### PRICE-EFFICIENCY RESULTS

Summary Tables
The results ofthe Engineering Analysis are summarized in cost-efficiency tables demonstrating the increased cost and efficiency due to each design option within each product class. The design option combinations are shown in order ofincreasing efficiency.
Table la. Results for the 50-Gallon Electric Water Heater: HFC-245fa-Blown Foam
DO# Label Selected Design Option Combinations EF Total Installed l_ l l________________________________________ 

# I Cost Existing Baseline 0.8600 345.66 0 12003 Baseline Baseline (245fa) 0.8601 349.01 1

.Heat Traps Baseline (245fa) + Heat Traps 0.8780 355.26 2 Insulated Tank Baseline (245fa)+ HeatTraps+ nsulatedTank 0.8822 361.39 Bottom Bottom 3 2"Insulation Baseline (245fa) +HeatTraps +InsulatedTank 0.8967 388.77 Bottom + 2" Insulation 4 2.5" Insulation Baseline (245fa)+ HeatTraps+ Insulated Tank 0.9077 408.07 ; i. Bottom +2.5" Insulation 5 IPlastic Tank Baseline (245fa) + Heat Traps +2.5" Insulation; 0.9099 444.50

.. + PlasticTank 6 13" Insulation Baseline (245fa) + HeatTraps +3"Insulation + 0.9180 510.83 |I 

### EP~~~~Plastic Tank
Table Ib. Results for the 50-Gallon Electric Water Heater: Water-Blown Foam
DO# Label Selected Design Option Combinations EF Total Installed 

### l_______I l_____ 

### Jl__ l Cost Existing Baseline 0.8600 345.66 0 2003 Baseline Baseline (Water-Blown) 0.8601 361.02 1 HeatTraps Baseline (Water-Blown) + Heat Traps 0.8780 367.27 2 Insulated Tank Baseline (Water-Blown) + Heat Traps + 0.8816 373.40 Bottom IInsulated Tank Bottom 3)2.5" Insulation Baseline (Water-Blown) + Heat Traps + 0.8895 394.82 |- |m> Insulated Tank Bottom +2.5" Insulation 4 3"Insulation Baseline (Water-Blown) + Heat Traps + 0.8981 459.23 !~ i.~Insulated Tank Bottom + 3"Insulation 5iPlasticTank Baseline (Water-Blown) + Heat Traps + 3" 0.9012 495.66 __ _____ IInsulation + PlasticTank

2Table 2a. Results for the 40-Gallon Gas-Fired WaterHeater: HFC-245fa-Blown Foam
DO# Label Selected Design Option Combinations EF Total Installed IJ________ _Cost Existing Baseline 0.544 330.15 0 !2003 Baseline iBaseline (245fa) 0.543 376.35 1 iHeat Traps !Baseline (245fa) +Heat Traps 0.552 380.57 2 !78% RE 'Baseline (245fa) +Heat Traps +78% RE 0.565 395.54 3 12" Insulation Baseline (245fa) + HeatTraps + 78% RE + 2"i 0.592 416.76 Insulation 4 2.5" Insulation Baseline (245fa) + Heat Traps + 78% RE + 0.599 431.47 2.5" Insulation 5 i80% RE Baseline (245fa) + Heat Traps + 80% RE + 0.615 468.25 S i2.5" Insulation 6 Side-Arm Baseline (245fa) + Heat Traps + 80% RE + 0.700 636.89 wI 2.5" Insulation +Side-Arm +Electronic Ignition 7 Plastic Tank Baseline (245fa) + Heat Traps + 80% RE + 0.709 654.60 2.5" Insulation +Side-Arm + Electronic Ignition + PlasticTank 8 3"Insulation Baseline (245fa) + Heat Traps + 80% RE +3" 0.715 716.40 Insulation + Side-Arm + Electronic Ignition +; tI iP~~~Plastic Tank
Table 2b. Results for the 40-Gallon Gas-Fired Water Heater: Water-Blown Foam
DO# Label Selected Design Option Combinations EF Total Installed Cost Existing Baseline 0.544 330.15 0 |2003 Baseline Baseline (Water-Blown) 0.544 380.30 1 hHeatTraps iBaseline (Water-Blown) + Heat Traps 0.552 384.53 2 78% RE Baseline (Water-Blown) + Heat Traps + 78% 0.565 399.50 RE 3 12" Insulation Baseline (Water-Blown) + Heat Traps + 78% 0.583 414.49 RE + 2" Insulation 4 2.5" Insulation Baseline (Water-Blown) + Heat Traps + 78% 0.591 430.58 RE + 2.5" Insulation 5 80% RE Baseline (Water-Blown) + Heat Traps + 80% 0.607 467.36 RE + 2.5" Insulation 6 Side-Arm Baseline (Water-Blown) + Heat Traps + 80% 0.691 635.99 j=i ~ XRE + 2.5" Insulation + Side-Arm + Electronic Ignition 7 iPlastic Tank Baseline (Water-Blown) + Heat Traps + 80% 0.700 653.71 RE + 2.5" Insulation + Side-Arm + Electronic |~<~~ Ignition + PlasticTank 8 -3"Insulation Baseline (Water-Blown) + Heat Traps + 80%i 0.706 714.61 RE + 3" Insulation + Side-Arm + Electronic "_______ l Ignition + PlasticTank

3Table 3a. Results for the 32-Gallon Oil-Fired Water Heater: HFC-245fa-Blown Foam
DO# Label Selected Design Option Combinations EF Total Installed Cost Existing Baseline 0.529 936.60 0 2003 Baseline Baseline (245fa) 0.529 939.86 1 Heat Traps Baseline (245fa) + HeatTraps 0.539 954.81 2 2" Insulation Baseline (245fa) + Heat Traps+ 2" Insulation 0.555 1,007.11 3 i2.5" Insulation Baseline (245fa) + Heat Traps+ 2.5" Insulation 0.558 1,023.23 4 13" Insulation Baseline (245fa) + Heat Traps+ 3" Insulation 0.561 1,048.03 5 78% RE iBaseline (245fa) + HeatTraps+ 3"Insulation + 0.582 1,167.39 Ig 178% RE I 6 Interrupted Baseline (245fa) + HeatTraps+ 3"Insulation +| 0.586 1,223.39 Ignition 78% RE + Interrupted Ignition 7 82% RE Baseline (245fa) +HeatTraps+ 3"Insulation + 0.616 1,434.34 Increased HX 78% RE + Interrupted Ignition + 82% REi Area Increased HX Area i
Table 3b. Results for the 32-Gallon Oil-Fired Water Heater: Water-Blown Foam
DO# Label Selected Design Option Combinations EF Total Installed 

## JF| Cost Existing Baseline 0.529 936.60 0 2003 Baseline Baseline (Water-Blown) 0.529 970.53 1 IHeat Traps Baseline (Water-Blown) + HeatTraps 0.539 985.48 2 2" Insulation Baseline (Water-Blown) + Heat Traps+ 2" 0.547 1,000.98 it gI' Insulation 3 J2.5" Insulation Baseline (Water-Blown) + Heat Traps + 2.5" 0.552 1,015.49 lji~~ Insulation 4 3" Insulation Baseline (Water-Blown) + Heat Traps + 3" 0.556 1,038.39 Insulation 5 78% RE Baseline (Water-Blown) + Heat Traps + 3" 0.577 1,157.75 Insulation + 78% RE 6 interrupted Baseline (Water-Blown) + Heat Traps + 3" 0.581 1,213.75 lgnition Insulation + 78% RE + Interrupted Ignition I 7 82% RE Baseline (Water-Blown) + Heat Traps + 3" 0.610 1,424.79 Increased HX Insulation + 78% RE + Interrupted Ignition +| Area 82% RE Increased HX Area

4Overviewof Engineering Analysis The objective ofthe Engineering Analysis is to determine the costs ofincreased energy efficiency for residential water heaters by developing price and efficiency data fordesign options and combinations ofdesignoptions foreach product class. This information will be used in subsequent components ofthe standards rulemaking process.
The Engineering Analysis uses computer simulation models and other analytical methods to investigate theefficiency improvements ofdesign options and interactions when multiple design options are used. The Engineering Analysis isbased onDOE's test procedure forresidential water heaters. Manufacturer, distributor, and installer markups, as well as sales tax, are applied to factory costs to arrive at thepurchase price ofthe water heater. Additional installation costsrequired for certain design options are included in the consumer price forthese design options.

