Monitoring air filter status in automotive HVAC system

摘要

A system and methods are provided for monitoring for a clogged or unclogged state of an air filter in an automotive HVAC system. The HVAC system includes a blower having a blower motor providing a driven airflow. A plurality of outlet registers is controllable to provide a plurality of circulation modes. An evaporator selectably cools the driven airflow, and the air filter passes the driven airflow. The method enters a baseline condition, wherein the baseline condition includes applying a moisture purge to the evaporator and selection of a predetermined circulation mode. The blower motor is controlled to maintain a testing speed. An energization of the blower motor is quantified while maintaining the testing speed. The energization is compared to a base value derived according to the baseline condition with the air filter in an unclogged state. A replacement action is triggered when the energization is greater than the base value.

主权项

1. A method of monitoring for a clogged or an unclogged state of an air filter in an automotive HVAC system, wherein the HVAC system includes a blower having a blower motor providing a driven airflow, a plurality of outlet registers controllable to provide a plurality of circulation modes, and an evaporator for selectably cooling the driven airflow, wherein the air filter passes the driven airflow, the method comprising the steps of:
entering a baseline condition, wherein the baseline condition includes applying a moisture purge to the evaporator and selection of a predetermined circulation mode; controlling the blower motor to maintain a testing speed; quantifying an energization of the blower motor while maintaining the testing speed; comparing the energization to a base value derived according to the baseline condition with the air filter in an unclogged state; triggering a replacement action when the energization is greater than the base value; and wherein the method of monitoring of the air filter is performed in a plurality of baseline conditions each corresponding to a respective circulation mode, wherein a plurality of base values are stored according to respective baseline conditions, and wherein the method further comprises the step of selecting a base value for use in the comparing step according to the predetermined circulation mode present in the HVAC system.