M e m o r a n d u m
FROM:
Michael Baker, SBW
TO:
RTF Staff
DATE:
February 11, 2013
RE:
Phase I Review and Update Recommendations: Grocery Door Gasket Replacement
This memo documents the results of EMP2’s detailed review of the UES (Unit Energy Savings) measure
Grocery Door Gasket Replacement. This measure has been classified by RTF staff as Proven. This
measure covers savings from replacing worn or damaged gasket on reach-in or walk-in door cases with a
replacement gasket that meets the manufacturer’s specification. EMP2 reviewed the RTF workbook file
ComGroceryDoorGasketReplacement_v1_0.xlsm. The review focused on the derivation of Unit Energy
Savings (UES).
Summary Recommendation. The status of this measure should be changed to Out-of-compliance.
The following recommendations lead to a change in status to Out-of-compliance.
1. A larger sample of test conditions is required than the tests conducted in one environment on
one reach-in and one walk-in unit.
2. The condition of baseline gaskets needs to be supported by measurements.
3. Savings for medium-temp reach-in cases need to be derived independently, rather than
estimated as 2/3 of the savings of low-temp cases, or this methodology needs to be supported
with engineering sources and calculations.
4. The amount of time that case and walk-in doors are open needs to be supported by
measurements on a larger sample.
5. The Average EER parameter needs to be derived transparently from publically available regional
data.
The following recommendations lead to a change in status to Under Review.
1. Calculations are not available for review, inputs are available from various supporting
documents but they need to compiled, the methodology shown with calculations, and sources
documented.
2. Remove outdated tabs from workbook and clearly define and describe resources and definitions
for current savings figures.
2820 Northup Way, Suite 230
Bellevue, WA 98004
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3. Measure definition needs to clarify that the measures are per door rather than per foot.
4. Measure definition needs to be clarified as to how damaged a length of gasket needs to be to
qualify for a rebate.
5. HVAC interaction should be considered in the estimation of measure savings.
6. Test results need to be normalized from lab conditions to regional average EER values.
7. The methodology used to calculate the Anomaly Impact Factor, which normalizes test results to
account for differences in environmental conditions between the baseline and efficient cases,
needs to be more fully documented.
Limitation of Review. PECI’s Engineering Specification for GrocerSmart™ 3.0 was not available or
included as part of this review. HVAC interactive factors used in the 6th Plan were not reviewed.
Alterations to Workbook and Documentation.

Since a standardized RTF measure workbook was not available, the standardized workbook
ComGroceryDoorGasketReplacement_v1_0.xlsm was developed using supporting information
from the RTF workbook DeemedMeasuresV26.xls and EnergySmartGrocer-March 2009V2_15.xls.

A sheet called “Summary” has been added to the workbook. This sheet describes how measures
are identified, lists important constants and their sources, describes the savings estimation
algorithm and the associated baseline and efficient case parameters and their sources for each
measure and UES component.

