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R-values of reflective insulation materials

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R-values of reflective insulation materials nicksanspam 04-28-2008
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Posted by JoeSpareBedroom on April 29, 2008, 8:12 am
>> > nicksans...@ece.villanova.edu wrote in
>>
>> >> 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$="yes"
>> >> 170 I=2*DIR+DIAG+2'index (0-5, skipping 3)
>> >> 180 T1=30'surface 1 temp (F)
>> >> 190 T2=70'surface 2 temp (F)
>> >> 200 DT=ABS(T2-T1)'temp diff
>> >> 210 TBAR=(T1+T2)/2'mean temp
>> >> 220 HR=.00686*((TBAR+460)/100)^3'radiation conductance (Btu/h-F-ft^2)
>> >> 230 E1=.05'surface 1 emittance
>> >> 240 E2=.05'surface 2 emittance
>> >> 250 E=1/(1/E1+1/E2-1)'effective emittance
>> >> 260 L=3.5'airspace width (inches)
>> >> 270
>> >> LGR=LOG(DT*L^3)/LOG(10)+3.4146-.004359*TBAR+3.6441E-06*TBAR^2'log10
>> >> Grashof 280 IF LGR<LOG(GR0(I))/LOG(10) THEN LNU=0: GOTO 320
>> >> 290 IF LGR>=LOG(GR1(I))/LOG(10) THEN LNU=A(I)+B(I)*LGR+C(I)*LGR^2:GOTO
>> >> 320'eq 5 300 LNU=A2(I)*(LGR-LOG(GR0(I))/LOG(10))^2
>> >> 310 LNU=LNU+A3(I)*(LGR-LOG(GR0(I))/LOG(10))^3'equation 6
>> >> 320 NU=10^LNU'Nusselt number
>> >> 330 K=.0003053*TBAR+.1575'air conductivity (Btu-in/F-ft^2-F)
>> >> 340 HC=K*NU/L'convection conductance
>> >> 350 R=1/(E*HR+HC)'US R-value (ft^2-F-h/Btu)
>> >> 360 PRINT "gap (in):",L
>> >> 370 PRINT "dir:",DIR$,"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
>>
>> > Another rap tune?
>>
>> In Basic....- Hide quoted text -
>>
>> - Show quoted text -
>
>>Can anyone understand what he posted, will it actualy help
>>themselves ! No..its nickys numbers, again.
>
> 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)
>

It would be even cooler to go read a book.



Posted by on April 29, 2008, 9:49 am

>What version of basic is this, looks like GWBasic...

Yup. IIRC, gwbasic.exe is still available free from a web site and runs from
a DOS prompt. BWbasic is almost identical and runs with Ubuntu linux. The new
ASHRAE comfort spec also contains a gwbasic program.

It's not easy to estimate the US R-value of a reflective insulation system.
It varies from about 1 to 10, depending on emissivities, airspace thickness,
mean temperature, temperature difference, and the direction of heatflow.
The complex table in the ASHRAE HOF rarely matches real situations, but
this program can help with that.

Nick


Posted by Solar Mike on April 29, 2008, 3:42 pm

> Yup. IIRC, gwbasic.exe is still available free from a web site and runs
> from
> a DOS prompt. BWbasic is almost identical and runs with Ubuntu linux. The
> new
> ASHRAE comfort spec also contains a gwbasic program.
>
> It's not easy to estimate the US R-value of a reflective insulation
> system.
> It varies from about 1 to 10, depending on emissivities, airspace
> thickness,
> mean temperature, temperature difference, and the direction of heatflow.
> The complex table in the ASHRAE HOF rarely matches real situations, but
> this program can help with that.
>

Thanks for that Nick I will google somewhere to download it from.
Was going to use 3 reflective air spaced layers behind a trickle solar panel
array system.

Mike



Posted by on April 29, 2008, 3:50 pm
On Wed, 30 Apr 2008 07:42:22 +1200, "Solar Mike"

>
>> Yup. IIRC, gwbasic.exe is still available free from a web site and runs
>> from
>> a DOS prompt. BWbasic is almost identical and runs with Ubuntu linux. The

        Isn't that special :-)

>> new
>> ASHRAE comfort spec also contains a gwbasic program.

        Oh, those radical modern bastards ! :-)

        How's your sliderule ? Still a slippin' and a slidin' ?


--
Click here every day to feed an animal that needs you today !!!
www.theanimalrescuesite.com/

Paul ( pjm @ pobox . com ) - remove spaces to email me
'Some days, it's just not worth chewing through the restraints.'
'With sufficient thrust, pigs fly just fine.'
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Posted by on April 29, 2008, 8:29 pm
wrote:

>.p.jm@see_my_sig_for_address.com wrote:
>> On Wed, 30 Apr 2008 07:42:22 +1200, "Solar Mike"
>>
>>>> Yup. IIRC, gwbasic.exe is still available free from a web site and runs
>>>> from
>>>> a DOS prompt. BWbasic is almost identical and runs with Ubuntu linux. The
>>
>>         Isn't that special :-)
>>
>>>> new
>>>> ASHRAE comfort spec also contains a gwbasic program.
>>
>>         Oh, those radical modern bastards ! :-)
>>
>>         How's your sliderule ? Still a slippin' and a slidin' ?
>
>I made mine into a really fine backscratcher. ;-p
>>
>>

        And, for those hard to reach places .....

        MULTIPLY !!!!!


--
Click here every day to feed an animal that needs you today !!!
www.theanimalrescuesite.com/

Paul ( pjm @ pobox . com ) - remove spaces to email me
'Some days, it's just not worth chewing through the restraints.'
'With sufficient thrust, pigs fly just fine.'
HVAC/R program for Palm PDA's
Free demo online at www.pmilligan.net/palm/
Free 'People finder' program now at www.pmilligan.net/finder.htm

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