To add to all the fun and confusion, i had this same conversation a few weeks ago with other LEED people in my office. My interpretation is that equipment rack room and IT closets fall into an exception of 90.1, more specifically Section G3.1.1 Baseline HVAC System Type and Description:<div>
<br></div><div>Exception b. If the baseline HVAC system is type 5, 6, 7 or 8, use separate single zone systems ... for any spaces that have occupancy or process loads or schedules that differ significantly. ... Examples where this exception may be applicable include, but are not limited to, computer server rooms, ...</div>
<div><br></div><div>Per this statement, you need to model the IT HVAC equipment as its own system type 3/4 and give it the appropriate efficiencies. Unfortunately this means that most LEED models with IT spaces that are small get penalties due to the equipment, as everyone has suggested.</div>
<div><br></div><div>Hope this sheds more light!</div><div><br></div><div>--Rob<br><div><br><div class="gmail_quote">On Tue, Jun 28, 2011 at 1:39 PM, Nick Caton <span dir="ltr"><<a href="mailto:ncaton@smithboucher.com">ncaton@smithboucher.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<div lang="EN-US" link="blue" vlink="purple">
<div>
<p class="MsoNormal"><span style="color:#1F497D">I should be quick to emphasize:
I’m only relating some personal experience here for others’ benefit
and to constructively add to the discussion. I appreciate James’s
perspective and accept there are probably a few good reasons for the way things
are in the world of DX data center cooling, considering the environment and physical
limitations. It seems obvious to me that 90.1 was not built to consider
minimum efficiencies for this sort of equipment/environment, but that won’t
stop others from trying to enforce the standard in spite of my opinions. The
section 2.3 reference is starting to make a lot of sense from this angle…<u></u><u></u></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="color:#1F497D">That said, I don’t think
it’s entirely unreasonable to expect some progress from the commercial industry
either. For smallish IT closets these days, perhaps a residential split with a
high EER/SEER is really the way to go. For larger cases requiring high-static
distribution or heavier capacities, I’m only advising that it never hurts
to take stock of who/what’s out there and what might fit the budget/performance/efficiency
requirements for the situation at hand. If nothing truly “fits the bill,”
at least we can rest easy knowing that’s the case and not wonder whether
we missed a better option.<u></u><u></u></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="color:#1F497D">An extra bit for Will and others
considering HVAC systems as “process loads:” this isn’t
always so tricky as it might seem =)! Rather than construe a custom fractional
schedule to approximate the system’s energy consumption (like a plug load),
there’s another approach: submeter these systems and report separately
on the LEED template… Report PS-B will show the monthly
consumptions/demands for the submeters after setting it all up. Following are
some quick/rough screengrabs illustrating the concept/setup:<u></u><u></u></span></p><div class="im">
<p class="MsoNormal"><span style="color:#1F497D"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><img width="732" height="541" src="cid:image002.png@01CC358C.111F76B0"></span><span style="color:#1F497D"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><img width="732" height="541" src="cid:image003.png@01CC358C.111F76B0"></span><span style="color:#1F497D"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><img width="1052" height="651" src="cid:image004.png@01CC358C.111F76B0"></span><span style="color:#1F497D"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="color:#1F497D">~Nick<u></u><u></u></span></p>
<div>
<p class="MsoNormal"><span style="color:#1F497D"><img width="119" height="37" src="cid:image001.jpg@01CC3585.D75C61A0" alt="cid:489575314@22072009-0ABB"></span><b><span style="color:#2D4D5E"><u></u><u></u></span></b></p>
<p class="MsoNormal"><b><span style="color:#2D4D5E"><u></u> <u></u></span></b></p>
<p class="MsoNormal"><b><span style="font-size:12.0pt;color:#2D4D5E">NICK CATON, P.E.</span></b><b><span style="font-size:12.0pt;color:#2D4D5E"><u></u><u></u></span></b></p>
<p class="MsoNormal"><span style="font-size:7.5pt;color:#CC9900">SENIOR ENGINEER<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:7.5pt;color:#CC9900"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;color:#2D4D5E">Smith &
Boucher Engineers</span><span style="font-size:7.5pt;font-family:"Times New Roman","serif";color:#CC9900"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;color:#2D4D5E">25501 west
valley parkway, suite 200<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;color:#2D4D5E">olathe, ks
66061<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;color:#2D4D5E">direct
<a href="tel:913.344.0036" value="+19133440036" target="_blank">913.344.0036</a><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;color:#2D4D5E">fax
<a href="tel:913.345.0617" value="+19133450617" target="_blank">913.345.0617</a><u></u><u></u></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><a href="http://www.smithboucher.com" title="blocked::www.smithboucher.com" target="_blank"><span style="font-size:10.0pt">www.smithboucher.com</span></a></span><u><span style="font-size:10.0pt;color:blue"> </span></u><span style="color:#1F497D"><u></u><u></u></span></p>
