Page 109 - Zero Net Energy Case Study Buildings-Volume 1

Energy Use – Actual Measurement
Metered data has been collected for the building since the first year, 2006-2007. This includes data from the large array of individual building meters as well as data from a set of meters on the amount of hot water and chilled water coming to the building from the Central Plant. All of the energy use in the building continues to be measured and accounted for, including that coming from the Central Plant in the form of heated or chilled water.
For reasons unrelated to the subject of this publication, the formal commissioning process for the building was interrupted and had to be taken over by the UC Merced facilities group. As a result, the post occupancy adjustments spanned both the regular commissioning period and the post- commissioning period. Part of the normal commissioning activity involved verifying the measure- ments being recorded by the meters, which was carried out by UC Merced with the assistance of Lawrence Berkeley National Laboratory (LBNL).
As reported in the 2009 CIEE measured performance case study for the Science & Engineering Building I4, the initial recorded data contained gaps, errors and implausibilities that resulted in the need to replace or recalibrate some meters. Once the subsequent measured results were evalu- ated and verified by LBNL to be “reasonable and consistent with all available data, including en- ergy balances with master utility meters”5,6, the performance of the building in a fully operational year could be recorded and reported.
The results of the first year of energy use data analysis showed the overall effectiveness of the design strategies employed for this building to exceed significantly the target of 80%-of-bench- mark. The first-year EUI (site energy) was measured at 207 kBtu/gsf-year, which is 64%-of- benchmark. The peak power demand, peak chilled water and hot water demand from the Central Plant were measured at similar performance levels below the target benchmark7.
At the time of these first measurements, the UC Merced facilities group began a program of response to observed energy use trends of each subsystem to make corrections and to improve the building’s overall performance. These observations and corresponding improvements are described in the following section.
Beyond these adjustments to the building components, the UC Merced group has been working with users to tailor their use patterns in program-supportive ways and to make the energy system controls more responsive to the users’ actual needs. This work with the users has resulted in a more energy efficient operation of the building and more awareness of energy use on the part of all users. This particular post-commissioning activity is proving to be the most interesting—and in some ways the most innovative—in terms of making even more significant reductions in total annual energy use. See the following section on continuing post-commissioning work.
SCIENCE & ENGINEERING BUILDING I
CASE STUDY NO. 5
4 “Measured Performance Case Study: Science & Engineering Building I, UC Merced”, Cali- fornia Institute for Energy and the Environment (CIEE) and the New Buildings Institute (NBI), 2009
5 Ibid. p. 4.
6 It should be noted here that interviews with owners and A/E teams for several ZNE projects indicated that problems with metering are commonplace and troubleshooting meter perfor- mance should be part of the regular commissioning process. Likewise, organization and analy- sis of data from all energy sub-systems should be set-up at the beginning and verified to be in a usable form. Finally, there should be periodic reporting of the organized data to confirm the quality and usefulness of the information.
7 Ibid. p. 6.
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