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APPLYING WEB-BASED REFRIGERATION CONTROLS FOR
ADDED PROFITABILITY, ENHANCED FOOD SAFETY AND EQUIPMENT
SUPERVISION
Ted Kohlenberger, CA Team Leader
National Resource Management, Inc. ~ Canton MA ~ 10/15/15
TOPICS AGENDA
Objectives Refrigeration/A quick review. Project details and approach Two project case studies – how these firms
reduced their refrigeration energy consumption by 30+%
Benefits of Continuous Performance Monitoring Enhancements beyond energy savings Presentation wrap Up Live demo of web-based systems in operation
OBJECTIVES
Improving energy and operating efficiency of refrigeration Brief review of refrigeration used in walk-in coolers and freezers Why refrigeration is overlooked by most efficiency experts Identifying the opportunities to reduce refrigeration operating
costs How to determine the economics (ROI) of a refrigeration retrofit Recommissioning, Retrofit and Continuous Performance Monitoring The human factor – why refrigeration opportunities exist
The Internet of Things (tIoT) & Value of Real Time Performance Monitoring Over time, can save up to 40% more than just retro-
commissioning. You can’t manage what you don’t measure. What to measure? Refrigeration equipment does not have a “check engine light” 30 to 40+% energy savings from comprehensive retrofit Why isn’t everyone doing this? …they did not know it was possible Refrigeration runs 24/7… a thief that is stealing profits day and
night
Basic refrigeration system equipment
Heat transfer basics
Low pressure side w/ “boiling” refrigerant High pressure side w/ suction gas heat
and heat of compression rejected to atmosphere
Cold (low pressure) and Hot (high pressure) sides
Follow the movement of heat energy
Energy Waste from Refrigeration Problems: (Swedish
Royal Institute, 2006 study) Following results were found during inspections that had
been announced in advance—in most cases, these refrigeration systems had been serviced prior to the inspection . So these results reflect the faults found “after” a typical preventive maintenance service!
Of 164 systems analyzed, 87% were operating with faults. On average, the systems were operating with 9.7%
reduction in COP (Coefficient of Performance) and an 8.7% reduction in capacity from nominal.
Assuming a corresponding increase in runtime, and increased demand costs, this suggests that more than 15.8% of the energy costs associated with commercial refrigeration may be waste due to poorly-operating equipment, even in systems that were recently serviced.
Couple the above with poor maintenance practices and waste can be up to 50%.
Why there is such a great opportunity for energy savings? There can be a huge reserve or GAP between Capacity and
Load as systems are sized to maintain temperatures on the hottest days of the year… and then some when considering extra capacity added by engineers, specifiers and equipment wholesalers.
All other days operate at partial loads and less than optimal efficiency.
Large cold storage rooms with high value products will frequently utilize redundant and/or oversized systems in case of failure, offering even greater potential for energy savings.
So why now/What has changed? Increasing energy rates and incentives from state mandated
programs. Innovation – new technologies and smarter controls.
Predictable savings. Excellent payback & ROI.
The big opportunity is in the reserve
Factors that Drive this Savings Opportunity Poor or unknown performance of refrigeration system. No “check
engine light” to warn on performance. Users don’t know what cooling really costs or how it works. Operates 24/7 with no history or metrics – can’t benchmark. Predictable savings, no set point tampering. If study reveals 87% of systems have issues, must assume they
all have issues. Old thinking – “We have done it this way for 20+ years”. RISK – if problems arise, can’t wait until Monday attitude. Requires “cultural” mindset shift of leaders and operators.
Some steps to stop the waste
Gain upper management support Identify an “energy champion” Establish and track key performance indicators
(KPI’s) Adopt a continuous improvement philosophy Mandate participation in training Document and replicate successes Energy efficiency must be managed for
continuous improvement and not be just a one-time event
A Lesson in Taking Ownership - Hans and Franz
Hans and Franz were sailing on a ship coming to America and along the way the seas got very rough, so much so that the ship was tossed about violently.
Franz came running to Hans and said, “Hans, the ship may be breaking apart, what should we do?”
Hans said, “What do we care, it’s not our ship.”
Calculate Evaporator Fan Energy UsageExample calculation for evaporator fans…
Example: (2) 4-fan units, at 115V/1 and 2 amps/fan motor.
Calculate using: Qty x V x a x pf = W
8 x 115 x 2 x .7 = 1,288 watts or 1.29 kW
Annual energy use = 8,760 hrs x 1.29 = 11,283 kWh
Assuming $.15/kWh cost = 11,283 x $0.15 = $1,692/yr
What if you could save 40 or 50 % of that figure?
