFR Part 430 Subpart B Appendix E as applied to electricwater heater models that have adaptive electronic controls. We are seeking this interim waiverto allow the initial marketing of our new product to claim the benefits ofthe "Energy Saving Cycle" as described in the petition forwaiver.

We feel that the interim waivershould be granted because it is likely that the petition for waiverwill be granted. The newtechnology addressed by the petition forwaiveryields a legitimate energy savings and improvement in the energy efficiency level ofthis category ofappliance. This improvement serves the interest and goal ofthe Department of Energy and thus should be supported. Allowing the waiverwill encourage other manufacturers to produce similar products creating a general improvement in energy conservation. As newtechnology is developed, test procedures need to be modified to accommodate the improvement and allow the benefits to be shown to the consumer. These are all good arguments as to why the waivershould be granted and thus the interim waiver be granted.

From an economic point ofview, American Water Heater Company has invested significantly in the development ofthis product and to not be able to present one of its bestfeatures would cause loss of sales and discourage further development.
Respectfully submitted,



## .. (I. '(\) 

# I

# -60'~.**J~~** TimothyJ. S enberger Sr. Vice Presi ent

- Product Engineering

TJS/meh

1100 E. FairviewAve., 

### P. O. Box 1378, Johnson City, TN 37605-1378, Tel: (423) 434-1500, Fax: (423) 434-1632I, the undersigned, on behalfofAmerican Water Heater Company, hereby certify that a copy ofthe foregoing Petition forWaiver and Petition for Interim Waiver, has been sent to each ofthe following known manufacturers ofdomestically marketed units ofthe same product type (as listed in Section 322(a) ofthe Act), as follows:

Rheem Water Heater Division Rheem Manufacturing Company 2600 Gunter Park Drive East Montgomery, AL 36109-1413 Attention: Scott D. Martin

A. O. Smith Water Products Company Rochelle Park, Suite 200 600 

### E. John Carpenter Freeway Irving, TX 75062-3990 Attention: Ronald Massa

Bradford White Corporation 200 Lafayette Street Middleville, MI 49333-9492 Attention: Eric M. Lannes

State Industries 500 Lindahl Parkway Ashland City, TN 37015-1234 Attention: John 

### R. Lindahl, Jr.

Lochinvar Corporation 2005 Elm Hill Pike Nashville, TN 37210-3807 Attention: Mr. William 

### L. Vallett, Jr.

I further hereby certify that the Assistant Secretaryfor Conservation and Renewable Energywill receive and considertimely written comments on the Application for Interim Waiver.

