[Bldg-sim] ASHRAE 90.1 Baseline LPD and occupancy sensor credit

[James Hansen]

Steven, see Table G3.2 of 90.1.  Ramana is correct that you can apply
reductions in connected lighting density for occupancy sensors in those
spaces that do not need them (but have them).

 

Ramana, to answer your question, the LPDs for the baseline model should
not be adjusted per Steven's quote of Table 3.1.

 

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From: bldg-sim-bounces at lists.onebuilding.org
[mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of Steven
Savich
Sent: Thursday, December 01, 2011 12:35 PM
To: 'Ramana Koti'; 'Bldg-Sim'
Subject: Re: [Bldg-sim] ASHRAE 90.1 Baseline LPD and occupancy sensor
credit

 

Ramana,

 

90.1-2007 Table G3.1 section 6 under Baseline Building Performance
states: " . . . No automatic lighting controls (e.g. programmable
controls or automatic controls for daylight utilitzation) shall be
modeled in the baseline building design, as the lighting schedules used
are understood to reflect the mandatory control requirements in this
standard."

 

You should not be adjusting the power density number to simulate
lighting controls, but adjusting the schedules to reflect occupancy
sensor operation.  For example, say there are a number of offices and
conference rooms in the proposed building that will have occupancy
sensor controls.  This should be simulated by inputting the LPD or
actual connected load, and creating a schedule with a 10% - 15%
reduction for each hour of operation per Table G3.2.  In the LEED
baseline model, the schedule for the offices would be not have the
occupancy sensor reduction, but the conference room and other spaces
required by 90.1 to have occupancy sensor control would use the reduced
schedule.  Clear as mud?

 

Steven

 

From: bldg-sim-bounces at lists.onebuilding.org
[mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of Ramana Koti
Sent: Thursday, December 01, 2011 8:21 AM
To: Bldg-Sim
Subject: [Bldg-sim] ASHRAE 90.1 Baseline LPD and occupancy sensor credit

 

All,

 

This question pertains to a LEED energy model per the ASHRAE 90.1
Appendix G. Occupancy sensors are required in spaces such as conference
rooms and employee lunch/break rooms per Section 9.4.1.2 and no lighting
power density credit can be taken for their use in the proposed design
model.

 

My question is, do the baseline maximum LPDs prescribed by ASHRAE, say
1.3 W/sf for conference rooms, already account for the power 10 or 15%
adjustment for occupancy sensor use or does the credit have to be
manually applied on top of the 1.3 W/sf in the Baseline model?

 

Thank you,

Ramana Koti.

 



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