Sound-based diagnostics for a combustion air inducer

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Solution Overview

Problem

Existing HVAC systems require manual inspection for diagnostics, leading to potential misdiagnosis, extended downtime, and the need for multiple technician visits due to the inability to self-diagnose faults and identify faulty components.

Innovation Solution

A sound-based diagnostic system that uses microphones to capture audio signals from HVAC components, analyzes these signals against an audio signature library, and outputs recommendations for faulty components and necessary repairs, enabling the HVAC system to self-diagnose and provide instructions for servicing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If manual inspection is used for HVAC diagnostics, then technicians can identify issues, but the process requires multiple trips and extended downtime

Engineering Contradiction:
Improvediagnostic accuracyVSAvoidsystem downtime
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system performs preliminary diagnostic actions by capturing audio signals and analyzing component sounds before the technician arrives. The microphones record operational sounds of HVAC components, and the processor analyzes these sounds to identify faults in advance, so that when the technician arrives, the diagnosis is already complete and parts can be prepared beforehand, eliminating multiple trips and reducing downtime

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The HVAC system performs self-diagnosis through its built-in microphones and processing unit. The system automatically monitors its own components, detects abnormal sounds indicating faults, and generates diagnostic reports without requiring external inspection, thereby enabling the system to service itself diagnostically and provide accurate information to technicians before their arrival

Inventive Principle:
Principle #25Self-service

2Ease of operation

If manual inspection is used for HVAC diagnostics, then technicians can service the system, but misdiagnosis and overlooking faulty components occur

Engineering Contradiction:
ImproveserviceabilityVSAvoiddiagnostic reliability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The system replaces manual mechanical inspection with an automated acoustic detection system. Microphones capture sounds from HVAC components, and a processor analyzes these acoustic signals to identify faults automatically. This substitution of manual inspection with automated sound analysis eliminates human error, misdiagnosis, and overlooked components while maintaining ease of serviceability, as technicians receive reliable diagnostic information before arrival

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Loss of information

If general error alerts are provided, then the system can notify of issues, but specific fault identification and component localization are not achieved

Engineering Contradiction:
Improveinformation completenessVSAvoidsystem complexity
Core Design Contradiction:
Loss of informationVSDevice complexity

Solution Approach 1:

The diagnostic system segments the HVAC system into individual components (compressor, condenser fan, evaporator fan, etc.) and analyzes the sound signature of each component separately. By capturing and analyzing audio signals from different locations within the HVAC system, the processor can identify which specific component is producing abnormal sounds, providing detailed fault identification rather than general error alerts, while managing complexity through modular audio processing

Inventive Principle:
Principle #1Segmentation

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This solution reduces downtime by accurately identifying faulty components and providing technicians with the necessary information and equipment before their visit, ensuring correct diagnosis and repair on the first attempt.

Implementation Method 1

receive an audio signal from a microphone

Methodology Applied
Scientific EffectMicrophone transduction:

Data Source

PatentUS11655993B2Sound-based diagnostics for a combustion air inducer
Publication Date: 2023.05.23 LENNOX IND INC
  • US11655993B2 patent drawing
  • US11655993B2 patent drawing
  • US11655993B2 patent drawing

AI summary

A device is configured to operate a Heating, Ventilation, and Air Conditioning (HVAC) system. The device is further configured to determine that the speed of a combustion air inducer exceeds a speed threshold value. The device is further configured to receive an audio signal from a microphone while operating the HVAC system and to determine an audio signature for the combustion air inducer is not present within the audio signal. The device is further configured to determine whether an audio signature for the integrated furnace controller is present within the audio signal. The device is further configured to determine a fault type based on the determination of whether the audio signature for the integrated furnace controller is present within the audio signal, to identify a component identifier for a component of the HVAC system that is associated with fault type, and to output a recommendation identifying the component identifier.