[Bldg-sim] change both U-EFF & UF/UWMat?

[Jeremy Poling]

Eric,

You can find that article at:
http://simulationresearch.lbl.gov/dirun/1901.pdf (page 6) if you want to
look at it in more detail.  In that on page 7, they state:

"The fictitious insulating layer is required to give the correct
effective resistance for the construction..." and also "The procedure
makes the approximation that the heat transfer through an underground
surface with no exposed perimeter, such as a basement floor, is zero."

The fictitious R is to more closely approximate the realistic conditions
of the earth contact.

JEREMY R. POLING, PE, LEED AP
Senior Sustainability Analyst
Strategic Services
Site Solutions | Operations | Sustainability

EPSTEIN

Epstein is a firm believer in sustainability. We ask that you please
consider the environment before printing this e-mail.

________________________________

From: bldg-sim-bounces at lists.onebuilding.org
[mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of Eric Shadd
Sent: Wednesday, September 16, 2009 3:55 PM
To: bldg-sim at lists.onebuilding.org
Subject: [Bldg-sim] change both U-EFF & UF/UWMat?

 

There was an article in BUILDING ENERGY SIMULATION, Vol 19,  No 1,
Spring 1998, called "Underground Surfaces How to Get a Better
Underground Surface Heat Transfer Calculation in DOE-2.1E".  It outlined
the process for converting F- and C-factors into DOE2 inputs.  That
article's process required changing both the U-EFFECTIVE and a
Ficticious R Material (Typically called UF/UWMat in eQUEST).

 

Does anyone know why they required changing both the U-EFFECTIVE and the
Ficticious R (UF/UWMat)?  We've run some parametrics and found the
energy use difference between changing only U-EFFECTIVE versus changing
both the U-EFFECTIVE and Ficticious R to be small.

 

-Eric

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.onebuilding.org/pipermail/bldg-sim-onebuilding.org/attachments/20090917/a45a95ec/attachment-0002.htm>