Hello there,
There is a sample summary of energy and metering capacity on page 200 of the reference guide, and some explanation on "Energy Use Breakdown" on page 198 saying that significant applications are thsoe responsible for 10% or more of the building's total consumption.
First question:
I'm working with an office building that chilled and hot water for the main HVAC is supplied by a heat pump chilling unit. This system also conditions the outdoor air. In addition to the main HVAC system, there are VRF units that also heat and cool some spaces. Is it correct to say that in this building the correct submetering categories would not be cooling, heating, and ventilation as three categories, but HVAC, as one category. The reason for considering HVAC as a single category is that the same equipment provide heating, cooling, and ventilation.
Second question:
Is my understanding correct that upstream equipment and downstream equipment should be represented in the same category (chilling unit + OAHU as a single category) ?
Third question:
The building use is office, but there is a server room that uses around 20% of the total annual energy of the building. I think there are three ways of treating the energy use of the server room: 1 - treat all the energy as server room; add the different uses to the respective office uses (server lighting + office lighting, server HVAC + office HVAC); 3 - treat all the sub-uses as separate uses (server, server room light, server room plug load, server room HVAC). Would it be separate these as categories if they are responsible for 10% or more of the building energy use?
Ben Stanley
Senior Sustainability ManagerWSP - Built Ecology
LEEDuser Expert
250 thumbs up
January 25, 2016 - 4:46 pm
Hi Noriko,
I have some thoughts on your questions above.
Question 1:
In my experience it is acceptable to consider major pieces of equipment as a separate category for the purposes of this credit. So, in this case, the heat pump chilling unit, OAHU, and VRFs could be considered separate stand alone systems to be metered. I think that approach could be better than lumping all of them as a single HVAC system. Though it could depend on the extent that different pieces of equipment are metered. See Question 2 below.
Question 2
I wouldn't combine the heat pump chilling unit and OAHU. The OAHU consumes electrical energy to run the fans for the unit, which would not be captured by just measuring the heat pump chilling unit.
Question 3
The serving room lighting and plug loads should be included with the lighting and plug loads for the rest of the building. IT energy associated with the server room should be considered a separate system. I think that questions 1 and 2 get at the HVAC equipment.