District Energy Systems-Chilled Water

Jeff. This is actually a little difficult because it is easy to look at this two different ways. First you comment that you are purchasing 'chilled water from a utility'. Well that should already be submetered in some fashion otherwise they would not be able to bill you. (Unless you really are getting it for free!). This would fall under the EA credits as would steam or hotwater supplied from a utility where these 'energy supplies' are metered and used to create your Energy Star number. Consequently I think that you are talking about a 'private' DES which is onsite of a campus style setup. If this is so then you may have a couple of options. 1. submeter each building and gain the numbers that you need for E* (and therefore fulfill the submetering requirement in the WE credit) or, 2. talk with the USGBC/GBCI about E* for the whole campus using the DES numbers only. (This would mean that you wouldn't get the WE credits but would shorten the whole process.

Jeff, Yes take it in Energy (You're supply an 'energy source' to the building just as you would have with steam). In WE c1 take it in Option 2, Other Process water. Why?, because the intent we wrote says, " To measure building and subsystem water performance over time to understand consumption...." The whole point of this is reduce potable water. I would class this as a synergistic process where the chilled water, (the costs of cooling that are energy related) and metering the potable water content of that chilled water. As to the EP...well if you're satisfying 2 or more in Option 2, then you stand to get it. (Note as with any EP always check the EP box in EVERY credit that EP complies..regardless of weather you use it or not...that helps that if one credits is denied later it's very simple to slip in another EP in the IO credits halfway through or even at the end)

I concur that metering of chilled water is an energy meter, not a water meter. On the other hand, In the case of a university campus, we also meter all of the make-up water that goes to our central plant cooling towers as part of our chilled water cooling process. For office buildings on the chilled water system and with no cooling towers, I presume that this district energy system (DES) approach of demonstrating subsystem water metering would be valid. The volume is in tens of millions of gallons, but all we need to demonstrate is that this is 100% of cooling tower water for that project, correct?