Multi-Zone Ventilation Control Using Maximum CO2 Sensor Readings

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Solution Overview

Problem

Conventional ventilation systems with CO2 sensors fail to control non-uniform CO2 concentrations effectively, leading to inefficient energy consumption and unnecessary start-stop operations of ventilation devices.

Innovation Solution

A control device that adjusts the number of operating ventilation devices based on the maximum CO2 sensor readings, starting additional devices closest to high concentration areas and optimizing fan volumes to maintain CO2 levels below a reference value, thereby minimizing energy usage and reducing hunting effects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If all ventilation devices are operated to keep CO2 concentration under reference value, then CO2 control is achieved, but energy consumption increases

Engineering Contradiction:
ImproveCO2 concentration controlVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The system dynamically adjusts the number of operating ventilation devices based on real-time CO2 concentration readings from multiple sensors. Instead of operating all devices continuously, the controller selectively activates or deactivates devices according to current environmental conditions, achieving both effective CO2 control and energy savings

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent divides the room into multiple zones with separate CO2 sensors and ventilation devices. Each zone is controlled independently based on its local CO2 concentration levels, allowing ventilation to be applied only where needed rather than uniformly across the entire space

Inventive Principle:
Principle #3Local quality

2Use of energy by moving object

If the number of operating ventilation devices is controlled based on average CO2 concentration, then energy consumption decreases, but hunting and unnecessary start-stop operations occur

Engineering Contradiction:
Improveenergy consumptionVSAvoidoperational stability
Core Design Contradiction:
Use of energy by moving objectVSStability of the object's composition

Solution Approach 1:

The system implements continuous feedback monitoring using multiple CO2 sensors distributed throughout the room. The controller receives real-time data from all sensors and adjusts ventilation device operation accordingly, creating a stable closed-loop control system that responds to actual local conditions rather than delayed average values

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent pre-configures multiple ventilation devices in different locations before operation begins. When CO2 concentration exceeds thresholds in specific zones, the system can immediately activate the nearest available ventilation device without delay, preventing hunting by having ready-to-use devices positioned strategically throughout the space

Inventive Principle:
Principle #10Preliminary action

3Device complexity

If a single CO2 detection unit is provided in the room, then device complexity is reduced, but non-uniform CO2 concentration cannot be controlled

Engineering Contradiction:
Improvesensor configurationVSAvoidCO2 concentration control
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent segments the room into multiple detection zones, each equipped with its own CO2 sensor. This segmentation allows the system to detect and control CO2 concentration variations in different parts of the room independently, accurately representing the non-uniform distribution of CO2 that a single sensor would miss

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3569943B1Ventilation system
Publication Date: 2023.10.18 DAIKIN INDUSTRIES LTD
  • EP3569943B1 patent drawingFigure 1~2
  • EP3569943B1 patent drawingFigure 3
  • EP3569943B1 patent drawingFigure 4~5

AI summary

In a system where a plurality of ventilation devices (10) are provided in one room, a control device (5) is provided to control, for the ventilation devices (10) operating, the number of the ventilation devices so that the detected values of the carbon dioxide sensors (13) are lower than the reference value.