This the 26th day ofApril 2001.DOE Wavier Model Comparison

AWHC Wholesale AWHC Retail AWHC Wholesale AWHC Retail RHEEM A.a. SMITH BRADFORD STATE LOCHINAR Models Electronic Models Electronic Models Standard Models Standard (RICHMOND, WHITE INDUSTRIES RUDD, GE) (RELIANCE, MAYTAG, SEARS) EE92-40H***D*** EE2H40HD****** E92-40H***D*** E2H40HD****** 81XH40D PEST-40 M-I-40T10DS PX-40-20RT STA040KK-3 MEH40-2 M-II-40T10DS 9-40-2KRT 82XR40-2 HE29-40T EXR40-2 SSX-40-2LRT 32746
EE122-40H***D*** EE2J40HD****** E122-40H***D*** E2J40HD****** 81XH40D PEST-40 M-I-40T10DS PX-40-20RT STA040KK-3 MEH40-2 M-II-40T1 ODS 9-40-2KRT 82XR40-2 HE29-40T EXR40-2 SSX-40-2LRT 32746 12-40-2ART
EE93-40H***D*** EE3H40HD****** E93-40H***D*** E3H40HD****** MR40245 PEHT-40 M-III-40T1 ODS 32049 MP40245 LT-40-2LRT EE123-40H***D*** EE3J40HD****** E123-40H***D*** E3J40HD****** MR40245 PEHT-40 M-III-40T1 ODS 32049 MP40245 LT-40-2LRT EE92-40R***D*** EE2H40RD****** E92-40R***D*** E2H40RD****** RMEMKR40-2 PES-40 M-II-40S10DS SSX-40-2LRS PE40M9A 9-40-2KRS EE122-40R***D*** EE2J40RD****** E122-40R***D*** E2J40RD****** RMEMKR40-2 PES-40 M-II-40S10DS SSX-40-2LRS PE40M9A 9-40-2KRS 12-40-2ARS EE93-40R***D*** EE3H40RD****** E93-40R***DH*** E3H40RD***H*** RMEMXR 40-2TI PEC-40 HE21240S LTSE40M12A 40-2LRS EE123-40R***D*** EE3J40RD****** E123-40R***D*** E3J40RD****** RMEMXR 40-2TI PEC-40 HE21240S LTSE40M12A 40-2LRS EE92-50H***D*** EE2H50HD****** E92-50H***D*** E2H50HD****** 81X52 D PEST-52 M-II-50T1 ODS PX-52-20RT STA052KK-3 ME52-2 9-52-2KRT RMEKR 50-2 HE2950T PE50T9A 32756 82XR52-2 SSX-52-2LRT EXR52-2 EE122-50H***D*** EE2J50HD****** E122-50H***D*** E2J50HD****** RMEXR 50-2TI M-II-50T1 ODS 12-52-2ART SE50T12A 32059

Page 1 of2DOE Wavier Model Comparison

AWHC Wholesale AWHC Retail AWHC Wholesale AWHC Retail RHEEM A.O. SMITH BRADFORD STATE LOCHINAR Models Electronic Models Electronic Models Standard Models Standard (RICHMOND, WHITE INDUSTRIES RUDD, GE) (RELIANCE, MAYTAG, SEARS) EE93-50H***D*** EE3H50HD****** E93-50H***DC*** E3H50HD***C*** MR50245 PEH-52 M-III-50T1 ODS HE21250T MP50245 LT-52-2LRT 32151 EE123-50H***D*** EE3J50HD****** E123-50H***DC*** E3J50HD***C*** MR50245 PEH-52 M-III-50T10DS HE21250T MP50245 LT-52-2LRT 32151 EE92-50R***D*** EE2H50RD****** E92-50R***D*** E2H50RD****** RMEMKR 50-2 PES-52 M-II-50S10DS PX-52-20RS PE50M9A SSX-52-2LRS 82MXR52-2 9-52-2KRS EMXR52-2 HE2950S , EE122-50R***D*** EE2J50RD****** E122-50R***D*** E2J50RD****** RMEMXR 50-2TI PEC-52 12-52-2ARS --" 1 ! SE50M12A HE21250S I I EE93-50R***D*** EE3H50RD****** E93-50R***DC*** E3H50RD***C*** LT-52-2LRS I ! EE123-50R***D*** EE3J50RD****** E123-50R***DC*** E3J50RD***C*** --"II**-~** EEZ3-50R***D*** EE3Z50RD****** EZ3-50R***DC*** E3Z50RD***C*** MSR50245 I EE92-65H***D*** EE2H65HD****** E92-65H***D*** E2H65HD****** 81X66D PEC-66 M-II-65R10DS HE2966T STA066KK-3

