Systems and methods for predicting HVAC filter change

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Solution Overview

Problem

Existing HVAC systems lack a simple and cost-effective method to accurately predict when air filters need replacement, especially in demand-operation systems, leading to premature or delayed filter changes due to fixed interval recommendations that do not account for varying usage and environmental factors.

Innovation Solution

A computer-implemented method and system that estimates air filter replacement status by correlating fan runtime with outdoor weather data, such as temperature, to determine a Total Runtime Value, compared to a Baseline Value, without requiring sensors or mechanical components, using a computing device to provide accurate and timely filter change notifications.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If fixed calendar period replacement is used, then ease of operation is improved, but reliability deteriorates because the filter may be replaced prematurely or beyond its useful life

Engineering Contradiction:
Improvefilter replacement schedulingVSAvoidfilter replacement timing accuracy
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The system uses weather data feedback to dynamically adjust filter replacement timing. By continuously monitoring outdoor temperature and comparing it to baseline conditions, the system determines actual fan runtime and adjusts the replacement schedule accordingly, ensuring the filter is replaced at the optimal moment rather than on a fixed calendar schedule.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The filter replacement interval is made dynamic rather than static. The system calculates a dynamic replacement interval based on actual weather conditions and fan runtime, allowing the replacement schedule to adapt to varying usage patterns throughout the year, particularly in demand-operation HVAC systems where runtime varies significantly with seasonal temperature changes.

Inventive Principle:
Principle #15Dynamics

2Measurement precision

If weather-based runtime estimation is used, then measurement precision is improved, but device complexity increases due to weather data processing requirements

Engineering Contradiction:
Improvefan runtime estimation accuracyVSAvoidweather data processing system
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system uses outdoor temperature as an intermediary variable to estimate fan runtime. Instead of directly measuring fan runtime or installing sensors in the HVAC system, the system leverages readily available weather data as a proxy indicator, simplifying the measurement process while maintaining reasonable accuracy for filter replacement scheduling purposes.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system creates a simplified model of actual fan runtime by copying weather data patterns. Rather than directly measuring complex HVAC system parameters, the system uses outdoor temperature data to generate an estimated runtime value that correlates with actual filter loading conditions, providing a practical approximation without requiring direct system instrumentation.

Inventive Principle:
Principle #26Copying

3Use of energy by moving object

If demand-operation HVAC system is used, then energy efficiency is improved, but reliability of fixed interval replacement deteriorates due to variable runtime across seasons

Engineering Contradiction:
ImproveHVAC system energy consumptionVSAvoidfilter replacement schedule accuracy
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The replacement schedule is made dynamic to match the dynamic operation pattern of demand-operation HVAC systems. Since these systems vary their runtime significantly with seasonal temperature changes, the system calculates a dynamic replacement interval based on accumulated weather data and estimated fan runtime, ensuring the filter is replaced based on actual usage rather than a static calendar schedule.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the replacement interval parameter based on weather conditions. By monitoring outdoor temperature and comparing it to baseline values, the system adjusts the effective replacement interval to reflect actual fan runtime accumulation, accounting for the variable operation patterns inherent in demand-operation HVAC systems that prioritize energy efficiency.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentUS11529580B2Systems and methods for predicting HVAC filter change
Publication Date: 2022.12.20 3M INNOVATIVE PROPERTIES CO
  • US11529580B2 patent drawing
  • US11529580B2 patent drawing
  • US11529580B2 patent drawing

AI summary

Computer-implemented systems and methods for estimating a replacement status of an HVAC air filter. Outdoor weather data (e.g., outdoor temperature information), is obtained. A Total Runtime Value of the HVAC system is determined based upon the obtained outdoor weather data. Finally, a replacement status of the air filter is estimated as a function of a comparison of the Total Runtime Value with a Baseline Value. By correlating air filter replacement status with an estimated runtime of the HVAC system, a credible predictor of air filter usage is provided. By estimating fan runtime based on easily-obtained outdoor weather data, the methods are readily implemented with any existing HVAC system and do not require installation of sensors or other mechanical or electrical components to the HVAC system.