</div>
<p class="MsoNormal"><span style="color:#1F497D"><u></u> <u></u></span></p>
</div><div>
<div style="border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in">
<p class="MsoNormal"><b><span style="font-size:10.0pt">From:</span></b><span style="font-size:10.0pt"> <a href="mailto:equest-users-bounces@lists.onebuilding.org" target="_blank">equest-users-bounces@lists.onebuilding.org</a>
[mailto:<a href="mailto:equest-users-bounces@lists.onebuilding.org" target="_blank">equest-users-bounces@lists.onebuilding.org</a>] <b>On Behalf Of </b>Andy
Phelps<br>
<b>Sent:</b> Tuesday, June 28, 2011 10:56 AM<br>
<b>To:</b> Will Mak; <a href="mailto:equest-users@lists.onebuilding.org" target="_blank">equest-users@lists.onebuilding.org</a><br>
<b>Subject:</b> Re: [Equest-users] Modeling Typical IT Rooms AC Units<u></u><u></u></span></p>
</div>
</div><div class="im">
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal"><span style="color:#1F497D">Will:<u></u><u></u></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="color:#1F497D">I couldn’t agree more with
you on Section 2.3. However, what matters is not what I think, but the
LEED/USGBC review team. <u></u><u></u></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="color:#1F497D">In my experience, I’ve
modeled data rooms in offices as a System 3/4 for the baseline and as scheduled
for the design case. I’ve modeled small rooms with a mini-split DX
unit, and also for larger rooms with CRAC style units (Liebert, DataAire,
etc). I haven’t had any issues with this in the review
process. In addition, from some internet research, it appears that
architects/engineers are getting large-scale data centers certified, so they
must be wanting us to split data center HVAC usage from server/process
usage. <u></u><u></u></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="color:#1F497D">Sorry that I do not have any
more insight than this, but I do understand your frustration with data
rooms/centers and applicability to 90.1. <u></u><u></u></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="color:#1F497D">I would also point you to some
addenda for 90.1 that does mention data centers and outlines some requirements
(addenda BU). It looks like these Liebert units would meet the
requirements for efficiency in this addenda. For the purposes of LEED
certification, I would caution to read all addenda, since LEED doesn’t
let you pick and choose addenda, there may be some addenda out there that might
hurt your energy savings percentage. <u></u><u></u></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="color:#1F497D">Andy</span><span style="color:#1F497D"><u></u><u></u></span></p>
<div style="border:none;border-bottom:solid windowtext 1.0pt;padding:0in 0in 1.0pt 0in">
<p class="MsoNormal" style="border:none;padding:0in"><span style="color:#1F497D"><u></u> <u></u></span></p>
</div>
<p class="MsoNormal"><span style="color:#1F497D"><u></u> <u></u></span></p>
</div><p class="MsoNormal"><b><span style="font-size:10.0pt">From:</span></b><span style="font-size:10.0pt"> James Hansen
[mailto:<a href="mailto:JHANSEN@ghtltd.com" target="_blank">JHANSEN@ghtltd.com</a>] <br>
<b>Sent:</b> Tuesday, June 28, 2011 10:36 AM<br>
<b>To:</b> Will Mak; Nick Caton<br>
<b>Cc:</b> <a href="mailto:equest-users@lists.onebuilding.org" target="_blank">equest-users@lists.onebuilding.org</a><br>
<b>Subject:</b> RE: [Equest-users] Modeling Typical IT Rooms AC Units<u></u><u></u></span></p><div class="im">
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal"><span style="color:#1F497D">Liebert is no less efficient
than any of the other computer grade self-contained units out there. The
problem is that the units have to fit the niche that has been created for
them. They need to be no more than 3’ deep to work with typical
server room design, they have to generally have high static fans to pressurize
under floor systems, and they have to be fully serviced from the front of the
unit. All of these have implications on the evaporator / condenser coil
layout, and thus efficiency. <u></u><u></u></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="color:#1F497D">There are certainly things that
you can do to improve computer grade AC unit design (like using the ECM motors
that have been popping up for a lot of manufacturers, and playing around with
higher space temperatures), but ultimately, you’re never going to have a
Liebert (or Stulz, etc) unit with an EER of 18. <u></u><u></u></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="color:#1F497D">Also, in almost all cases, the
efficiencies you are getting from the manufacturer or manufacturer’s rep
are probably based on the abnormal operating conditions of a server room (68,
70, 72 degrees) – make sure you are properly accounting for this in
eQuest, as these are not ARI conditions. <u></u><u></u></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><u></u> <u></u></span></p>
<p class="MsoNormal"><b><span style="color:teal">GHT
Limited<br>
</span></b><b><span style="color:black">James
Hansen</span><span style="color:black">, PE, LEED AP<u></u><u></u></span></b></p>
<p class="MsoNormal"><b><span style="font-size:10.0pt;color:black">Senior Associate</span><span style="color:black"><u></u><u></u></span></b></p>
