Process Energy in eQUEST

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Hello Chen

I'm not an expert on eQuest but i know that proses loads must be at
least 25% of the cost of total energy consumption unless you have
documentation to support the opposite. You have to increase
miscellaneous loads until you get at least 25% .

I hope that helps

Regads

Hi
all,

I am building a
model for LEED project and I have some questions confused me for a long
time, does anybody know the answers or can give me some
suggestions?

1. All the
property information I have is only a part of all the information
listed in eQUEST, if I can't find the information in equipment spec., could
I leave it in default value or I need to find out anyway? If I leave
it in default value, will it effect the result a lot?

2. The area is 19211
ft2 in document and I import the Building Area 19211 ft2 in wizard screen 1 of
25, but after I footprint the shape with CAD file, there is an information
"Dimensions Specified Above: 17775 ft2". Does it mean the area of this building
now is 17775 ft2 not 19211 ft2? Will it be accepted if the building area is not
the same as the document?

3. The reference
guide shows the process energy should be at least 25% of all energy cost. If the
process energy is less than 25% after I finish building the model, how could
I increase the process energy to 25%?

Oscar B.'s picture
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Chen,

My understanding about the process energy is that you need to have the proposed values. If your process energy does not equal 25% of your total energy than I usually give an explanation why I don't have so much process load. The reviewer wants to make sure that you took into account all your process load (refrigeration, cooking equipment, elevator, etc. )

The difference between areas I don't usually find that in e-Quest but Hap program will have that because of the load calculations that does not include the interior cavity wall of spaces. If your model is in e-Quest, than I will investigate more and talk to the architect.

I hope this helps.

Crina Bosch

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In response to Chen's original queries:

1. It's up to the modeler (you) to review and determine the
appropriateness of defaults used. I have found default inputs provided
by eQuest and the libraries for items like material properties
(mass/conductivity), space-dependent occupancies and plug loads, and so
forth are sensible and appropriate for general use, but I have to stress
that caveat. I don't think anyone can holistically state that any
given default is appropriate for every situation. The effects of any
given input for a particular project are most easily explored on your
own ;).

2. In your example, if you only define 17775 ft2 of space for your
footprint, then that is all you are modeling. If there is a good reason
for the large discrepancy, you may be able to proceed and explain the
reasons in your submitted documentation later, but it would probably be
easiest to incorporate the missing areas into your model to avoid that
line of questioning altogether.

3. I stopped artificially inflating/adjusting process loads to 25%
some time ago. There is much discussion on this topic in the archives
(notably, {bldg-rate}) if you wish to know all the reasons, but in brief
you are much better off using a specific plug load density (watts/ft2)
and defining any other process loads independently (elevator equipment,
kitchen loads, etc.). I understand the 90.1 Users Manual to be commonly
cited for space-appropriate plug load densities and scheduling. I have
found referencing a known standard like the Users Manual for plug loads
and providing a brief description of how non-plug-load process loads are
being handled is generally sufficient for LEED documentation. Not too
difficult.

I caution anyone presently relying on the 25% "option/suggestion" to
consider: one can end up between a rock and a hard place where select
proposed equipment will not be of sufficient capacity to handle the
arbitrarily inflated internal loads, resulting in unmet hours that
cannot be resolved in a straightforward fashion.

~Nick

NICK CATON, P.E.

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Chen,

Just to add to the responses to your question #2, the area you entered in Screen 1 in the DD wizard for the shell is used in Screen 2 to calculate dimensions when a pre-defined building shape is used. You can see this if you change a dimension and watch the other dimensions automatically change to get close to the area entered in Screen 1. The values may be off a bit due to rounding of the dimensions figured out in Screen 2.

When you enter a custom footprint, the traced area overrules the area you entered in Screen 1.

________________________________
Keith Swartz, P.E., LEED AP

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