Summaries
Test Kitchen – Cooler
(1) KE2 Evaporator Efficiency controller
- Reduction of overall time spent in defrost by 50%
- More constant room temp
QSR Baraboo – Cooler
(1) KE2 Evaporator Efficiency controller
- KE2 Evap monitoring revealed defective TXV
- More than 50% reduction of defrosts, to less than one per day
- More constant room temp
QSR Baraboo – Freezer
(1) KE2 Evaporator Efficiency
- Defrost cycles reduced by 47%
- Room temperature fluctuations are reduced to a few degrees
- Coil temperature never exceeds 55°F
PRELIMINARY - Test Kitchen
With over 500 locations in the U.S., this growing QSR chain wanted to fully understand the performance and benefits of the KE2 Evaporator Efficiency controller (KE2 Evap) prior to transitioning to the controller in their restaurants.
In June of 2012 the corporate offices of this QSR began testing with the installation of two KE2 Evaporator Efficiency controllers at their test kitchen location. The system was run using the mechanical controls, and the KE2 Evap was installed for monitoring only. The system was then switched to KE2 Evap control.
The results of the Test Kitchen installation were improved temperature control - less variation in temperature, and a reduction in defrost cycles (Figure 1). However, the relatively light activity of the test kitchen walk-ins were not a complete test of how the controller would perform in a busy restaurant. It was time for the second step — install the KE2 Evap on the freezer and cooler at an established QSR location.
Figure 1 - Test Kitchen - Cooler - Transition from Mechanical to KE2 Evap Control
The cooler was set for one (1 hour 15 min.) defrost per day. The rise in room temp is seen on the graphs above. Once converted to KE2 Evap control, less than one defrost per day was needed. Additionally, the defrost cycle was shorter, resulting in more constant room temperature.
FIELD TEST - Baraboo Cooler For the field test site, the company selected the QSR in Baraboo, Wisconsin.
KE2 Evaps were installed in August of 2012 for monitoring only. Then, after a few weeks of gathering system performance data using the mechanical controls, the system was switched to KE2 Evap control.
Conclusion
With the KE2 Evap controlling the systems, a defective TXV was identified on the cooler and corrected. Once this issue was corrected, the KE2 Evap’s adaptive control required less than one defrost per day to maintain a frost free evaporator coil, and provide extremely stable room temp.
| Figure 2 - Baraboo Cooler with KE2 Evap Faulty TXV Identified | Figure 3 - Baraboo Cooler with KE2 Evap July, 2013 |
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Monitoring of the Cooler’s superheat revealed |
Even in the summer heat, the KE2 Evap only required |
FIELD TEST - Baraboo Freezer
The freezer at Baraboo was also converted to KE2 Evap control. After using the KE2 Evap to monitor the existing system operation (Figure 4) the system was switched to KE2 Evap control (Figure 5.)
| Figure 4 - Baraboo Freezer with Mechanical Controls August, 2012 |
Figure 5 - Baraboo Freezer with KE2 Evap October, 2012 |
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Existing defrost controls performed 15 defrosts in a 5-day period. Coil temperature spikes to 70˚F during defrost, and room temperature fluctuates constantly. |
During the first week of KE2 Evap control, defrost cycles are reduced to 8 in 5 days. The coil temperature never exceeds 55˚F, and when not in defrost, room temperature only fluctuates by a few degrees. |
Conclusion
The walk-in freezer at Baraboo experienced nearly a 50% reduction in defrost cycles. Both room and coil temperature control improved when converted to KE2 Evap control.
Summaries
QSR Black River Falls Freezer
(1) KE2 Evaporator Efficiency controller
- 70% reduction in defrost cycles for 30-day period
- More stable temperature
- Ice accumulation eliminated
- Reduced compressor, fan & heater runtime, resulting in energy savings
QSR Black River Falls Cooler
(1) KE2 Evaporator Efficiency controller
- 42% reduction in defrost cycles for 30-day period
- More stable temperature
- Reduced fan runtime, resulting in energy savings
FIELD TEST - Black River Falls
Having completed successful testing of the KE2 Evaporator Efficiency controller in the test kitchen, and in a QSR restaurant in Baraboo Wisconsin, a second test location was selected for testing in a “problem” walk-in.
The QSR location in Black River Falls, WI was experiencing some icing issues in their walk-in freezer. In September 2013, Leer engineers and a KE2 Therm representative, installed KE2 Evaps on the Black River Falls freezer and cooler.
The KE2 Evaps monitored the existing systems for one month, while the mechanical controls were still controlling the system. Then, in October, the systems were converted to KE2 Evap control. Remote communication to the controllers was established, which allowed for remote monitoring and data collection.
| Figure 6 - Black River Falls Freezer Performance graph from November 20, 2013 |
Figure 7 - Black River Falls Freezer - Converted to KE2 Evap Control October 23, 2013 |
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The freezer experienced as few as three defrosts in seven days (an 89% reduction), room temperature is more stable, and coil temperature is below 55°F during defrost. |
This graph shows the room temp of the freezer before and after the conversion to KE2 Evap control. The room temperature is clearly improved using the KE2 Evap. |
Freezer - Black River Falls
| BEFORE Ice accumulation on walls and ceilings |
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AFTER |
Conclusion
BRF Freezer - In addition to a 70% reduction in defrost cycles, the icing issue was eliminated and there is significant improvement in the performance. The compressor, fan and heater are running less, saving energy and reducing wear and tear on the equipment. Having monitoring capability allowed a low refrigerant charge issue to be identified and corrected.
| Figure 8 - Cooler Converted to KE2 Evap Control Oct. 23, 2013 |
Figure 9 - Cooler Converted to KE2 Evap Control Oct. 23, 2013 |
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Graph identifies low refrigeration charge issue, |
Converted to KE2 Evap set to control a room |
Conclusion
BRF Cooler - The walk-in cooler at Black River Falls experienced noticeable improvement in temperature control when converted to KE2 Evap control. The KE2 Evap’s monitoring capabilities helped correct a refrigeration equipment issue, that could have resulted in lost product.
