Adoption of direct expansion (DX) ammonia system designs has increased amid an ever-evolving environment of refrigerant-based regulations. DX designs reduce the required refrigerant charge, which potentially reduces the impact of ammonia-specific regulations and harnesses the inherent benefits of ammonia as a highly efficient refrigerant.
The reduction of overall system components within DX system designs also offers opportunities for energy savings, but only if all the pieces and parts are optimized. Choosing the right refrigeration oil is key to maximizing energy savings in any system design, providing essential wear protection at the compressor, and removing waste heat.
Maximizing overall system efficiency also requires selecting a lubricant well suited for the designed collection or return of any oil that carries over past the oil separator. Miscibility defines the ability of a refrigerant-lubricant combination to form a homogeneous mixture across an identified range of temperatures. Traditional mineral oils, which are widely used in ammonia liquid overfeed systems, are immiscible with ammonia and require removal via draining from dedicated oil collection vessels. In the absence of sufficient drain points, immiscible lubricants can quickly foul DX evaporators and wreak havoc on operational efficiencies.
Enter: Summit’s RPS Series refrigeration lubricants. A specially formulated polyalkylene glycol (PAG) synthetic ammonia compressor lubricant designed to function in ammonia refrigeration systems utilizing DX evaporators and rotary screw compressors. Its optimum miscibility with ammonia is unique, allowing easier oil return to the compressor with no oil accumulation inside the system.
Advantages of RPS Series lubricants in your DX refrigerant system include:
- Minimal oil carryover
- Improved thermal efficiency and productivity gains
- Reduced maintenance downtime
Contact Summit’s Refrigeration market manager Justin Daily (justin.daily@us.kluber.com) or your Summit distributor today to make sure you’re getting the most out of your DX system.
Please keep in mind not all DX system designers provide PAG-based lubricants with the initial design. Consult Summit’s technical team for guidance regarding product selection and change-out procedures when replacing these products.