5Technological Issues
There are impending regulatory changes outside ofthe DOE energy efficiency standards process that will impact the manufacture or installation ofwaterheaters. Some ofthese changes affect the efficiency ofwater heaters as well.
Insulation
Most residential waterheaters are insulated with polyurethane foam in the space between thetank and thejacket. The insulation isfoamed into place using polyols and isocyanurate that react toform apolyurethane foam. A blowing agent included inthe mixture is vaporized by the heat ofthereaction, creating a frothy massthat hardens quickly into closed-cell foam insulation. Currently, water heater manufacturers use HCFC-141b, an ozone-depleting substance, as a blowing agent. As aresult ofthe Montreal Protocol, the U.S. Environmental Protection Agency has scheduled thephase-out ofthis blowing agent by theyear 2003. Water heater manufacturers must use another blowing agent afterthat time.
The industry is considering anumber of blowing agents including HFC-245fa, HFC356mffm, HFC-134b, cyclo-pentane, and water-blown foam. Although the above blowing agents are currently being investigated as possible replacements to HCFC-141b by the waterheater industry, the analysis presented in this report is based on two leading candidates, HFC-245fa and water-blown foam. Water-blown foams are created when wateris introduced into the chemical mixture andparticipates in the reaction leading topolyurethane releasing CO2 which provides the blowing activity.
The analysis for the DOE water heaterenergy efficiency standards is based on the properties ofinsulation using these two technologies and the mostrealistic estimates ofcosts and physical parameters available for each. The average increase inconductivity resulting from replacing HCFC-141b with HFC-245fa is 3.0%, and replacing with water is 42.0%. Since the efficiency and energy use characteristics ofwaterheaters with HFC-245fa and water-blown insulation are not the same as those with HCFC-141b insulation, it was necessary to compensate forthe higherk-factors. This was accomplished by modeling the waterheaters with thicker insulation. In addition to the extravolume and cost ofinsulation, the amount and cost ofsteel used for the water heaterjacket were also increased.

Flammable Vapor Ignition
Current designs for gas-fired waterheaters rely on a standing pilotto ignite the main burner. Ifflammable vapors are in the air near a water heater, there is the possibility of unintended ignition. This is a potential safety problem because water heaters are often installed in garages and basements, where flammable liquids such as gasoline or paint thinners may beused.

6The Consumer Product Safety Commission (CPSC) is working with GRI and the water heater industry todevelop a testprocedure forgas-fired waterheater designs that will prevent ignition offlammable vapors. The Department expects the American National Standards Institute (ANSI) will adopt atest procedure forwater heater resistance to igniting flammable vapors in 1999.
From discussions withthe Water Heater Industry Joint Research and Development Consortium, DOEwill use aplaceholder value of$35 as additional cost for designs toprevent ignition offlammable vapors. In this analysis, the extra $35 is applied to the manufacturer costof all design options forgas-fired water heaters, including the 2003 baseline design. Thus, the added cost ofpreventing flammable vapor ignition does not impactthe cost effectiveness ofany energy efficiency design improvement although itmay have an effect on choice ofenergy source. The design is assumed nottorequire electricity atthe water heater or modifications ofthe venting system. No changes in efficiency are expected from flammable vapor ignitionresistant water heater designs. Venting
Use ofgas-fired water heaters with flue-loss efficiency greater than 80% with existing venting systems that are not designed for low temperature flue gases canpotentially lead to excessive corrosion and failure ofthe vent system in certain climates. Recovery efficiencies (RE) beyond 80% are associated with flue-loss efficiencies exceeding 84%, resulting influe gas condensation within the waterheater's flue, which leadsto corrosion and a shortened life. To ensure that condensation would not occur within the flue system, only flue baffle improvements withmaximum REs of80% were included indesign options selected for further analysis. By keeping the RE ceiling at 80%, itwas assumed that blowers would notbe needed. However, the Department recognizes thatpotential venting problems that may occurin the 78% to 80% RE range couldrequire type-B ventconnectors and chimney relining. Therefore, where necessary, the costs ofventing modifications to gaswater heater installation costs have beenincluded. According to theNational Fuel Gas Code (ANSI Z223.1), Type-B vent connectors are needed for any portion ofthe venting systems that are exposed to coldconditions (i.e., unconditioned spaces). Type-B vent connectors are required only whenrecovery efficiency (RE) approaches the 78% level. Itwas estimated that, ofhomes with single wall vent connectors, 25% willrequire Type-B connectors. Additional modifications, which include the relining ofmasonry chimneys, will be needed when an 80% threshold isexceeded. This occurs in 25% ofhomes withmasonry chimneys.

7BaselineModels
The baseline unit represents themost common size waterheater with an efficiency equal to the minimum allowed by the current energy efficiency standards foreach fuel type. The general characteristics ofthebaseline model foreach ofthethree primary product classes (i.e., electric, gas-fired, and oil-fired) are provided below. An in-depth description ofeach ofthebaseline models is provided in the Technical Support Document.
Electric WaterHeaters
The baseline model isa 50-gallon (190-liter) glass-lined steel tank with 1/2 in. (3.8 cm) of polyurethane foam insulation blownwith HCFC-141b. The heater has two elements, each with an input of4,500 W. The elements are interlocked so that only one canbe energized at atime. The baseline energy factor is 0.86, the energy efficiency standard for this size and type ofwater heater.
Gas-Fired WaterHeaters
Thebaseline model ofgas-fired water heaters is abottom-fired, 40-gallon (150-liter), glass-lined steel tank with a4-in. (10-cm) center flue. The inputrate is 40,000 Btu/hr (11,700 W), with apilot rated at 450Btu/hr (120 W). The tankis insulated with a nominal 1in. (2.5 cm) ofpolyurethane foam blown with HCFC-141b. The current energy efficiency standard for this size and type ofwater heater is 0.54 EF. Ithas arecovery efficiency of76%.
Oil-Fired WaterHeaters
The baseline oil-fired water heater isa center-flue design. It has arated volume of32 gallons (120 liters), and is insulated with 1in. (2.5 cm) ofpolyurethane foam blownwith HCFC141b. The inputrate is 0.65 gallonsper hour (2.5 liters/hr) ofoil or 90,000 Btu/hr (26,000 W). It has an EF of0.53, the current energy efficiency standard. The first hour rating is 105 gallons (398 liters), andthe RE is 75%. The burner motor, which powers boththe blower and oil pump, is rated at 1/8 hp (282 W). The baseline model uses an intermittent ignition system.

8Efficiency Calculations
The design options for each ofthe three classes ofwater heaters were modeled either with computer simulation programs or an energy calculation method. The output from the computer simulations was used to determine the energy efficiency characteristics ofthe water heater (e.g., the EF, RE, and standby heat loss coefficient (UA)), based on the DOEtest procedure.
WATSIM Model forElectric WaterHeaters
WATSIM is a detailed electric waterheating simulation program developed by the Electric Power Research Institute. WATSIM contains two simulation algorithms; one for the detailed simulation ofwaterheater tanks and the other for controlling water draw profiles for use withthe tankmodel. Since the simulation analysis mustbe performed according to the requirements oftheDOE test procedure, the water draw profile is specified to the 64.3 gallon (243.4 liter) draw pattern in the testprocedure. WATSIM does not include the EF, RE, and UA calculations from the DOE test procedure. However, it does provide detailed temperature profiles ofthe water inside the tank ofthe water heater during the simulation run. These temperature readings are used to determine the EF and otherparameters ofthe water heater using the test procedure calculations. A spreadsheet calculates the efficiency characteristics according to the DOE test procedure from the results from WATSIM.
TANK Model for Gas-Fired WaterHeaters
TANK is adetailed gas-fired waterheater simulation program developed by Battelle for the GasResearch Institute. TANK calculates energy flows throughout the waterheater including heat gained or lost by the water, flue heat losses,jacket heatlosses, fittings heat losses, and combustion chamber heat losses. TANK calculates theEF, RE, and UA from the DOE test procedure.
WHAM Energy Calculation for Oil-Fired WaterHeaters
A simplified water heater analysis model (WHAM) was used forthe engineering analysis for oil-fired water heaters. WHAM is based on the DOE 24-hour test procedure. Themodel is an equation to calculate average daily energy consumption from the RE, UA, and rated input (Pon).

