Method for operating an HVAC system

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Solution Overview

Problem

HVAC systems face challenges in balancing ventilation rates to maintain occupant comfort and reduce energy consumption, especially during conditions like pandemics where increased ventilation is necessary to minimize pathogen spread, while also managing indoor air quality and energy costs.

Innovation Solution

A method and system for determining optimal ventilation rates using a learned model that considers sensed values and user inputs, allowing for different operating modes such as health, energy savings, and balanced modes to adjust ventilation based on comfort conditions and IAQ thresholds, with a user interface for manual control and real-time feedback.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the ventilation rate is increased to reduce pathogen spread, then health and safety are improved, but energy consumption increases

Engineering Contradiction:
Improvepathogen reductionVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The system dynamically adjusts ventilation rates based on real-time occupancy detection and environmental conditions. The controller modifies fresh air intake dynamically rather than maintaining a fixed high ventilation rate, allowing the system to provide adequate pathogen reduction when needed while conserving energy during periods of low occupancy or favorable outdoor conditions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes operational parameters (ventilation rate, fresh air intake) based on detected occupancy levels and environmental conditions. When occupancy is detected, the system increases ventilation to reduce pathogens; when no occupancy is detected or outdoor conditions are favorable, the system reduces ventilation to minimize energy consumption.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the ventilation rate is set high to maximize pathogen reduction, then indoor air quality is improved, but the HVAC system may lack heating and cooling capacity to maintain comfort

Engineering Contradiction:
Improveindoor air qualityVSAvoidcomfort conditions
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The system dynamically balances ventilation rate adjustments with heating and cooling capacity management. When increasing fresh air intake for improved air quality, the controller simultaneously adjusts HVAC component operation to maintain temperature and comfort conditions, ensuring both indoor air quality and thermal comfort are satisfied.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system uses real-time feedback from occupancy sensors and environmental monitors to adjust ventilation rates while maintaining comfort. The controller continuously monitors indoor conditions and modifies ventilation and HVAC operation accordingly, ensuring that increased ventilation for air quality does not compromise heating and cooling capacity needed for comfort.

Inventive Principle:
Principle #23Feedback

3Use of energy by moving object

If the ventilation rate is minimized to reduce energy costs, then energy efficiency is improved, but pathogen spread risk increases

Engineering Contradiction:
Improveenergy efficiencyVSAvoidpathogen spread
Core Design Contradiction:
Use of energy by moving objectVSObject-affected harmful factors

Solution Approach 1:

The system changes ventilation parameters based on detected occupancy and environmental conditions. During unoccupied periods or when outdoor conditions are favorable, the system minimizes ventilation to improve energy efficiency. When occupancy is detected or indoor air quality deteriorates, the system increases ventilation to reduce pathogen spread risk, thus dynamically optimizing the balance between energy efficiency and health safety.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system dynamically adjusts ventilation rates based on real-time conditions rather than maintaining a fixed low rate for energy efficiency. The controller modifies fresh air intake in response to occupancy detection and environmental factors, allowing the system to achieve energy efficiency during appropriate periods while preventing pathogen spread when needed.

Inventive Principle:
Principle #15Dynamics

4Adaptability or versatility

If multiple operating modes are provided for different priorities, then system adaptability is improved, but device complexity increases

Engineering Contradiction:
Improveoperating mode flexibilityVSAvoidcontrol system complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The controller is designed to perform multiple functions: it detects occupancy, monitors environmental conditions, determines fresh air intake rates, controls HVAC components, and manages multiple operating modes. This multi-functional design allows the system to adapt to different priorities (energy efficiency, pathogen reduction, comfort) without requiring separate control systems for each function, thus improving adaptability while managing complexity through integration.

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

Data Source

PatentEP4300000A1Method for operating an HVAC system
Publication Date: 2024.01.03 HONEYWELL INTERNATIONAL INC
  • EP4300000A1 patent drawingFigure 1
  • EP4300000A1 patent drawingFigure 2
  • EP4300000A1 patent drawingFigure 3

AI summary

Methods and systems for operating a Heating, Ventilating and Air Conditioning (HVAC) system in accordance with one of a plurality of operating modes. The plurality of operating modes include one or more of a health mode, an energy savings mode and a balanced mode. In some cases, the operating modes include two or more energy saving modes. The currently operating mode is selected based on the current operating conditions of the building and the desired goals of the building operator. The goals can include, for example, reducing energy usage, reducing pathogen risks, increasing air quality and/or a combination of these goals. In some cases, the operating modes are autonomously controlled. In some cases, the operating modes are manually controlled.