[BLDG-SIM] Process Loads and LEED

["David S Eldridge" <DSE@xxxxxxxxxxxxxxxxx>]

Varkie, I can see merits for the 2.1 method and the 2.2 method.  On the one hand, the process loads are to some degree out of our control.  But on the other hand, if you have a building with such massive load density why would the rating system want to exclude all of that energy from sustainable practices?

 

I like the idea of consistency when considering all of the energy for energy optimization, on-site renewables and green power - there are projects out there that might earn fewer EAC1 points under v2.2 than under 2.1.  The percentage savings were changed between the versions so it's hard to say if it is more or less likely to earn a certain amount of EAC1 points - I would be interested to see a summary if the data is available about EAC1 points under v2.1 compared to v2.2.  Probably about the same?

 

For a high load density building like yours - definitely going to be harder.  The only suggestion as far as EAC1 points that I could offer would that if your design has receptacle load at 6 W/ft2 there is probably a significant diversity in that load, maybe it won't turn out as badly as you fear.

 

In regard to ventilation, you are going to use the outside air requirements from the proposed design and apply that outside air quantity to both models.  There isn't a "baseline ventilation rate" - use equal CFM of OA for both models.  Also, OA may be determined from local building codes rather than ASHRAE - that would also apply equally to both models.

 

The one exception would be that Demand Control Ventilation could potentially be used in the proposed model to reduce OA if DCV isn't required prescriptively, and if your minimum OA from code is less than what is required by ASHRAE 62.

Hope this helps!

 

David

 

 

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From: BLDG-SIM@xxxxxxxx [mailto:BLDG-SIM@xxxxxxxx] On Behalf Of Varkie Thomas
Sent: Monday, March 05, 2007 9:14 AM
To: BLDG-SIM@xxxxxxxx
Subject: [BLDG-SIM] Process Loads and LEED

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.

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