Statewide Utilities Codes and Standards Program
2011CASE Initiative
MEMORANDUM
To:
September 29, 2010
C&S Statewide team
Cc:
From: Cathy Chappell, Matthew Haro (HMG)
Doug Scott (Vacom)
Re:
Stakeholder Meeting Notes, Wed. September 22, 2010
ATTENDEES
Cathy Chappell, Matthew Haro, Erin Reschke (HMG); Doug Scott, Pranav Godbole (Vacom);
Seran Thamilseran, Payam Bozorgchami (CEC); Stuart Tartaglia (PG&E); Steve Gayle (Source);
Robert Eidson (Aztec-Energy); David Hinde, John Guerrieri, Scott Martin (Hill Phoenix); Knute
Fredholm (RETA); Glenn Gallagher (CARB); Kara Bush (CA grocers); Samuel Yana Motta, Chris
LaPietra, Ron Vogl (Honeywell); Jamy Bacchus (NRDC); Sean Gouw (SCE); Mike Straub
(Heatcraft); Haider Khan, Cliff Timko, Pamela Mathis (ICF); Cavell Hollis, Travis Lumpkin
(Kysor/Warren); Buzz Schaeffer, Dan Manole, Jeff Berge, Clay Rohrer (Hussman IR); Jon McHugh
(McHugh Energy); Ron Gorman (Sempra); Ron Vallort (ASHRAE); Lance Durr (Stater Bros); Viktor
Anderson; Roger Ansted (Altech); Glenn Barrett (danfoss); Dan Bertocchini, Kevin Brown, Kevin
Galbraith, Richard Heath, Bob Krahn, Martin Luckcuck, Charles Mensah, Tim Peters, George
Ronn (Supervalu); Rolf Blom (parker); Mary Boucher (ES); Bruce Campbell (URI); Sam Cantrell
(Raley’s); Patti Conlan (Arkema); Andrew Cook; Frank Davis, Jerry Stutler (Sprouts); Peter
Gibson, Armin Hauer, Louis Moffa (ebmpapst); Barry Greive, Larry Meeker (Target); Tim Gwyn,
Tom Wolgamot (DC Engineering); Steve Hagen (Fresh and Easy); Geo Harris (SW Refrigeration);
Bruce Hierlmeier (zero-zone); Tom Hutchison (enreps); Jeremy Litow, Scott Moore, Paul Schertz
(PECI); David Menninger (Kroger); Rajan Rajendran (Emerson); Maryline Rassi (AHRI); Sarah
Widder
MEETING NOTES
Slide 16
Q. What are the size limitations for small stores? What is the smallest size store that will be
covered?
A. There is no specific size cut off yet, but the intent is not to include the very small convenience
stores because they have different equipment than what is being studied. We will probably use
a square footage value.
D:\106751829.doc 10/4/2010 8:59 AM
MEMORANDUM (continued)
To: C&S Statewide Team
Re: Stakeholder Meeting Notes
October 4, 2010
Slide 19
Q. How did you determine the impact of floating head pressure on charge size?
A. When aggressively floating head pressure with evaporative condensers , unintended ambient
sub-cooling may cause increased charge size.
Slide 21
Q. What did you use and/or how did you come up with sizing numbers used to create building
prototypes?
A. Savings by Design (SBD) average values were used. SBD numbers are from actual stores and
provide values for case line-ups and walk-in sizes, etc.
Slide 22
Comment: Concerned that the kWh numbers for the pie chart are too low - would expect to see
1.1 to 1.2 million kWh for annual refrigeration.
Floating Head Pressure (FHP)
Makes assumptions on realistic control.
Comment: I would think that there should be two calculations for this measure, one for Air
Cooled Condensers (ACC) and one for evaporative coolers (Evaps). The reasoning is that floating
head pressure has different impact on system performance between ACC’s and Evaps. Need to
compare compressors and condensers.
Comment: There may be inefficiencies mandating a certain TD set point for different system
designs. Depending on the compressor and condenser sizing, a different TD may be needed to
minimize the load of the compressor and the condenser.
Response: Fixed set point vs. variable set point: Control using ambient is a minimum not a
requirement. If a better strategy can be defined, it could be used instead, such as load
following. We have to determine how to do this in the code language.
Comment: There may be problems with retrofits because size constraints will limit equipment
selection and may cause certain control measures to be ineffective.
Comment: Fans should be cycling near or at floating set-point which would reduce kWh load.
