FS-Curtis RNB Series

RNB is a line of non-cycling refrigerated air dryers rated by flow in SCFM, spanning roughly 11 SCFM through 1,200 SCFM. Non-cycling means the refrigeration circuit runs continuously rather than modulating with load.

The refrigeration circuit runs continuously regardless of air demand. That delivers a very stable dew point and a simple, reliable machine, at the cost of running the refrigeration compressor even when little air is flowing. It suits steady demand; variable demand favors an energy-saving design.

Match the model's SCFM rating to the actual flow your compressor delivers at your working pressure, then verify the rating holds at your inlet air temperature and ambient room temperature. Undersizing on paper is less common than derating losses from hot inlet air.

Both are non-cycling refrigerated dryers covering overlapping flow ranges. They differ in design generation, construction, and available options and configurations. Selection generally comes down to the flow rating, footprint, and connection arrangement suited to your installation.

Correct — A particulate filter upstream protects the dryer, and a coalescing filter downstream catches oil aerosol before it reaches the tools. Installing a dryer with no filtration around it is a common shortcut that shows up later as contaminated air at the point of use.

After the compressor and aftercooler, before the distribution piping. It needs adequate clearance around the condenser for airflow, and ambient temperature within the model's rating. A dryer packed into a hot, unventilated corner will not reach its rated dew point.

Clean the condenser periodically, verify the condensate drain functions, and check for rising dew point as an early sign of a problem. Non-cycling dryers are mechanically simple and generally reliable when the condenser stays clean and the drain works.