[BLDG-SIM] Bug in Window 5.2

[Jeff Hirsch]

Joe,

I left phone messages and sent email to people in the Windows group
in 2004 on this issue; nobody ever return my messages.

I then contacted Sue Reilly and Charlie Curcija (see message below);
they confirmed my suspicions that the film coeff's in the report were wrong.
We never claimed the bug was in calculation, but that there was a bug in
the Windows 5 reports; you can see that in the email from me that Mahabir
posted to bldg-sim.  Mike's email also only says it is a bug in the report.

Charlie contacted the W&D group, as well, about the problem and they said it
didn't matter for DOE-2 (see below) ... I corrected that notion as you can see from
the message below.  Again, W&D seems to have ignored my explanation.

There are huge numbers of people using DOE-2.2 and eQUEST and some
still using DOE-2.1E ... but I was told (indirectly, as they - W5 support - did
not bother to reply to me at all) that they only focused on EnergyPlus needs
as that was what people used.

So, now the user community considers it a DOE-2/EnergyPlus issue; that the
problem was ignored due to it being only a DOE-2 issue. That seems to be a
reasonable conclusion based on the actual record, even though it may not
be a correct conclusion.

The claim that the W5 group did not know of the specific DOE-2 issue and that
it was just in the last few months it was raised is incorrect as you can see
from my email below.  Many people have raised this issue with
the group, and it was ignored.  Why it became perceived as political
is obvious to the outside world; the only thing that seemed to get it attended
to now was a user pointing out that it seemed to be political.  

So, making it "political" seemed to be the only thing that got action; maybe that is
a lesson that users will take to heart.

---
Jeff Hirsch
James J. Hirsch & Associates
Building Performance Analysis Software & Consulting
12185 Presilla Road
Camarillo, CA 93012-9243 USA
phone: (805) 553-9000
fax: (805) 532-2401
email: Jeff.Hirsch at DOE2.com
web: http://DOE2.com


----- Original Message ----- 
From: Jeff Hirsch 
To: D. Charlie Curcija 
Sent: Thursday, September 30, 2004 6:14 AM
Subject: Re: surface heat transfer coeff in W5


In addition to the hin being wrong, the center of glass u seems to be the
overall u instead.  The combination of the hin and center of glass u value
being incorrect create a VERY bad situation for DOE-2.1E users and
mildly bad situation for 2.2 users.

The info you were given on use of Hin and u-center by DOE-2.1E is
incorrect; 2.1E reads the second line of the table at the bottom of the
Window 5 DOE-2 report and collects the inside and outside h's and
u-center (not u-overall);
these are then used to calculate the "bare glass" u-value (no h's)
which is used by the custom weighting factor calculation.  If the
wrong h's or u are used then the custom weighting factors for the
spaces using that glass will be wrong. Since custom weighting
factors are the default (and very important to the hourly
load calculation) the hourly calculation for those spaces can
be way off.

These values are NOT used for the hourly window conductance
calculation; that is done using a set of therm program routines
contained within the DOE-2 LOADS program, but the LOADS
verification reports also use the U-bare values to report the
overall window U-value as well as the overall wall, facade, and
building u-values. These incorrect values confuse many users
of DOE-2 versions.

I have gotten MANY runs from people using W5 library entires
(which is very common) with badly incorrect space loads due to
this bug. There is no user fix for this problem in 2.1E if the
W5 tables are not corrected so both hin and u-center are
corrected.
---
Jeff Hirsch
James J. Hirsch & Associates
Building Performance Analysis Software & Consulting
12185 Presilla Road
Camarillo, CA 93012-9243 USA
phone: (805) 553-9000
fax: (805) 532-2401
email: Jeff.Hirsch at DOE2.com
web: http://DOE2.com


  ----- Original Message ----- 
  From: D. Charlie Curcija 
  To: Jeff Hirsch 
  Cc: Mahabir S Bhandari 
  Sent: Thursday, September 30, 2004 5:10 AM
  Subject: surface heat transfer coeff in W5


  Hi Jeff,

      Attached is a document that details how are surface heat transfer coefficients calculated in W5.  In terms of DOE2 report from W5, I believe that convective portion only for indoor coeff. is reported from W5, which is a bug, but apparently (according to my LBL colleagues), it does not affect DOE 2.1E somehow.  I haven't gotten definitive answer yet, but preliminary it looks that way.  Let me know if I can be of further help.

  Charlie

  Carli, Inc.
  18 Tanglewood Rd.
  Amherst, MA 01002
  TEL: (413) 256-4647
  FAX: (413) 256-4823
  email: curcija at fenestration.com
  web: www.fenestration.com

  STATEMENT OF CONFIDENTIALITY
  The information contained in this electronic message and any attachments to this message are intended for the exclusive use of the addressee(s) and may contain confidential or privileged information.  If you are not the intended recipient, please notify Carli Inc. immediately at either 413-256-4647 or at home at fenestration.com, and destroy all copies of this message and any attachments.
    



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