Page 2 of 10
MEMORANDUM (continued)
To: C&S Statewide Team
Re: Stakeholder Meeting Notes
October 4, 2010
Remote Condenser Specific Efficiency
This measure is compared relative to FHP with variable speed so these are incremental savings.
With the adjustments, savings might be a little too conservative.
Q. How do you account for the life expectancy of the equipment?
A. TDV accounts for equipment replacement cost over the expected life of the measure.
Q. What is the time frame evaluated for cost effectiveness?
A. 15 year lifetime of the equipment
Comment: We know that EC motors save money over the year compared to non-variable speed
fans. Yet, your specific efficiency graphs indicate that EC motor condensers are inefficient. That
doesn’t seem to make sense. The flexibility of EC motors is what saves money. Looking at
annual consumption of the motors, would show that they are much more efficient [than full
speed efficiency implies, since] motors aren’t running at full speed at most times.
Response: Capacity and power at full speed was used as the basis for the specific efficiency
calculation. The savings analysis is based on annual operation, and assumes variable speed and
floating head pressure as the “baseline” reference, and takes into account operation at variable
speed. The standard would still have to define a certain rating point for specific efficiency.
Comment: If you pick 70 Btuh/W, you are eliminating EC motors.
Response: Not for all manufacturers, and since EC maximum speed can be set, EC efficiency can
be readily “dialed in” to match a desired specific efficiency.
Q. How do we prevent inherently variable speed EC motors from running over their “rated
speed?”
A. The electronics in the EC motor can be programmed for the maximum fan speed.
Q. How much modeling data will be made available?
A. Data will be made available upon request by interested parties.
Q. Where do the equipment costs come from? Do you account for changes in material costs
(changes in the price of copper, etc.)?
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MEMORANDUM (continued)
To: C&S Statewide Team
Re: Stakeholder Meeting Notes
October 4, 2010
A. List price from the manufacturer is used. We assumed escalation for all materials. Potential
future changes/variation in material costs is not included.
Q. Why do you care about fin spacing (FPI) on condensers?
A. Changing the FPI is a way to circumvent the measure and too many fins lead to rapid fouling.
Most chains limit FPI in their specifications anyway.
Q. What about row limitations?
A. This should not be a problem since choice of rows (and other design choices by manufacturer)
is all inherently addressed in specific efficiency, without dictating design.
Floating Suction Pressure
Q. Is it better to control by valve closure? Measure case temperature and close the valve when
the temperature is met. This reduces load to zero. How does that help me if I set at highest
possible temp for worst case? It seems completely redundant.
A. Other controls (liquid solenoids, suction valves) have to be secondary to floating suction, so
the control system has to have enough intelligence to do this. The overall case load doesn’t
change by cycling the solenoid for control. The purpose of floating suction is to operate the
compressors at the highest suction that meets the load and reduce lift and save energy. Rather
than cycling the solenoid, the liquid solenoid (or suction stop) stays open and the coil operates
at a closer TD and the suction pressure can be no lower than necessary.
Comment: Does not make sense, it won’t save energy.
Mechanical Subcooling
The minimum design requirement may have no cost, if the savings in low temp compressor HP is
considered. The requirement (only LT subcooling with a MT system) would be the minimum
requirement; subcooling LT and MT with a higher temperature system would provide more
savings and go beyond the minimum requirements.
Q. You say that it’s relatively no cost. What about the additional insulation cost?
A. Common practice is already to have insulation on liquid lines.
Q. What about reducing line sizes and refrigerant charge through sub-cooling?
A. Yes, the line size and charge can be reduced, often one line size reduction due to lower mass
flow and higher allowable pressure drop, but it would be difficult for the standard to mandate
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MEMORANDUM (continued)
To: C&S Statewide Team
Re: Stakeholder Meeting Notes
October 4, 2010
line sizing for mechanical sub-cooling. There is the potential for a negative performance impact
if done improperly.
Comment: If sub-cooling fails, flashing results and risks product integrity while waiting for
repairs.
Comment: HFC does not belong in an energy code, advantage to mechanical sub-cooling.
Evaporator Coil Specific Efficiency
It looked like a good opportunity initially, but when we dug more deeply, it was more
complicated. Airflow and airside TD gives a nice product line, but a lot of variation in efficiency
and the amount of air circulated per unit of capacity. Info available to do this measure is
inadequate, until there is a standard test. Showed a lot of potential, but needs to go into the
next code cycle, it needs standards and certification before we draw the line.
