# Residential Water Heater Efficiency Standards: Engineering Analysis JimLutz Lawrence Berkeley National Laboratory Q11/ 11/09/98 Engineering- WaterHeaters 1 RI 

## RI

# Modeling - Existing Baseline *ElectricWater Heaters

- 50 gallonrated volume -EF = 0.858

- 4.5 kW input

- 1.5 inch insulation * tomeetminimumNAECA EF



# - modeling fitting losses inWATSIM * to match default fitting losses in TANK * 1/8 in. insulation * reduced conductivity and convection 11/09/98 Engineering - Water Heaters 2

# Modeling - Existing Baseline *Gas-firedWater Heaters

- 40 gallonrated volume -EF = 0.5446

-RE= 75.5%

- 

# 40,000 Btu/hr input

- 400 Btu/hrpilot light

- .981 inch insulation

- insulation conductivity same as electric waterheaters 11/09/98 Engineering - Water Heaters 3

# Modeling - Analytic 

# Baseline * Change blowing agent to HFC-245fa * Insulation conductivity increased 3% * Insulation thickness increased

- electric to 1.55 inches

- gas-fired to 1.00 inches 

# * No other changes

11/09/98 Engineering - Water Heaters

# Simulation Modeling * Tools

- WATSIM * for electric water heaters * developed byEPRI



## - 

# TANK * forgas-fired waterheaters * developed byBattelle for GRI 

# * DOE testprocedure * National average energyprices 11/09/98 Engineering - Water Heaters 5

# Manufacturer Costs - Data Sources * GAMA

- existingbaseline

- mostdesign options 

# * Minniear, West (consultants)

- sheetmetal and foam insulation

- plastic tank

- side arm heater

- oil-fired waterheaters 

# * Williams (Allied Signal)

- projected foam component costs 

# * Gilchrist (Perfection)

- heattraps 11/09/98 Engineering - WaterHeaters 6

# Foam Component Costs Components Fraction Component Total Cost Total Cost % Cost (HCFC-141b) (HFC-245fa) 

### $/lb $/lb $/lb blowing agent (HCFC-141b) 13% $1.50 $0.20 - blowing agent (HFC-245fa) 13% $4.00 -$0.52 Isocyanurate 51% $075 $038 $0.3 polyols 31% $0.65 $0.20 $0.20 catalysts, refractants, etc. 5% $4.50 $0.23 $0.23 Total 100% $1.00 $1.32
11/09/98 Engineering - Water Heaters 7

# Cost forInsulation andJacket Electric Water Heaters Existing Baseline Analytic Baseline (HCFC-141b) (HFC-245fa) 

# Thickness Cost Thickness Cost 1.5 in. $11.64 1.55 in. $13.78 2.0 in. $19.86 2.0 in. $22.37 2.5 in. $24.94 2.5 in. $28.19 Cost includes foam,jacket and foam dams 11/09/98 Engineering - Water Heaters 8

# Cost ofDesign Options Electric Water Heaters Design Option Average Cost Existing Baseline (HCFC-141b) (1) $125.56 Analytic Baseline (HFC-245fa) (2) 

# $127.70 

# HeatTraps (metal) (1) 

# $4.01 HeatTraps (plastic) (1) 

# $4.01 2" Jacket Insulation (1)(2) 

# $13.49 2.5" Jacket Insulation (3) 

# $23.77 

# Insulate Tank Bottom (1) $30.37 Plastic Tank (3) 

# $27.25 (1)- from GAMA (2)- adjusted forHFC-245fa (3)- from Minniear 11/09/98 Engineering - Water Heaters 9

# Markup Electric Water Heaters * Retail Price =$188.18

- from LBNL Water Heater Database

- average of50 units

- 50 gallon, 5yearwarranty, no extra features

- with 5.2% average sales tax 

# * Manufacturer Cost =$125.56

- from GAMA

- average of4manufacturers

- existing baseline model 

# * Markup 1.4987 11/09/98 Engineering - Water Heaters 10

# Installation Cost Electric Water Heaters Installation -$160.73

- from LBNL Water Heater Database

- average of41 units

- 50 gallon, 5yearwarranty, no extra features



## - delivery, removal andpermit fees included 

# * Same installation cost for all design options

11/09/98 Engineering - Water Heaters

# Cost Efficiency Table Electric Water Heaters Design Options Energyt TotaTotl Annual Payback Factor Manufacturer Installed Operating years Cost * Cost ** Cost *** * 0 Existing Baseline 0.858 $125.56 $348.91 $390.75 NA Oa Analytic Baseline 0.858 $127.70 $352.12 $390.75 NA

