[BLDG-SIM] Process Loads and LEED

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, a cost savings of an estimated $15-$30 per computer per year can 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

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.