# ---i

ME66-2 32766 I RMEKR65-2 SSX-66-2LRT ! I 82XR66-2 EXR66-2 PE65T9A EE122-65H***D*** EE2J65HD****** E122-65H***D*** E2J65HD****** 12-66-2ART EE93-65H***D*** EE3H65HD****** E93-65H***DC*** E3H65HD***C*** EE123-65H***D*** EE3J65HD****** E123-65H***DC*** E3J65HD***C*** RMEXR 65-2TI PEH-66 M-III-65R10DS 32069 EE92-80H***D*** EE2H80HD****** E92-80H***D*** E2H80HD****** RMEKR80-2 PES-80 32786 STA082KK-3 82XR80-2 SSX-82-2LRT EXR80-2 EE122-80H***D*** EE2J80HD****** E122-80H***D*** E2J80HD****** PEC-80 12-82-2ART EE93-80H***D*** EE3H80HD****** E93-80H***DC*** E3H80HD***C*** EE123-80H***D*** EE3J80HD****** E123-80H***DC*** E3J80HD***C*** RMEXR 80-2TI PEH-80 M-III-80R10DS HE21282T SE80T12A 32089 LT MR85245 82-2LRT MP85245

Page 2 of2WATER HEATER COMPANY April 26, 2001

Assistant Secretaryfor Conservation and Renewable Energy United States Department of Energy 1000 Independence Avenue, SW Washington, DC 20585

To Whom It May Concern:
Subject: Petition forWaiver


### Specific Requirements to be Waived: American Water Heater Company seeks a waiver in the application ofthe "Uniform Test Method for Measuring the Energy Consumption ofWater Heaters" contained in 10 CFR Part430 Subpart BAppendix E as applied to electricwater heater models that have adaptive electronic controls.
Utilizing a microprocessor-based control on an electricwater heaterallows a level of intelligence to be added to the control logicthat is not possible with the conventional electro-mechanical control systems used today. One use ofthis intelligence is to have the control adjust the stored water temperature based on the actual hotwater usage pattern to determine the lowest possible temperature to store waterthat will meet the needs ofthe consumer. The result ofthis new control logic is a reduction in energy consumption. Such a control cycle will be identified as an "Energy Saver Cycle".

American Water Heater plans to commercialize a microprocessor-based control system with an Energy Saver Cycle. However, we are unable to characterize and marketthe true efficiency benefit tothe consumerthrough the "Uniform Test Method for Measuring the Energy Consumption ofWater Heaters" ratings process. The test procedure does not allowthe efficiency benefit of an Energy Saver Cycle to be demonstrated. These types of intelligent electronic controls are more expensive and without the abilityto demonstrate the benefits in terms ofenergy savings, it is difficultto justifythe additional cost to the consumer. We are specifically petitioning to allow the
use ofan alternate test procedure described below to rate and label the efficiency ofawater heaterwhen using the "Energy Saver Cycle".



### Basic Models and all Manufacturers: (See attached list)


### Design Characteristics:
Background Information The predominate energy loss ofatank type electricwater heater is the standby loss associated with storing the hotwater. There are two methods of reducing these losses; one can increase the effectiveness ofthe insulation system, or reduce the stored watertemperature. The "Energy Saver Cycle" saves energy by reducing the stored watertemperature.

1100 E. FairviewAve., 

### P. O. Box 1378, Johnson City, TN 37605-1378, Tel: (423) 434-1500, Fax: (423) 434-1632Page 2

The study report "Baseline Results and Methodology ofthe Consumer Sub-group Analysis for Residential Water Efficiency Standards", submitted to the Department of Energy October 1998, shows that the average set point temperature of residential water heaters varies widely across the United States. The northern states tend to be hotterwith average set points as high as 142°F and the south as low as 123°F. This corresponds inverselywith the average inlet watertemperature in the same areas. Atthe time of use, the hotwater is blended with cold waterto produce the desired use temperature. This process of blending causes the usage quantity of hotwaterto change inverselywith the stored watertemperature. For example: A shower lasting 10 minutes with a delivered watertemperature of 105°F and a flow rate of2.5 gallons/minute uses 25 gallons ofwater. If 135°F hotwater, supplied by a water heater, is blended with cold water at 58°F, the showerwill consume 9.74 gallons ofcold waterand 15.26 gallons of hotwater. In contrast, ifthe hotwater supply temperature were reduced to 115°Fthe usage proportions would change to 4.39 gallons of cold waterand 20.61 gallons of hotwater. The energy consumed and the quantity of water used in the shower is the same in both cases butthe proportion of heated watergoes up. The important difference is that, in the time between showers, the energy consumed to maintain the stored watertemperature goes down by 29.85% when the water is stored at 115°Fversus 135°F. The person taking the showerdidn't knowthe difference exceptthey had to use more hot waterto get the desired temperature. As the stored watertemperature is further lowered, eventuallythe water heaterwill not be able to supply the needed amount of blended hot water and the watertemperature will have to be increased.

