Abstract: Various systems and methods are provided for supplying heat to a passenger compartment during a filter regeneration event. In one example, a first phase of a filter regeneration event is initiated for a filter in an internal combustion engine based on one or more parameters, with heat produced by the engine then supplied to a heater core during the first phase, and the first phase extended if heating is requested for a duration based on ambient temperature. The engine may be operated at reduced efficiency during the filter regeneration event, and in some embodiments, the method may further include injecting an additional amount of fuel during a second phase of the filter regeneration event after the first phase ends to cause soot combustion in the filter.