| View previous topic :: View next topic |
| Author |
Message |
The Spanker
Joined: 10 Nov 2006
Posts: 207
|
 Posted: Tue Aug 05, 2008 9:49 am
Hey RJ! About that graph... |
 |
|
|
In the newest NEWSLETTER, there is a fascinating graph.
I've taken the liberty of copying it here and adding some comments (actually they're accolades!!!  ). Please click the linky
 |
|
| Back to top |
|
 |
GRB
Guest
|
Posted: Tue Aug 05, 2008 10:46 am
|
|
|
|
I knew someone would be all over the graph when I saw it!
The way I read it was that there isn't alot of difference between 1/2" an 2"... completely opposite of the point he was thinking of making.! |
|
| Back to top |
|
|
fishtail-99
Joined: 17 Apr 2007
Posts: 1437
|
Posted: Tue Aug 05, 2008 12:03 pm
|
|
|
|
| Truly amazing graph! Again if you believe what is on it, the difference in R factor between a 3/4" wall and a 2" wall is about 5%. RJ is very fond (it brings tears to his eyes) of that photo showing the difference in wall thickness between a BGE and a Kamado. The difference that he alleges in this R factor business is negligible by his own data. |
|
| Back to top |
|
|
The Spanker
Joined: 10 Nov 2006
Posts: 207
|
Posted: Tue Aug 05, 2008 12:50 pm
|
|
|
|
| GRB wrote: | | The way I read it was that there isn't alot of difference between 1/2" an 2"... completely opposite of the point he was thinking of making.! |
| fishtail-99 wrote: | | ... the difference in R factor between a 3/4" wall and a 2" wall is about 5%. ...The difference that he alleges in this R factor business is negligible by his own data. |
I seriously wanted to nail him on that point too. BUT the accompanying text states that this was using the 1970 forumla... the stuff that he is fond of stating was very similar to Corningware ... and hence the data he obtained (as if!) wouldn't necessarily apply to the refractories. I know I'm giving them far too much credit. But, it's defensible just the same.
But the thinness of those test sheets... Wow! The thinnest standard gauge wire (.7mm) used in chicken wire is FOUR times thicker than the alleged 1/150" ceramic sheet he tested! The man was a fool to waste his talents on cookers. |
|
| Back to top |
|
|
Schadenfreude
Joined: 19 Sep 2007
Posts: 20
|
Posted: Tue Aug 05, 2008 1:12 pm
|
|
|
|
| No damn way he did that "research". Probably just scribbled it a couple of days ago. Or, if it is from '95, it was invented for his now (in)famous "business plan". |
|
| Back to top |
|
|
Nerka
Joined: 28 Oct 2006
Posts: 187
Location: Ekwok, Alaska
|
Posted: Tue Aug 05, 2008 3:10 pm
|
|
|
|
I don't think the graph would be a curve like that. I think it should be a linear line, if you double your thickness you double your r value.
_________________
http://www.nerka-naknek.net.ms |
|
| Back to top |
|
|
The Spanker
Joined: 10 Nov 2006
Posts: 207
|
Posted: Tue Aug 05, 2008 5:41 pm
|
|
|
|
| Nerka wrote: | | I don't think the graph would be a curve like that. I think it should be a linear line, if you double your thickness you double your r value. |
I think you're right... the r value should be increasing with thickness. The reciprocal of the r value is the u value which is a measure of conductivity and would better describe what the y axis is depicting. And from my very brief reading tonight, contrary to the graph's assertion, there is no "% R factor" that is used in this manner as there is no upper limit for R with a variable thickness.
I know we have far more mathematically-learned people on board than yours truly who put down his slide rule for a hickory paddle a long time ago; mebbe one of them will chime in. |
|
| Back to top |
|
|
Nerka
Joined: 28 Oct 2006
Posts: 187
Location: Ekwok, Alaska
|
Posted: Tue Aug 05, 2008 8:58 pm
|
|
|
|
| The Spanker wrote: |
I know we have far more mathematically-learned people on board than yours truly who put down his slide rule for a hickory paddle a long time ago; mebbe one of them will chime in. |
Yea where is Syzygies when you need him?
I was wrong in thinking the r value would follow a linear path.
| Quote: | | Doubling the thickness of insulation will not double the R-value. |
from Wikipedia
But RJ's formula for the r value seems to be off.
| Quote: | | The world-wide definition of R-value is kelvin square meters per watt (K·m²/W) |
from Wikipedia
I would have loved it if there was a graph there.
_________________
http://www.nerka-naknek.net.ms |
|
| Back to top |
|
|
|
