I must admit we miss the function
capabilities of 2.1e. Not that I used it very often but I’ve got a
computer geek that did. We end up faking things more often when we used to be
able to plug our own patch into the code. I seem to remember hearing that this
ability was `almost’ in 2.2 but the last bit of implementation is
awaiting sufficient interest (i.e. $). Perhaps Scott can update us.
I’m also under the impression, from
good sources, that the bulk of the 2.2 code is so closely based on 2.1e that
the historical verification is still valid. Perhaps not as much with new 2.2
features.
Loop errors can be a pain, especially since they aren’t caught in
BDL processing. We’ve managed to prevent most of them by careful review
of inputs but they still occasionally pop up. Other than that the latest 2.2
versions have rarely crashed and even the latest eQuest versions crash much
more infrequently than earlier versions.
As for features – I’m sure we
could all list a number that we’d love to see. In a perfect world….
Let’s keep up the discussion.
-----Original Message-----
From: postman@xxxxxxxx
[mailto:postman@xxxxxxxx] On Behalf Of Fred
Porter
Sent: Wednesday, February 05, 2003
3:30 PM
To: BLDG-SIM@xxxxxxxx
Subject: [BLDG-SIM] DOE 2.1 vs DOE
2.2
The loops and plant in DOE 2.2 are great, the real OA
HXs, and better economizer ctrls are great, and the window module is nifty, and
Equest is amazing freeware, but .....
We still use DOE 2.1 in lots of commercial work. In my experience DOE 2.2
crashes much more often. Often this seems to be associated with excessive flow
demands on a loop, but the process of debugging is much more frustrating than
errors caught by the BDL processor. Perhaps some checking is built into Equest
or PowerDOE, and so is not done in BDL. Recent versions are better, but not
immune by any means.
DOE 2.2 does not implement the custom "functions" which we use to
input better space daylight level correlations derived from Radiance, etc, to
the DOE2 daylighting routine. Occasionally we've used functions for other
things, but this usually did seem like an exercise better suited to academia!
Only version 41j of DOE2.2 had tower free cooling, in 41i this feature was
removed. Perhaps there is a work-around I have not thought of; many of our
larger modeled buildings use flat-plate HXs for modest winter CHW loads. (The
Canadians use these extensively instead of air-side economizers, for a variety
of good reasons.)
We've never found a GUI or wizard that managed multiple ECM runs as well as
some spreadsheet or database methods we use. The available front-ends for 2.1
and 2.2 do generate initial model inputs, particularly geometry, nicely in most
cases. As far as I know, both can be used for code compliance, as long as the
code or design does not require or use waterside economizing.
Anyone else care to comment?
Chris Jones wrote:
We use DOE2.1e in our shop. Primarily because of
the significant verification against measured data that has been done on
DOE2.1e over the years. The other reason is that ASHRAE 90.1 and in
particular LEED require simulation using DOE2.1e.
Here in Canada, the Model National Energy Code, Performance Option required
simulation using EE4 (a free compliance tool http://www.ee4.com
) that used the DOE2.1e engine from Hirsh and Associates. Similar to
eQuest, you can use EE4 to quickly generate an input file then edit it for you
particular situation.
We use eQuest extensively, sometimes using the
wizard mode to get started, sometimes not. We began using DOE2.1d when it was
first available on PC platforms and kept with it through PowerDOE and the
`never officially released DOE2.2. We often use eQuest to create BDL code which
we then edit with a text editor. I must admit I m sometimes surprised to
hear of modelers (often in Academic situations) still working with 2.1e when
`2.2 is a significant improvement and is absolutely free via eQuest.
I, like John, am holding off on EnergyPlus until I can
justify the tremendous expense of training my people on a new product that is
still not ready for prime time. Eventually, I hope, but not yet. I m guessing
five years before there is a product that is enough better than eQuest to
justify the investment. (And that s assuming eQuest doesn t continue to
improve).
I imagine that there are numerous eQuest users that are not
aware of the BLDG-SIM forum. Too bad it would be nice to see more interaction
around the eQuest program. Perhaps SCE/EDR could provide an information
blurb about this forum on their web site or to everyone who down loads eQuest.
Mark E. Case, P.E.
etc Group, Inc.
Salt Lake City, Utah