I recently presented a Making Sense webinar with my colleague Seth Hoehn, where we explored the many advantages of shifting controls from the refrigeration rack to the case through the use of case controls and electronic expansion valve (EXV) technologies. Case controls can precisely monitor conditions in real time and offer dramatically improved operational and energy efficiencies, especially when coupled with the use of an EXV. At the end of the day, we detailed four ways that first costs and ongoing savings can be achieved through shifting controls from the refrigeration rack to the case.
- Electrical installation. A case control architecture provides savings through reduced field wiring: Up to 30 percent reduction in branch feeder wiring; potential elimination of circuit panels and breakers; elimination of line and low voltage control home runs to the rack; simplified connections at the case; and the installation benefits of OEM factory wiring.
- Piping and refrigerant. Shifting from individual liquid and suction lines at the rack to a loop system with common liquid and suction lines at the case reduces pipes, fittings, insulation, hangers and labor — and the potential for refrigerant leakage. The simplified piping results in material savings of up to 50 percent, and refrigerant charge reduction of 10 percent or more. This architecture also enables temperature and rack control at the case itself.
- Maintenance and leak reduction. Another benefit of the case control architecture is a reduction in commissioning/startup time by two to three days. This is due to quicker leak checks, reduced refrigerant charge, and not having to set superheat (since it is automated via electronics). The persistent data that’s available from the electronic controls and EXVs eliminates the need for seasonal maintenance and adjustments of mechanical TXVs, while providing “eyes into the system” for ongoing, remote visibility and diagnostics.
- Ongoing energy savings. The precise control enabled at the case level reduces energy used at the evaporator, eliminating the pressure drops and other parasitic losses associated with traditional systems. Case controls with EXVs allow for low condensing operation, which significantly reduce energy at the rack through continuous, automatic superheat regulation. Once installed, a case control system promises to deliver significant energy savings for years.
We often hear that a barrier to utilization of case controls and EXVs is the investment required to get started. But, as we’ve shown, equipment costs are quickly offset by the savings. When you consider the reduction in first costs — from simplified installation of electrical distribution and piping systems to faster startup times — and the ongoing energy and maintenance savings that can be realized annually, we feel there’s a compelling case to use case controls and electronic expansion valves.
Our next webinar will be presented live from the AHR Expo show floor in New York City on January 21, 2014 — details coming soon! If you want to view any of our previous Making Sense webinars, they are available for download on our website at www.emersonclimate.com/makingsensewebinars.
Director of Product Management, Retail Solutions
Emerson Climate Technologies