The adaptive control logic continually adjusts stored watertemperature within specified limits to getto the temperature where the maximum demand event can be met by the quantity and temperature ofwaterstored in the heater. This "Energy Saver Cycle" will produce real energy savings in a significant numberof households and thus deserves to have a test procedure designed to allow the efficiency benefits to be demonstrated. The current test procedure doesn't allowthis because the mean tanktesttemperature is fixed at 135°F.
Energy Saver Cycle Qualification test: It is simple for a manufacturerto put an electronic control on a water heaterand label a cycle as an "Energy Saver Cycle" without having an adaptive control that will adjust stored water temperature based on usage. Some examples ofother controls that would not qualifyforthis modified test procedure could be, a conventional control with a fixed but lowerset pointwhich is identified as an "Energy Saver Cycle" or an off peaktype control that simply adjusts the set point based on the time ofthe day. This newtest is required to prove that the control meets the "Energy Saver Cycle" criteria as a qualifierto use the energy savertest modifications. The object ofthe test is to confirm thatthe control does adaptthe stored watertemperature based on water usage. The following simple test would be used to prove thatthe control adapts watertemperature to water usage.

1. The unit is set up perthe "Uniform Test Method for Measuring the Energy Consumption of Water Heaters", 10CFR430.23. 2. The unit is run on normal cycle and the thermostat is adjusted until the mean tanktemperature is 135°F. Then the control is switched to the "Energy Saver Cycle" and a series ofsmall draws
are made. Each draw should be sufficient to cause the lowerelementto come on. The lower element will reheat the water until it shuts offatwhich time anotherdrawwill start. This sequence will continue until the mean tanktemperature, at the element shutoff point, is 125°FPage 3

or less. The mean tanktemperature afterthe first cycle should be 135°F and the last cycle will be 125°F or less to show thatthe control will lowerthe set point in response to a lowwater usage situation. 3. Then the draw size will be changed to be large enough thatthe control will adjust the temperature up. Aftereach reheat the drawwill be repeated until the control has adjusted the set point up enough to return the mean tanktemperature backto the 135°F point. At this point, the test would have proven thatthe control adjusts set point up and down based on actual water usage. Ifthe control can not demonstrate the adaptive abilityto adjust stored water temperature based on actual usage, itwill not qualifyto use the proposed modified procedure. 4. This test is somewhat cumbersome in that a large numberofdraw reheat cycles would be required to complete the test. In our case, itwould require approximately 100 cycles. The test could be automated and allowed to run over night to speed up the qualification process. The test should only have to be run once for a given manufacturer's control. Once the control has been qualified, any units using that control would qualifyforthe Energy Saver Cycle test sequence.

Test Procedure Changes: Staying with the principal that the delivered hotwater energy doesn't change as the stored water temperature changes, the following changes are required to allow the energy savings ofan "Energy Saver Cycle" to be demonstrated and evaluated. 1. The size ofthe sixwaterdraws will be adjusted such thatthe BTUs ofdelivered hotwater (BTUs to heatthe waterfrom 58F to deliverytemperature) is equal to BTUs forthe six 10.7 gallon draws heated from 58F t0135F. This calculation = (Gallons X Lbs.lgal.X Specific Heat X (delivered temp. -58F)

