[Equest-users] Building area method ASHRAE 90.1

[RobertWichert]

To bring up a topic from a year ago (below) I have a question about 
using the Space by Space approach with a multi-family building. There is 
a BAM Category for Multi-Family, but not a Space by Space category for 
multi-family (except for dormitories).

Is there a work-around for space by space with multi-family?

I apologize if this has been covered before.


On a working Saturday.



-- 
Robert Wichert P.Eng. LEED AP BD&C
+1 916 966 9060
FAX +1 916 966 9068







===============================================

*Nick Caton*  
     ncaton at smithboucher.com
          <mailto:equest-users%40lists.onebuilding.org?Subject=Re%3A%20%5BEquest-users%5D%20Building%20area%20method%20ASHRAE%2090.1&In-Reply-To=%3CECDF361A89E5FA479BE7E64C658B52050D8E2006%40SANDBINC4.sbi.smithboucher.com%3E>

     /Wed May 23 17:57:42 PDT 2012/
     

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------------------------------------------------------------------------
David's summary looks pretty good to me!

I want to emphasis a great point that came up along the way: Space by 
space can result in more LEED points by 'padding the baseline,' sure... 
But "real" savings result from closely reviewing the proposed design, 
which in turn generates opportunities to identify specific means of 
design improvement.

I'll share a related strategy. Consider: Engaging the lighting designer 
and improving design doesn't require tallying the space-by-space totals. 
If I recognize significant improvements can be made with revised 
layouts, fixture reselection, and/or tweaked control schemes, I have 
found it VERY productive to simply share with the lighting designer (and 
design team leaders, if necessary) posed scenarios: "If you can reduce 
your installed watts by just 10%, the LEED models will earn 2 more LEED 
points." "If you define your astronomical timeswitch to shut off 
non-critical lighting after 2AM, the project earns a LEED point." Such 
'carrot on a stick' proposals normally get the intended results with 
minimal friction, engage the designers in a positive way ("Hey, I just 
earned the easiest LEED point ever!") and performing the exploratory 
simulations to compose these proposals can be a lot less effort on the 
modeler relative to a standard-focused space-by-space analysis (I'm 
thinking of big buildings).

 >/From another perspective: Some of us lighting designers are sensitive 
creatures =D... We may have a tough exterior, but deep inside it hurts 
my poor fragile feelings if someone claims "Standard XYZ states 
bla-bla-bla and therefore you suck at your job." This advice applies to 
designers of any discipline, of course. If you want to pursue improving 
design with a standards-centric base, be mindful of this possibility. 
Making everyone happy to be working with an energy modeler can be quite 
a challenge, but the results are rewarding. / Hope that was 
illuminating! ~Nick

[cid:489575314 at 22072009-0ABB 
<http://lists.onebuilding.org/listinfo.cgi/equest-users-onebuilding.org>] NICK 
CATON, P.E. SENIOR ENGINEER Smith & Boucher Engineers 25501 west valley 
parkway, suite 200 olathe, ks 66061 direct 913.344.0036 fax 913.345.0617 
www.smithboucher.com From: equest-users-bounces at lists.onebuilding.org 
<http://lists.onebuilding.org/listinfo.cgi/equest-users-onebuilding.org>

[mailto:equest-users-bounces at lists.onebuilding.org 
<http://lists.onebuilding.org/listinfo.cgi/equest-users-onebuilding.org>] On 
Behalf Of David Eldridge Sent: Wednesday, May 23, 2012 4:54 PM To: 
eQuest Users Subject: Re: [Equest-users] Building area method ASHRAE 90.1

Patrick, the space-by-space LPD aren't mandatory requirements, so you'd 
be able to trade lighting power through space-by-space or BAM. Someone 
will have to perform the take-off either way to calculate the BAM 
weighted LPD for the Proposed case, so you aren't saving much time on 
the Proposed model. (Only saving the time to actually assign the Watts 
to the zone in the model.) There will be a small time savings in 
Baseline model creation by not determining and entering space-by-space 
power usage into the model. I agree with Bill that 90.1's wording about 
"...if a lighting design exists..." points me towards space-by-space if 
at all possible. But GBCI seems to accept both, regardless of possible 
BAM inaccuracies which as Nick pointed out may or may not be 
significant, so the main result of this gigantic thread is:

1. Use the same method in both cases.

2. Several people think 90.1 suggests space-by-space if the lighting 
system is designed.
     a. Not always (ever?) enforced/requested by GBCI.
     b. When the model is being used to inform the design or calculate 
incentives, this is the more accurate approach if there is variance in 
the spaces for control types, LPD values, and occupancy schedules.