Comment: Don’t drive an efficiency standard at the expense of product quality. I am concerned
about how this will affect air flow rates in cases.
Response: Evaporator coil specific efficiency is only for walk-ins
Q. Do you need to include an electronic expansion valve?
A. We need to include the cost, but don’t mandate it
Evaporator Coil Variable Speed
Comment: Concerned about air circulation problems in the case with variable speed and how
this will impact product quality. Even now with constant speed fans you sometimes end up with
warm spots.
Q. Are we potentially going about this the wrong way by requiring a large amount of additional
equipment (variable speed drives) just to achieve a small amount of energy savings. What about
sustainability?
A. Underlying assumption is EC motors with inherent variable speed capability, not addition of a
VFD. We need to think about what can be done by Jan. 1, 2013, when code takes effect.
Comment: Concerned that this measure is too advanced of a technology for now. This may be a
measure that is not common practice, can’t make judgment on this if we don’t have any point of
reference and we don’t have costs.
Page 5 of 10
MEMORANDUM (continued)
To: C&S Statewide Team
Re: Stakeholder Meeting Notes
October 4, 2010
Response: Agree it is not currently in use for supermarkets. Conceptually very simple, and (as
noted for specific efficiency) there is often excess air circulation, and variable speed is in wide
use in refrigerated warehouses. It may make more sense on medium profile coils in larger
boxes.
Comment: Concerned that the maintenance cost for this measure is too low given the number
of coils involved, especially relative to other maintenance costs that have been shown for other
measures. Commenter did not have any other cost estimates.
Liquid Suction Heat Exchangers
Get more cooling out of each lb of refrigerant. Higher suction, more superheat. Was common
prior to R-22, then went away due to R-22 superheat sensitivity, but for HFC refrigerants this is
pretty attractive. Placement is important, if you aren’t doing mechanical sub-cooling, it helps the
expansion valve work better. Only applies to DX systems, and doesn’t pencil out on HT SST.
Q. Are these products readily available?
A. Yes (response from the audience)
Comment: These heat exchangers provide a large source of refrigerant leakage due to line
breakage, usually at the liquid elbows, due to expansion. We remove them regularly.
Response: We want to define a good solution that would be reliable, and evaluate using the cost
of a good solution.
Q. Do we have to mandate the use of a heat exchanger? What about other methods such as
welding the lines inside the case together.
Q. What if we have mechanical sub-cooling as well? Does this have a benefit if you are mech.
subcooling? And what temp are you seeing?
A: Low temperature analysis assumes 55 F mechanical subcooling (at entry) and 17 F of
subcooling by LSHX.
Q. Would it be easier or more cost-effective to subcool to a lower temp than to put in this
equipment?
A. The benefit is sub-cooling gained from suction superheat that would otherwise be nonproductive superheat, not only from more subcooling. Gave example of leaving gas temperature
and return gas temperatures at compressors.
Page 6 of 10
MEMORANDUM (continued)
To: C&S Statewide Team
Re: Stakeholder Meeting Notes
October 4, 2010
Q. Are you going to have to insulate the liquid line in the medium temperature cases? Does it
cause service (maintenance) issues?
A. No. No difference from what already exists if for example a MT system is subcooled (and lines
in the case are not insulated).
Q. How will this be enforced?
A. Several ways:
 Building inspectors would look for any necessary equipment. Some sort of commissioning is
needed for controls based measures
 Control measures will need acceptance testing
 Acceptance tests require certification. Licenses are required for design (engineer) and
construction (contractor)
 Mechanical (HVAC) compliance forms are filled out by an engineer. Mechanical (HVAC)
acceptance forms are filled out by a contractor. We would expect a similar requirement for
refrigeration systems.
Q. For measure costs is commissioning included?
A. Yes.
LED Case Lights
Q. What about pre-emption problems? AHRI will challenge this, because it is federally regulated
equipment.
A. We are aware of pre-emption issues and working through them with the CEC.
Display Case Lighting Control
Comment: You should allow for the use of motion sensing controls as well.
Open Upright Freezers
Q. (To the Audience) Is there a good reason to allow open upright freezers?
A. Need to ask merchandiser.
A. They are still around but not commonly used. Most stores are taking them out, but they are
still being sold.
Page 7 of 10
MEMORANDUM (continued)
To: C&S Statewide Team
Re: Stakeholder Meeting Notes
October 4, 2010
Q. How would we do this in a remodeling, is it a marketing issue?
A. Offer it as an incentive.
Hot Gas Defrost
Comment: We use it as common practice with no problems.