9Overall AnalyticApproach
In this report, a distinction has been made between baseline models containing current technologies and future baseline models which are expectedto meet new mandated regulations. The former are referred to as "existing" baseline models and the latter as "2003" baseline models. An important energy-saving feature ofexisting water heatertechnology is the insulationbased on HCFC-141b as ablowing agent. The future regulatory phase-out ofHCFCs by theyear 2003 necessitate a replacement for HCFC-141b. The two strongest candidates for replacements are the HFC-245fa blowing agent and water-blown foam insulation. Consequently, the engineering analysis is performed on two parallel paths, one for HFC-245fa and one for water-blown foam insulation. An ANSI testprocedure covering theprevention offlammable vapor ignition, expected in 1999, will require a change in thebasic design ofgas-fired water heaters. The engineering analysis also addresses the cost ofthis change; we have assumed there is no effect on water heater energy factor. Additionally, for the purposes ofthe analysis, arepresentative, or "typical" tank size (rated volumes of50-gal for electric, 40-gal for gas-fired, and 32-gal for oil-fired) has been chosen from all the standard sizes for each fuel type.

10Electric WaterHeaters Modeling Design Options
Four design options are being considered to improve the efficiency ofelectric water heaters. Each design option isbriefly discussed below.
2003 Baseline Models. As explained above in the Technological Issues section, HFC245fablowing agent has a3.0% higher conductivity than HCFC-141b and water-blown insulation has a 42.0% higher conductivity than HCFC-141b. The thickness ofthe HFC-245fa foam insulation surrounding the tankwas increased to 1.55 in. (3.94 cm) to compensate for the increased conductivity ofthe insulation. The thickness ofthe water-blown foam insulation surrounding thetank was increased to 2.12 in. (3.38 cm) to compensate for the increased conductivity ofthe insulation.
Heat Traps. The heat conducted and convected through the water pipes accounts for a significant portion ofthe total standby loss in atypical residential-size water heater. A heat trap is
a device that keeps the buoyant hot water from circulating through apiping distribution system because ofnatural convection. When there isno drawofhot water,thisprevents water in the hot water outlet line from settling back into the tank as it cools off; and prevents hot water in the tank from circulating back outinto the cold waterinlet line. By containing the hot water inthe storage tank, the heat trap minimizes standby loss. Heat traps can be integral to the tank design or independently attached to the inlet and outlet pipes during installation.
Increased Jacket Insulation. Most water heaters on the market today have at least 1-in. (2.5 cm) thickjacket (sides and top) foam insulation, while some manufacturers provide 2- to 3- in. (5.1 to 7.6 cm) thick insulation aswell. Although increasing theinsulation thickness reduces the standby loss, the increase in the overall diameter ofthe water heater may pose some installation problems. There will also be an increase in shipping costs because fewer heaters will fitin a truck. Because ofthese potential installation problems, maximum insulation thicknesses were limited to 3in. (7.6 cm) for this analysis. In the HFC-245fa 2003 baseline model, we simulated the performance ofan electric water heater insulated with 2-, 21⁄2/, and 3-in. (5.1 cm, 6.4 cm, and 7.6 cm) foam insulation. In the water-blown 2003 baseline model, weused 2/2 and 3-in. (6.4 cm and 7.6 cm). Inparticular, DOE would likecomments and data on howthe manufacturers might deal withthe increased insulationthicknesses in small places. Insulating the TankBottom. The bottom ofthetank ofan electric waterheater can be insulated to reduce the standby heat losses. Currently, manufacturers may place fiberglass insulation inthe space beneath the concave bottom ofthe waterheater tank. WATSIM models the heat transfer through the bottom ofthetank by two separate parallel heat transfer paths

- "bottom" and "support ring". The "bottom" represents the area ofthe concave dome andthe "support ring" represents the perimeter, which is acontinuation ofthe tank wallbelow the bottom

11ofthe tank. The "bottom insulation" portion ofthis assembly fills the domed space underneath the tank. Putting insulation under the support ring breaks a majorheat transfer path to thejacket. Thebottom insulation conductivity reflects the different characteristics ofHFC-245fa and waterblown insulation.
Plastic Tank. This design is athin steel shell with an internal plastic tank. To modelthis tank with WATSIM, the tank wall thickness and conductivity were modeled as plastic instead of steel. The conductivity ofthe plastic/steel composition is virtually identical to plastic. The support ring material was changed from steel to foam insulation.

12ManufacturerCosts
Manufacturer cost estimates for a 50-gallon (190-liter) electric water heater were disaggregated into variable (material, labor, transportation, overhead) and fixed (capital, product design) costs. Design option variable costs and fixed costs were provided on aperunit basis and expressed asan incremental increase overthe existing baseline design. The breakdown ofthe manufacturing costs for all designoptions are given in Tables 5a and 5b. Existing Baseline Model. Cost estimates for the existing baseline model-a waterheater with 1 /2in. (3.8 cm) offoamedjacket insulation using HCFC-141b as a blowing agent-were supplied by GAMA. Thematerial costs for aparticular thickness ofinsulation were determined by either subtracting from or adding to GAMA's baseline costs. The material costs ofHCFC141b foam insulation and sheet metal were estimated by an independent consultant.
2003 Baseline Model. To convert the baseline manufacturer costs for foam insulation blown withHCFC-141b to HFC-245fa or water-blown insulation, the amount and cost of materials are used. Material costs associated with aparticular level ofHFC-245fa or water-blown insulation were determined by addingto thebaseline costs associated with a comparable level of HCFC-141b foam insulation. Table 4 shows the calculation of the total foam cost for HFC-141b, HFC-245fa, andwater-blown insulation,based on the component cost estimates.
Table 4 Foam Components Cost Estimate Foam Components Fraction Component Total Cost Total Cost Total Cost of Foam Cost (141b) (245fa) (Water-Blown) % $/lb $/lb $/lb $/lb HCFC-141b 13.00% $1.50 $0.20 HFC-245fa 13.00% $4.00'

- $0.52 Water-Blown 13.00% $1.502

- - $0.20 isocyanurate 51.00% $0.75 $0.38 $0.38 $0.38 polyols 31.00% $0.65 $0.20 $0.20 $0.20 catalysts, refractants, etc. 5.00% $4.50 $0.23 $0.23 $0.23 Total 100.00%

_ $1.00 $1.32 $1.00 'Source: Allied Signal 2Source: Consultant, manufacturers Heat Traps. Manufacturer costs formetal and plastic heattraps were provided by GAMA. The costs reflect the addition ofheattraps to boththe supply and draw lines.
Increased Jacket Insulation. GAMA provided variable cost and fixed cost data for jacket insulation increases from abaseline level ofl'/2 in. (3.81 cm) to a thickness of2.0 in. (5.1 cm) only. To generate variable cost and fixed cost datafor other thicknesses ofinsulation, the dataprovided by a consultant was usedto calculate ratios ofvariable and fixed costfor 2 in., 2/2 in., and 3in. insulation compared to the baseline thickness. GAMA's costs for upgrading to 2.0 in. (5.1 cm) insulation, modified forboth HFC-245fa and water-blown foam, were multiplied by
13those ratios to approximate the variable and fixed costs for 2/2 in. (6.4 cm) and 3in. (7.6 cm) of insulation. The overhead portion ofthe variable cost for models with 3in. (7.6 cm)jacket insulation include 25% additional shipping cost due to reduced transport capacity. Insulating the TankBottom. Manufacturer costs for insulating thetank bottom were based on data from consultants.
Plastic Tank.Manufacturer costs for a plastic tank electric water heater design were based on data provided by a consultant. The plastic tank design option fixed costswere provided asthe "lump sum" amount required to convert the baselineproduction to the new design. The per unit cost was calculated by amortizing itover a five-year period and dividing itby the assumed baseline model production volume of40,000 units peryear.
Design Option Retail Prices For purposes ofthis analysis, the retail price is the costto the consumer ofonly the water heater. The cost ofinstalling the water heater is not considered partofthe retail price and is discussed later.
The retail price for the existing baseline 50-gallon (190-liter) electric waterheater (with HCFC-141b foam insulation) wasthe median price from alarge number ofretailers, wholesalers, plumbing contractors and utilities. This data canbe found in the WaterHeater Price Database (http://www.eren.doe.gov/buildings/codes_standards/applbrf/waterheater.htm). This database was developed from information gathered from over 130 contacts from allregions ofthe U.S. It contains information on over 1100 models, including retail prices, fees (installation, delivery, etc.), and warranties. Detailed product specification information (e.g., certified EF, 1st hourratings) from manufacturer's product literature and the GAMA and CEC directories were also included.
The price ofa waterheater depends on the length ofthe manufacturer's warranty. The baseline models chosen for this analysis have upto 6-year warranties. The 5- to 6-year warranty is the shortest warranty period offered by water heater manufacturers (although a 1-year warranty is offered in special cases) and is typically reserved forthose models which are produced in large volumes (i.e., baseline models). A longer warranty, in addition to raising theprice, may indicate the presence of features notnormally found inbaseline models. The median retail price of electric water heaters is $181.58.

