Dunham-Bush has added new features to its advanced Oil-Free Magnetic Bearing Centrifugal Chiller- PROMETHEUSDCLC-M. These new features include the innovative design falling film evaporator and the environmentally friendly HFO Refrigerant, R513A & R1234ze.

Falling Film Evaporator:

  • Improved Chiller Efficiency

Thinly coated refrigerant covering the evaporator copper tube will evaporate faster than a fully submerged tube surrounded with refrigerant.  This will result a better heat transfer, higher heat transfer coefficients and eventually lead to a more efficient chiller.

  • Less Refrigerant Required

As the falling film evaporators don’t require all the tubes to be submerge with refrigerant inside the shell, the amount of refrigerant can be reduced.

Using the falling film evaporator, the amount of refrigerant needed for the same cooling capacity can be reduced by at least 20% as compare to the traditional flooded evaporator design.

  • Reduced Refrigerant Consumption Cost

Falling film evaporator reduced refrigerant consumption and thus able to lower cost of traditional HFC and expensive HFO blends for the chiller.

Environmentally Friendly HFO Refrigerant:

  • HFO R513A

R513A is classified as “A1” refrigerant which is non-toxic and non-flammable. It is also Zero Ozone Depletion Potential (ODP) and low Global Warming Potential (GWP). The GWP of R513A is a 56% decrease from R134a. In addition to this, the refrigerants are largely the same in terms of capacity and efficiency. The transition requires very little changes in the system and oils and is easily replaceable into R134A system.

  • HFO R1234ze

R1234ze is a non-toxic, very low Global Warming Potential (GWP<1) and Zero Ozone Depletion Potential (ODP) refrigerant.  This gas is classified as “A2L” refrigerant according to ASHRAE standard 34. However, with a very minimal GWP, this gas takes environmental leadership while achieving the best energy performance levels.


  • High Efficiency Magnetic Bearing Technology
  • Inverter Driven Dual-Stage Compressor
  • Oil Free Operation with Less Maintenance
  • Low Noise with Compact Footprint
  • Improved Performance and IPLV
  • AHRI Certified