What if the load is larger… then, savings are bigger and ROI gets better as larger systems generate larger savings and more generous financials.
Energy Calculations
Compressor: 460V, 25 RLA, 3 ph, 30% duty cycle Load: (460 x 25 x √3 x .75pf) ÷ 1000 = 14.94 kW Consumption: 8760 hrs x 30% x 14.94 kW = 39,260
kWh Condenser Fans: 2 Fans 460V, 2.8 RLA, 3 ph
Load: (2 x 460 x 2.8 x √3 x .7pf) ÷ 1000 = 3.12 kW Consumption: 8760 hrs x 30% x 3.12 kW = 8,208 kWh
Evaporator fans: 6 fans, 460V, 1 amp, 1 ph, 24/7 operation: Load: (6 x 460 x √1 x .7pf) ÷ 1000 = 1.93 kW Consumption: 8760 hrs x 100% x 1.93 kW = 16,924
kWh Total energy consumed is apprx 64,392 kWh
Interactive Effect of Evaporator Fan Energy Use Evaporator fans: (2) 3-fan units, 460V, 1 amp, 1 ph, 24/7
operation Load: (460 x 6 x √1 x .7pf) ÷ 1000 = 1.93 kW Consumption: 8760 hrs x 100% x 5.6 kW = 16,924 kWh
Refrigeration load from fan heat w/ stated assumptions: A 3,413 Btu/kWh B 12,000 Btu/Ton C COP (coefficient of performance) of apprx 1.6 kW/Ton
(ASHRAE/Industry) D 16,924 kWh usage of evaporator fans in cooler Formula D x (A ÷ B) x C = kWh needed by compressor to remove fan
motor heat 16,924 x (3413 ÷ 12000) x 1.6 = 7,702 kWh Compressor usage includes 7,702 kWh for removal of evaporator motor
heat
Rejected heat represents apprx 12% of the system usage
In Review…
Damaging compressor short-cycling
Improper refrigerant charge Improper pressure controls
settings Inadequate system
maintenance Dirty condenser and/or
evaporator coils Expansion valve (TXV)
adjustments
Evaporator fan motors are heaters and can be cycled
Exploit the Gap, when capacity is greater than refrigeration load
Replace inefficient fan motors with EC technologies
Utilize real-time monitoring for continuous commissioning
Use data to pro-actively service before poor performance eats away profits
There is no “check engine” light so pay attention using supervision and tools
Equipment/System issuesSavings Opportunities
Presentation Take- Aways
Every refrigeration system can be improved to save energy and improve supervision.
Web-based tools and management allows for cost-effective and valuable “continuous commissioning” activity.
Utility cost increases and TOU tariff structures make energy measures more valuable than ever.
If uncertain as to what can be done, reach out to an expert for consultation and collaboration.
Case studies/trends/examples
Hardware Architecture
ArchitectureControllers
Gateway
Ethernet
Internet
Web Server
Data server
Local PC
User
Marquez Brothers/Case Study #1
Marquez Brothers is a California based manufacturer of Mexican cheeses and related dairy products with distribution throughout the southwest including CA, AZ, NV, CO and TX. After saving 30+% at their San Diego location six additional warehouses were retrofitted. SCE engineers liked the concept and wanted to perform their own engineering analysis at the City of Industry Marquez location as an emerging technology project. SCE engineers provided a scope of work and additional funding for instrumentation over and above a normal installation to verify savings.Required repairs were made, the systems were monitored for a two week period to set a benchmark.The new control strategies were activated and monitored for two additional weeks to compare performance and results.Their 70 page report available at http://www.etcc-ca.com/images/stories/et_08.10_ibrmcs_final_report.pdf
The following is a summary of the results
Marquez Brothers Results
From SCE report
Marquez Brothers Run Times
Results - Comparing run times of compressors and fans.
