Residential Water Heater

Efficiency Standards

Engineering Analysis Introduction

Terry Logee

U.S. Department of Energy

Office of Codes and Standards

November 9, 1998 Engineering Introduction

EE-RM-97-900 COMMENT 38DD
Design Option Screening

* Technological feasibility

* Practicability to manufacture, install and

service

* Adverse impacts on product utility or

product availability

* Adverse impacts on health and/or safety

November 9, 1998 Engineering Introduction

EE-RM-97-900 COMMENT 38DD
Selected Design Options

Design Options -Description Gas Electric Oil

Heat Traps X X X

Plastic Tank X(1) X

Increased Jacket Insulation X X X

Insulating the Tank Bottom X

Improved Flue Baffle X X

Increased Heat Exchanger Surface Area X

Flue Damper (Electromechanical) X

Side-Arm Heater X

Electronic (or Interrupted) Ignition X X

(1) used in conjunction with the side-arm heater option

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EE-RM-97-900 COMMENT 38DD
Eliminated Design Options

* Air Atomized Oil Burner

* Power Vented Gas Water Heaters

* Increased Heat Exchanger Surface Area for

Gas Water Heaters

* Heat Pump Water Heaters

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EE-RM-97-900 COMMENT 38DD
Heat Pump Water Heaters

* Federal Technology Alert - cost-effective

only in select regions

* Comments to 1994 NOPR - cost, noise,

space, reliability & electric rate increases

· No Sales & Service Infrastructure

* 50% of some utility customers reported

space too small

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EE-RM-97-900 COMMENT 38DD
Technological Issues

* New Blowing Agents for Insulation

* Preventing Ignition of Flammable Vapors

for Gas Water Heaters

* Venting of High Efficiency Gas Water

Heaters

November 9, 1998 Engineering Introduction

EE-RM-97-900 COMMENT 38DD
New Blowing Agents

* HCFC 141b - Phaseout by 2003

* HFC 245fa - Good Alternative

- 3% Increase in Conductivity

- More Costly, $4/lb

* NIST has tested HCFC 141b, HFC 245fa &

Water-CO2 foams

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EE-RM-97-900 COMMENT 38DD
Preventing Ignition of

Flammable Vapors

* Water Heater Consortium, CPSC & GRI

working on this problem

* ANSI Test Method Circulated for Comment

* Prototype Design(s) Demonstrated

* DOE Assumed Cost of $35 for Baseline

Design, No Impact on Efficiency

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EE-RM-97-900 COMMENT 38DD
Venting

* Safety Concern due to Corrosion of Vent

system if Flue Loss Efficiency >83%

* No Technological Barrier to High

Efficiency Water Heaters

* Design Options <78.5% Recovery

Efficiency (<83% flue loss efficiency)

* DOE Included Cost of Type B Vent

Connectors in Replacement Installations

November 9, 1998 Engineering Introduction

EE-RM-97-900 COMMENT 38DD
Manufacturers Cost Data

* GAMA data covers baseline, heat traps, 2"

insulation, flue baffle, flue damper & IID

* Consultants provided data for all oil-fired

designs, HFC 245 insulation, plastic tank &

side arm heater

* Costs used in Engineering Analysis are

Average Costs

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EE-RM-97-900 COMMENT 38DD
Electric Water Heater Costs

*Baseline represents full production costs

*Design options represent incremental costs

Design Design Variable Costs Total Incremental Fixed Incremen.

Option Options Cost Per Unit (a) Variable Cost Mfg. Cos

Level Materials Labor Overhead Costs (j) Product Capital

(g) (h) (i) $ per Unit) Design Costs ($ per Unit)

($ per Unit ($ per Unit)

0 Existing Baseline(141b) - 1.5" (3.8cm) $62.16 $12.41 $50.99 $125.56 $0.00 $0.00 $125.56

Oa Analytic Baseline (245fa) - 1.5" (3.8 cm) $2.14 $0.00 $0.00 $2.14 $0.00 $0.00 $2.14