Installation and Maintenance Costs
The installation cost isthe costto install the water heater and isnot considered part ofthe retail price. The cost ofinstallation covers all labor and materials associated with replacing an existing water heater. Delivery, removal, and permit fees are also included.

14Installation cost data for the 50-gallon (190-liter) baseline electric waterheater came from the Water Heater Price Database. The median installation cost is $155.00. None ofthe design options considered for this analysis, with the exception of3in. insulation, increased the installation cost. Design options that include 3in. insulation require an additional cost to install the wider units innarrow spaces (e.g., disassemble and reassemble doorjambs).
There is virtually no maintenance ofresidential electric water heaters. Thus, maintenance costs were not included for the baseline model or forthe different design options.

Cost-Efficiency Data
The results ofthe design option analysis for 50-gallon (190-liter) electric water heaters are presented for the two 2003 baselines. Table 5a presentsresults using HFC-245fa-based blowing agent and Table 5b results for water-blown insulation. Included inthe cost-efficiency tables are the following: disaggregated manufacturer costs, retail prices, installation costs, energy factor, andenergy use. The existing baseline design with HCFC-141b foam insulation is also presented inthe two tablesto show the manufacturer cost and retail price differences. Energy costs were from national average energy prices forthe year 2003 from DOE/EIA'sAnnualEnergyOutlook1999.
The results show that, for HFC-245fa-based blowing agent, the highestEF attainable is 0.918 which can be achieved through the use ofplastic heat traps, 3in. (7.6 cm)jacket insulation, insulated tank bottom, and aplastic tank. This design saves 233 kWh/yr in electricity. Forwaterblown insulation, the highest EF attainable is 0.901, which canbe achieved through the use of plastic heat traps, 3in. (7.6 cm)jacket insulation, insulated tankbottom, and aplastic tank.

15Table 5a. Cost-Efficiency Table for 50-gallon (190-liter) Electric Water Heaters

- HFC-245a 2003 Baseline IncrementalVariable Costs Total Mfg to Energy Use Total Cost Design Total Total Mfg Retail Retail Install. Maint. Energy Recovery UA Daily Yearly Installed Operating

No. Design Options Mat'l Labor Overhd Var. Fixed Cost Markup Price Ct Cot Factor Efficiency kWh/day kWh/yr $/yr $/yr

0 Existing Baseline S62.16 $10.57 $49.00 $121.73 $0.00 $121.73 1.57 $190.66 $155.00 $0.00 0.8600 98.00% 3.64 13.58 4958 345.66 390.72 Oa 2003 Baseline 64.30 $0.00 $0.00 $123.87 $0.00 $123.87 1.57 $194.01 $155.00 $0.00 0.8601 98.00% 3.64 13.58 4958 349.01 390.70 1 HeatTraps $2.59 $0.19 $0.82 $3.60 $0.39 $127.86 1.57 $200.26 $155.00 $0.00 0.8780 98.00% 3.06 13.34 4868 355.26 383.64 2 InsulatedTank $4.87 $0.31 $1.18 $6.36 $1.54 $131.77 1.57 $206.39 $155.00 $0.00 0.8822 98.00% 2.92 13.28 4846 361.39 381.94 Bottom 3 2" Insulation $13.54 $0.81 $4.88 $19.23 $6.15 $149.25 1.57 $233.77 $155.00 $0.00 0.8967 98.00% 2.46 13.08 4775 388.77 376.30 4 2.5"Insulation $19.36 $1.31 $8.58 $29.25 $8.46 $161.58 1.57 $253.07 $155.00 $0.00 0.9077 98.00% 2.13 12.94 4725 408.07 372.33 5 PlasticTank $22.25 $1.99 $11.42 $35.66 $25.31 $184.84 1.57 $289.50 $155.00 $0.00 0.9099 98.00% 2.05 12.92 4717 444.50 371.73 6 3" Insulation $29.44 $2.49 $16.20 $48.13 $27.61 $199.61 1.57 $312.64 $198.19 $0.00 0.9180 98.00% 1.80 12.82 4678 510.83 368.70

Table 5b. Cost-Efficiency Table for 50-gallon (190-liter) Electric Water Heaters

- Water-Blown 2003 Baseline Incremental VariableCosts Total Mfg to Energy Use Total Cost Design Total Total Mfg Retail Retail Install. Maint. Energy Recovery UA Daily Yearly Installed Operating

No. Design Options Mat'l Labor Overhd Var. Fixed Cost Markup Price Cost Cost Factor Efficiency kWh/day kWh/yr S/yr $/yr 0 ExistingBaseline $62.16 $10.57 $49.00 $121.73 $0.00 $121.73 1.57 $190.66 $155.00 $0.00 0.8600 98.00% 3.64 13.58 4958 345.66 390.72 Oa 2003 Baseline $71.97 $0.00 $0.00 $131.54 $0.00 $131.54 1.57 $206.02 $155.00 $0.00 0.8601 98.00% 3.64 13.58 4957 361.02 390.68 1 HeatTraps $2.59 $0.19 $0.82 $3.60 $0.39 $135.53 1.57 $212.27 $155.00 $0.00 0.8780 98.00% 3.06 13.34 4868 367.27 383.64 2 Insulated Tank $4.87 $0.31 $1.18 $6.36 $1.54 $139.44 1.57 $218.40 $155.00 $0.00 0.8816 98.00% 2.94 13.29 4849 373.40 382.17 Bottom 3 2.5" Insulation $8.44 $0.69 $3.99 $13.12 $8.46 $153.12 1.57 $239.82 $155.00 $0.00 0.8895 98.00% 2.67 13.17 4809 394.82 378.98 4 3" Insulation $14.85 $1.19 $8.33 $24.37 $10.76 $166.67 1.57 $261.04 $198.19 $0.00 0.8981 98.00% 2.42 13.06 4769 459.23 375.81 5 PlasticTank $17.74 $1.87 $11.17 $30.78 $27.61 $189.93 1.57 $297.47 $198.19 $0.00 0.9012 98.00% 2.31 13.04 4760 495.66 375.13 Notes: 1)Allcosts andpricesin 1998$. 2) Incremental variable and fixed costs are per unit costsand arerelative tothe 2003 baseline. 3) Forthe baseline model with HCFC-141b, thetotal variable costs are provided. 4) Retail prices are calculated based on themanufacturer cost-to-retail price markupof 1.56624

.

