ASHRAE Journal - November 2013 - 72

Column The performance gap

performance-critical aspects of the job among project
stakeholders.
Implementation errors or changes. Based on the
investigation, there were no known project implementation errors or changes that could have significantly
contributed to the performance gap.
Nonetheless, mistakes and changes in the field during implementation or commissioning are common.
They should be communicated back to the project
development team to make sure they are consistent
with the intended operation and to quantify potential
performance impact. Corrective measures may be
required.
Inadequate communication. There are two
instances where lackluster communication contributed to the performance gap. The energy model relied
on hourly occupancy and gaming machine data from
the owner to calculate internal loads. Although the
analyst followed up with the owner about this data,
internal delays prevented access to a full data set
until after the proposal deadline. Assumptions were
made to fill in the missing data that contributed to
the modeling error. The second instance occurred in
the rush just before the deadline. The energy analyst
had communicated internally that the model was
not fully mature and needed additional time for vetting. In order to meet the deadline, it was agreed that
the financial analysis would be labeled as "preliminary" and the final model would be submitted later.
After a quick review by the owner, the proposal was
approved. However, there was no deliberate conversation between the mechanical contractor and the
owner regarding the preliminary status of the financial analysis prior to approval. Missing the window
of opportunity to discuss status of the energy model
with the owner meant the mechanical contractor had
to choose between risking a potential savings shortfall
in the long term and appearing disingenuous to the
owner in the near term. The model was not revisited
and the errors were not caught until after the performance year.
Strong communication must be maintained among all
stakeholders from project inception through operation.
In this case, communications were foregone with the
pressure of an imminent deadline. In the instance where
the critical conversation window was missed, the wiser
decision would have been to reset expectations as soon as
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possible to hedge against potentially worse ramifications
in the future.
Lack of accountability. The owner desired a condensed timeline, low project first cost, occupant
comfort improvement, and a reduction in natural gas costs. They appeared less concerned about
achieving a specific savings or payback target. From
the mechanical contractor's perspective, the energy
project had a low cost and lacked a contractual savings guarantee so their main focus was to meet
owner expectations, keep development costs low,
and gain timely project approval. Given that there
was relatively little financial risk in modeling inaccuracy, a peer review of the energy model was omitted to fit the timeline despite the analyst's concerns.
A cursory peer review or more time for analysis
would have likely caught the mistakes that contributed the most model error.
It is important to consciously consider the motivations of all stakeholders in energy projects. In
this case, an important quality control measure
was bypassed to save time. Peer reviews should be
conducted as a priority regardless of direct financial incentive and especially when the model is
rushed.

Conclusion
Most often the performance gap is caused by a combination of the five common pitfalls examined in this
column. In this ERV upgrade project, two of the five
pitfalls contributed to an energy savings shortfall.
Inadequate communication brought on by an abbreviated project timeline and a lack of financial accountability contributed to energy analyst's modeling errors
and the resulting performance gap. Although this
owner is satisfied with a measured 38% annual natural gas reduction from this project, the mistakes made
along the way can be easily replicated with more dire
consequences.
Owner and investor confidence can be maintained by
continuously improving our processes and earnestly
learning from our mistakes. This case study illustrates
the benefits of a "post-mortem" analysis as one tool for
eliminating the performance gap. Future columns will
provide additional insight from new construction and
retrofit energy projects on how to close the performance
gap.

ASHRAE Journal - November 2013

Table of Contents for the Digital Edition of ASHRAE Journal - November 2013