We have a child care center in the SE US. We did very well on envelope, lighting, and mechanical design (53% reduction in those areas). The building has a commercial kitchen with several additional dishwashers and clothing washer/dryer combos throughout the building (kids are always hungry and messy). We are tied into a CEP using steam and chilled water. We are modeling using Trace 700.

Here is our problem:

In spite of our great performance in the "building's" performance, our energy model only shows a 21% overall improvement due to what appears to be a "weighting" issues between, HVAC/Envelope/Lighting, hot water, & plug loads (process energy).

The hot water and plug loads requirements are so high per 90.1, that these loads are 68% of the total building energy usage. As you know, design and proposed process loads must equal each other. With plug/process energy loads at 34% of the total, this hurts our overall savings average. A question was raised after reading the NC guidebook, i.e. shouldn’t we be using “25% of the baseline building energy cost” as our default process energy or are we required to use the actual loads even if they are above 25%? The guide book is unclear abouot going above 25% (you just can't go below). Obviously, if we can use 25% rather than 34% that will be a great benefit. Also, to avoid circular reference, do we model the building alone (HVAC, Service Water, & Lighting) and use 25% of that? What is the definition of "total energy cost of the baseline building?"

Also, along these same lines, we placed our hot water requirements from the kitchen and dishwashing into the service HW category. Further discussion suggested that commercial kitchen HW water use is essentially process water like process water from an industrial setting and as such it should be excluded from the calcs. Is this the case? The LEED guide book just notes “service” water heating as regulated (non-process). If this water is process water, aren’t we able to exclude the process water from our energy calcs all together? We exclude these items from our water reduction calcs for good reason. Isn’t this the same?

I am probably over thinking the issue so I can use some input from anyone who has knowledge in this area. Thank you in advance.