[Bldg-sim] EPACT Simulations Questions

[David S Eldridge]

When making a partial qualifier analysis, the other aspects of the proposed building are relaxed to match the baseline building.

If you are attempting an HVAC partial qualifier for instance, the proposed and baseline building would be identical for lighting design and envelope design, and you'd have to achieve 20% under the newer rules.  (16-2/3% for a building partially qualifying under the old rules.)

The 20% (16-2/3%) will then be wholly attributable to the HVAC systems.  To partially qualify for envelope, you'd repeat this process in a second set of simulations with the proposed envelope, but baseline lighting and HVAC while claiming 10% savings (16-2/3%).  Etc.

If your client had a whole-building qualifier, then you would have all different aspects of your proposed design incorporated, but have to achieve 50% savings.  The savings do not have to be allocated to each partial area in this case.

It won't be too hard to make a spreadsheet to show the savings.  Similar to what you might have done for any other ECB or Appendix G analysis.

David

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David Eldridge, PE
LEED(r) AP

Grumman/Butkus Associates | 820 Davis Street, STE 300 | Evanston, IL 60201 | Ph: (847) 328-3555 | Fax: (847) 328-4550

Energy Consultants and Design Engineers
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From: bldg-sim-bounces at lists.onebuilding.org [mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of Nick Anderson
Sent: Tuesday, January 06, 2009 3:18 PM
To: bldg-sim at lists.onebuilding.org
Subject: [Bldg-sim] EPACT Simulations Questions

Building simulations for EPACT credits require that the building energy and power costs be reduced by 50%.  The tax credit has been extended to 2013.

The energy and power cost savings must come from a 16-2/3% reduction in three categories: Building envelope, HVAC and SHW, and Lighting.  There is a guideline called  "Energy Savings Modeling and Inspection Guidelines for Commercial Building Federal Tax Deductions" Second Edition, which is Technical Report NREL/TP-550-40467, May 2007.

In this guideline, they describe the technique on pages 3 and 4 to calculate the costs and % cost reductions due to the Lighting, and HVAC/DHW electricity use.  Nowhere does it describe how they want you to calculate the cost and cost reductions due to the building envelope, despite the fact that 16-2/3% of the energy savings are required to come from this category.

Does anybody know what to do for the building envelope and the EPACT deduction?

Has anyone seen a spreadsheet available already created to do the cost allocations based on the outputs from a simulation program (in my case Trane Trace 700)?  There are quite a few available for the simple "Interim Lighting Rule" but none that I have found for the full model.

Also, in April 2008, an IRS Notice 2008-40 called "Amplification of Notice 2006-52" describes being allowed to change the portion of the savings for the building envelope to 10% if the Lighting and HVAC/DHW savings are increased to 20% each (for a total remaining at 50% energy and power cost reduction).

Has anybody seen this used?  I have searched around for examples of EPACT and all places still reference the 16-2/3% thresholds.



Nick Anderson

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