Coolers
Prior to Control With Controls Actual Savings
Compressor Run
Evap Fan Run
Avg temp
Compressor Run
Evap Fan Run
Avg temp
Compressor Run
Evap Fan Run
Temp delta
Small Cooler TODO 27.1% 100% 40.6 °F 18.5% 36.9% 39.5 °F -31.7% -63.1% -1.1 °F
Freezer TODO * ** 52.2% 100% 8.9 °F 34.5% 44.1% 4.6 °F -33.9% -55.9% -4.3 °F
Big Cooler TODO 35.9% 100% 38.0 °F 22.7% 51.1% 37.6 °F -36.8% -48.9% -0.4 °F
Cooler 1 Z1 31.7% 100% 37.7 °F 29.0% 45.9% 37.5 °F -8.5% -54.1% -0.2 °F
Cooler 1 Z2 37.7% 100% 37.3 °F 29.4% 45.4% 37.6 °F -22.0% -54.6% 0.3 °F
Cooler 2 Z1 38.2% 100% 38.6 °F 15.2% 35.9% 39.6 °F -60.2% -64.1% 1.0 °F
Cooler 2 Z2 19.7% 100% 40.9 °F 18.0% 49.9% 39.6 °F -8.6% -50.1% -1.3 °F
Cooler 3 Z1 + 0.7% 100% 37.5 °F 21.4% 44.0% 37.5 °F 2957.1% -56.0% 0.0 °F
Cooler 3 Z2 16.0% 100% 36.8 °F 14.9% 34.0% 37.4 °F -6.9% -66.0% 0.6 °F
Cooler 3 Z3 39.0% 100% 36.2 °F 20.7% 45.3% 37.7 °F -46.9% -54.7% 1.5 °F
Cooler 4 Z1 18.9% 100% 39.8 °F 18.3% 39.6% 37.6 °F -3.2% -60.4% -2.2 °F
Cooler 4 Z1 20.6% 100% 42.0 °F 13.4% 39.3% 37.7 °F -35.0% -60.7% -4.3 °F
Averages 28.1% 100.0% 21.3% 42.6% -26.7% -57.4% -0.9 °F
Marquez Brothers Metered SavingsProjected annual energy savings with new control system using Remote Monitoring and ControlFrom actual power meter readings on each of 4 largest compressors and main utility meter
Coolers14 day kWh
SavingsAnnualized
kWh Savings Cost Savings
$0.14 /kWh
Cooler 1 Z1 975.6 25,366 $3,551
Cooler 1 Z2 525.3 13,658 $1,912
Cooler 3 Z2 1,799.7 46,792 $6,551
Cooler 3 Z3 4,243.1 110,321 $15,445
SCE Power Meter 9,580.4 249,090 $34,873
Marquez Brothers Summary GW1Summary Screen displays data for user
Summary screen shows current values, states and 7 day statistics
User friendly and easy to understand by users
Marquez Brothers Summary GW2Summary Screen displays data for user
(continued) Summary screen for Gateway 2
Marquez Brothers Summary GW3
Summary Screen displays data for user (continued) Summary screen for Gateway 3 which also
shows data on anti-sweat door heater controls
Life Technologies/Case Study #1
Life Technologies headquartered in Carlsbad, CA is a global biotech company The facility has two freezers and eight coolers served by a total of 22 independent refrigeration systems of which most are redundant systemsRefrigeration retrofit project was developed utilizing a San Diego Gas & Electric’s incentive program.The project called for four groups controlling a total of 22 zones and three areas with heated glass doors resulting in annual energy savings of 649,913 kWh.
Life Technologies Summary GW1Summary Screen displays data for user (continued)
Summary screen for Gateway 1 which also shows data on anti-sweat door heater controls
Life Technologies Summary GW2Summary Screen displays data for user
(continued) Summary screen for Gateway 2
Life Technologies Summary GW3
Summary Screen displays data for user (continued)
Summary screen for Gateway 3 warehouse cooler
Life Technologies Summary GW4
Summary Screen displays data for user (continued)
Summary screen for Gateway 4 warehouse freezer
Typical Cooler Trends
Typical trend with all variables shown
Electric Defrost Trend – Thermostat Mode
Trend for freezer showing thermostatic defrost
Typical Run Time Trend
Run times can be displayed in hours, days and weeks
14 day performance trend showing run times and temperature
Note average % across window
Typical Extended Run Time Trend
Run times can be displayed in hours, days and weeks
22 week performance trend showing run times and temperature
Note average % across window
Trend showing Short-cycling ProblemEquipment issues revealed in trends with data 7-20 seconds
Short cycling due to low refrigerant and dirty filter
Customer saving over $7,000 monthly but could be more if they fixed several equipment problems
Stuck solenoid
Condenser fan failures
Examples of Savings and Issues
Group 2 with more issues
Wasted Energy due to Stuck Sol Vlv
Review of real-time systems…
See how clients and their technicians use web-based, remote system management to reduce their energy, operating and maintenance costs by staying on top of their refrigeration system’s performance.
Freezer High Temp Alarm (Harvard)
Cooler Low Temp Alarm (Harvard)
Email Alarm Message to Users
In addition to the email message alarms can be configured to be sent as a text message to users. With smart phones you get trend as well.
Recent Equipment Failure & Repair
Check in on live RSM sites…
