[Equest-users] EnergyPlus--Quest Competitor or Natural Evolution

[Dan.Monaghan at bentley.com]

Karen and Carol,

 

Attached is a PDF that illustrates you points that knowledge is kingJ

 

Anyone who deals with MEP systems will enjoy this post.

 

Dan Monaghan | Global Marketing Manager
Building Performance Group

Bentley Systems, Incorporated

Phone: +1-410-207-5501| Skype: dmonaghan.skype
E-mail: dan.monaghan at bentley.com <mailto:christine.byrne at bentley.com>  |
URL: www.bentley.com <http://www.bentley.com/> 
Address: Bentley | 40 Dunvegan Rd. | Baltimore| MD | 21228 | USA 

 

  <http://www.bentley.com/> 

 

 

 

From: Karen Walkerman [mailto:kwalkerman at gmail.com] 
Sent: Monday, April 13, 2009 1:28 PM
To: Carol Gardner
Cc: Glenn Haynes; equest-users at lists.onebuilding.org; Dan Monaghan
Subject: Re: [Equest-users] EnergyPlus--Quest Competitor or Natural
Evolution

 

I agree that there are some serious disconnects occurring between the
design, modeling, construction and building operation.  I have been on
projects where the design engineer claimed that all pumps will operate
at variable speeds, but no control valves were specified for coils,
meaning that while pumps are supplied with VSDs, no variable speed
pumping is actually possible.  I've also seen projects reported where
the design team touted the installation of high-efficiency boilers (94%
or better), and then also claimed to be saving pumping energy by running
loop temperatures hot, around 180 F.  You have to be very careful with
this combination.  I don't know of a boiler that can provide 94%
efficiency at 180F supply water temperature without some very fancy heat
exchangers.

Sometimes field changes are made that cut into the energy performance of
a building.  Simple pipe distribution and pumping changes can have large
energy performance impacts.  Simple misplacement of a DP sensor in a
pumping loop can result in inadequate flow to heating and cooling coils.
This often results in an efficient pumping system being forced into an
all-on position so that all systems are provided with adequate flow.
Each building tells its own story.  I've seen fantastic engineers
produce horrible models because they understand how buildings work, but
not how computer programs think.

When I first started watching this list-serve, someone said "if you
can't develop a simple excel spreadsheet calculation to estimate what
you are trying to model, you shouldn't be modeling it."  I think that we
all need to take this to heart.  You should be able to explain each and
every result.  If you can't, look through hourly outputs.  See how the
program is calculating things.  Figure out what is going on.  All of the
output reports available from eQuest allow for a window into the
calculation mechanism of the program that is absolutely fantastic.  It
is unlikely that I will use a modeling program that doesn't provide me
with this sort of transparency, and post-processing ability.

I have looked through Energy Plus.  On the surface it seems that there's
some valuable functionality available that is not currently available in
eQuest, but without a fully-functional graphical user interface, and
extensive testing, none of that matters.  Precision does not equal
accuracy.

--
Karen




On Mon, Apr 13, 2009 at 12:32 PM, Carol Gardner <gems at spiritone.com>
wrote:

I agree with Glenn. I have always regretted the split that occurred
between the eQUEST team and the EnergyPlus team that occurred lo so many
years ago now. We users have paid for that the most. Just think what
tools would be available right now if all those experts were still
working together.....

William cited operations as the reason for green buildings not
performing as they should; Dan thinks it is the tool's fault. I think
we, as energy modelers, better look in the mirror to see who is at
fault. There are a lot of untrained new people entering this field who
think that by possessing an engineering degree, or some other advanced
degree, they should be able to jump right in and do this work. I have
been doing it for 25 years now using a variety of tools and I can tell
you that any tool I use is only as good as my ability to make it work,
and I am still learning how to do that.

It is not correct to assume that the funding for eQUEST is insignificant
just because federal $ are no longer available for it. As far as I know
eQUEST is funded at a level that the current eQUEST team is hard pressed
to spend because there are not enough of them doing the work as well as
not enough hours in the day. Also, they are constantly making changes
and improvement which address the past concerns that people had about
the algorithms, heat balance methodology, etc.

Each team, the EnergyPlus team and the eQUEST team. is composed of
highly educated and trained professionals that are capable of developing
great tools for our use. Each one will eventually function as well as a
user can make it function. And, that again is the biggest problem. The
user, not the tool. We can wish for a model to do this or to do that but
as long as there are users out there, you know who you are, who are
untrained and inexperienced, bad results will be obtained using whatever
tool is used.

Carol Gardner PE




Glenn Haynes wrote:


Mr. Koran has made some good points on the power of government funding
to assure that EnergyPlus will eventually overtake DOE2 and eQuest. But
this doesn't guarantee a better simulation code. Doe2 has the backing of
decades of usage and testing by millions of experienced building
simulation modelers worldwide. It has undergone thousands of corrections
and improvements during its lifetime, and has evolved to the point that
it has been widely accepted and used as the benchmark by which other
simulation codes are tested and proven.

