[BLDG-SIM] eQuest question

Steven Gates steve.gates at doe2.com
Wed May 4 16:00:12 PDT 2005


The calculation of effective U-values is extremely important.  In addition,
local factors may have a significant effect on the effective ground
temperature, and the resulting heat transfer.  

Many buildings, including most residential buildings, have landscaping
immediately around the majority of the perimeter.  This landscaping shades
the ground, may be mulched, and is usually irrigated.  In the summer, I
suspect that the ground temperature is more likely a function of the wetbulb
temperature, rather than the drybulb.  In the winter, mulching will act as
an insulating layer.

Commercial buildings may have large expanses of concrete or black asphalt
poured around the perimeter.  I would expect that both of these surfaces
would influence the effective ground temperature, with unshaded black
asphalt resulting in the highest ground temperature.

Is anyone aware of studies that have attempted to identify and address these
types of local factors?

-----Original Message-----
From: postman at gard.com [mailto:postman at gard.com] On Behalf Of Jeff Haberl
Sent: Wednesday, May 04, 2005 7:12 AM
To: BLDG-SIM at GARD.COM
Subject: [BLDG-SIM] eQuest question

FYI

I would be very careful about underground calcs in DOE-2. I'm not sure about
DOE 2.2, but DOE-2 users need to follow the latest advice from LBNL
regarding effective U-values. 

Also, there is the issue of ground temps. DOE-2 uses the temps from the
weather tape, and if this is Tmy-2,  Then these are synthetic temps from
Kusuda's work in the 1960-70s, which may or may not be accurate. DOE-2 also
does not calc infiltration below grade, so this needs adjusting. Finally,
you must have CWFs turned to get an accurate answer. 

Jeff
BB 8=!  8=)  :=)  8=)  ;=)  8=)  8=(  8=)  :=')  8=)  8=)  8=? BB

Jeff S. Haberl, Ph.D., P.E.............................jhaberl at esl.tamu.edu

Professor......................................................Office Ph:
979-845-6507

Department of Architecture.......................Lab Ph: 979-845-6065 

Energy Systems Laboratory.......................FAX: 979-862-2457 

Texas A&M University..............................77843-3581

College Station, Texas, USA.......................URL: www-esl.tamu.edu

BB 8=/  8=)  :=)  8=)  ;=)  8=)  8=()  8=) 8=?  8=)  8=)  8= BB


-----Original Message-----
From: postman at gard.com <postman at gard.com>
To: BLDG-SIM at gard.com <BLDG-SIM at gard.com>
Sent: Wed May 04 08:45:17 2005
Subject: [BLDG-SIM] eQuest question


Don,
In addition to Renee's points, heres my 2 bits

1. I havent done it by converting an external wall to an underground wall
before. I would be wary of just changing the properties (i.e. construction
materials). I think there is a different thermal calculation set for
underground walls than exterior walls (no solar radiation for instance), but
to be honest I havent read the DOE2.2 documentation on this. What I normally
do (and this might be what Renee was describing) is to right click on the
space that you want the underground wall. It offers 3 child components that
you can create - exterior, interior, and underground. I would pick
underground, and then copy its properties from the exterior wall, before
deleting the extrior wall.

2. If you are modelling district energy (either steam or chilled water), you
should also create meters for them.

4. yes - you can model it as an exterior shade.

Vikram Sami,  LEED AP
Direct Phone 404-253-1466 | Direct Fax  404-253-1366

LORD, AECK & SARGENT ARCHITECTURE
Responsive Design * Technological Expertise * Exceptional Service
www.lordaecksargent.com




-----Original Message-----
From: postman at gard.com [mailto:postman at gard.com]On Behalf Of Renee J.
Azerbegi
Sent: Tuesday, May 03, 2005 11:22 PM
To: BLDG-SIM at GARD.COM
Subject: [BLDG-SIM] eQuest question


Don, See below for your answers.
Renee

-----Original Message-----
From: postman at gard.com [mailto:postman at gard.com] On Behalf Of Don Saal
Sent: Tuesday, May 03, 2005 3:19 PM
To: BLDG-SIM at GARD.COM
Subject: [BLDG-SIM] eQuest question

To all,

A few questions regarding the modeling ability of eQuest:

1.  Can you model portions of a given shell as underground and exterior
wall?  If so, how (in the detailed mode)?


YES - IN DETAILED EDIT COPY THE EXISTING WALL THAT IS PARTIALLY UNDERGROUND
AND ADD ANOTHER WALL. CHANGE THE HEIGHT OF EACH WALL SO THAT THE TOTAL IS
THE SAME AS THE ORIGINAL WALL. CHANGE THE UNDERGROUND WALL TYPE TO
UNDERGROUND WALL AND DEFINE THE CHARACTERISTICS.

2.  The building in question gets its chilled and hot water from a central
facility.  Can you model this?

YES. IN DETAILED EDIT MODE MODEL AS DISTRICT HOT WATER AND DISTRICT CHILLED
WATER. INCLUDE THE EFFICIENCY OF THE HEAT EXCHANGERS (CONVERTERS).

3.  Can custom wall types, area types, etc be created to be used in the
Design Wizards?  Or can custom types only be used in the detailed mode?

I BELIEVE ONLY IN DETAILED EDIT MODE YOU CAN CREATE CUSTOM FEATURES.

4.  In the detailed mode, can you identify an exterior wall adjacent to a
conditioned space (ie another building that is not being modeled)?

YES.

Thank you for any input.  If you know of any resources (for eQuest
specifically) that address these issues and others please let me know.

SEE WWW.DOE2.COM FOR LIBRARY OF INFORMATION ON DOE2.2 (EQUEST/POWERDOE)

RENEE, AMBIENT ENERGY, INC.

Sincerely,


Don Saal, PE
Mechanical Systems

Affiliated Engineers, Inc.
5802 Research Park Blvd.
Madison, WI 53719

Phone: 608-236-1150 (direct)
Fax: 608-238-2614
Email: dsaal at aeieng.com


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