UFMat value

2 posts / 0 new

So I have been reading through the archives and I have learned that once you define constructions in the wizard mode, equest generates construction layers and an arbitrary material (typically UWMat or UFMat, etc.) that are used in the detailed mode.
I believe the value of resistance generated here is a result of equest making 'continuous' layers by applying framing factors and such.

I am modeling a research lab that consists of two floors that are entirely submerged underground. The walls and roof structure are 20" thick cast-in-place concrete with a bituminous waterproofing sheet.
The bottom floor structure is simply a 6" thick concrete slab on grade with a vapor retarder.

I input the construction details as best I could in the wizard mode and I plan on adding concrete layers to make the walls and roof structure 20"thick (as 12" is the thickest dimension in wizard for cast in place concrete).

Equest generated a UWMat for all the underground walls and they have reasonable R-values ranging from 01. To 6.0

However, equest generated a UFMat that exists under all of my slab areas that has a resistance of 100 and thus a U-value of 0.01. This seems completely unreasonable considering a 6" concrete slab.
It seems that equest generated appropriate value for the thicker, underground concrete walls, but somehow the underground floor material got assigned a ridiculous resistance.

Even though this building will primarily be a load driven model, I am uneasy about bottom floor envelope resistance especially because the floor to wall ratio of the envelope is significant.
Is this something I should modify or just go with?

Thanks in advance for any input..

Lyle Keck

Offline
Joined: 2011-09-30
Reputation: 1

considered a ?slab on grade? if it is two stories below ground, due to the
depth the slab edges won?t be exposed to fluctuating temperatures as if it
was on grade at the surface.

You?ll have to decide if the values are reasonable or not (or how the
changes affect the desired results), but there is some impact from being so
far below ground that are included in that material property.

David

*
*

David S. Eldridge, Jr., P.E., LEED AP BD+C, BEMP, BEAP, HBDP

*
*

*From:* equest-users-bounces at lists.onebuilding.org
[mailto:equest-users-bounces at lists.onebuilding.org] *On Behalf Of *Lyle Keck
*Sent:* Tuesday, April 19, 2011 1:49 PM
*To:* equest-users at lists.onebuilding.org
*Subject:* [Equest-users] UFMat value

So I have been reading through the archives and I have learned that once you
define constructions in the wizard mode, equest generates construction
layers and an arbitrary material (typically UWMat or UFMat, etc.) that are
used in the detailed mode.

I believe the value of resistance generated here is a result of equest
making ?continuous? layers by applying framing factors and such.

I am modeling a research lab that consists of two floors that are entirely
submerged underground. The walls and roof structure are 20? thick
cast-in-place concrete with a bituminous waterproofing sheet.

The bottom floor structure is simply a 6? thick concrete slab on grade with
a vapor retarder.

I input the construction details as best I could in the wizard mode and I
plan on adding concrete layers to make the walls and roof structure 20?thick
(as 12? is the thickest dimension in wizard for cast in place concrete).

Equest generated a UWMat for all the underground walls and they have
reasonable R-values ranging from 01. To 6.0

However, equest generated a UFMat that exists under all of my slab areas
that has a resistance of 100 and thus a U-value of 0.01. This seems
completely unreasonable considering a 6? concrete slab.

It seems that equest generated appropriate value for the thicker,
underground concrete walls, but somehow the underground floor material got
assigned a ridiculous resistance.

Even though this building will primarily be a load driven model, I am uneasy
about bottom floor envelope resistance especially because the floor to wall
ratio of the envelope is significant.

Is this something I should modify or just go with?

Thanks in advance for any input..

*Lyle Keck** *

Offline
Joined: 2011-09-30
Reputation: 2000