[Equest-users] dwelling unit / residential LPDs

[David Eldridge]

The only gray area to me is when the design would only partially provide the
lighting – i.e. it isn’t a fair comparison for the proposed design at 0.5
W/ft2 if there is some expectation of receptacle-based fixtures to also be
included as supplemental lighting sources.



If the intention is for the proposed design to provide *all* of the
lighting, then I believe it to be fair game.  Especially hotel rooms, where
the interior designer will have included receptacle-based fixtures if they
are intended, it should be relatively clear what is included in the initial
fit out.



With apartments or condos I think you are less likely to have the design
intended to cover 100% of the occupied lighting, but if that’s the case for
your projects the standard seems to allow it.



Apartments are further complicated since the kitchen, bathroom, and corridor
lighting is often completely provided, where the bedroom and living areas
may not partially provided.  However, the 1.1 W/ft2 (or 0.7 W/ft2 for
multifamily) seems to be for a whole apartment including a weighting of all
the different spaces in a typical apartment.  Maybe the 0.7 W/ft2 is
intended to allow for supplemental sources in a living room although this
hasn’t been my take on it.



David



*
*



David S. Eldridge, Jr., P.E., LEED AP BD+C, BEMP, HBDP

*Grumman/Butkus Associates*

*
*



*From:* equest-users-bounces at lists.onebuilding.org [mailto:
equest-users-bounces at lists.onebuilding.org] *On Behalf Of *James Hansen
*Sent:* Wednesday, December 08, 2010 2:43 PM
*To:* Aleka Pappas; equest-users at lists.onebuilding.org
*Subject:* Re: [Equest-users] dwelling unit / residential LPDs



Is there a CIR or something that says that residential LPD is unregulated?



Table G3.1 is pretty specific about residential unit lighting for the
proposed model (see below):





As long as the lighting is shown on building plans and permanently wired,
you are allowed to use the actual lighting power.   I have done 10+
residential projects where we’ve listed 1.1 W / sq ft for the living /
bedroom areas for the baseline building, and used the actual density for the
proposed model, and been approved.  There certainly isn’t anything wrong
with doing it the ECM route, but where, specifically, does it say you can’t
take credit for any residential unit lighting efficiencies?



*GHT Limited
**James Hansen, PE, LEED AP*

*Senior Associate*

1010 N. Glebe Rd, Suite 200

Arlington, VA  22201-4749

703-338-5754 (Cell)

703-243-1200 (Office)

703-276-1376 (Fax)

www.ghtltd.com

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*From:* equest-users-bounces at lists.onebuilding.org [mailto:
equest-users-bounces at lists.onebuilding.org] *On Behalf Of *Aleka Pappas
*Sent:* Wednesday, December 08, 2010 3:25 PM
*To:* equest-users at lists.onebuilding.org
*Subject:* Re: [Equest-users] dwelling unit / residential LPDs



That 1.1 W/SF from section 9 doesn't apply to apartment or condo dwelling
units.  Residential unit LPD is unregulated.  We calculate savings for
residential lighting as an exceptional calculation using a baseline LPD
sited from research (which is kind of all over the place), and calculate
savings for installed lighting systems that provide for full illuminance in
specific spaces in the residential units.  The lighting is scheduled on for
750 hours/ year (from an old LEED CIR).  These calcs have been approved in
the past for LEED EAc1 under NC 2.2 and 3.0.

*Aleka Pappas*

*Building Energy Engineer

GROUP14 ENGINEERING, INC. *
Inspiring better buildings.
1325 E. 16th Ave, Denver, CO 80218
Direct: 720.221.1082/ Main: 303.861.2070/Fax: 303.830.2016
APappas at group14eng.com
www.group14eng.com

*Group 14 is the Carbon Group on the periodic table. Group14 Engineering
offers building energy optimization, LEED coordination, commissioning,
energy audits, LEED EBOM, and greenhouse gas analysis to reduce building and
communities’ carbon footprint.*


On 12/8/2010 7:25 AM, Bishop, Bill wrote:

Joe,



The dwelling units exception in Appendix G applies to “spaces in which
lighting systems are connected via receptacles and are not shown or provided
for on building plans.” You say you’ve worked hard to reduce lighting energy
use, so presumably, you’ve designed the lighting for the spaces and it
appears on the plans. Therefore, you are justified in using your actual
lighting design for the proposed building model, and the LPD value for the
baseline, which should be 1.1 W/ft2 for living quarters per Table 9.6.1.