<p class="MsoNormal"><span style="font-size:7.5pt;color:black">1010 N. Glebe Rd, Suite 200</span><span style="color:#1F497D"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:7.5pt;color:black">Arlington, VA 22201-4749</span><span style="color:black"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:7.5pt;color:black"><a href="tel:703-338-5754" value="+17033385754" target="_blank">703-338-5754</a> (Cell)</span><span style="color:black"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:7.5pt;color:black"><a href="tel:703-243-1200" value="+17032431200" target="_blank">703-243-1200</a> (Office)</span><span style="color:black"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:7.5pt;color:black"><a href="tel:703-276-1376" value="+17032761376" target="_blank">703-276-1376</a> (Fax)</span><span style="color:black"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="color:teal"><a href="http://www.ghtltd.com/" target="_blank"><span style="font-size:10.0pt">www.ghtltd.com</span></a><u></u><u></u></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><u></u> <u></u></span></p>
</div><div>
<div style="border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in">
<p class="MsoNormal"><b><span style="font-size:10.0pt">From:</span></b><span style="font-size:10.0pt"> <a href="mailto:equest-users-bounces@lists.onebuilding.org" target="_blank">equest-users-bounces@lists.onebuilding.org</a>
[mailto:<a href="mailto:equest-users-bounces@lists.onebuilding.org" target="_blank">equest-users-bounces@lists.onebuilding.org</a>] <b>On Behalf Of </b>Will
Mak</span></p><div><div></div><div class="h5"><br>
<b>Sent:</b> Tuesday, June 28, 2011 8:47 AM<br>
<b>To:</b> <a href="mailto:equest-users@lists.onebuilding.org" target="_blank">equest-users@lists.onebuilding.org</a><br>
<b>Subject:</b> [Equest-users] Modeling Typical IT Rooms AC Units<u></u><u></u></div></div><p></p>
</div>
</div><div><div></div><div class="h5">
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal"><span style="font-size:10.0pt">Hey
all,<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt">I’m
working on a LEED energy model for an office building that has a couple
standard sized data rooms for server storage. They will be served by a couple
air cooled Liebert units. I started inputting information about the units in
the proposed design model and requested EER information from our vendor. The
EER value was provided but also pointed me towards ASHRAE 90.1-2007 Section 2.3
as the reason why EER values aren’t typically provided for these types of
units (he claims the cooling of the server rooms would be considered process
cooling):<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt">ASHRAE
90.1-2007 Section 2.3 - The provisions of this standard do not apply to:<u></u><u></u></span></p>
<p><span style="font-size:10.0pt">a.</span><span style="font-size:7.0pt;font-family:"Times New Roman","serif"">
</span><span style="font-size:10.0pt">Single-family
houses, multi-family structures of three stories or fewer above grade,
manufactured houses (mobile homes), and manufactured houses (modular)<u></u><u></u></span></p>
<p><span style="font-size:10.0pt">b.</span><span style="font-size:7.0pt;font-family:"Times New Roman","serif"">
</span><span style="font-size:10.0pt">Buildings
that do not use either electricity or fossil fuel, or<u></u><u></u></span></p>
<p><span style="font-size:10.0pt">c.</span><span style="font-size:7.0pt;font-family:"Times New Roman","serif"">
</span><b><span style="font-size:10.0pt">Equipment
and portions of building systems that use energy primarily to provide for
industrial, manufacturing, or commercial processes</span></b><span style="font-size:10.0pt">.<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt">I’ve
typically model the scheduled units on the proposed design model and System
Type 3 or 4 on baseline model. However, if the above Section 2.3 applies,
should we be modeling the systems that serve IT rooms in an office building as
“process energy” and be equal?<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt"><u></u> <u></u></span></p>
<p class="MsoNormal"><b><span style="font-size:12.0pt;color:#C75B12">William Mak, LEED AP BD+C</span></b><span style="font-size:9.0pt;color:#1F497D"><br>
</span><span style="font-size:8.0pt;color:black">Mechanical Design Engineer</span><span style="font-size:9.0pt;color:black"><br>
</span><span style="font-size:9.0pt;color:#1F497D"><br>
</span><b><span style="font-size:10.0pt;color:#C75B12">EPSTEIN</span></b><span style="font-size:9.0pt;color:#1F497D"><br>
</span><span style="font-size:8.0pt;color:black">Architecture<br>
</span><span style="font-size:8.0pt;color:#C75B12">Interiors</span><span style="font-size:8.0pt;color:black"><br>
Engineering<br>
</span><span style="font-size:8.0pt;color:#C75B12">Construction</span><span style="font-size:8.0pt;color:black"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:8.0pt;color:black">Sustainability<br>
<br>
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<p class="MsoNormal"><span style="font-size:8.0pt;color:black">E:</span><span style="font-size:8.0pt;color:#0070C0"> <a href="mailto:wmak@epsteinglobal.com" target="_blank">wmak@epsteinglobal.com</a></span><span style="font-size:8.0pt;color:black"><br>
W:</span><span style="font-size:8.0pt;color:#C75B12"> <a href="http://www.epsteinglobal.com/" target="_blank"><span style="color:#C75B12">www.epsteinglobal.com</span></a></span><span style="font-size:9.0pt;color:black"><br>
<br>
</span><span style="font-size:10.0pt;font-family:Webdings;color:#00B050">þ</span><span style="font-size:8.0pt;color:black">
Epstein is a firm believer in sustainability. We ask that you please consider
the environment before printing this e-mail.<u></u><u></u></span></p>
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