[BLDG-SIM] Process Loads and LEED

[gail]

The exact wording of the LEED v2.2 requirements may be helpful in moving
this discussion forward.  Per LEED EAc1 requirements:

"The default process energy cost (must) be 25% of the total energy cost for
the Baseline building.  For buildings where the process energy cost is less
than 25% of the baseline building energy cost, the LEED submittal must
include supporting documentation substantiating that process energy inputs
are appropriate."
...
"For EA Credit 1, process loads shall be identical for both the Baseline
building performance rating and for the Proposed building performance
rating.  However, project teams may follow the Exceptional Calculation
Method (ASHRAE 90.1-2004 G2.5) to document measures that reduce process
loads.  Documentation of process load energy savings shall include a list of
the assumptions made for both the base and proposed design, and theoretical
or empirical information supporting these assumptions."

Buildings with 60% process energy cost probably will likely be negatively
impacted by these modeling requirements (it is probable that these buildings
will have a tougher time showing substantial Percentage Energy Improvement
than buildings having only 25% process loads).  However, if the project can
demonstrate that energy improvements have been made to the process energy
systems versus standard practice, then the energy savings achieved through
these process system efficiency measures can be used to document improved
Percentage Improvement using the Exceptional Calculation Methodology.  As
Leonard mentioned, the process energy will also impact cooling loads
substantially, and improvements to the cooling equipment and controls would
also help the overall building performance.

Gail Stranske
CTG Energetics, Inc.

