Page 46 - Zero Net Energy Case Study Buildings-Volume 3

CASE STUDY NO. 12
THE J. CRAIG VENTER INSTITUTE
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Zero Net Energy Case Study Buildings: Volume 3
alternatively, provide for a more enhanced ability of the system to dehumidify when going from natural ventilation to cooling.
3. Analyze the physical design using natural ventilation software to verify proper size and location of openings to achieve the correct air flow patterns and quantities to ensure comfort conditions.
4. Include low-wattage backup fans if using a “thermal chimney” approach to natural ventila- tion, to ensure good air movement under less-then ideal conditions.
Post-Occupancy: Metering Systems
As described above in the section on measured performance of the building, a comparison of the metering system of the building with the SDG&E electric meter revealed that the data as reported by the metering system was not complete. (This was also found to be the case in at least one other case study building in this book.)
This seems to be the result of several possible factors. The meter specified should be appropri- ate to quantities being measured and should be checked for proper calibration. More significant- ly, the single line diagram for the system should be coordinated by the electrical and mechanical engineers to make sure that all loads are being included (or not double-counted).
But more important, perhaps, is that the metering system should be designed to provide ready information both to the maintenance staff—identifying where loads are increasing unusually or other indications of malfunction—and to the occupants by providing useful information about their behavior. An example at JCVI was a missed opportunity to provide feedback to lab person- nel by separately metering the steam generator for the autoclaves or the dishwashers, which is a large energy-using equipment item and whose use is very amenable to behavioral change.
Another useful design feature of the metering system could be to make sure that the data being recorded on each circuit is in the same category (that is, lighting, pumps, fans, heating, cooling, etc.). This would ensure that performance data can be easily compared to the energy modeling results. While this is interesting to the energy modeling engineer, it also can often give an indica- tion of a system or behavioral problem.
The commissioning plan should include verification that the metering system is in fact operating correctly and, if possible, checked against the public utility’s site meter to verify consistency.
Post-Occupancy: HVAC System
The use of chilled beams was a new idea for laboratories, but with some training the subcontrac- tors accepted the new technology and provided lower competitive bids. This idea of training the subcontractors prior to bid essentially overcame the natural conservatism of the building indus- try, which tends to be risk-averse and opts for well-known technologies.
Post-Occupancy: Electric Lighting
At an appropriate time in the future, the fluorescent light fixtures can be gradually replaced by LED fixtures, which are now cost-competitive will result in a further reduction in the building EUI.