16Gas-Fired WaterHeaters

Modeling Design Options
The following seven design options are being considered to improve the efficiency ofgasfired water heaters:
* heat traps * increasedjacket insulation * improved flue baffle * electronic ignition * flue damper * side-arm heater * plastic tank
Each design option is briefly discussed below along with a description ofhowit was modeled withTANK. The discussion begins withthe analysis ofthe baseline models using polyurethane insulation blown with HFC-245fa and water-blown insulation. As noted above, these baseline models are referred to asthe two "2003" baseline models.
2003 Baseline Model. As discussed above in the section on the electric 2003 baseline model, HFC-245fa blowing agent has a 3.0% higher conductivity thanHCFC-141b and waterblown insulation has a42.0% higher conductivity than HCFC-141b. To compensate for the increased conductivity, the thickness ofthe HFC-245fa-based insulation and the thickness ofthe water-blown insulation were increased accordingly.
Heat Traps. Metal and plastic heat traps were analyzed for gas-fired waterheaters. Both types ofheat trapsprevent the losses associated withthe circulation ofhot water intothe plumbing.
Increased Jacket Insulation. Most waterheaters on the market today have at least 1-in. (2.5 cm)thickjacket (sides and top) foam insulation, while somemanufacturers provide 2- to 3- in. (5.1 to 7.6 cm)thick insulation as well. Although increasing the insulation thickness reduces the standby loss, the increase in the overall diameter ofthe water heater may pose some installation problems. There will also be an increase in shipping costs because fewer heaters will fit in atruck. Because ofthese potential installationproblems, maximum insulation thicknesses
were limitedto 3in. (7.6 cm) forthis analysis. Inboth 2003 baseline models, we simulated the performance ofan gas-fired water heater insulated with 2-, 2/2, and 3-in. (5.1 cm, 6.4 cm, and 7.6 cm) foam insulation. In particular, DOEwould like comments and data on howthe manufacturers might deal withthe increased insulation thicknesses in small spaces.

17Improved FlueBaffle. The standard flue baffle is atwisted strip ofmetal inserted into the flue. Itincreases the turbulence offlue gases and improves heat transfer to the walls ofthe flue. The geometry ofthe flue baffle canbe modified to increase its effectiveness. An improved flue baffle can increase the recovery efficiency (RE) from 76% to about 78-85%, depending on the specific geometry. (See discussion ofimpacts ofRE levels under Technological Issues section). Inthis analysis, two levels ofRE were considered: 78% and 80%. These RE levels are achieved through the use of two types ofimproved flue baffle designs.
Electronic Ignition. This design option is an intermittent ignition device (IID) that lights the main burner directly by generating a spark. It operates only atthe beginning ofeach on-cycle in contrast to the standing pilotignition system which is constantly on. Flue Damper (Electromechanical). Gas-fired water heaters are equipped with a draft hood connecting the flue to a ventpipe or chimney. During off-cycle, the water heater loses heat by natural convection up the flue. An electromechanical flue damper can be installed inthe vent pipe to minimize the off-cycle heat losses. The dampers open before combustion starts and close immediately after combustion stops.
This design option always has an electronic ignition system associated with it. Since electricity is required for the operation ofthe flue damper, itwas assumedthat the standing pilot would be converted to an electronic ignition system in order to take advantage ofthe electrical power that exists at the water heater.
Side-Arm Heater. The side-arm heater design avoids large flue losses through the removal ofthe flue from the center ofthe tank. Water iswithdrawn from thebottom ofthe tank and heated overa burner in a small, separate heat exchanger. Water isreturned to the top ofthe tank. A small circulation pump moves water through the heat exchanger when the burner is on.

Plastic Tank. The lower heat conductivity ofa plastictank reduces the amountofheat conducted through the tank wallto the insulation. Because plastic cannot withstand high temperatures, it was only considered in conjunction withthe side-arm water heater design.

18ManufacturerCosts
All manufacturing cost estimates for a40-gallon (150-liter) gas-fired water heater were disaggregated into variable (material, labor, overhead, transportation) and fixed (capital, product design) costs. Design option variable and fixed costs were provided on aper unitbasis and expressed as anincremental increase over the existing baseline design. The breakdown ofthe manufacturing costs for all design options are given in Tables 6a and 7a. Existing Baseline Model. Cost estimates for the existing baseline model-a water heater with 1in. (2.5 cm) foamedjacket insulation using HCFC-141b as a blowing agent-were supplied by GAMA. The material costs for aparticular thickness ofinsulation were determined by adding to or subtracting from GAMA's baseline costs. The material costs ofHCFC-141b foam insulation and sheet metal were estimated by an independent consultant.
2003 Baseline Model. To convert the baseline manufacturer costs for foam insulation blown with HCFC-141b to HFC-245fa or water-blown insulation, the amount and cost of materials are taken into account. Material costs associated with aparticular level ofHFC-245fa or water-blown insulation were determined by adding to thebaseline costs associated with a comparable level ofHCFC-141b foam insulation. The material costs ofHFC-245fa foam insulation and water-blown insulation were based on estimates by Allied Signal, see Table 4.
2003 Baseline Model with Flammable Vapor Ignition-Resistant Design. To prevent the ignition offlammable vapors, gas-fired water heater manufacturers will need toredesign their product. Based on discussions withthe Water Heater Industry Joint Research and Development Consortium, DOE added $35 to the total manufacturing cost ($15 variable costs and $20 fixed cost) for product redesign. Heat Traps. Manufacturer costs for metal and plastic heat traps were provided by GAMA. The costs reflect the addition ofheat traps to boththe supply and draw lines.
Increased Jacket Insulation. GAMA provided variable and fixed cost data forjacket insulation increases from a baseline level of 1.0 in. (2.54 cm) to athickness of2.0 in. (5.1 cm) only. To generate variable cost and fixed cost data for other thicknesses ofinsulation, the data provided by a consultant was used to calculate ratios ofvariable and fixed cost for 2 in., 2'/2 in., and 3in. insulation compared to thebaseline thickness. GAMA's costs for upgrading to 2.0 in. (5.1 cm) insulation, modified for both HFC-245fa andwater-blown foam, were multipliedby those ratiosto approximate the variable and fixed costs for2/2 in. (6.4 cm) and 3in. (7.6 cm) of insulation. Note that the overhead portion ofthe variable cost formodels with 3in. (7.6 cm) jacket insulation includes 25% additional shipping cost due to reduced transport capacity. Improved FlueBaffle. Manufacturer costs for the improved flue baffle design were based on data from GAMA. The costs were based on two flue baffle configurations, the first of which increased the RE to 78%, and the second to 80%.

19Electronic Ignition. Manufacturer costs for electronic ignition were based onthe replacement ofa standing pilot with an intermittentpilot ignition device. The cost ofthe electronic ignition system was based on data from GAMA.
Flue Damper (Electromechanical). Manufacturer costs for including an electromechanical flue damper with a gas-fired water heater were based on data from GAMA. Because electromechanical flue dampers were analyzed only in conjunction with electronic ignition systems, the incremental manufacturer costs ofboth design options are combined. Because electricity is required for the operation ofthe flue damper, we assumed that the standing pilot would be converted to an electronic ignition system in order to take advantage ofthe electrical power atthe water heater.
Side-Arm Heaterand Plastic Tank. Manufacturer costs for the side-arm heater for a gas-fired water heater design were based on data from a consultant. We included the costs for six types ofside-arm heater designs; 76%, 78 %, and 80% RE designs that use either metal orplastic tank. Forthis analysis itwas assumed that the cost difference between thethree RE designs was equal to the cost ofthe improved flue baffle design. Side-arm heaters were analyzed only in conjunction with electronic ignition systems. Therefore, the incremental manufacturer cost ofthe ignition system is also included. As discussed previously, plastictanks cannotbe considered as a stand-alone design option for standard center-flue gas-fired water heaters due to the high temperature ofcombustion. Thus, plastic tanks can onlybe considered withindirect heating designs, such as a side-arm heater.

Design Option RetailPrices
The retail price isthe cost to the consumer ofonly the water heater. The retail price for an existingbaseline 40-gallon (150-liter) gas-fired water heater (with HCFC-141b foam insulation) wasthe median price from alarge number ofretailers, wholesalers, plumbing contractors and utilities. This data canbe found inthe Water Heater Price Database (see http://www.eren.doe.gov/buildings/codes_standards/applbrf/waterheater.htm).
Theprice ofawater heater depends onthe length ofthemanufacturer's warranty. The baseline models chosen forthis analysis have up to 6-year warranties. The 5- to 6-year warranty is the shortest warranty period offered by water heater manufacturers (although 1-year warranties have been offered in special cases) and istypically reserved forthose models which are produced inlarge quantities (i.e., baseline models). A longerwarranty, in addition toraising the price, may also indicate the presence offeatures notnormally found inbaseline models. The median retail price for abaseline 40-gallon (150-liter) gas-fired water heater is $163 (without taxes).

