# =N LS

Thermal Performance of Water Heaters Using Alternative Foam Blowing Agents A. HunterFanney

Robert R. Zarr Heat TransferGroup NationalInstitute ot Standardsand Technology November 10. 1998 

# NI Acknowledgements

o 

### BASF

- Michael Kurpu 

### * BradJfrdWhite

- F,'.ric L.anis 

### * NationalInstitute tU Standards and Technology

- Keith Eberhart

- Jareb Keiav-Paprocki

- Stirt/le' 7. Vloreh(ise 

### * PacificNorthw'vest Laboratories l - 'crrclt freeman 

## Page 1

# NISr Overview * Goal * Scope * TechnicalApproach * Apparatus * ExperimentalResults + 

### Summarv



# Goal * Measure and Compare

- Thermal Conductivitv ofPolvlirethaneFluums

Produced Using Blowing Agelnts * HCFC - 14lb *IF - 0/4CO "*HFC- 245fa

- Energy Factorsof Water Heaters Insulated

With Resulting Polyurethane Foams


### Page 2

# NIST Scope * Blowving Atgennts

- l('f'(" I4'h [ I

- flF'('- 24. ta f . 

### * Foar Block Specimensx ''

- 24' 2V x 2.6 inl (nominal) 

### * Water Heaters 1

- Residential

- Electric- .

- 

### .o (;allon (nominal) ' ', . 

# N-IST Technical Approach * Water HeatersInsulatedand Foam Blocks Produced

Siimu/ltaneousllV fr Each Blovwin- A-gent

- 4 f'oam'Block Specimens

- 4 Water Heater Specimens 

### * Insulation ProductionDatesand NIST MeasurementDates

Selected to Ensure t EquivalentAging ttowing Production t|hermal C(mductim it, Elapsed iime | laergy Factor Elapsd Timte Atent Da euremen t ae l M r met Das (Days) t [4il, ! , lt," [ q*i. 's.l , * 20 %- l q' If;,4 

### I..... ...... i . ,.......... - 

### . 

## Page 3

# -NIST Experimental Apparatus + Thermal Conductivity Measurements

- NIST 1-meter GuardedHot Plate Vation's StandardforThermal Conductivity Measurements * ASTM Test Method C 177 

## * Energy Factor andOverall HeatLoss Area Coefficient Measurements

- VIST WaterHeaterLaboratory * Supply Water Temperature Control * Ambient TemperatureControl

FullyAutomated * Infrared Imaging System 

# =NIST ExperimentalResults * Thermnal Conductivity 

### * OverallHeat-Loss-Area Coefficient * t

Eergy Factor


## Page 4

# NIST Thermal Conductivity Measurement Conditions SPECIMENS_ M.iccrlal i rFh!kncs |Bu!k [,1el.< | i2 HO/rCO. S | ! 2 .. ) TEST CONDITIONS Hot 6S-rt7- ! C;ii ouri r in- Amicn Arir IF I F 'F 1001) 7 5 3I | 120 o? ; ' 

### 1 I'() j .D,. if) "I I 110 .; S 7i i(), : 

# Nt Thermal Conductivity of Polyurethane Foams

-z ;FCf41b FC

24a -

-_- - r - - '^ *,.-.„., *w ^ ^ * .
2 - _ _ - I , | j ....-s. _. g 5



### Page 5

# N LS Thermal Conductivity of Polyurethane Foams H0/CO, Versus HCFC -141b Ihcrnli Coulduclvity Btuln/h-t: -F UDltftrcnce M1 c.n Tcilperatur lr 'F: HCFC-1 lb 1-O/CO: Percent *3 3 0.146 0211 426 I3 0.218 425 113

S 1O.9 0.225 415 HFC-24Sfa VeYrus HCFC -14lb Therilu l Cunlducrivity i Btu il/h

t 'F) Dlifereilc lMeasll rnmr:rature i 'F. HCFC-14 b IIFC-245fa Percent 3i 0 148 0.144 -2.9 I13 0153 0.149 -2.5 101s 0. Io5 0.153 -3.4 