Supporting workbook and formulas were not available for review. In an attempt to recreate the
approved savings methodologies, EMP2, Inc included four additional tabs “gaskets 2012
worksheet”, “Normalized EER”, “gasket 2012 summary”, and “Door Open Times”. These
worksheets attempt to identify the methodologies that support the RTF approved figures.
o
A sheet called “gaskets 2012 worksheet” has been added to the workbook. This
worksheet source is from PECI and shows how the Emerson Laboratory Test Results
were modified to determine RTF approved savings figures (savings do not all match).
o
A sheet called “normalized EER” has been added to the workbook. This worksheet
source is from PECI and shows how the savings for the reach-in low temperature
case savings was normalized to account for discrepancies between the damaged
and full gaskets test provided by Emerson Test Laboratory Results. This also shows
how the 1.7 kWh per day discrepancy was calculated.
o
A sheet called “gaskets 2012 summary” has been added to the workbook. This
worksheet attempts to verify how the RTF approved savings were derived using
various figures from the November 2008 presentation and Emerson Test Laboratory
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Results. This worksheet also includes supporting material from the Nov, 2008 RTF
meeting – a statement from PECI describing typical gasket damage, and the table
summarizing door open times.
o
A sheet called “Door Open Times” has been added to the workbook. This sheet
shows results from metering of cooler and freezer door open times (presumably by
BPA). In addition, some summary statistics have been added.
Recommendations for Updates. The RTF should implement the following recommendations:
1) Workbook Structure and Formulas
a)
The worksheets “gaskets 2012 worksheet”, “Normalized EER”, “gasket 2012 summary”, and
“Door Open Times” need to be updated and fully documented, with formulas clearly shown.
This deficiency causes a change of status to Under Review.
b) Most of the supporting documentation in ComGroceryDoorGasketReplacement_v1_0 support
figures from an outdated calculation methodology or support measures outside of the door
gasket replacement measure. The original savings methodology was based on an ASHRAE
infiltration calculation. Now that the savings are based on actual infiltration lab testing results
these outdated tabs should be removed (gaskets, gaskets 2009, RI Gaskets, and WI Gaskets).
Other tabs that do not support this measure also need to be removed (general, RF Background).
The gasket background tab needs to be updated to support current savings methodology and
savings figure. This deficiency causes a change of status to Under Review.
2) Documentation
a) No recommendation.
3) Measure Definition
a) The measure definition was initially based on a per foot of gasket. Measures approved at the
November 2008 meeting were on a per door basis. The current documentation doesn’t clearly
specify the measure definition as based on a per door basis. EnergySmartGrocer- March 2009V2_15.xls still includes per linear foot measures in addition to per door measures. The per foot
savings values appear to be derived from the per door savings combined with linear feet per
door from the presentation at the meeting. However, the basis is not clear for the linear feet per
door values for walk-in spaces in that presentation (in the cost section). The values are too low
for a complete gasket replacement on a walk-in door. The definition of both per door (complete
replacement or partial?) and per linear foot measures needs to be clarified. This causes a status
change to Under Review.
b) The measure definition states that the new gasket “must replace a worn or damaged gasket.”
This statement is too vague since it could apply to gaskets which are effective infiltration
barriers as well as those which are not. This specification should be updated as a result of
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investigations into the condition of baseline gaskets. This causes a status change to Under
Review.
4) UES Savings Estimation Method
a) At the core of the savings estimates are laboratory tests on one reach-in freezer and one walk-in
environmental unit configured to simulate conditions of a walk-in freezer and a walk-in cooler
with simulated damaged and undamaged gaskets. These limited test conditions do not meet the
standards for statistical, meta-statistical, or calibrated engineering methods of estimating
savings. A larger sample of test conditions is required to validate the conclusions. This causes a
status change to Out-of-compliance.
b) Savings estimates are based on laboratory testing of freezers and coolers with simulated
damaged gaskets. The damaged gasket condition was achieved by creating spaces in the gaskets
in an attempt to simulate gasket conditions that are stated in the RTF Status Report Power Point
Presentation given in November of 2008 as follows.
These observations do not constitute a sufficiently quantitative basis to establish the condition
of the baseline gaskets. ADM (2008) found a significantly lower rate of gasket damage than that
described above. ADM found that gaskets were often replaced for aesthetic reasons while they
were still effective at preventing infiltration. The ADM study, which applied only to reach-ins,
was not able to estimate the condition of replaced gaskets with high confidence. The infiltration
allowed in the field by baseline gaskets needs to be determined by measurement. This causes a
status change to Out-of-compliance.
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c) Three of the four measures are directly supported by individual laboratory test procedures as
performed by Emerson Technologies (Reference 1,2,3). However, the savings figure for the
reach-in glass doors medium temperature measure is simply estimated assuming a 67% factor of
the reach-in glass door low temperature measure figures. This estimation method must be
documented with supporting data or revised based on similar test procedures for reach-in glass
door medium temperature studies. This causes a status change to Out-of-compliance.
d) HVAC interaction should be considered in the estimation of measure savings. The net electric
HVAC interaction factor assumed in the 6th Plan for lighting measures in groceries was 1%. The
gas impact was negative .01 therms per kWh saved. The electric impact is small, but should be
noted. Impacts will need to be re-estimated for this measure based on the reduction in heating
load in the environment that corresponds to the reduction in cooling load inside the refrigerated
space (rather than based on kWh saved). This problem causes a change of status to Under
Review.
e) Test results need to be normalized from lab conditions to regional average EER values, which
PECI is currently under contract to the RTF to update. This deficiency causes the measure to
change the status to Under Review.
5) Input Parameters
a) The Emerson Laboratory Test Results savings were modified by estimates of the percent door
open time as shown in the November 2008 Power Point Presentation. These door open times
are based on actual field measurements but the % open times have a large variance and the
mean has low confidence. The median door open time was used for three of the four cases,
apparently to compensate for the impact of significant outliers in the data; the mean was used
for the fourth. A large enough sample size such that the mean can be used with confidence is
required for this parameter. The ADM study estimated this parameter for reach-ins with a high
level of confidence. However, it is not possible to completely evaluate this study as a source for
this parameter without a more detailed look at the data than is provided by the report. This
deficiency causes a status change to Out-of-compliance.
b) The Average EER parameter is based on proprietary DOE 2.2-R simulations of Northwest grocery
environments. This parameter needs to be derived transparently from publically available data.
This deficiency causes a change of status to Out-of-Compliance.
c) Based on the November 2008 Grocery Store Measures – RTF Status Report III-4 Power Point
Presentation it appears that an anomaly impact factor of 1.7 kWh per day was applied to the
savings based on page 16 of 24 of the presentation. This increases the laboratory testing result
savings by roughly 100%. This has a large impact on savings with little supporting
documentation. EMP2, Inc. included an additional worksheet titled “Normalized EER” that
describes how this anomaly was derived. This worksheet was provided by PECI. The
PowerPoint states that the normalization is due to differences in the test conditions between
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the baseline and measure test. The methodology used to calculate this anomaly needs to be
fully documented. This causes a status change to Under Review.
Additional Considerations.
1) Sunset criteria – Five years from date of approval.
2) The ADM study offers an alternative savings estimation methodology, based on field measurements
of infiltration, combined with engineering calculations of the energy impacts of the infiltration.
However, the engineering calculations were not calibrated to actual energy consumption data.
Sources
Energy Usage of a Reach-In Freezer With Various Gasket Conditions, Design Services Network, Test
Performed by Max Gingrich, Report Prepared by Steve Pfister & Georgi Kazachki, Design Services Network,
August 21, 2008.
2
Energy Usage of a Walk-In Freezer With Various Gasket Conditions, Design Services Network, Test
Performed by Max Gingrich, Report Prepared by Steve Pfister & Georgi Kazachki, Design Services Network,
September 20, 2008.
3
Energy Usage of a Walk-In Cooler With Various Gasket Conditions, Design Services Network, Test Performed
by Max Gingrich, Report Prepared by Steve Pfister & Georgi Kazachki, Design Services Network, October 21,
2008.
4 Commercial Facilities Contract Group Direct Impact Evaluation Final Report, ADM Associates, Inc. for California
Public Utilities Commission Energy Division, February 18, 2010
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