Comment: We always have trouble with it. Constant problem with leaks. Maintenance is an
issue.
Comment: The measure is complicated because you have to balance the tradeoff between case
performance and system performance
Comment: CA hasn’t been a big market for hot gas defrost because it hasn’t been done
correctly. Would be a good discussion to have with others.
Comment: PNNL has baseline data, comes from manufacturers data, estimated based on what
was available. Uncomfortable making it available for this, since it was intended for a different
(unrelated) purpose.
Q. Isn’t this measure energy neutral (electric heater vs. hot gas)? Have you looked at whole
system impact?
A: The analysis is more complicated than just the electric heater energy because the case needs
to make up for time spent in defrost, which is different for electric defrost. The main problems
related to extra piping and additional leaks caused by hot gas defrost.
Comment: If you mandate electric defrost, it could limit an alternative defrost.
Response: Doesn’t mandate electric, but prohibits gas defrost
Heat Reclaim For Space Heating
Q. Do we have to mandate that the heat reclaim be used for space heating? What about other
uses such as hot water or snow melt?
A. Intent is flexibility to allow lots of ways to use heat reclaim. It needs to be specific to building
energy use (not snow melt), but others
Page 8 of 10
MEMORANDUM (continued)
To: C&S Statewide Team
Re: Stakeholder Meeting Notes
October 4, 2010
Q. Can this work with floating head pressure?
A. Yes
Comment: Almost a contradiction, mandating floating head, which then means you can’t get
heat reclaim.
Response: There are ways to accomplish heat reclaim with floating head pressure. For a direct
system, the practice by contractors in CA uses a reclaim holdback valve, allowing condensing in
HR coil at required SCT and regular floating head pressure at condenser.
Comment: What about HVAC limitations for retrofits? You should only trigger this measure if
both the compressor and HVAC system are being replaced.
Comment: For retrofits this will greatly increase charge size, especially if the HVAC and
refrigeration systems are not located close together
Comment: There are also problems with condensing in the heat reclaim coils.
Comment: This measure (and all reach codes discussed) is not necessarily feasible.
No Open Upright Cooler cases
Q. (To the Audience) What factors should be considered if we prohibit open cases?
A. Answers from the Audience:
 HVAC loading impact
 Potential problem with produce in a case is misting
 Merchandizing is the largest problem. Sales fall with closed cases and offset the energy
savings.
 May be a disincentive to remodel. May be unintended consequences.
 It would be easier to argue for beverage and dairy in cases and not produce and meat
 In general the attendees were in favor of the no open case measure from an energy savings
standpoint
End of Presentation Discussion
Comment: There seems to be a tenuous connection between GHG emissions and energy
efficiency. Concerned that CARB is using T24 as a failsafe in case AB32 is voted down. Concerned
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MEMORANDUM (continued)
To: C&S Statewide Team
Re: Stakeholder Meeting Notes
October 4, 2010
that CARB mandated refrigerant types may not allow us to meet the Title 24 requirements for
energy efficiency. Labeling the requirements as an energy measure to make sure it gets through.
Don’t see how looking at direct emissions has anything to do with energy code.
Response: Need to look at the whole bldg. as the way to get a better solution.
Comment: Don’t tell us the technology, but have a whole bldg. level. Some agreed that we need
to make sure that refrigeration requirements don’t negatively impact energy efficiency. We all
want to reduce energy, requiring a specific method impedes any innovative ideas.
Comment: Concerned that there is going to be too many bodies governing the handling and use
of refrigerants: EPA, CARB, Title 24, etc.
Comment: Concerned about problems with interpretation of all of these regulations by
different inspectors and governing bodies.
Q. What policies exist for when regulations overlap?
A. Overlap should not happen. AB32 only has leak inspection and maintenance measures for
existing systems. Title 24 addresses new construction and design issues.
Comment: Mandated measures stifle innovation. We should set a goal without specifying what
pieces are needed to meet the goal.
Response: The performance approach is not ready yet but that is the ideal method. Presently we
are just trying to eliminate the worst offenders.
Comment: I think the leak reduction in refrigerant system is similar to refrigerant leak reduction
HVAC or duct leak reduction in buildings. This is to ensure the system is capable of efficient
operation and can be maintained at that level. When it is not regulated a high duct leak rate is
high energy use now and forever.
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