So my advice is let's not be hasty in writing off such a powerful legacy
and jumping to something newer just because it is receiving more funding
at this point in time. Wasn't DOE2 conceived and developed under federal
(DOE) funding decades ago? Do we need to start over with a new baby? We
can all point out weaknesses in a tool that we are all intimately
familiar with, but have we spent enough time and effort to look as
carefully and critically at EnergyPlus? Not yet, because we can't until
EnergyPlus (or any other newer software) has undergone as much usage and
scrutiny as DOE2 and its derivitives.

No matter how much money is spent on a newer code, I will personally put
more faith and confidence in the more tried and proven code. That kind
of confidence can't be bought; it can only develop over a long time.
When EnergyPlus has been proven to my satisfaction to be better than
DOE2, then I will be happy to switch.

Remember McIntosh computers and their windows GUI? Has Microsoft created
a better product? I don't think so, but we have been unhappily forced to
switch because most other people have, and it was all due to money and
its power, not a better product. As grass roots users of DOE2, let's
stick together and demand that EnergyPlus be proven to our satisfaction
to be at least as good as DOE2 before we switch. After all, we pay our
government to serve our needs, not to use our money to dictate our
choices.

Glenn Haynes, PE

------------------------------------------------------------------------

*From:* equest-users-bounces at lists.onebuilding.org [mailto:
equest-users-bounces at lists.onebuilding.org] *On Behalf Of *Bill
*Sent:* Sunday, April 12, 2009 11:00 PM
*To:* Dan.Monaghan at bentley.com; equest-users at lists.onebuilding.org
*Subject:* Re: [Equest-users] EnergyPlus--Quest Competitor or Natural
Evolution

I work mostly in the existing buildings (non- or pre-"green) markets,
but to the extent green buildings don't live up to the promises is
largely due to operaitons, not design. Many green buildings are more
complex, and since even more traditional buildings typically have
significantly sub-optimal operations, it is only logical that green
buildings will suffer at least as much when compared to
expectations/simulation results.

Some interesting documentation of green building performance is
available at www.newbuildings.org <http://www.newbuildings.org>.



As far as Energy Plus and eQuest, I only have experience with DOE-2 and
eQuest. EnergyPlus should be superior since it was built using the best
of DOE-2 and BLAST. IIRC, it was moving away from a
transfer-function-based simulation to a heat balance-based simulation.
This should also help it to be superior in some circumstances. DOE-2
derivative simulation tools are generally weak at simulating suboptimal
operations, and are very poor at simulating certain controls
improvements or retrocommissioning measures. I don't know how much
better EnergyPlus is in this regard.

At any rate, because of federal funding, and that some (many/most?)
federal projects and organizations will only allow EnergyPlus, it seems
certain that EnergyPlus is the future. My use of DOE-2 dates back to
before there were convenient interfaces and we dealt only with BDL and
user-defined functions, and we needed the stacks of documentation to
know what we were doing. I certainly believe that as more interfaces for
EnergyPlus are developed, more students come out of school with
knowledge of EnergyPlus, and more of us learn EnergyPlus, it will see
greater and greater use.

William E. Koran, P.E.
Senior Engineer
Q u E S T
Quantum Energy Services and Technologies

Web: www.quest-world.com <http://www.quest-world.com/>



------------------------------------------------------------------------

*From:* equest-users-bounces at lists.onebuilding.org [mailto:
equest-users-bounces at lists.onebuilding.org] *On Behalf Of *
Dan.Monaghan at bentley.com
*Sent:* Sunday, April 12, 2009 7:05 PM
*To:* equest-users at lists.onebuilding.org
*Subject:* [Equest-users] EnergyPlus--Quest Competitor or Natural
Evolution

Thanks to all the people who responded to my question.

A few of you ask me to post the result from my very unscientific survey.

The list is split 50%, 50% in their opinion that EnergyPlus will become
a natural transition to eQuest.

The basic sentiment is that eQuest is recognized to be less capable, but
faster and easier to use.

However, almost all who responded recognized that as the demand for
high-performance buildings grows, the ability to/ //accurately/ predict
energy consumption, C02 emissions, occupant comfort and life cycle costs
are going to become more important. I read this to mean that the demand
for detailed analysis tools like EnergyPuls is likely to increase.

Someone asked me why Bentley cares. We believe that there's a hole in
the U.S. energy analysis/simulation market. We believe, as this survey
indicates, that the tools available to U.S. designers seem to fall into
two camps. Tools that are easy-to-use, but inaccurate/incomplete. Or,
tools that are precise, but difficult to use and slow.

Unfortunately, because of this we see:

1. Many "green" building don't live up to the promises

2. Robust energy simulation is typically reserved for "special"
projects, or certain project types.

3. Accurate energy analysis is typically siloed, as oppose to integrated
into the design process

As the leader in building engineering and analysis software or mission
is "sustaining the worlds infrastructure". As such we're working on
solving this problem, www.bentley.com/eps <http://www.bentley.com/eps>.



*Dan Monaghan | Global Marketing Manager
Building Performance Group*

*Bentley Systems, Incorporated*

*Phone*: +1-410-207-5501| *Skype*: dmonaghan.skype

*E-mail*: dan.monaghan at bentley.com <mailto:christine.byrne at bentley.com>*
**| URL:* www.bentley.com <http://www.bentley.com>


*Address*: Bentley | 40 Dunvegan Rd. | Baltimore| MD | 21228 | USA

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