20Installation and Maintenance Costs
The installation cost is the cost to the consumer ofinstalling the waterheater and is not considered part ofthe retail price. The cost ofinstallation covers all labor and material costs associated withreplacing an existing water heater. Delivery, removal, and permit fees are also included. Installation cost for the 40-gallon (150-liter) baseline gas-fired waterheater came from the Water Heater Price Database. The median installation cost is $159.00. Four design options were assumed to increase the cost ofinstalling agas-fired water heater: the improved flue baffle, electronic ignition, the electromechanical flue damper, and the side-arm heater. For several designs, the reported flue efficiency is close to 80%. For these designs, itis assumed a Type-B vent connector orchimney relining may berequired to ensure that condensation does not occur in thevent system.
The three remaining design options (electronic ignition, electromechanical flue damper, and side-arm heater) allrequire electricity to operate. The installation costwas increased in order to include the cost ofinstalling an electric circuit forthese design options. This installation cost estimate was also based ondata from GRI.
The electromechanical flue damper was the only design option that was assumed to have a maintenance cost. The maintenance cost ofthe flue damper was based on aprior DOE analysis.

Cost-Efficiency Data
The results ofthe design option analysis for40-gallon (150-liter) gas-fired water heaters are presented inTables 6a, 6b, 7a, and 7b. Included in the cost and efficiency tables are disaggregated manufacturer costs, retail prices, installation costs, maintenance costs, energyefficiency and energy use data.
The existing baseline design with HCFC-141b foam insulation ispresented in Tables 6a through 7b to show the manufacturer cost and retail price differences. Alsopresented are the costs for incorporating a design toresist igniting flammable vapors. Energy costs were from national average energy prices for 2003 from theAnnualEnergyOutlook1999.
The costs for all the design option combinations are shown in Tables 6a and 7a and the efficiency data is shown in Tables 6b and 7b. The results showthat, for the HFC-245fa-based blowing agent, the highestEF attainable is 0.7149, which canbe achieved through the use of plastic heat traps, 80% RE, 3 in. (7.6 cm) insulation, side-arm heater, electronic ignition, and plastic tank. This designproduces gas energy savings of7.79 million Btu/year. For water-blown insulation, the same design has an EF of0.7062 and a gas energy savings of7.53 million Btu/year.

21Table 6a. 245fa Insulation40-gal (150-liter) Gas-Fired WaterHeater: Cost Data

IncrementalCosts Total Mfg to Design Total Total Mfg Retail Retail Install. Maint.

No. Design Options Material Labor Overhead Variable Fixed Cost Markup Price Cost Cost

0 Existing Baseline $75.02 $10.74 $48.02 $133.78 $0.00 $133.78 1.28 $171.15 $159.00 $0.00 Oa Analytic Baseline $0.00 $.0 0.00 $0.00 $15.00 $20.00 $169.89 1.28 $217.35 $159.00 $0.00 I HeatTraps $2.75 $0.16 $0.19 $3.10 $0.20 $173.19 1.28 $221.57 $159.00 $0.00 2 78%RE $3.72 $1.41 $1.57 $6.70 $3.04 $179.63 1.28 $229.81 $165.73 $0.00 3 2" Insulation $13.33 $2.00 $6.53 $21.86 $4.47 $196.22 1.28 $251.03 $165.73 $0.00 4 2.5" Insulation $18.27 $2.59 $11.49 $32.35 $5.48 $207.72 1.28 $265.74 $165.73 $0.00 5 80%RE $18.27 $2.59 $11.49 $32.35 $5.48 $207.72 1.28 $265.74 $202.51 $0.00 6 Side-Arm $86.55 $6.46 $38.18 $131.19 $11.77 $312.85 1.28 $400.24 $236.64 $0.00 7 PlasticTank $91.80 $7.26 $42.38 $141.44 $15.37 $326.70 1.28 $417.96 $236.64 $0.00 8 3" Insulation $97.86 $7.85 $49.26 $154.97 $16.38 $341.24 1.28 $436.56 $279.83 $0.00 Notes: 1)All costs and prices in 1998$. 2)Incremental variable and fixedcosts areper unit costs and are relative to the 2003 baseline. 3) For thebaseline model with HCFC-141b,the totalvariable costs areprovided. 4)Retail prices are calculated based on themanufacturer cost-to-retail pricemarkup of1.27934

. Table 6b. 245fa Insulation 40-gal (150-liter) Gas-Fired WaterHeater: Efficiency Data

Fuel EnergyUse Electrical Energy Use Total Cost Design Energy Recovery UA Thermal Daily Yearly Daily Yearly Installed Operating

No. Design Options Factor Efficiency Efficiency Btu/day MBtu/year kWh/da kWh/year $/yr $/yr

0 Existing Baseline 0.5436 75.71% 13.99 78.10% 78558 28.67 0.00 0.00 330.15 184.04 Oa Analytic Baseline 0.5434 75.72% 14.02 78.08% 78579 28.68 0.00 0.00 376.35 184.09 1 HeatTraps 0.5523 75.61% 13.16 78.08% 77843 28.41 0.00 0.00 380.57 182.36 2 78%RE 0.5649 77.17% 12.79 79.80% 75644 27.61 0.00 0.00 395.54 177.21 3 2" Insulation 0.5921 77.99% 10.91 79.75% 73297 26.75 0.00 0.00 416.76 171.72 4 2.5" Insulation 0.5986 78.18% 10.53 79.74% 72787 26.57 0.00 0.00 431.47 170.52 5 80% RE 0.6146 80.22% 10.21 81.87% 70320 25.67 0.00 0.00 468.25 164.74 6 Side-Arm 0.6999 80.00% 4.79 78.00% 58438 21.33 0.08 29.32 636.89 139.21 7 Plastic Tank 0.7092 80.00% 4.29 80.00% 57671 21.05 0.08 29.32 654.60 137.42 8 3" Insulation 0.7149 80.00% 3.99 80.00% 57210 20.88 0.08 29.32 716.40 136.34

22Table 7a. Water-Blown Insulation 40-gal (150-liter) Gas-Fired Water Heater: Cost Data

Incremental Costs Total Mfg to Design Total Total Mfg Retail Retail Install. Maint.

No. Design Options Material Labor Overhead Variable Fixed Cost Markup Price Cost Cost

0 Existing Baseline $75.02 $10.74 $48.02 $133.78 $0.00 $133.78 1.28 $171.15 $159.00 $0.00 Oa Analytic Baseline $0.00 $0.00 $0.00 $15.00 $20.00 $172.98 1.28 $221.30 $159.00 $0.00 1 HeatTraps $2.75 $0.16 $0.19 $3.10 $0.20 $176.28 1.28 $225.53 $159.00 $0.00 2 78% RE $3.72 $1.41 $1.57 $6.70 $3.04 $182.72 1.28 $233.77 $165.73 $0.00 3 2" Insulation $10.18 $1.82 $4.99 $16.99 $4.47 $194.44 1.28 $248.76 $165.73 $0.00 4 2.5" Insulation $14.48 $2.59 $11.49 $28.56 $5.48 $207.02 1.28 $264.85 $165.73 $0.00 5 80%RE $14.48 $2.59 $11.49 $28.56 $5.48 $207.02 1.28 $264.85 $202.51 $0.00 6 Side-Arm $82.76 $6.46 $38.18 $127.40 $11.77 $312.15 1.28 $399.35 $236.64 $0.00 7 PlasticTank $88.01 $7.26 $42.38 $137.65 $15.37 $326.00 1.28 $417.07 $236.64 $0.00 8 3"Insulation $93.37 $7.85 $49.26 $150.48 $16.38 $339.84 1.28 $434.78 $279.83 $0.00 Notes: 1)All costs andprices in 1998$. 2)Incremental variable and fixedcosts areper unit costs and are relative tothe 2003baseline. 3)For thebaseline model with HCFC-141b, the total variable costs areprovided. 4)Retail prices are calculated based on themanufacturer cost-to-retail price markup of1.27934

. Table 7b. Water-Blown Insulation 40-gal (150-liter) Gas-Fired Water Heater: Efficiency Data

Fuel Energy Use Electrical Energy Use Total Cost Design Energy Recovery UA Thermal Daily Yearly Daily Yearly Installed Operating

No. Design Options Factor Efficiency Efficiency Btu/day MBtu/year kWh/day kWh/year $/yr $/yr

