In 2016, Innovative Refrigeration Systems was contracted to refrigerate a brand new pizza distribution center in Appleton, Wisconsin.
The 275,000 ft² facility operates at -15℉ on an ammonia charge of only 6,000 lbs. To achieve such a low ammonia charge, we had to engineer a brand new design.
Our low-charge design used custom direct expansion evaporators, which allowed the elimination of a high-pressure receiver. Our design also replaced the thermosyphon oil cooling with glycol circulated through the same evaporative condenser that cools the ammonia.
A typical facility like this would have about 25 lbs of ammonia per ton of refrigeration–thanks to our low-charge design, our client’s facility uses only 7 lbs of ammonia per ton.
Our mini-penthouses were used on the roof, with some modification: modulating control valves with a PID loop were used for super heat/quality control of each evaporator.
The project has a double-wide, pre-fabricated mechanical house, and an extensive steel structure that includes a condenser platform and staircase to the roof. Our field team did a great job of setting the house, erecting the platform, and installing the 2 evaporative condensers–all in one day!
We also installed 33 additional temperature sensors at various heights around the facility, as well as return air sensors at each penthouse unit. These help ensure that the facility is always within 2℉ of the control point.
Inside the completed facility, the freezer temperatures are -15℉, and the dock operates at 30℉. We were able to employ reheat on the dock using an underfloor system that utilizes waste heat. In total, the freezing space has over 19 miles of glycol tubing in the floor, which prevents the actual ground underneath the building from freezing.
Lastly, we implemented an HMI system and set up the customer with our popular ePSM platform to help them with process safety management.
Despite the brutal winter weather, and several weather-related delays, our team worked around the clock and delivered the completed project on time.
We have an ongoing 10-year warranty plan with the client, and have been servicing the project since its completion.