1 Oa + Heat Traps (plastic) 0.876 $131.71 $358.13 $383.66 0.85 2 1+ 2" Jacket Insulation 0.890 $145.20 $378.35 $378.15 2.08 3 1+ 2.5" Jacket Insulation 0.901 $155.48 $393.75 $374.22 2.52 4 3+ Plastic Tank 0.908 $182.73 $434.59 $372.01 4.40 5 3+ Insulate Bottom 0.908 $185.85 $439.27 $372.41 4.76 from data submitted by GAMA and consultants ** includes retail markup (1.49874) and installation cost *** DOE testprocedure, electricity price = 0.0787 $/kWh **** payback = (change ofinstalled cost) - (change ofoperating cost)
11/09/98 Engineering - WaterHeaters 12

# Cost for Insulation andJacket Gas-fired Water Heaters Existing Baseline Analytic Baseline (HCFC-14 1b) (HFC-245fa) 

# Thickness Cost Thickness Cost

0.981 in. $8.66 1.000 in. $9.77

1.981 in. $17.17 1.981 in. $19.36 2.481in. $21.43 2.481in. $24.26 Costincludes foam,jacket and foam dams

11/09/98 Engineering - WaterHeaters 13

# Cost ofDesign Options Gas-fired Water Heaters Existing Baseline (HCFC-141b) (1) 

# $137.61 Analytic Baseline (HFC-245fa) (2)(5) 

## $173.72 

# Heat Traps (metal) (1) 

## $3.32 

# Heat Traps (plastic) (1) 

## $3.32 

# 2" Jacket Insulation (1) (2) 

## $16.56 

# 2.5" 

# Jacket Insulation (3) 

# $28.01 Improve Flue Baffle (1) $6.47 Flue Damper (1)(4) 

## $172.86 

# Side ArmHeater (RE=76%) (3) (4) 

# $109.51 

# Side Arm Heater (RE=78%) (3)(4) 

# $115.98 (1)- from GAMA (2)- adjusted for HFC-245fa (3)- fromMinniear (4)- w/ electronic ignition (5)- w/ flammable vapor ignitionresistant design 11/09/98 Engineering - WaterHeaters 14

# Markup Gas-fired Water Heaters * Retail Price $157.74

- from LBNLWater Heater Database

- average of52units

- 40 gallon, 5year warranty, noextra features

- with 5.2% average sales tax 

# * Manufacturer Cost =$137.61

- from GAMA

- average of4manufacturers

- existing baseline model 

# * Markup 1.1463 11/09/98 Engineering - Water Heaters 15

# Installation Cost Gas-fired Water Heaters Installation $159.52

- from LBNL Water HeaterDatabase

- average of48 units

- 40 gallon, 5yearwarranty, no extra features

- delivery, removal andpermit fees included

- essentially same as electric waterheaters

11/09/98 Engineering - WaterHeaters 16

# Extra Installation Costs Gas-fired Water Heaters * installing Type-B vent connector

- for increased RE (from 76% to 78%)

- 51% households



## - $54.01 average cost 

# * adding electricity

- 32% households require new circuit

- $33.90 average cost 

# * cost data from GRI report
11/09/98 Engineering -Water Heaters 17

# Design Option Combinations Gas-fired Water Heaters Selected Design Option Combinations Design Option Combinations Not Selected

AnalyticBaseline +Flue Damper ,,___ _ _-iew/lIID I F +HeatTraps - +2" insulation +Se Am " - ""---- , +Side ArmHeater 

# 1

w/llD&RE=78% +2.5" insulation -- -+ Improve Flue I __ '__ ____________I ' 

### H Baffle +Side Arm Heater + _ Flue Damper w/llD &RE=76% . I.. w IID +Improve Flue + Improve Flue Baffl+ Ip e Baffle Baffle 11/09/98 Engineering - WaterHeaters 18

