# Residential Water Heater Efficiency Standards Engineering Analysis Introduction Terry Logee U.S. Department ofEnergy Office ofCodes and Standards

November 9, 1998 Engineering Introduction

# Design Option Screening * Technological feasibility * Practicability to manufacture, install and service * Adverse impacts onproduct utility or product availability * Adverse impacts onhealth and/or safety

November 9, 1998 Engineering Introduction

# Selected Design Options

Design Options -Description Gas Electric Oil HeatTraps 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 withthe side-arm heater option

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# Eliminated Design Options * AirAtomized Oil Burner * PowerVented Gas Water Heaters * Increased Heat Exchanger Surface Area for Gas Water Heaters * HeatPump Water Heaters

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# Heat Pump Water Heaters * Federal Technology Alert

- cost-effective onlyin 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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# Technological Issues * New Blowing Agents forInsulation * Preventing Ignition ofFlammable Vapors for Gas Water Heaters * Venting ofHighEfficiency Gas Water Heaters

November 9, 1998 Engineering Introduction

# New Blowing Agents * HCFC 141b

- Phaseoutby 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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# Preventing Ignition of Flammable Vapors * Water Heater Consortium, CPSC & GRI working onthisproblem * ANSI TestMethod Circulated for Comment * Prototype Design(s) Demonstrated * DOE Assumed Cost of$35 forBaseline Design, No Impact onEfficiency

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# Venting * Safety Concern due to Corrosion ofVent system ifFlue Loss Efficiency >83% * No Technological Barrier to High Efficiency Water Heaters * Design Options <78.5% Recovery Efficiency (<83% flue loss efficiency) * DOE Included Cost ofType B Vent Connectors inReplacement Installations
November 9, 1998 Engineering Introduction

# Manufacturers Cost Data * GAMA data covers baseline, heattraps, 2" insulation, fluebaffle, flue damper & IID * Consultants provided data for all oil-fired designs, HFC 245 insulation, plastic tank& side armheater * Costsused inEngineering Analysis are Average Costs

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# Electric Water Heater Costs *Baselinerepresents fullproduction costs *Designoptions represent incremental costs

Design Design Variable Costs Total Incremental Fixed Incremen. Option Options CostPerUnit (a) Variable Cost Mfg. Cos Level Materials Labor Overhead Costs (j) Product Capital (g) (h) (i) $perUnit) Design Costs ($ perUnit) ($ per Unit ($ perUnit) 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

1Oa +Heat Traps (plastic) $4.73 $0.20 $0.83 $5.76 $0.39 $0.00 $6.15 2 1+Incr. Insulationto2" (5.1 cm) $13.32 $0.71 $4.49 $18.52 $1.12 $0.00 $19.64 3 1+ Incr. Insulationto 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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# Gas-Fired Water Heater Costs *Baseline representsfull productioncosts *Designoptions represent incremental costs Option Options CostPerUnit (a) Variable Cost Mfg. Cos Level Materials Labor Overhead Costs (j) Product Capital 

### (g) (h) J (i) $ perUnit Design Costs '$ perUnit ($ per

### Unit$ per Unit) 0 ExistingBaseline $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

1Oa +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-ArmHeaterw/Increased RE $97.70 $7.43 $32.48 $137.61 $5.93 $28.43 $171.97 4a 3a + Side-ArmHeaterw/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 November 9, 1998 Engineering Introduction 12

# Oil-Fired Water Heaters *Baselinerepresents fullproduction costs *Designoptions represent incremental costs

Design Design Variable Costs Total Incremental Fixed Incremen. Option Options Cost PerUnit (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

1Oa + HeatTrap (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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