There appears to be no stopping the HVACR industry's move to an expanded use of carbon dioxide as a refrigerant.
In response, Emerson Climate Technologies, a business segment of Emerson, has announced expanded offerings of electronic controllers, expansion valves, and system protectors, all designed to work together in subcritical and transcritical systems that use CO2 as their refrigerant. Emerson’s portfolio of products and solutions to operate and manage CO2 systems are included below.
Facility Management System – the E2 controller, designed to provide complete control of HVAC units, refrigeration racks, condensers and lighting, is now capable of controlling and providing remote visibility of the entire CO2 cascade or booster system. Recent updates to the E2 refrigeration controller include CO2 suction group control and compressor synchronization for booster systems. Emerson also provides CO2 leak detectors that interface with the E2 and can alert individuals of potentially hazardous conditions. The E2 can seamlessly interface with third-party devices using Echelon, Modbus and BACnet and is part of Emerson’s Intelligent Store architecture, an integration of hardware, services and best practices that measure, manage, optimize and sustain operational cost savings across an enterprise.
Compressors – Emerson’s semi-hermetic for transcritical CO2, Copeland Scroll and Copeland Scroll Digital compressors for subcritical CO2 applications are available in a variety of horsepower. They have been optimized for CO2 pressures providing industry leading energy efficiency in a variety of applications, such as supermarkets, ice rinks and convenience stores. The semi-hermetic compressors are equipped with CoreSense, providing enhanced protection and remote status information to the E2 via Modbus communications.
Case Controllers – Emerson’s XR and XM controllers are designed to optimize case energy efficiency including a night setback mode to reduce energy consumption during off hours. They feature digital control of all critical functions (temperature/superheat/defrost) in refrigerated case applications for both stepper and pulse expansion valves. Equipped with a con-based display and Modbus communications to the E2, Emerson’s XR and XM controllers make it easy to see the exact status of the case and its interaction with the entire system.
Electronic Expansion Valves – provide a linear capacity modulation range from 10 to 100% and fast reaction times for the dynamic system pressures present in CO2 systems. CX valves are compatible for use with transcritical CO2 pressures and EX valves for use with subcritical CO2 pressures. Common applications include the high pressure and bypass valves in CO2 booster systems and heat reclaim valves for larger loads such as walk-in coolers/freezers.
Valves, Controls and System Protectors – Emerson has developed a wide range of valves, controls and system protectors that fulfill the requirements of all common CO2 applications. Emerson offerings include UL recognized oil controls, filter driers, moisture indicators, solenoid valves, check valves, ball valves, pressure controls and transmitters.
“Because CO2 provides non-ozone depleting, non-flammable and low GWP properties, it offers an ideal solution to reduce environmental impact that won’t be subject to future HFC regulations. Emerson’s portfolio of components provides a highly integrated and reliable system that can be monitored from anywhere,” said Mitch Knapke, market manager, food retail, Emerson Climate Technologies. “However, implementing a CO2 system is not without challenges, specifically higher pressures, up to1500 psi, reduced energy efficiency in high ambient temperatures and a lack of experienced technicians. For this reason, Emerson is available to help customers evaluate whether a CO2 solution is right for them and provide assistance at customer test sites.”