## - FiredWaterHeater E n gineering Analysis-Overview

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## I David Winiarski Pacific Northwest National Laboratory

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## -FiredWaterHeater 

# ineering Analysis Methodology

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### Key Notes:



### · No readilyavailable oil firedsimulation model * Designoptionperformancebasedon engineering calculations forenergyloss, assumptionsabout achievable performance, andin one case, component levelresults from TANKsoftware * WaterHeaterAnalysis Model (WHAM) used for energy consumption calculations * Cost data obtainedfrom industry consultants and limitedphone surveys

# AalyticModelAssumptions

M M 

### : 32 gal. Intermittant Ignition Nominal Volume 90,000 Btu/hr Energy Factor Fuel Input Rate (EF) = 0.529 282 Watts RecoveryEfficiency Electric Consump. (RE) = 0.75

1in. Foam Insulation Standby Heat Loss Coef (HFC-245fa) (UA) = 14.494 Btu/hr-F

# Ds7ignMlodifications Considered

: Heat Traps * Increased JacketInsulation i 

## Improved Flue Baffle * Increased Heat Exchanger Surface Area m Interrupted Ignition

# .E ergy Calculations
l WHAM equation used to estimate energy consumption 

### ~ ? vol.dens.Cp,(Ttadl- Tin) 1 o(T- T l 

### b) Qi= 1- + 24.UADo(Ttank- Tamb) `OE POtDOE * 24- Loss_continuous + (24-Burner Operating Hours) Loss_flue_off + (Burner Operating Hours Loss_flue_on) = Qdraw/EF- Qdra * Loss_continuous + Loss_flue_on =Input (1
- Recovery Efficiency)

# ling Techniques Analytic Model Change insulation to 245fa based foam - performance same as 

## B; g ,baseline model ei I1 Analytic Model + Heat Reduction in UA from TANK traps simulation .2 #1+ 2 in.insulation Reduction incontinuous losses I ________from tank 3 #2 + Improved Flue Recovery Efficiency raised to 0.78 Baffle 4 #2 + Increased Heat Recovery Efficiency raised to 0.82 Exchanger Area 5a #3 + Interruptible Ignition Assume 20 sec. igniter on-time per firing 5b #4 + Interruptible Ignition Assume 20 sec. igniter on-time per firing

# ' ergy lmpact of Design Opions

, DDesign EF RE UA ___:~f~

__________ _________ (Btu/hr-F) iO 0 Existing 0.529 0.750 14.494 Oa Analytic model 0.529 0.750 14.494 1 Oa + Heat Traps 0.539 0.750 13.595 2 1+ 2 in. Foam Insulation (tank only) 0.555 0.751 12.241 3 2 + Improved Flue Baffle 0.576 0.780 11.786 4 2 + Increased Heat Exchanger Area 0.606 0.820 11.216 5a 3 + Interrupted Ignition 0.580 0.785 11.708 5b 4 + Interrupted Ignition 0.610 0.825 11.142

# stImpact of Design Option
Design MFG Cost Retail Annual Simple Pricea ' b Energy Payback Cost (yrs) 0 Existing $139.25 $445.60 $217.94

--- Oa Analytic model $140.27 $448.86 $217.94 1 Oa + Heat Traps $144.94 $463.81 $213.96 3.7 2 1+ 2 in. Foam Insulation $155.89 $498.85c $207.80 6.7 3 2 + Improved Flue Baffle $193.19 $618.210 $200.08 10.5 4 12 + Increased Heat Exchanger Area $259.14 $829.25c $190.40 14.5 5a 3 + Interrupted Ignition $210.69 $674.21C $196.41 11.2 5b 4 + Interrupted Ignition $276.64 $885.25c $186.64 14.5 a A markup of 3.2 was applied to manufacturing cost to estimate retail price. bBase burner cost not included. cAn additional $18.25 per installation was added to the installation expense to account for the use ofa longer blast tube and nozzle on 50% of the burners. This additional cost must be added to the retail price to calculate the simple payback

# ?Ii-specific areaswhereDOE would

~,e comments * Use ofadditionalinsulation with existing 

## burners. | * Baseline manufacturing costand

" manufacturer-to-retail markup assumed m Manufacturing cost estimates fordesign options * Industry impact ofspecific design options