How do you do U-Values???

user12

Any help at all??

Crow92

You need to find the resistance of each material,(sometimes it is given)

You will need these two formulas,

Conductivity/Thickness = Resistance, K/T=R

and

Thickness x Resistivity = Resistance, Txr=R

*Don't forget to add in the resistance of the surface area of internal/exteral

Add together all the resistance and then This formula gets you the U-Value


1/Total resistance= U-Value.


*If it's for a new housing within regulations the U-Value is supposed to be under 0.27 but that's not always right.

Hope it helps

user12

Crow92 wrote: »

You need to find the resistance of each material,(sometimes it is given)

You will need these two formulas,

Conductivity/Thickness = Resistance, K/T=R

and

Thickness x Resistivity = Resistance, Txr=R

*Don't forget to add in the resistance of the surface area of internal/exteral

Add together all the resistance and then This formula gets you the U-Value


1/Total resistance= U-Value.


*If it's for a new housing within regulations the U-Value is supposed to be under 0.27 but that's not always right.

Hope it helps

Im sorry but am lost!!...whats up with the small and big letters?

Crow92

K=Conductivity

Small r = Resistivity

T = Thickness

big R = resistance

Your gotta make a box with all the materials and all thoses above^^^^ as headings.

Dunno how else to exlain it but thats how you do it,

user12

Crow92 wrote: »

K=Conductivity

Small r = Resistivity

T = Thickness

big R = resistance

Your gotta make a box with all the materials and all thoses above^^^^ as headings.

Dunno how else to exlain it but thats how you do it,

Ok im kinda getting it now thanks!!!...see the formulas,dya multiply or divide>>
lost there

Smcgie

Info here:

Linky

Crow92

where i wrote 'x' you multiply
where i wrote '/' you divide

the goal is to use one of the formula's to get the resistance of Everything and then to divide

1/ total resistance,

hope that helps

Crow92

Smcgie wrote: »

Info here:

Linky

The info is too broad and so much extra than what you need to deal with :rolleyes:

user12

Crow92 wrote: »

where i wrote 'x' you multiply
where i wrote '/' you divide

the goal is to use one of the formula's to get the resistance of Everything and then to divide

1/ total resistance,

hope that helps

ok say the conductivity was 1.430 and the thickness was 0.012.and i divide 1.430 by .012 and get 119.16666667
but the answer is .00839??
what am i doin wrong