# Ni Overall Heat-Loss-Area Coefficient 

# I ^ ^J -- 

### 0), Pa= Q,., , I .2,1 = li, . T' l , -7- 1 ,'.)) 

### Page 6

# FN 

# Overall Heat-Loss-Area Coefficient Setting the hot water load to zero and rearranging Eqs. 1.2. and 3, yields Qy,, is the electrical energy supplied to the water heater. Btu Q,,, is the thermal energy removed/lost from the storage tank. Btu Q,,we,, is the change in stored energy. Btu Qh,, isthe hot water load. Btu Q., is the heat loss from the storage tank, Btu 

### 7',,,v, is the average storage tank temperature i F) 71, is the ambient temperature 'F) r is the test duration. (h) and q is the heating element efficiency (0.98) 

# N LST Overall Heat-Loss-Area Coefficients Tank Number Blowing Agent Overall Heat-Loss-Area Coefficient (Btu/°Fhrl -)24a2 !2-5 7 l1 *l6 I19242-1 2-.6-h | W.lt O i 16 l"242 12.53 7 aiO i *lh0'] 2'42-12- S66 Wrcr/'1:C, 1 1a)242-12-6 7* | Walter,''O, 3j 192421--12 86 38 Wa1er/O, 36 10242 12 56 ' Water/C( O. : .l) i1-12-1io-!2 1it. IlS It242 !' I1)t-.. | & a 4i .27 i ) 242 i].10o-q 

### 1 ] lj', 1 - I 14):.{~.).c) 

## ~ 44K-, .* 

## ~ P g * 2o

1,27 IPage 7I .C 

## Page 7

# NI ST MeasuredHeat-Loss-Area Coefficient Versus BlowingAgent

Heat-Loss-Area Coefficient

'.:'. '-F .. Q l .2 hwl '- 

## i * I 111: st i Q, 

## !S .98 0 1 ! i mE - - - - .98 = "' ' ' t ' (ItS



### Page 8

# NlST 

# Energy Factor Versus Overall

Heat-Loss-Area Coefficient

*32 0 - +- . .


### I ! 3 83 * 

# -NLS, Measured Energy Factor Blowing Agent - HCFC- 141b 31ownq e HCFC · ;

r,. .. ,,,., 

### Page 9

# rNtSTMeasuredEnergy Factor BlowingAgent -H 20 

# /CO 2 Bloing Aent: N:0 CO_ 

# I'C02 1 ,,i- ,, I i.



# =NlS MeasuredEnergy Factor BlowingAgent - HFC 245fa
I alongiqA lge HFC. 21Sf


## ~I '''-*

## ~ ag 10----1


## Page 10

# ExperimentalResults
ENERGY FACTOR VERSUS BLOWING AGENT



# N IST| 

# Average Energy FactorVersus BlowingAgent 0.900 0 395 - 0.390

. II : 0 0887

0865 o0 88 81 *80 !

)360 

### Page 11

# NIST Test Tank Infrared Image

I Test Tank Infrared Image I tR-1 E ; Freeze

32.1 30.5 7728. L 27.3 25.7 24.1 1253941 .IMl C L" 98-05-20 12:07:40.74 Bradford Hhite Test Tank LS



### _ \ £ 

# -NISTTest Tank InfraredImage 1IR-1 

### Freeze 29.4 28.3 27.2 

### 26a.01 24.9 

## 23.8 22.6 21.5- 771286822.I1116 L. 98-07-07 11:56:25.85 Bradford Uhite Test Tank 

## Page 12

# Nlsr Summary + PolyurethaneBlock Specimens and Water

Heaters ProducedUsing3 BlowingAgents

- HCFC 141b

- 10/('0,

- HFC- 24'5a 

### * Thermal Conductivity Measurements

- HIO/C(O. Speciniens 43% (Greater Than IC'FC- 141b

- HFC - 245fa Specimens '3%Less Than Hi(FC- /4 lb 

### * Average OverallHeat-Loss-Area Coefficients

- l(CF( - 141b- .' /9Btu/' f hrr

- 11,0/CO, - 3.84 Btl/ F hr

- HFCA - 245fa - 3.22 Brta Fhr 

# *NIST Summary

* Energy Factor 

## Not a Strong Functionof Overall Heat-Loss-Area Coefficient

- Doubling .UA Results in a 8% Decrease in EF



### · Average Energy Factor Measurements

- fC1F( - 141b - ).Y87

- IH,(/('O,- 0.870

- 

### 1GFC- 24fa - f - 4 + 

### InfraredImages Show Significant Thermal Shunts

- Tank Bottom/Top

- Drain Valve

- Heating Element Surrounds

### Page 13