Methods to monitor air filter life in fan motor controller and apparatus for same

An air filter system comprising:

• a constant volume fan motor;
• a signal indicative of revolutions per minute of the constant volume fan motor;
• a fan attached to the constant volume fan motor;
• a filter for filtering a dirty air stream, wherein the fan blows the dirty air stream through the filter;
• a notification output;
• a digital device connection for receiving a profile, wherein the profile comprises a plurality of values;
• a non-volatile memory for storing the profile;
• a motor controller connected to the non-volatile memory, wherein the motor controller receives the signal indicative of revolutions per minute from the constant volume fan motor;
• a control signal to control the constant volume fan motor, wherein the motor controller sends the control signal to the constant volume fan motor;
• wherein the motor controller monitors air flow through the filter and determines a value indicative of accumulated air flow through the filter;
• wherein the motor controller determines a value indicative of accumulated time in use of the filter;
• and
• wherein the motor controller uses the profile, the value indicative of accumulated air flow through the filter, the value indicative of accumulated time in use of the filter, and the signal indicative of revolutions per minute to monitor usage of the filter.