Refrigeration Performance - Technical Data
Refrigeration Unit without OmniFresh (baseline)
With exception of regular condensation events which consistently produces large amounts of standing water, this cooler appears, at first glance, to be running within reasonable limits.
The wide range of humidity, however, translates into artificially short compressor run cycles making this unit very inefficient. More importantly the very low humidity acts to accelerate the migration of water out of stored food contributing to premature spoilage and micro-organism growth. Thermostat settings are kept artificially low in order to keep defrost temperatures below 41 degrees F to protect the stored products. The defrost cycles are too close together and temperatures too high. The compressor is cycling much too often due to the amount of ice and liquid water in the cooler.
This a dangerous place to store fresh food for more than a day or two.
Refrigeration Unit with OmniFresh
Within a week of installing OmniFresh humidity has been stabilized in the 80% to 99% range which ensures healthful food and discourages spoilage and microbial contamination. Mould growth has been eliminated because no visible condensate exists. Odours, which were nearly overwhelming before, have been virtually eliminated.
Water migration out of fresh foods has been controlled.
Without resetting or repairing the thermostat the average high temperature has been reduced by 5 degrees F. The dew point plot, now tracks temperature, as it should and compressor cycles have been reduced by nearly 40%.
Refrigeration Performance
Refrigeration Unit 1 (Graphs above)
| Description | Baseline | OmniFresh | Change | Improvement |
| Readings | 1153 | 1153 | NA | NA |
| Elapsed Time (hours) | 96.1 | 96.1 | NA | NA |
| Maximum High Temp (F) | 45 | 43.4 | 1.6 | 4% |
| Minimum Low Temp (F) | 32.6 | 35.2 | 2.6 | 8% |
| Mean Temp (F) | 37.4 | 37.4 | 0 | 0% |
| Time Weighted Average Temp (F) | 37.3 | 37.4 | 0.1 | 0% |
| Defrost Cycles | 8 | 8 | 0 | 0% |
| Defrost: Total Time (min) | 570 | 502 | 68 | 12% |
| Max. Relative Humidity (%) | 96.5 | 99 | 2.5 | 3% |
| Min. Relative Humidity (%) | 62.5 | 68.5 | 6 | 10% |
| Mean Relative Humidity (%) | 82.5 | 95 | 12.5 | 15% |
| Time Weighted Average RH (%) | 80.2 | 89.7 | 9.6 | 12% |
| Total Time (min.) at or below 80% RH | 2330 | 1165 | 1165 | 50% |
| Compressor Cycles | 215 | 204 | 9 | 4% |
| Compressor Run Time (Min.) | 3081 | 2174 | 907 | 29% |
Refrigeration Unit 2 (Supporting Data)
| Description | Baseline | OmniFresh | Change | Improvement |
| Readings | 1379 | 1379 | NA | NA |
| Elapsed Time (hours) | 114.9 | 114.9 | NA | NA |
| Maximum High Temp (F) | 43.5 | 44.6 | 1.1 | 3% |
| Minimum Low Temp (F) | 35.2 | 34.2 | 1 | 3% |
| Mean Temp (F) | 39.4 | 38.5 | 0.9 | 2% |
| Time Weighted Average Temp (F) | 39.1 | 38.3 | 0.9 | 2% |
| Defrost Cycles | 20 | 20 | 0 | 0% |
| Defrost: Total Time (min) | 2508 | 1908 | 600 | 24% |
| Max. Relative Humidity (%) | 88.5 | 91.5 | 3 | 3% |
| Min. Relative Humidity (%) | 64.0 | 73.0 | 9 | 14% |
| Mean Relative Humidity (%) | 81.5 | 88.0 | 6.5 | 8% |
| Time Weighted Average RH (%) | 80.1 | 87.0 | 6.9 | 9% |
| Total Time (min.) at or below 80% RH | 3035 | 80 | 2955 | 97% |
| Compressor Cycles | 231 | 217 | 14 | 6% |
| Compressor Run Time (Min.) | 3115 | 2403 | 712 | 23% |
Refrigeration Unit Performance Summary
Food safety, extension of shelf life and elimination of odour and taste transferal are all important to anyone who manages refrigerated space. However, these may be secondary to budget considerations when it comes to the primary mission statement. What if you could have all these and save money too?
The charts presented here show that dramatic improvements in energy use, maintenance and food costs are available in even the best run coolers. The first is in a major national food chain; the second in a state correctional facility. Both users strive, constantly, to reduce costs and improve performance. Operational parameters, in both, are maintained or improved while reducing energy expense.
Controlling humidity, stabilizing temperature, and dew point all make it easier for compressors to do their job.
Energy costs are reduced when equipment performance improves. The Water Activity Charts on the next two pages demonstrate what this kind of change in a cooler means to food budgets, food safety, and food spoilage.