... element1. TypesBlowing type: insulated type with wave radiator, uninsulated type with wave radiator, insulated type with inserted foil radiator, insulated type with comb radiator ... fan: insulated type with fan, uninsulated type with fan.Convecting type air heater: There is not a fan, the heat is dispersed ... , room heater.3. Notice in appliance.Blowing type:1) This type of PTC air heater need a fan to ...