Compact High Performance Fan Heaters - CR/CS Series The CR/CS series of compact high performance fan heaters prevent formation of condensation and frost and provides an evenly distributed interior air temperature in enclosures with electric/electronic components. The plastic enclosure provides double insulation and acts as protection against contact. Compact design Double insulated DIN Rail Mount Enclosure Heaters Heaters specifically intended for anti-condensation and frost protection in control and equipment cabinets. All types are supplied with DIN rail mounting hardware.