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R-values of reflective insulation materials

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Posted by nicksanspam on April 28, 2008, 3:20 pm
 
Adapted from "Prediction of the thermal performance of single and
multi-airspace reflective insulation materials" by Andre O. Desjarlais
and David W. Yarbrough, from ASTM STP 1116--Insulation Materials, Testing
and Applications, Ronald S. Graves and Donald C. Wysocki, editors, 2nd volume,
October 1991, pp 24-43:

20 DATA 2.5,5.09,7.5,1.4959,-0.608,6.359e-2,6.5572e-3,2.7129e-4
30 DATA 3.5,4.68,7.82,-1.3771,.2989,5.93e-3,1.2676e-3,8.7056e-2
40 DATA 2.5,4.35,7.2,-2.2234,0.6784,-3.028e-2,1.6481e-3,2.3528e-2
50 DATA 0,0,0,0,0,0,0,0
60 DATA 2.5,3.49,6.8,-.862,.2912,-3.863e-4,.16645,-1.397e-2
70 DATA 2.5,4.14,6.9,-.3,.0381,2.409e-2,1.5679e-2,-3.4369e-2
80 FOR I=0 TO 5
90 READ GR0(I),GR1(I),GR2(I),A(I),B(I),C(I),A2(I),A3(I)
100 NEXT I
110 DIR=0'heatflow direction
120 IF DIR=-1 THEN DIR$="down"
130 IF DIR=0 THEN DIR$="horiz"
140 IF DIR=1 THEN DIR$="up"
150 DIAG=0'0 for up or down, 1 for diagonal heatflow
160 IF DIAG=0 THEN DIAG$="no" ELSE DIAG$="yes"
170 I=2*DIR+DIAG+2'index (0-5, skipping 3)
180 T10'surface 1 temp (F)
190 T2p'surface 2 temp (F)
200 DTS(T2-T1)'temp diff
210 TBAR=(T1+T2)/2'mean temp
220 HR=.00686*((TBAR+460)/100)^3'radiation conductance (Btu/h-F-ft^2)
230 E1=.05'surface 1 emittance
240 E2=.05'surface 2 emittance
250 E=1/(1/E1+1/E2-1)'effective emittance
260 L=3.5'airspace width (inches)
270 LGR=LOG(DT*L^3)/LOG(10)+3.4146-.004359*TBAR+3.6441E-06*TBAR^2'log10 Grashof
280 IF LGR<LOG(GR0(I))/LOG(10) THEN LNU=0: GOTO 320
290 IF LGR>=LOG(GR1(I))/LOG(10) THEN LNU=A(I)+B(I)*LGR+C(I)*LGR^2:GOTO 320'eq 5
300 LNU(I)*(LGR-LOG(GR0(I))/LOG(10))^2
310 LNU=LNU+A3(I)*(LGR-LOG(GR0(I))/LOG(10))^3'equation 6
320 NU^LNU'Nusselt number
330 K=.0003053*TBAR+.1575'air conductivity (Btu-in/F-ft^2-F)
340 HC=K*NU/L'convection conductance
350 R=1/(E*HR+HC)'US R-value (ft^2-F-h/Btu)
360 PRINT "gap (in):",L
370 PRINT "dir:",DIR$,"diag:",DIAG$
380 PRINT "T1 (F):",T1,"T2 (F):",T2
390 PRINT "Tmean (F):",TBAR,"dT (F):",DT
400 PRINT "E1:",E1,"E2:",E2
410 PRINT "Eeff:",E
420 PRINT "R-value:",R

gap (in):      3.5
dir:           horiz        diag:          no
T1 (F):        30           T2 (F):        70
Tmean (F):     50           dT (F):        40
E1:           .05           E2:           .05
Eeff:          2.564103E-02
R-value:       2.461726

Nick


Posted by JoeSpareBedroom on April 29, 2008, 4:55 am
 

In Basic....



Posted by ransley on April 29, 2008, 7:33 am
 
Can anyone understand what he posted, will it actualy help
themselves !  No..its nickys numbers, again.

Posted by Solar Mike on April 29, 2008, 10:08 am
 
What version of basic is this, looks like GWBasic or TurboBasic, something I
last used about 15 - 20 years ago. Can you still get it. Have been running
VB.Net last 8 years, and VB6 before that.
If someone could point me in the direction of where to get a suitable
windows version to run this, would be cool to try running the code.

Cheers
Mike (NZ)



Posted by JoeSpareBedroom on April 29, 2008, 12:12 pm
 
It would be even cooler to go read a book.



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