Time-based and sound-based prognostics for restrictions within a heating, ventilation, and air conditioning system

A Heating, Ventilation, and Air Conditioning (HVAC) analysis method, comprising:

• operating an HVAC system, wherein operating the HVAC system comprises sending a command to initiate a heat cycle;
• determining an amount of time to close a pressure switch, wherein the pressure switch is configured to close when an air pressure generated by a combustion air inducer is above a predetermined threshold value;
• after activating the microphone
• determining the amount of time to close the pressure switch exceeds a time threshold value;
• after determining that the amount of time to close the pressure switch exceeds the time threshold value, automatically activating a microphone configured to capture an audio signal of the combustion air inducer;
• after activating the microphone, receiving a first audio signal from the microphone while operating the HVAC system;
• identifying an audio signature for the combustion air inducer from an audio signature library comprising a plurality of audio signatures, wherein:
• each audio signature identifies one or more attributes for a portion of an audio signal;
• each audio signature is associated with a fault type for the HVAC system;
• and
• each fault type is associated with a component identifier for a component of the HVAC system;
• determining the audio signature for the combustion air inducer is present within the first audio signal;
• determining a fault type based on the determination that the audio signature for the combustion air inducer is present within the first audio signal;
• identifying a first component identifier for a first component of the HVAC system that is associated with fault type;
• and
• outputting a recommendation identifying the first component identifier.

A Heating, Ventilation, and Air Conditioning (HVAC) analysis device, comprising:

• a memory operable to store an audio signature library comprising a plurality of audio signatures, wherein:
• each audio signature identifies one or more attributes for a portion of an audio signal;
• each audio signature is associated with a fault type for an HVAC system;
• and
• each fault type is associated with a component identifier for a component of the HVAC system;
• and
• a processor operably coupled to the memory, configured to:
• operate the HVAC system, wherein operating the HVAC system comprises sending a command to initiate a heat cycle;
• determine an amount of time to close a pressure switch, wherein the pressure switch is configured to close when an air pressure generated by a combustion air inducer is above a predetermined threshold value;
• determine the amount of time to close the pressure switch exceeds a time threshold value;
• after determining that the amount of time to close the pressure switch exceeds the time threshold value, automatically activate a microphone configured to capture an audio signal of the combustion air inducer;
• after activating the microphone, receive a first audio signal from a microphone while operating the HVAC system;
• determine an audio signature for the combustion air inducer is present within the first audio signal;
• determine a fault type based on the determination that the audio signature for the combustion air inducer is present within the first audio signal;
• identify a first component identifier for a first component of the HVAC system that is associated with fault type;
• and
• output a recommendation identifying the first component identifier.