Series R Helical Rotary Screw Chiller (RTWD / RTHD)

The Series R is Trane's water-cooled helical rotary screw chiller family, built around a proprietary low-speed direct-drive compressor that has only four moving parts. The compressor uses suction-gas cooling to maintain a consistently low motor temperature, extending motor life in continuously loaded installations. An electronic expansion valve with reduced moving parts handles high-lift conditions reliably — important in heat-recovery or heat-pump modes where the condenser pressure is deliberately elevated.

Three model lines serve distinct duty profiles. The RTWD (80–250 tons, R-513A or R-515B) includes expanded heat-pump heating capability to 165 °F (74 °C) and handles process cooling down to leaving fluid temperatures of 10 °F (-12 °C). The RTHD (175–400 tons, R-513A) targets larger comfort-cooling and process-cooling loads, producing leaving fluid as low as 5 °F (-15 °C) and condenser water up to 111 °F (44 °C). The RTZA heat pump variant (80–250 tons, R-1233zd(E) with GWP = 1) delivers hot water to 210 °F (99 °C) using medium-temperature heat sources, suited to industrial decarbonisation. A falling-film evaporator across all variants reduces refrigerant charge compared with flooded-shell designs.

In aviation and airport contexts, Series R chillers are applied to mid-scale terminal cooling, MRO hangar climate control, and catering facility process cooling where water-cooled equipment is viable. The heat-recovery mode is well matched to airport domestic-hot-water or snow-melt loads. Support for single- and dual-point power connections allows integration into existing electrical infrastructure without rewiring.