On 3/6/07, Leonard Sciarra <leonard_sciarra at gensler.com> wrote:
>
>  Maybe I am naive, and I have not read the NC 2.2 reference guide yet, but
> process loads would affect an internally load dominated building, ie, my
> cooling loads would be different hence my equipment selection between a low
> density office vs a "financial trading floor" type situation. LEED and
> gaming the system aside, from a real design point they are important, and
> could affect envelope component selection.
>
> Leonard Sciarra,  AIA, LEED ap
> 312.577.6580 (Dir)
> G E N S L E R | Architecture & Design Worldwide
> 30 West Monroe Street
> Chicago IL, 60603
> 312.456.0123
> leonard_sciarra at gensler.com
>
>
>  ------------------------------
> *From:* BLDG-SIM at gard.com [mailto:BLDG-SIM at gard.com] *On Behalf Of *Varkie
> Thomas
> *Sent:* Tuesday, March 06, 2007 11:23 AM
> *To:* BLDG-SIM at gard.com
> *Cc:* BLDG-SIM at gard.com
> *Subject:* [BLDG-SIM] Process Loads and LEED
>
>  Vaibhav: Your reference makes the situation worse.
>
> The LEED energy savings rating system using the bottom line *percent*savings over baseline appears to penalize buildings with high process loads
> when you also consider LEED-NC Version 2.2 EA Credit 1 page 174 "The
> default process energy cost is 25% of the total energy *cost* for the
> baseline building".
>
> What has the process energy cost (or the process energy use) got to do
> with building design related to energy efficiency (architecture-envelope,
> lighting, HVAC, DHW) except power supply for the process?  The process
> energy within an office building can vary from 0.5 w/sf  (minimal use of
> computers and office equipment) to more than 6.0 w/sf for a
> financial/trading (Wall Street) type of building.  If the baseline process
> energy is limited to 25% percent of total and the proposed process energy
> use is more than 60% of the total then does this mean that the building
> design is energy inefficient and does not qualify for LEED certification?
>
> Process energy could be part of the analysis if there is a baseline
> standard for various types of computer and office equipment (varies
> considerably and hard to define and prescribe for the numerous types
> processes that occur in just office buildings) and the equivalent proposed
> equipment is more efficient.  This comes under "Exceptional Calculation
> Method" category along with several other energy efficient building design
> options such as double-wall buildings for which you get 1 point (I think).
>
> According to LEED-NC Version 2.2 EA Credit 1 page 174 "process energy is
> considered to include, but is not limited to, office & general miscellaneous
> equipment, computers, elevators & escalators, kitchen cooking &
> refrigeration, laundry washing & drying, lighting exempt from lighting power
> allowance (e.g. lighting integral to medical equipment) and other (e.g.
> waterfall pumps).  Do all submissions for LEED certification include all
> this.  At the construction documents submission stage, what is the level of
> modeling detail that is required regarding floor spaces and zones and all
> the systems, plant and equipment shown on the drawings and specifications.
> Can you use eQUEST, select the type of building, and let the "Wizard" do the
> zoning and assume most of the baseline data?   I don't think we are all
> playing the same game, on the same level playing field and using the same
> rules to show percent energy savings for LEED certification.
>
> I also have some reservations about how various energy saving systems are
> modeled with different computer programs.  The programs should be studied
> and compared with the same case studies of different types of buildings with
> different systems and plants and showing how each program should be used to
> demonstrate energy savings from different energy conservation measures such
> as UFAD.
>
> Building operation data can now be viewed on the web, collected for
> meaurement & verification (M&V) and can be used to check computer modeling
> results.  In the case of a M&V project at IIT, the web based control systems
> show mainly temperatures.  Sub-meters and data loggers should be included in
> the control specifications so that the performance of the major systems,
> plant & equipment can be monitored separately and compared with computer
> results.  At the moment we are comparing the building utility meter reading
> with the bottom line building energy use calculated by the computer program.
>
>
> Process loads do not affect energy code and Std-90 compliance since "
> percentages" are not involved.
>
> V.C. Thomas
>
>
> ----- Original Message -----
> From: Vaibhav Potnis <vaipotnis at hotmail.com>
> Date: Tuesday, March 6, 2007 8:14 am
> Subject: [BLDG-SIM] Process Loads and LEED
> To: BLDG-SIM at gard.com
>
> However I wanted to point out that for a LEED energy analysis, process
> energy has to be maintained at 25% of total energy cost of the Baseline
> Building Performance ( LEED- 2.2 Ref Guide page 182). I prefer taking
> exceptional calculatins for process energy to simplify the calculations as
> well as the review.
>
> Hope this helps.
>
> Vaibhav Potnis
> www.greenbuildingservices.com
>
> ------------------------------
>
>  From: *"Brandon Nichols" <BrandonN at Hargis.biz>*
> Reply-To: *BrandonN at Hargis.biz*
> To: *<BLDG-SIM at gard.com>*
> Subject: *[BLDG-SIM] Process Loads and LEED*
> Date: *Mon, 5 Mar 2007 11:05:04 -0800*
>
>  Varkie,
>
> Something we have been noticing in schools lately is a high receptacle
> load, which we believe is attributable to increased usage of computers,
> approaching and in some areas exceeding 5 W per square foot -- the kinds
