Second Nature - SNLT2

SNLT2 – CO2 Low-Temperature, Secondary Coolant Technology

Second Nature® low-temperature (SNLT2), secondary coolant refrigeration systems utilize CO2 as the heat transfer fluid. Since CO2 has excellent thermodynamic and transport properties, the CO2 secondary refrigerant removes heat from display cases and walk-in freezers via copper piping that is significantly smaller than what is typically required in traditional, direct expansion (DX) systems. And, since HFC refrigerant is confined to the primary system located in the machine room, the total refrigerant charge and the potential for leaks are greatly reduced. SNLT2 systems allow for significant reductions in the amounts of copper and HFC refrigerants required, providing sustainability benefits that will pay dividends throughout the life of the system.

  • Reduction in HFC charge — as much as 75%.
  • Reduced line sizes equate to reduction in copper piping used and lower installation costs.
  • Avoid costly refrigerant retrofits that also impact sales floor activity.
  • CO2 is an inexpensive fluid with an extensive distribution network.
  • Low return gas temperature in a close-coupled system equals improved energy performance.
  • More efficient use of coils since they are flooded, and oil is eliminated from the system.
  • Reduced system complexity lowers maintenance costs.
  • Faster pull-down after defrost – improved frozen food product quality.
  • No TXVs required in display cases; standard refrigeration solenoids used – simplified maintenance.
  • Hillphoenix SmartValve™ incorporated on the CO2 condenser-evaporators for superior superheat control.
  • CO2 is 3,700 times less harmful to the environment than R404A.
  • Experience of use of SNLT2 in an actual store:
    – Reduced energy cost – proven 2-3% lower energy usage when compared to traditional DX system.
    – Reduced copper usage – for example, 45% reduction in installed weight of copper pipe = 948lbs or the equivalent of 3,655 lbs (1.8 Tons) of CO2 emissions.
    – Reduced refrigerant charge – 70% less LT refrigerant charge = 900 lbs. less R-507 which will avoid emissions equivalent to 4,331 tons of CO2 over 10 year life.
    – Reduced refrigerant leaks – helping you avoid excessive maintenance costs.

SNLT2 Refrigeration Systems Diagram

Please consult Hillphoenix Engineering Reference Manual for dimensions, plan views and technical specifications. Specifications subject to change without notice. Designed for optimal performance in store environments where temperature and humidity do not exceed 75°F and 55% R.H. Certified to UL 471, ANSI/NSF Standard 2,7,51 and CAN/CSA C22.2.

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