IPMVP Vol III requires the M&V Plan to include the "expected overall M&V accuracy" (pg 9) and in Section 4.5.9 Option D: Uncertainty it refers to ASHRAE Guideline 14 for guidance. ASHRAE Guideline 14 gives an accuracy example of 10% uncertainty with 90% confidence - I have seen this accuracy statement in a M&V Plan before, but I doubt it was determined using the rigorous calculations in the Guideline. The Guideline is also not really meant to be used on new buildings...
Does anyone have experience determining an overall M&V accuracy, with or without ASHRAE Guideline 14?
Is a 10% uncertainty with 90% confidence statement typically used with Option D?
Any in-sight or guidance would be greatly appreciated.
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5907 thumbs up
February 26, 2013 - 12:00 pm
Make sure you have both a monthly and annual target for each energy end use. It is not sufficient to have only an annual total accuracy target. Typically the targets are expressed as +-XX%. The target can vary but is usually in the 5% to 20% range depending on the situation and the project. +-10% is a very commonly used value in alignment with Guideline 14.
There was a post by Gord Shymko in one of these EAc5 credit forums with more detail on this issue. Might want to search the other versions of LEED under this credit.