1 Oa + Heat Traps (plastic) $4.73 $0.20 $0.83 $5.76 $0.39 $0.00 $6.15

2 1 +Incr. Insulation to 2" (5.1 cm) $13.32 $0.71 $4.49 $18.52 $1.12 $0.00 $19.64

3 1 + Incr. Insulation to 2.5" (6.4 cm) $19.14 $1.22 $8.15 $28.51 $1.41 $0.00 $29.92

4 3 + Plastic Tank $24.39 $2.02 $11.35 $37.76 $4.41 $15.00 $57.17

5 3 + Insulate Bottom $19.14 $1.22 $8.15 $28.51 $1.41 $0.00 $29.92

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EE-RM-97-900 COMMENT 38DD
Gas-Fired Water Heater Costs

*Baseline represents full production costs

*Design options represent incremental costs

Option Options Cost Per Unit (a) Variable Cost Mfg. Cos

Level Materials Labor Overhead Costs (j) Product Capital

(g) (h) J (i) $ per Unit Design Costs '$ per Unit

($ per Unit $ per Unit)

0 Existing Baseline $75.02 $12.49 $50.10 $137.61 $0.00 $0.00 $137.61

Analytic Baseline + Resistant Flammable

Oa Vapor $16.11 $0.00 $0.00 $16.11 $0.00 $20.00 $36.11

1 Oa +Heat Trap $18.86 $0.16 $0.21 $19.23 $0.13 $20.07 $39.43

2 1 + 2" Jacket Insulation $28.45 $0.76 $5.14 $34.35 $0.72 $20.92 $55.99

3a I +2.5"Jacket Insulation $33.35 $1.36 $10.07 $44.78 $1.31 $21.35 $67.44

3b 2 + Improved Flue Baffle29.42 $2.05 $6.46 $37.93 $2.44 $22.09 $62.46

3c2 + Electronic Ignition& Flue Damper $157.28 $8.16 $32.73 $198.17 $4.22 $26.46 $228.85

3d 2 + Side-Arm Heater w/Increased RE $97.70 $7.43 $32.48 $137.61 $5.93 $28.43 $171.97

4a 3a + Side-Arm Heater w/ Standard RE $101.63 $6.74 $36.09 $144.46 $4.80 $27.69 $176.95

4b 3a + Improved Flue Baffle $34.32 $2.65 $11.39 $48.36 $3.03 $22.52 $73.91

4c 3a + Electronic Ignition & Flue Damper $162.18 $8.76 $37.66 $208.60 $4.81 $26.89 $240.30

54a + Improved Flue Baffle $102.60 $8.03 $37.41 $148.04 $6.52 $28.86 $183.42

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Oil-Fired Water Heaters

*Baseline represents full production costs

*Design options represent incremental costs

Design Design Variable Costs Total Incremental Fixed Incremen.

Option Options Cost Per Unit (a) Variable Cost Mfg. CosI

Level Materials Labor Overhead Costs (j) Product Capital

(g) (h) (i) $ per Unit Design Costs $ per Unit

($ per Unit $ per Unit)

0 Baseline (HCFC141b)- 1" foam $85.00 $18.25 $36.00 $139.25 $0.00 $0.00 $139.25

Oa Analytic (HFC245fa)- 1" foam $1.02 $0.00 $0.00 1.02 0.00 $0.00 $1.02

1 Oa + Heat Trap (plastic) $3.97 $0.05 $0.15 $4.17 $1.52 $0.00 $5.69

2 1 + Increased Insulation to 1.981" (5.032 $9.56 $0.34 $3.70 $13.60 $2.24 $0.80 $16.64

32 + Improved Flue Baffle (78% RE) $13.31 $0.89 $4.70 $18.90 $22.24 $12.80 $53.94

42 + Increased Heat Exchanger Surface $26.81 $2.09 $7.95 $36.85 $22.24 $60.80 $119.89

5a3 + Interrupted Ignition $29.81 $0.89 $4.70 $35.40 $23.24 $12.80 $71.44

5b4 + Interrupted Ignition $43.31 $2.09 $7.95 $53.35 $23.24 $60.80 $137.39

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