0 Existing Baseline 0.5436 75.71% 13.99 78.06% 78558 28.67 0.00 0.00 330.15 184.04 Oa Analytic Baseline 0.5436 75.91% 14.10 78.06% 78522 28.66 0.00 0.00 380.30 183.96 I HeatTraps 0.5523 75.80% 13.24 78.08% 77756 28.38 0.00 0.00 384.53 182.16 2 78% RE 0.5651 77.40% 12.86 79.77% 75625 27.60 0.00 0.00 399.50 177.17 3 2" Insulation 0.5829 77.89% 11.59 79.75% 74045 27.03 0.00 0.00 414.49 173.47 4 2.5" Insulation 0.5906 78.09% 11.08 79.74% 73384 26.79 0.00 0.00 430.58 171.92 5 80%RE 0.6066 80.13% 10.75 81.87% 70926 25.89 0.00 0.00 467.36 166.16 6 Side-Arm 0.6907 80.00% 5.30

- 59220 21.62 0.08 29.32 635.99 141.05 7 Plastic Tank 0.6997 80.00% 4.80 -58453 21.34 0.08 29.32 653.71 139.25 8 3"Insulation 0.7062 80.00% 4.45 57916 21.14 0.08 29.32 714.61 137.99

23Oil-FiredWaterHeaters

Modeling Design Options
The following five design options are being considered to improve the efficiency ofoil-fired water heaters:
* heat traps * increasedjacket insulation * improved flue baffle * increased heat exchange surface area * interrupted ignition Each design option isbriefly discussed below along with a description ofhow itwas modeled. Since there is no oil-fired water heater simulation model, the oil-fired water heater is analyzed using spreadsheet-based calculations. The discussion begins with the analysis ofthe baseline models using polyurethane insulation blown with HFC-245fa and water-blown insulation. As noted previously, these baseline models are referred to as the two "2003" baseline models.
2003 Baseline Model. As discussed above inthe sections on the electric and gas 2003 baseline models, HFC-245fa blowing agent has a3.0% higher conductivity than HCFC-141b and water-blown insulation has a42.0% higher conductivity than HCFC-141b. To compensate for the increased conductivity, the thicknesses ofthe HFC-245fa-based insulation and the water-blown insulation were increased in the 2003 baseline models toprovide the sameEF performance required by thepresent standard.
Heat Traps. The impact ofboth metal and plasticheat traps were analyzed for oil-fired water heaters. Bothtypes ofheat traps prevent the losses associated withthe circulation ofhot water into the plumbing.
Increased JacketInsulation. Most oil-fired water heaters on the market today provide at least 1-in. (2.5 cm) thickjacket (sides andtop) insulation. The analysis assumes that polyurethane foam insulation is used on the baselineperformance model. Although increasing the insulation thickness reduces the standby loss, itdoes affect manufacturing costs, shipping costs, and may present installation problems. Because ofthese potential problems, the maximum insulation thicknesses were limitedto 3 in. (7.6 cm) for this analysis. This appears to be the maximum thickness ofinsulation used by any manufacturer ofpresentresidential electric, gas, or oil water heater models. For HFC-245fa foam insulation, we simulated the performance ofan oil-fired water heater insulated with 2, 2/2, and 3-in. (5.1 cm, 6.4 cm, and 7.6 cm) HFC-245fa-based insulation in addition to the 2003 baseline model. Similarly, forwater-blown foam insulation, we simulated the performance ofan oil-fired waterheater insulated with 2, 21/2, and 3-in. (5.1 cm, 6.4 cm, and 7.6 cm) foam insulation in addition to the 2003 baseline model. In this regard, DOE would likecomments and data on howthe manufacturers might deal with
24the increased insulation thicknesses in small spaces. Improved Flue Baffle. The standard flue baffle is atwisted strip ofmetal inserted into the flue. It increases the turbulence offlue gases and improves heattransfer tothe walls ofthe flue. The geometry ofthe flue baffle can be modified to increase its effectiveness. For present oil-fired water heater designs, it isbelieved that an improved flue baffle can increase the recovery efficiency (RE) ofa baseline design from 76% to about 78% at relatively low cost. Efficiency improvements beyond this are more difficult to achieve with aflue baffle due to thehighheat rate ofoil-fired waterheaters and the fast transit times for the flue gases. Inthis analysis, improvements to the flue baffle design were assumed to bring the recovery efficiency to 78%.
Increase Heat Exchange Surface Area. This design option represents anumber ofpossible design modifications that would increase the surface area for heat exchange. Recovery efficiencies of up to 82% are reported by the manufacturer for available products; 82% RE is used here torepresent the improvement offered by this design option. The use ofthis type ofinternally finned flue is assumed topreclude the use ofimproved flue baffles, and hence the increased heat exchange surface area design option is an alternative to theimproved flue baffle design option. InterruptedIgnition. This design option is an interrupted ignition device that ignites the burner directly by generating a short-lived spark. This isin contrast to the intermittent ignition system ofthe baseline model, which is constantly on duringthe on-cycle.

25ManufacturerCosts All manufacturing cost estimates for a 32-gallon (120-liter) oil-fired water heater were disaggregated into variable (material, labor,overhead, transportation) and fixed (capital, product design) costs. Design option variable and fixed costs were calculated on aper unit basis and expressed as an incremental increase over the existing baseline design. The breakdown ofthe manufacturing costs for all design options are given in Tables 8a and 9a. Existing Baseline Model. Cost estimates for the existing baseline model-a water heater with 1-in. (2.5 cm) foamedjacket insulation using HCFC-141b as a blowing agent-were provided by an independent consultant. Industry estimates for manufacturers' costs ofoil-fired water heaters were not collected by GAMA.
2003 Baseline Model. To convert the manufacturer costs for the existing baseline model to that ofthe 2003 baseline model with either HFC-245fa or water-blown insulation, the amount and cost ofmaterials are taken into account. The additional material costs (primarily foam and sheet metal costs) associated with the 2003 baseline model level ofHFC-245fa or water-blown insulation were determined by adding to the baseline the costs associated with acomparable level ofHCFC-141b foam insulation.
Heat Traps. Fixed and variable cost estimates forheat traps are based on data from independent consultants.
Increased Jacket Insulation. Fixed and variable costs to increase HFC-245fa-based insulation and water-blown insulation from the nominal 1in. ofthe baseline 2003 designs to 2 in., 2'/2 in., and 3 in. were calculated based on the increased cost for the additional foam andjacket material as well as for miscellaneous foaming materials, paint, shipping cartons, labor, and overhead. These latter costs were based on dataprovided by independent consultants. Additional shipping costs were estimated based on information for the same thickness increase provided by GAMA for gas-firedwater heaters.
At least 50% ofall installations ofoil-fired waterheaters areretrofits ofa new water heater to an existing oilburner. This creates an additional cost sincethe extra insulation thickness affects the burner placement and hence the combustion characteristics ofthe water heater. The suggested solution is akit withreplacement nozzle and blast tubes. Totalmanufacturer and installation cost forthis kit was estimated by an industry consultant and applied to 50% ofinstallations ofoil-fired water heaters with insulation greater than 1in. thick. We assumed that any cost to make existing oil burners workwith 2003 baseline models could be attributed to the change in foam thickness caused by the 2003 phase-out ofHCFC-141b andnot to efficiency improvements mandated by the standard. Finally, an additional average installation costof$8.00 was estimated for oil-fired water heaters with 3in. ofinsulation. This additional cost was added toreflect difficulties that may be encountered in placing new oil-fired water heaters in existing construction.

26ImprovedFlue Baffle. Estimated manufacturer variable and fixed costs forthe improved flue baffle design were based on data provided by an independent consultant.
Increased Heat Exchange Area. Costs were estimated for an enhanced heat exchange design option that could provide 82% recovery efficiency. Estimated manufacturer variable and fixed costs for the increased heat exchange area design were based on dataprovided by an independent consultant. InterruptedIgnition. Manufacturer costs for interrupted ignition were based on the replacement ofthe intermittent ignition system common in existing oil-fired burner designs with an interrupted ignition system. Cost estimates for the interrupted ignition design option were based on data provided by an independent consultant and aburner manufacturer.

