Hello All -
I don't know whether I am understanding the R value input in eQuest in the
way its supposed to be.
In the Building Envelope Constructions *(3-25) in the DD Wizard:*
Construction: Custom, layer by layer construction
Layer-by layer: Arena Roof (name of the roof I have created)
In the layer by layer window I use the 'Specify Resistance' (under the spec
method) option and insert the overall R value of the roof directly below in
the box.
When I go to the.inp file, I see the following -
"EL1 Roof Construction" = CONSTRUCTION
TYPE = U-VALUE
U-VALUE = 30
ABSORPTANCE = 0.6
ROUGHNESS = 1
It says the U -value is 30 which is really low. Am I missing something here
in understanding the U-value and R value. (I have inserted the r value as 30
not the U value)
Thank you for your comments in advance.
--
*Pranita.
*
It sounds like you are trying to use a U-value as a layer. This will give
you problems. Create a material with the resistance you want and then use it
as one of the layers for your wall (construction).
Carol
Hi Pranita,
U-value is the inverse of R value. A U-30 is the equivalent of R-0.03. Likewise, if you have an R-30 roof, you would have a U-(1/30) = U-0.03. Is it possible you entered in R-value where you were meant to enter U? I would check, and maybe try to change what you've entered.
Be careful about which units you're using, though. I think the wizards use IP units, but the INP file has metric? Not sure.
Good luck!
Alex Krickx
I am re-phrasing my question:
* *
*In "Building Envelope Constructions" window (3 of 25) I put an Overall
R-Value of 30 h-ft2-?F/Btu...*
*But, when I go into the .inp file in the roof construction details, I see a
U Value of 30 Btu/h-ft2-?F!?*
*It is not the same thing!*
* *
*Does it mean I enter the U value though eQuest is asking for R-value (DD
wizard). *
*Why is eQuest not converting the R-value entered to U-value.*
* *
*Please let me know.*
* *
*Thanks in advance!*
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