# =(6851 BTU for 10.7 gal. heated from 58F t0135F) Since the delivered watertemperature is not a constant during a draw, this calculation could be accomplished by using "Simpson's Rule" method oranothersuitable numerical method to integrate the delivered watertemperature-volume function. The water draw is started and the total is calculated every 5 seconds until the 6851 BTU ofdelivered hotwaterenergy is reached. The actual volume of each drawwill vary inversely as the delivered watertemperature varies. The Energy Saver Cycle typically draws about 90 t01 00 gallons versus the 64.2 gallons ofthe current test procedure. The hotwaterenergy delivered in both cases is the same. One approach to running this modified test on a heaterwith an "Energy Saver Cycle" would be to set up the heateras "normal" with the thermostat setto give a mean tanktemperature of 135°F. Then run the test draw sequence repeatedly until the temperature adjustment logic of the control lowers the temperature to the lowest stable temperature. At that point, afull 24 hour efficiencytest would be conducted to determine the efficiency ofthe heater using Energy Saver Cycle. This would require over 100 draw and reheat cycles using our control algorithm. This approach is impractical. The practical approach is to run the control in normal mode and adjust the watertemperature to the lowest stable temperature that the "Energy Saver Cycle" would reach ifthe above approach were used. 2. Definition of lowest stable temperature: This is the lowest watertemperature set point such that when the six draw sequence in step 1 is performed, the control will not adjust the set point higher. In our control logic, the set point is increased ifthe cold water rises far enough in the tankto cause the upperelementto come on. Thus for our control logic, the lowesttemperature where the draw sequence in step 1 doesn't cause the upperelementto come on is our "lowest stable temperature". Othercontrol logic could result in another "lowest stable temperature" point. To determine this temperature, the testerwould need to know the temperature adjustment logicforthe Energy Saver Cycle. He would setthe test watertemperature to the lowest stable temperature based on that logic. He then would observe the draw quantities and temperatures during the efficiencytest to see that atemperature adjustment condition was notPage 4
present. Ifa temperature adjustment would have been made the test is invalid and the test would need to be repeated at a highertemperature. 3. In the current procedure, the mean tanktemperature is to be adjusted to 135F. There are three places in the calculation ofefficiencywhere the raw data is adjusted back to 135Fto correctfor variation between actual and ideal test conditions. Since the Energy Saver Cycle test doesn't
run at 135F mean tanktemperature, this correction needs to be changed to reflect the newtest conditions. This means thatthe hard coded 135 values in the calculations must be changed to
a variable so the actual value can reflect the currenttest conditions. The most appropriate variable is "Tsu" which is the maximum mean tanktemperature observed afterthe sixth draw. In the current procedure, Tsu must be 135F 

### ±5F and is the logical equivalent ofthe 135F of the current procedure. Thus the calculation of Qda is changed from Qda

# =Qd

- (( Tstby.2

- Ta.stby.2)

- (135

- 67.5)) UAtstby.2 to Qda

# =Qd

- (( Tstby.2

- Ta.stby.2)

- (Tsu

- 67.5)) UAtstby.2 and

QHW.77 changed from QHW.77 

### =

# :tMi Cpi(135F

- 58F) to QHW.77 

### =

# :tMi Cpi(Tsu

- 58F)

i=\ 

### Nr i=\ 

### Nr

Ef ' h d f Ef 

### Mi Cpi(135F-58F) t Ef 

### Mi Cpi(Tsu -58F) IS C ange rom 

# =LJ 0 

# =LJ
i=\ 

### Qdm i=l 

### Qdm

Conclusion: Newtechnologies can foster changes that obsolete current practices. American Water Heater's adaptive control has created an energy saving control method that was not anticipated or covered by the current DOE test procedure. This waiverwill allow the efficiency benefits ofthis improved control method to be demonstrated while the test procedures are modified to keep up with technology. This change in control method will reduce water heater energy consumption, and thus its adoption by the industry should be encouraged. This can best be done by granting this waiverand modifying the test procedure. Confidential test data, which demonstrates the energy efficiency benefit, can be made available upon your request.
Respectfully submitted,**~------.",** /"

Ineering