PTC heater with shell1. Configuration.TypeSpecialtyExcellenceshortcomingOthersAluminium shellAluminium shell, with wire and insulating filmFast heat conduct, large powerThe shell is electric conductor, may affect the ... , heating a surfaceCeramic shellCeramic shell, with wire and ceramic insulationLow cost, small bulk, insulating shellNot suitable for large power, easy to crackSuitable ...