Vehicle HVAC Cabin Air Filter Usage Estimation

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Solution Overview

Problem

HVAC systems in vehicles face decreased efficiency and functionality due to particulate blockage of cabin air filters over time, necessitating an effective method to estimate filter usage and determine optimal replacement timing.

Innovation Solution

A vehicle HVAC system incorporating sensors and a controller to provide feedback signals based on cabin and ambient air temperatures, air distribution modes, and other parameters, which are combined with distance-based usage estimation to determine the overall usage level of the cabin air filter, allowing for timely replacement and maintaining system performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of stationary object

If the cabin air filter is used over time, then the HVAC system provides continuous cabin air filtration, but the filter becomes blocked by particulates decreasing HVAC efficiency and functionality

Engineering Contradiction:
Improvefilter service lifeVSAvoidHVAC system efficiency
Core Design Contradiction:
Duration of action of stationary objectVSReliability

Solution Approach 1:

The system performs preliminary estimation of filter usage based on operating conditions (distance traveled, ambient temperature, humidity, air quality) before the filter actually becomes blocked. This allows proactive monitoring and alerting to replace the filter before it reaches a blocked state that would decrease HVAC efficiency, thus maintaining reliability while extending effective service life.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system continuously monitors multiple parameters (distance traveled, ambient temperature, humidity, air quality indicators) and uses this feedback to dynamically estimate filter usage and update replacement timing predictions. This feedback mechanism allows the system to adapt to actual operating conditions, providing accurate reliability assessment throughout the filter's service life.

Inventive Principle:
Principle #23Feedback

2Ease of operation

If traditional fixed-interval filter replacement is used, then replacement scheduling is simple, but it does not account for varying usage conditions affecting actual filter life

Engineering Contradiction:
Improvereplacement scheduling simplicityVSAvoidfilter usage estimation accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The system transitions from a static fixed-interval replacement schedule to a dynamic estimation approach that continuously adapts to varying operating conditions. Multiple sensors monitor parameters such as distance traveled, ambient temperature, humidity, and air quality, allowing the system to adjust filter usage estimates in real-time based on actual environmental stressors, thereby improving measurement precision while maintaining ease of operation through automated electronic monitoring.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the parameters used for replacement scheduling from a single fixed time or distance interval to multiple dynamic parameters including distance traveled, ambient temperature ranges, humidity levels, and air quality indicators. By integrating these varying parameters, the system achieves accurate filter usage estimation that reflects actual operating conditions, replacing filters based on real usage rather than arbitrary intervals.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If multiple sensors and complex feedback signals are implemented, then filter usage estimation accuracy improves, but system complexity increases

Engineering Contradiction:
Improveusage estimation accuracyVSAvoidsensor and controller complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The controller leverages existing multi-functional sensors already present in modern vehicles for other HVAC control purposes (temperature sensing for climate control, humidity sensing for defogging, distance tracking for odometer functions). By repurposing these universal sensors for filter usage estimation, the system improves measurement precision without adding dedicated complex sensing hardware, thereby minimizing the increase in device complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system merges the filter usage estimation function with the existing HVAC control system by integrating sensor data already being collected for climate control purposes. The controller combines multiple existing sensor inputs (temperature, humidity, distance) that were previously used separately for different HVAC functions, now synthesizing them into a unified filter usage estimate. This merging approach improves estimation accuracy while avoiding the complexity of separate dedicated monitoring systems.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentUS11433733B2Heating, ventilation, and air conditioning system and a method for detecting cabin air filter usage
Publication Date: 2022.09.06 FORD GLOBAL TECH LLC
  • US11433733B2 patent drawing
  • US11433733B2 patent drawing
  • US11433733B2 patent drawing

AI summary

A vehicle heating, ventilation, and air conditioning (HVAC) system including a cabin air filter, a sensor for providing a sensor reading, and a controller for determining a feedback signal from the sensor reading, wherein the controller determines a cabin air filter expected blockage level from the feedback signal. The feedback signal relates to a usage modifier of the cabin air filter, wherein the controller at east partially adjusts the estimated usage the cabin air filter from the usage modifier.