> of loads I used to figure for "technology intensive" office areas just a few
> years ago.
>
> In researching an energy question for a school today, I came across this
> web page and case study which I thought was relevant to your question:
>
> http://www.energystar.gov/index.cfm?c=power_mgt.pr_power_management
>
>
> http://www.energystar.gov/ia/products/power_mgt/North_Thurston_Case_Study.pdf
>
> Essentially they summarize how, by consistently implementing power
> management on computer monitors and CPUs using a simple utility program, acost savings of an estimated $15-$30 per computer per yearcan be realized (on personal workstations I would add, not systems required
> to be continuously online).  Multiplied across thousands of computers, the
> bottom line annual savings can be substantial.
>
> How to account for this in energy modeling software I have a general idea:
>
> 1) Assign the baseline receptacle load to "occupied hours"; e.g. 5 W/SF
> 'always on'
> 2) Assign a diversified receptacle load schedule to the alternate analyses
>
> But quantifying the diversified load schedule is the hard part -- it will
> no doubt vary significantly depending on the occupancy.  Though not fully
> developed, this may provide a starting point for one method to reduce
> process electrical loads in a LEED analysis.
>
>
> Regards
>
> Brandon Nichols, PE
> Mechanical
> HARGIS ENGINEERS
> 600 Stewart St
> Suite 1000
> Seattle, WA 98101
> d | 206.436.0400 c | 206.228.8707
> o | 206.448.3376 f | 206.448.4450
> www.hargis.biz
>
>  ------------------------------
> *From:* BLDG-SIM at gard.com [mailto:BLDG-SIM at gard.com] *On Behalf Of *Varkie
> Thomas
> *Sent:* Monday, March 05, 2007 7:14 AM
> *To:* BLDG-SIM at gard.com
> *Subject:* [BLDG-SIM] Process Loads and LEED
>
>  LEED-NC Version 2.2 page 173 "Optimize Energy Performance" states
> "Demonstrate a *percentage* improvement in the proposed building
> performance -- " and  "For the purpose of this analysis, process energy is
> considered to include, but is not limited to, office and general
> miscellaneous equipment, computers, elevators & escalators, kitchen cooking
> & refrigeration, laundry washing & drying --- "
>
> On page 174 "For EA Credit 1, process loads shall be identical for both
> the baseline building performance and the proposed building performance"
>
> Assuming the same space process load is used in the baseline and proposed,
> then a building with a receptacle load density of say 1.0 w/sf will
> produce a much greater percent savings compared to the same building with a
> receptacle load density of say 6 w/sf.
>
> Page 173 "must comply with the mandatory provisions (Sections --- ) in
> Standard 90.1-2004 (without amendments)"  There is no mention of Standards
> 62 for ventilation & occupancy density or Standard 55 for indoor comfort
> conditions.  Does this mean that the baseline can be based on the proposed
> ventilation, occupancy density and indoor comfort conditions?  According to
> Standard 62-2004 the occupancy density for general office space is 200 sf/P
> (from 142 sf/P in 62-2001 and I think 100 sf/P earlier).  This produces a
> low percent system outdoor air and energy conservation measures such as
> "occupancy based ventilation" and "outdoor air to relief air heat recovery"
> have little effect.  Std 62-2004 (also Std 90.1-2004 for lighting)
> provides design criteria for a limited number of space types such as a
> prison cell (improved from 50 sf/P & 20 cfm/P in 62-2001 to 40 sf/P & 10
> cfm/P in 62-2004) .  This makes it difficult to determine baselin e
> conditions using Std 62.
>
> I am looking at a financial institution building with high occupancy and
> receptacle load densities.
>
>  ----- Original Message -----
> From: David S Eldridge <DSE at grummanbutkus.com>
> Date: Monday, March 5, 2007 10:36 am
> Subject: [BLDG-SIM] Process Loads and LEED
> To: BLDG-SIM at gard.com
>
> Varkie, I can see merits for the 2.1 method and the 2.2 method.  On the
> one hand, the process loads are to some degree out of our control.  But on
> the other hand, if you have a building with such massive load density why
> would the rating system want to exclude all of that energy from sustainable
> practices?
>
> I like the idea of consistency when considering all of the energy for
> energy optimization, on-site renewables and green power - there are projects
> out there that might earn fewer EAC1 points under v2.2 than under 2.1.
> The percentage savings were changed between the versions so it's hard to say
> if it is more or less likely to earn a certain amount of EAC1 points - I
> would be interested to see a summary if the data is available about EAC1
> points under v2.1 compared to v2.2.  Probably about the same?
>
> For a high load density building like yours - definitely going to be
> harder.  The only suggestion as far as EAC1 points that I could offer would
> that if your design has receptacle load at 6 W/ft2 there is probably a
> significant diversity in that load, maybe it won't turn out as badly as you
> fear.
>
> In regard to ventilation, you are going to use the outside air
> requirements from the proposed design and apply that outside air quantity to
> both models.  There isn't a "baseline ventilation rate" - use equal CFM of
> OA for both models.  Also, OA may be determined from local building codes
> rather than ASHRAE - that would also apply equally to both models.
>
> The one exception would be that Demand Control Ventilation could
> potentially be used in the proposed model to reduce OA if DCV isn't required
> prescriptively, and if your minimum OA from code is less than what is
> required by ASHRAE 62.
> Hope this helps!
>
> David
>
>
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