LEED Treatment of District Systems Pump Energy

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Hi Everyone,

I have not seen my specific situation adequately addressed in the LEED
documentation, so I would be interested to hear others' opinions on the

I am modeling a building which relies on a central plant for heating and
cooling. The plant serves only a few buildings. Heating enters the
buildings as HW, not steam. My building is designed such that there are no
hot water pumps.the BAS communicates back to the central plant pump system,
which adjusts flow appropriately. All flow within the building is
controlled by valves. My basic question is, in which models do I include HW
pump energy (that's 4 models.Step 1 Baseline and Proposed, and Step 2
Baseline and Proposed)?

Here are my thoughts. For certain I need to include HW pumps in the Step 2
Baseline, as for any Baseline using System 7. That leaves only 3 models to
ponder. The LEED guidance I have read leads me to believe I should include
HW pumps in Step 1 Baseline as well. The intention of Step 1 is to model
the buildings independent of the central plant, which would lead me to not
include the HW pump energy in my Step 1 Proposed model. Am I now cheating
by including the pump energy in the Baseline but not the Proposed for Step

For Step 2, LEED documentation indicates that secondary pump energy needs to
be modeled in the proposed aggregate building/DES model. This would lead me
towards not modeling the central plant pumps, but again, is that cheating?
A portion of the central plant pump energy is certainly being used to push
water through my building.

Thanks for any thoughts/opinions you may have,


Christian Kaltreider's picture
Joined: 2011-09-30
Reputation: 1

Thanks for this information, Bob. You are correct that I'm referring to the
earlier guideline (Required Treatment of District Thermal Energy in LEED
Version 2.2 and LEED for Schools, Version 1.0, 2008).

I should have been clearer in my post: This is a LEED 2.2 project, and the
model was originally created using the Version 1 guidance referenced above.
This project was started before the newer 2010 document (Version 2). The
model was submitted using the Step 1, Step 2 method of Version 1. I am now
trying to address the reviewer's comments. I did not create the original
model, but I have inherited it since the original modeler is not here any
longer. For addressing the comments, I think I should maintain the Version
1 format in which we submitted.

I'll do what seems to be most fair and accurate based on what I read in both
documents and the main intent of apples-to-apples comparisons. I was just
hoping someone else out there had come across this situation.

Thanks again,


Christian Kaltreider's picture
Joined: 2011-09-30
Reputation: 1

I have used E-Quest before, and some other modelling software (Trane
Trace) and now I have purchased EnergyPro from EnergySoft
http://www.energysoft.com/ . I am in California and this software is
pretty ubiquitous for CA Title 24 Energy Code calculations.

I am wondering if there are a number of EnergyPro users on this list,
and therefore questions on EnergyPro might be OK to post, or if there is
another list or forum that would be more appropriate to use.

Your advice is appreciated.

Robert Wichert P.Eng. LEED AP

RobertWichert's picture
Joined: 2011-10-02
Reputation: 201

I haven't seen much discussion on this forum in regards to EnergyPro. It
doesn't look like there is a separate EnergyPro specific list on
onebuilding.org. If you have a question, the bldg-sim list would be the
most appropriate place to pose it.

The main resource I used when I was stumbling my way through my first
EnergyPro model was to directly e-mail their technical support at
support at energysoft.com. There is a Yahoo user's group at
http://tech.groups.yahoo.com/group/EnergyPro/, however the discussion there
is infrequent and almost all of it seems geared towards California Title-24

If you're trying to do anything other than T24 compliance I would highly
recommend you stay away from EnergyPro. The program has a steep learning
curve, is not great for modeling any sort of complex building or system, and
there is little support available.


Robby Oylear's picture
Joined: 2011-09-30
Reputation: 202

You need to have an apples to apples comparison, and you need to account for
the pump energy.

As you indicate, the Step 2 baseline, is a standalone building, System #7,
with pump energy included.

Your step 2 Proposed Case should account for the all pumping energy in some
way. You have variable primary pumping, so the requirement to model
secondary pumping in the building is not applicable, but you still need to
account for all the pumping energy. Whether it is modeled in the plant or
building is irrelevant. I'd probably model it in the building for simplicity

Your step 1 models should have identical plant conditions. If all the
pumping is in the plant, then I would leave the pump energy out of both
Step 1 cases.


Chris Schaffner, PE

Christopher Schaffner's picture
Joined: 2011-09-30
Reputation: 0

That makes perfect sense to me. This is the approach which seems to best
follow the intent of the LEED modeling process.

Thanks for your input,


Christian Kaltreider's picture
Joined: 2011-09-30
Reputation: 1


We're running into a similar issue on a project using the newer guidance and the default standard cooling system COP of 4.4 as we know very little about our plant itself - though they do seem to be using variable speed secondary pumps. Our building itself has no pumps - all pumping is central.

The COP of 4.4 is meant to include the central plant pumping - but it's unclear whether this would also cover the case where all pumping is central. Do we model the total central plant at a COP of 4.4 and include no pumping energy in our building or do we add pumps equal to the baseline in our building assuming that this 4.4 wasn't allowing for that extent of pumping?

We'd like to meet the intent of the guidance, but also not unfairly penalize the project by being overly conservative. As we're not sure how the 4.4 was derived, it's difficult to know where to go.

What do you think?

Thanks for any thoughts

corinnebenedek's picture
TRACE 700 User
Joined: 2010-10-18
Reputation: 0

There is an EnergyPro Users group:
see the following website:

Between the group and support at EnergySoft, I think you'll be able to get
most of your questions answered.


Luke Morton's picture
Joined: 2011-10-02
Reputation: 200