Regards,

Bill



*William** Bishop, PE, BEMP, LEED® AP **|** Pathfinder Engineers &
Architects LLP*

Mechanical Engineer



134 South Fitzhugh Street                 Rochester, NY 14608
T: (585) 325-6004 Ext. 114                F: (585) 325-6005

wbishop at pathfinder-ea.com           www.pathfinder-ea.com

P   Sustainability – the forest AND the trees. P
------------------------------

*From:* equest-users-bounces at lists.onebuilding.org [
mailto:equest-users-bounces at lists.onebuilding.org<equest-users-bounces at lists.onebuilding.org>]
*On Behalf Of *Nick Caton
*Sent:* Tuesday, December 07, 2010 7:16 PM
*To:* Joe Snider; equest-users at lists.onebuilding.org
*Subject:* Re: [Equest-users] dwelling unit / residential LPDs



Hey Joe,



If you’re looking to start somewhere…  I know the NEC (NFPA 70) lays out a
clear method of estimating dwelling unit lighting loads within Article 220.
It starts off seeming high (3W/SF), but there are heavy demand factors that
vary with the total calc’d load following within the same article: i.e.
first 3,000 @ 100%... 3,000 to 120,000 @ 35% etc…



While I’ve yet to fall back on the NEC as an energy modeling resource, I’m
unaware of any better direct source for residential lighting loads… I
imagine if you dig hard enough, one of the ASHRAE handbooks probably has
something along these lines as well that might give you a different sum.



I think ASHRAE Fundamentals does have a clear thing or two to say regarding
what percentage of the lighting load should end up in a space vs. a plenum
when you are talking about different lamp sources (incandescent vs. CFL…) –
something to be aware of if you want to pursue this avenue.



~Nick



[image: cid:489575314 at 22072009-0ABB]

* *

*NICK CATON, E.I.T.*

PROJECT ENGINEER

Smith & Boucher Engineers

25501 west valley parkway

olathe ks 66061

direct 913 344.0036

fax 913 345.0617

www.smithboucher.com* *



*From:* equest-users-bounces at lists.onebuilding.org [
mailto:equest-users-bounces at lists.onebuilding.org<equest-users-bounces at lists.onebuilding.org>]
*On Behalf Of *Joe Snider
*Sent:* Tuesday, December 07, 2010 5:24 PM
*To:* equest-users at lists.onebuilding.org
*Subject:* [Equest-users] dwelling unit / residential LPDs



I have reviewed the archives and found a few threads on this topic but
couldn’t find either good resolution, or a clear enough string to reply to,
so I thought I would re-post:



ASHRAE 90.1 App G doesn’t let you include dwelling units in typical LPD
calcs.  They say you need to plug in the same number for both proposed and
baseline.



But you can apparently pursue exceptional calcs to justify any cost savings
in LEED.  But you need to show some kind of analysis as to how you chose a
baseline, such as a study or something presumably that shows typical w /sf
for residential.



We have worked very hard to reduce energy use in lighting in a few high-rise
residential projects and would like to be able to receive credit for that on
our energy model.



Has anyone been through this with USGBC and / or know of a good resource for
a baseline w / sf for residential?



In advance, thank you very much.  Great forum.



Sincerely,



Joe Snider



---

Joe Snider, AIA, LEED AP

* *

*SEQUIL Systems, Inc*.

*high performance sustainable structures*



1 SE 4th Ave, Suite 205

Delray Beach, FL 33483

t: 561.921.0900

f: 561.208.6090



www.SEQUIL.com
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