3. Although BAM may not provide the most accurate predictions of energy 
usage, it may still be "legal" for EAC1 point calculation purposes.

David David S. Eldridge, Jr., P.E., LEED AP BD+C, BEMP, BEAP, HBDP 
Grumman/Butkus Associates

From: equest-users-bounces at lists.onebuilding.org 
<http://lists.onebuilding.org/listinfo.cgi/equest-users-onebuilding.org><mailto:equest-users-bounces 
at lists.onebuilding.org 
<http://lists.onebuilding.org/listinfo.cgi/equest-users-onebuilding.org>> [mailto:equest-users-bounces 
at lists.onebuilding.org 
<http://lists.onebuilding.org/listinfo.cgi/equest-users-onebuilding.org>] On 
Behalf Of Patrick J. O'Leary, Jr. Sent: Wednesday, May 23, 2012 2:41 PM 
To: Bishop, Bill Cc: eQuest Users; Oscar B.

Subject: Re: [Equest-users] Building area method ASHRAE 90.1 referencing 
this comment: "The only obvious case for using the Building Area Method 
to determine modeled LPD is the case that Nick mentioned where lighting 
neither exists nor is specified." or when the lighting 
designer/electrical engineer has higher lighting densities that exceed 
one (or more) of the space-by-space maximum allowable lpds but 
compensates for it by having lower lpds in other spaces such that the 
whole building lpd does not exceed the maximum allowable by the whole 
building method.

On 5/23/12 7:45 AM, Bishop, Bill wrote: Building Area and Space-by-Space 
are not methods for designing lighting systems. They are prescriptive 
requirements for demonstrating lighting energy compliance in 90.1. The 
LPD allowances in Tables 9.5.1 and 9.6.1 do not need to be complied with 
if using energy modeling to demonstrate compliance for 90.1 and for 
LEED. (Only the Mandatory Provisions of 9.4 need to be met for the 
lighting design.) Energy modelers only need to know the lighting power 
and space use categorizations of the design as shown on the drawings 
(along with schedules and controls), not the process used to design it 
(which typically considers light levels in footcandles or lux).

I think that if a lighting system has been designed, a strong argument 
can be made that the space-by-space method needs to be used in both the 
proposed and baseline cases, and that lighting power needs to be entered 
individually for each space/zone. "If construction documents are 
complete, the proposed building lighting system power is modeled as 
shown on the design documents." (ASHRAE 90.1 User's Manual, p. G-17) 
"The LPD for the proposed design is taken from the design documents for 
the building. The LPD specified in the models must correspond to the 
spaces within each thermal block." (ASHRAE 90.1 User's Manual, p. 11-14 
and also p. G-18) The only obvious case for using the Building Area 
Method to determine modeled LPD is the case that Nick mentioned where 
lighting neither exists nor is specified. As Maria Karpman, Nick and 
Patrick have mentioned, you are likely to show higher energy savings 
using the Space-by-Space method. Beyond that, using Space-by-Space 
allows you to give valuable feedback to the design team, which I would 
argue is a responsibility of energy modelers. It is routine for me to 
point out areas of potential improvement of the lighting design in every 
project I model, based on the allowances in Table 9.6.1. "Yes, Ms. 
Architect, that is a lovely looking light fixture, but 2.6 W/ft2 of 
lounge lighting is more than twice the baseline allowance." I don't know 
how you give helpful feedback if you are just comparing two 
building-averaged lighting power densities. Regards, Bill 
-<http://lists.onebuilding.org/listinfo.cgi/equest-users-onebuilding.org>

  

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