27

### Design Option RetailPrices and Installation and Maintenance Costs
The retail price isthe cost to the consumer of justthe water heater. The retail price foran existing baseline 32-gallon (120-liter) oil-fired water heater (with HCFC-141b foam insulation) was based onthe data reported by 29 companies dealing in oil-fired water heating equipment. Based on this data, the following costs were established: an average consumer cost for a base performance oil-fired water heater without burner is $446; an average consumer cost for an oil burner for an oil-fired water heater is $285; and an average installation cost for new oil-fired waterheater is $491.
A typical manufacturer to consumer markup of320% was used across all oil-fired water heater design options based on the $446 figure forthe existing baseline oil-fired water heater cost (without burner), and the estimated manufacturing cost of$139.25. This is shown inTable 8a.


### Cost-Efficiency Data
The results ofthe design option analysis for 32-gallon (120-liter) oil-fired water heaters are presented in Tables 8a, 8b, 9a, and 9b. Included in the cost and efficiency tables are disaggregated manufacturer costs, retail prices, installation costs, maintenance costs, and energy-efficiency and energy use data. The existing baseline design with HCFC-141b foam insulation ispresented in Tables 8a through 9b to show the manufacturer cost and retail price differences. Energy costs were from national average energy prices for 2003 from theAnnualEnergy Outlook1999.
The costs for all the design option combinations are shown in Tables 8a and 9a and the efficiency data is shown in Tables 8b and 9b. For the design options analyzed, the results suggest a maximum EF of0.6161 can be achieved through the use ofplastic heat traps, increased heat exchange surface area, 3in. (7.6 cm) insulation, and interrupted ignition. This design produces energy savings of 3.80 millionBtu/year ofoil and 33.28 kWh/yr ofelectricity. Using water-blown insulation, the same design has an EF of0.6103 and anenergy savings of3.57 million Btu/year ofoil and 31.53 kWh/yr of electricity.

28Table 8a. 245fa Insulation 32-gal (120-liter) Oil-Fired Water Heater: Cost Data

Incremental Costs Total Mfg to Total Cost Design Total Total Mfg Retail Retail Install. Installed Operating Maint.

No. Design Options Material Labor Overhead Variable Fixed Cost Markup Price Cost $/yr S/yr Cost

0 Existing Baseline $85.00 $18.25 $36.00 $139.25 $0.00 $139.25 3.2 $445.60 $491.00 936.60 217.94 $97.14 Oa 2003 Baseline $1.02 $0.00 $0.00 $1.02 $0.00 $140.27 3.2 $448.86 $491.00 939.86 217.94 $97.14 1 HeatTraps $3.97 $0.15 $0.05 $4.17 $1.52 $144.94 3.2 $463.81 $491.00 954.81 213.96 $97.14 2 2" Insulation $10.59 $0.44 $3.24 $13.29 $3.04 $155.58 3.2 $497.86 $509.25 1,007.11 207.84 $97.14 3 2.5" Insulation $13.69 $0.59 $4.86 $18.16 $3.24 $160.65 3.2 $514.08 $509.25 1,023.23 206.46 $97.14 4 3" Insulation $16.96 $0.73 $6.47 $23.18 $3.44 $165.87 3.2 $530.78 $517.25 1,048.03 205.53 $97.14 5 78% RE $20.71 $1.28 $7.47 $28.48 $35.44 $203.17 3.2 $650.14 $517.25 1,167.39 197.96 $97.14 6 Interrupted Ignition $37.21 $1.28 $4.49 $44.98 $36.44 $220.67 3.2 $706.14 $517.25 1,223.39 194.03 $97.14 7 82% increased HXarea $54.46 $3.03 $11.72 $62.93 $84.44 $286.62 3.2 $917.18 $517.25 1,434.43 184.66 $97.14 Notes: 1)Allcosts and prices in 1998$. 2) Incremental variable and fixed costs areper unit costs and are relative tothe 2003baseline. 3) Forthebaseline model with HCFC-141b,the totalvariable costs are provided.

Table 8b. 245fa Insulation 32-gal (120-liter) Oil-Fired Water Heater: Efficiency Data

Fuel Energy Use Electrical Energy Use Design Energy Recovery UA Daily Yearly Daily Yearly

No. Design Options Factor Efficiency Btu/day MBtu/year kWh/day kWh/year 0 Existing Baseline 0.5290 75.00% 14.49 76860 28.05 0.241 88 Oa 2003 Baseline 0.5290 75.00% 14.49 76860 28.05 0.241 88 I HeatTraps 0.5388 75.00% 13.59 75456 27.54 0.236 86 2 2" Insulation 0.5547 75.08% 12.25 73298 26.75 0.230 84 3 2.5" Insulation 0.5584 75.09% 11.95 72812 26.58 0.228 83 4 3" Insulation 0.5610 75.10% 11.74 72482 26.46 0.227 83 5 78%RE 0.5824 78.00% 11.31 69814 25.48 0.219 80 6 Interrupted Ignition 0.5863 78.52% 11.23 69815 25.48 0.082 30 7 82% RE Increased HX 0.6161 82.54% 10.69 66438 24.25 0.078 28 Area

29Table 9a. Water-Blown Insulation 32-gal (120-liter) Oil-Fired Water Heater: Cost Data

Incremental Costs Total Mfg to Total Cost Design Total Total Mfg Retail Retail Install. Installed Operating Maint.

No. Design Options Material Labor Overhead Variable Fixed Cost Markup Price Cost $/yr $/yr Cost

0 Existing Baseline $85.00 $18.25 $36.00 $139.25 $0.00 $139.25 3.2 $445.60 $491.00 936.60 217.94 $97.14 0 2003 Baseline $2.01 $0.13 $1.41 $3.54 $1.36 $144.15 3.2 $461.28 $509.25 970.53 217.94 $97.14 I Heat Traps $4.96 $0.28 $1.46 $6.69 $2.88 $148.82 3.2 $476.23 $509.25 985.48 213.96 $97.14 2 2" Insulation $7.64 $0.44 $3.30 $11.38 $3.04 $153.67 3.2 $491.73 $509.25 1,000.98 210.60 $97.14 3 2.5" Insulation $10.17 $0.59 $4.95 $15.71 $3.24 $158.20 3.2 $506.24 $509.25 1,015.49 208.78 $97.14 4 3" Insulation $12.84 $0.74 $6.60 $20.17 $3.44 $162.86 3.2 $521.14 $517.25 1,038.39 207.49 $97.14 5 78% RE $16.59 $1.29 $7.60 $25.47 $35.44 $200.16 3.2 $640.50 $517.25 1,157.75 199.83 $97.14 6 Interrupted Ignition $33.09 $1.29 $7.60 $41.97 $36.44 $217.66 3.2 $696.50 $517.25 1,213.75 195.87 $97.14 7 82%RE Increased HX $46.59 $2.49 $10.85 $59.92 $84.44 $283.61 3.2 $907.54 $517.25 1,424.79 186.41 $97.14 Area Notes: 1)Allcosts and prices in 1998$. 2) Incremental variable and fixedcosts are perunit costs and arerelative to the2003 baseline. 3) For thebaseline model with HCFC-141b, thetotal variable costs areprovided.
Table 9b. Water-Blown Insulation 32-gal (120-liter) Oil-Fired Water Heater: Efficiency Data Fuel Energy Use Electrical Energy Use Design Energy Recovery UA Daily Yearly Daily Yearly

No. Design Options Factor Efficiency Btu/day MBtu/year kWh/day kWh/year 0 Existing Baseline 0.5290 75.00% 14.49 76860 28.05 0.241 88 Oa 2003 Baseline 0.5290 75.00% 14.49 76860 28.05 0.241 88 1 Heat Traps 0.5388 75.00% 13.59 75456 27.54 0.236 86 2 2" Insulation 0.5474 75.04% 12.86 74270 27.11 0.233 85 3 2.5" Insulation 0.5522 75.06% 12.46 73629 26.87 0.231 84 4 3" Insulation 0.5556 75.09% 12.18 73176 26.71 0.229 84 5 78%RE 0.5769 78.00% 11.73 70473 25.72 0.221 81 6 Interrupted Ignition 0.5808 78.52% 11.65 70474 25.72 0.083 30 7 82% RE Increased 0.6103 82.54% 11.09 67066 24.48 0.079 29 HX Area

30