Which of the following components would be found on a heat pump but not a central air conditioning system?(Category: AC & Heat Pump) •   an insulated suction line •   house air fan •  an Emergency Heat switch •   a crankcase heater •   outdoor fan

An emergency heat switch because A heat pump can both heat and cool a home by reversing the flow of refrigerant. Because it relies on extracting heat from the outside air (even in winter), it sometimes needs backup heat for very cold days—this is where the Emergency Heat switch comes in.