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 calendar-based 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:
Improveease of filter replacementVSAvoidfilter replacement accuracy
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The system continuously monitors outdoor temperature data and compares it against historical baseline data to dynamically determine filter replacement timing. This feedback mechanism allows the system to adapt to actual usage conditions rather than following a rigid calendar schedule, thereby improving replacement accuracy while maintaining ease of operation through automated notifications.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The filter replacement schedule is made dynamic by adjusting the replacement timing based on actual outdoor temperature conditions and usage patterns. Instead of a static calendar-based interval, the system calculates runtime based on actual environmental conditions, allowing the replacement schedule to adapt to varying seasonal and operational conditions.

Inventive Principle:
Principle #15Dynamics

2Loss of energy

If demand-operation HVAC systems are used, then energy efficiency is improved, but measurement precision deteriorates because runtime varies with seasonal conditions

Engineering Contradiction:
Improveenergy consumptionVSAvoidfilter usage measurement
Core Design Contradiction:
Loss of energyVSMeasurement precision

Solution Approach 1:

The system uses outdoor temperature feedback to accurately measure and track filter runtime. By continuously monitoring temperature data and comparing it to baseline conditions, the system can precisely calculate actual filter usage despite varying seasonal demand patterns, thereby maintaining measurement precision while preserving energy efficiency benefits.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system changes the measurement parameter from fixed calendar time to temperature-corrected runtime. By using outdoor temperature as a proxy for actual system operation intensity, the system accurately measures filter usage under varying demand conditions, enabling precise tracking without requiring continuous HVAC operation.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If visual inspection methods are used, then device complexity is reduced, but reliability deteriorates because users may forget or misinterpret filter status

Engineering Contradiction:
Improvesystem complexityVSAvoidfilter status determination
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The system performs self-service by automatically monitoring outdoor temperature conditions and calculating filter runtime without requiring user intervention. The system generates and sends automated replacement notifications, eliminating the need for users to manually inspect or interpret filter status while maintaining low complexity through use of readily available temperature data.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The manual visual inspection process is replaced with an automated electronic monitoring system that uses outdoor temperature data to track filter usage. This substitution eliminates human error and forgetfulness while keeping the system simple by relying on publicly available weather data rather than complex sensors or mechanical devices.

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

4Device complexity

If outdoor temperature data is used to estimate runtime, then device complexity is reduced, but measurement precision may deteriorate due to environmental factors

Engineering Contradiction:
Improvesystem implementation complexityVSAvoidruntime estimation accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The system uses outdoor temperature data as a proxy or copy of actual HVAC runtime conditions. By correlating temperature patterns with typical system operation, the system estimates filter usage without directly measuring it, thereby maintaining low complexity while achieving sufficient precision for filter replacement decision-making.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The system changes the measurement approach from direct runtime monitoring to temperature-based estimation. By using outdoor temperature as a surrogate parameter that correlates with actual usage conditions, the system achieves acceptable measurement precision while avoiding the complexity of installing and maintaining additional sensors or monitoring equipment.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentUS11241646B2Systems and methods for predicting HVAC filter change
Publication Date: 2022.02.08 3M INNOVATIVE PROPERTIES CO
  • US11241646B2 patent drawing
  • US11241646B2 patent drawing
  • US11241646B2 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.