ASHRAE Journal - February 2023 - 56

TECHNICAL FEATURE
of implementing the measurement
and verification plan throughout the
post-retrofit period.
2. Measure the energy use and/or
demand before the retrofits are applied
(baseline). Record factors and
conditions that govern energy use
and demand.
3. Measure the energy use and/or
demand after the retrofits are applied
(post-retrofit period). Record
factors and conditions that govern
post-retrofit period use and demand.
4. Project and adjust the baseline
FIGURE 2 Guideline 14's general approach for
measurement of energy and demand savings.
Prepare M & V Plan Showing
Compliance Path
Measure Baseline Energy Use and
Record Governing Conditions
Measure Post-Retrofit Energy Use
And Record Governing Conditions
Project Baseline and
Post-Retrofit Energy Use to
A Common Set of Conditions
(Usually Post-Retrofit Conditions)
and post-retrofit period energy use
and demand measurements to a
common set of conditions. These
common conditions are normally
those of the post-retrofit period, so
only baseline period energy use and
demand need to be projected (i.e.,
weather normalization).
5. Calculate savings by subtracting the post-retrofit
Projected Baseline Use Minus
Projected Post-Retrofit Use = Savings
Report Savings,
(And Uncertainty if Following
A Performance Compliance Path)
level can be measured during the
baseline period, and the energy use
of the equipment or subsystem can
be measured post-installation for a
short-term period or continuously
over time.
The retrofit isolation approach
should be used when the wholebuilding
approach is not appropriate
and the savings in question can
be determined by measurements
taken at a specific equipment item
or subsystem. The whole-building
approach may not be appropriate
if the savings to be determined are
relatively small or if there is an unrelated
change in the building served
by the meter(s). The retrofit isolation
approach may not be appropriate for
determining the individual savings
from the implementation of several
period use and/or demand from the projected baseline
period use and/or demand.
6. Determine the uncertainty in the cumulative savings.
In all three of the paths this requires the determination
of and reporting of the level of uncertainty in
the cumulative savings computed to date. This level of
uncertainty in reported savings should not be greater
than 50% of the total savings in the post-retrofit reporting
period (at the 68% confidence level). In the WholeBuilding
Prescriptive Path, the uncertainty calculations
are replaced by prescribed requirements (see Annex B of
the Guideline for more information).
What are the Basic Measurement Methods in
Guideline 14-2023?
The three basic measurement methods in Guideline
14-2023 include: the Retrofit Isolation Approach,
the Whole-Building Approach (prescriptive and
performance) and the Whole-Building Calibrated
Simulation Approach.
Retrofit Isolation Approach
The retrofit isolation approach is intended for retrofits
where the end-use capacity, demand or power
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ASHRAE JOURNAL ashrae.o rg
F E B R U A RY 2023
EEMs, when their cumulative or interactive savings cannot
be determined by measurements taken at one or
more specific equipment items or subsystems.
Guideline 14-2023 relies heavily on previously developed
standards for the laboratory measurement of
temperature, pressure, airflow, liquid flow, power,
thermal energy, and the testing standards for chillers,
fans, pumps, motors, boilers and furnaces. Guideline
14-2023 also relied on the previous work that developed
in-situ measurement techniques for various
energy consuming devices including lighting systems,
pumps, blowers, chillers, thermal storage and airside
HVAC systems. Such work also included procedures
and results from ASHRAE Research Project 827 RP-
Methodology Development to Measure In-Situ Chiller,
Fan and Pump Performance; Research Project 1004 RP-
Methodology Development to Determine the Long-Term
Performance of Cool Storage Systems from Short Term
Measurements; Research Project 1093 RP-Compilation
of Diversity Factors and Schedules for Energy and
Cooling Load Calculations; and Research Project 1050
RP-Development of a Toolkit for Calculating Linear,
Change-Point Linear, and Multiple-Linear Inverse
Building Energy Analysis Models.
Guideline 14 has classified the retrofit isolation
approach according to whether the load is fixed or
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