ESCO ESCO Commissioning and Retro-Commissioning 5

Question 1

Studies such as LBNL's commissioning cost-effectiveness research report what typical whole-building energy savings range for retro-commissioning existing buildings?

Accepted Answer

About 10–20%

Answer

LBNL meta-analyses found median existing-building commissioning savings of roughly 16% with paybacks of about a year.

Question 2

Which commissioning deliverable gives building operators the system descriptions, sequences, setpoints, and maintenance information they need for long-term operation?

Accepted Answer

Systems Manual

Answer

The Systems Manual collects operational information so that staff can keep systems performing as commissioned.

Question 3

An RCx investigation finds that chilled water pumps run at constant speed despite having VFDs installed, with the drives locked at 60 Hz in hand mode. What is the appropriate fix?

Accepted Answer

Return the VFDs to automatic control based on a differential pressure setpoint

Answer

Restoring automatic DP-based speed control uses the existing VFDs and gains cube-law pump energy savings.

Question 4

Under ASHRAE Guideline 0 and Standard 202, when should the commissioning process ideally begin on a new construction project?

Accepted Answer

During the pre-design phase

Answer

The Cx process starts at pre-design so the OPR can guide design, construction, and acceptance.

Question 5

In an ESPC, savings from an RCx measure can degrade over time. Which contract provision best protects persistence of these savings?

Accepted Answer

Ongoing M&V with periodic re-commissioning or trend reviews included in the performance period services

Answer

Operational savings tend to drift, so periodic verification and recommissioning keep the guaranteed savings intact.

ESCO - Energy Service Company Practice Test

ESCO - Energy Service Company Practice Test

ESCO ESCO Commissioning and Retro-Commissioning 5