Chilled Water Use for part of a floor

Annie - Did you receive any feedback? We are wondering the same thing with regard to natural gas. IE: If base building mechanical units serve more than one tenant, does this credit require the tenant of a LEED for Commercial Interiors project to somehow meter or allocate the portion of the gas use of these units to their space? If so, what is the most effective way of doing this? Or - is the metering of natural gas, synthetic natural gas, propane, fuel oil, diesel fuel, biofuel, and other fossil fuels only required for items that are unique to the tenant space/LEED Project in question?

Ditto ditto! Per Option 2 on this credit we are to install energy metering for "any individual energy end uses that represent 10% or more of the total annual consumption of the tenant space." Our current project is mostly concerned with chilled water. Our TI project is 5,000 sf in a 300,000+ sf office building. It seems unfeasible to meter certain base building resources at this level. We're also curious for future projects and how this would relate to natural gas.

We have a similar situation in that we have large rooftop air handlers, boilers, a fluid cooler system, gas supply etc. that service the overall building. The tenant spaces will occupy only portions of a single floor. Is it possible to meter the base building systems and then apply this to tenant spaces based on square footage? Or are these base building systems excluded from the tenant space metering?

Yes you would need to meter all fuel sources including chilled water and natural gas. No you can't simply prorate this based on area. The only way I can think of is to develop a methodology to derive this energy use for that space. One way might be to measure supply air temps to determine when the cooling is on and also the air flow through the VAV boxes assuming you have those in the system. You potentially could also examine the loads and the schedule for each of the spaces on that air handler (you would need to get data from the other tenant(s) on that floor) and then prorate the cooling energy use based on a weighted average load basis for the area served. Either way you definitely need to measure the chilled water to the air handler. Without being able to directly measure these energy uses you could try to derive it. I would think that the methodology should be automated to record and report the energy use in accordance with the required metering characteristics. In these situations this is not an easy credit to achieve.