# Cost Efficiency Table Gas-fired Water Heaters Design Options Energy Total Total Annual Payback Factor Manufacturer Installed Operating years Cost * Cost ** Cost ***   0 Existing Baseline 0.545 $137.61 $317.26 $166.34 NA Oa Analytic Baseline 0.544 $173.72 $358.65 $166.34 NA

1 Oa+ Heat Traps (plastic) 0.554 $177.04 $362.45 $164.71 2.31 2 1+ 2" Jacket Insulation 0.580 $193.60 $381.44 $159.64 3.42 3 1+ 2.5" Jacket Insulation 0.587 $205.05 $394.56 $158.60 4.63 4 3+ Side Arm Heater 0.662 $314.56 $553.99 $133.61 5.97 5 2+ Improve Flue Baffle 0.595 $200.07 $442.87 $154.64 7.19 8 from data submitted byGAMA andconsultants **  includes retail markup (1.1463) andinstallation cost *** DOEtestprocedure, electricity price =0.0787 $/kWh and gasprice = 5.82 $/MMBtu **** payback = (change ofinstalled cost)- (change ofoperating cost)
11/09/98 Engineering - WaterHeaters 19

# Request for Stakeholder Comments * Baseline and incremental manufacturing costs for all design options * Retail prices and installation costs * Markup * Maintenance Costs

11/09/98 Engineering - Water Heaters 20

# Modeling - Design Options electric waterheaters Design Option Descriptive Parameters Analytic Design Option Baseline Values Metal HeatTraps Feed-through Insulation Conductivity 0.000240 0.000240 Btu/ft-min-°F Btu/ft-min-°F Feed-through Natural Convection 0.185 0.063 Btu/hr-°F Btu/hr-°F Plastic Heat Traps Feed-through Insulation Conductivity 0.000240 0.000240 Btu/ft-min-°F Btu/ft-min-°F Feed-through Natural Convection 0.185 0.063 Btu/hr-°F Btu/hr-°F 2Inch Insulation Insulation Thickness 1.55 in. 2.00 in. 2.5 Inch Insulation Insulation Thickness 1.55 in. 2.50 in. Insulate Tank Bottom Support Ring Conductivity .40 0.000472 Btu/ft-min-°F Btu/ft-min-°F Bottom Insulation Thickness 0.75 in. 1.5 in. Bottom Insulation Conductivity 0.000333 0.000240 Btu/ft-min-°F Btu/ft-min-°F Plastic Tank Tank Wall Thickness 0.063 in. steel: 0.0853 in. plastic: 0.126 in Tank Wall Conductivity .40 0.0018 Btu/ft-min-°F Btu/ft-min-°F Support Ring Conductivity 0.40 0.000236 Btu/ft-min-°F Btu/ft-min-°F Bottom Insulation Thickness 0.75 in. 1.0 in. Bottom Insulation Conductivity 0.00033 0.000240 Btu/ft-min-°F Btu/ft-min-°F 11/09/98 Engineering -Water Heaters 21* * 

# Modeling - Design Options gas-fired waterheaters Design Option Descriptive Parameters Analytic Design Option Baseline Values Metal Heat Traps Heat Traps 0 1 Plastic Heat Traps Heat Traps 0 - 2 Inch Insulation Insulation Thickness 1.000in. 1.981 in. 2.5 Inch Insulation Insulation Thickness 1.000 in. 2.481 in. Improved Flue Bale Excess Combustion Air 42.0 34.0 Flue Baftle Eftectiveness Multiplier 2.000 2.200 Electronic Ignition PilotInput 400 Btu/hr 0Btu/hr (intermittent pilot ignition system) On-cycle Power Consumption 0 W 15.7 W ignition system) _ __ _ Off-cycle Power Consumption 0 W 0.4 W Electromechanical Off-cycle Pressure Loss Coefficient12.4047 156 FlueDamper Tprt-cycle Power Consumption W 5.0 W Side Arm Heater (1) Metal Tank, 2" insulation, EF =0.655 RE = 76% Plastic heat traps, IID Metal Tank, 2" insulation, EF =0.668 RE = 78% Plastic heat traps, IID Plastic Tank, 2" insulation, EF =0.662 RE =76% Plastic heattraps, IID Plastic Tank, 2" insulation, EF= 0.675 RE =78% Plasticheat traps, IID (1) Side Arm Heater not modeled withTANK 11/09/98 Engineering -Water Heaters 22