Window Ventilation Control for Energy-Saving Building Air Conditioning

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Solution Overview

Problem

Existing air-conditioning systems do not effectively achieve energy savings by automatically opening and closing building openings like windows and doors, despite advancements in ventilation fan control and environmental monitoring, as they prioritize ventilation performance over energy efficiency.

Innovation Solution

An air-conditioning system comprising an opening/closing device, an air-conditioning device, and a controller that monitors environmental information to selectively open or close building openings based on Predicted Mean Vote (PMV) indices, date, and time, as well as security and presence detection, to optimize energy usage and comfort.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the ventilation fan is operated to improve ventilation performance, then air flow is secured, but energy consumption increases

Engineering Contradiction:
Improveventilation performanceVSAvoidenergy consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The system changes the operational parameters by switching between natural ventilation mode (openable portion open, fan off) and mechanical ventilation mode (openable portion closed, fan on) based on environmental conditions, thereby optimizing energy consumption while maintaining ventilation performance

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system dynamically adjusts the state of the openable portion and fan operation based on real-time environmental information, transitioning between different ventilation modes to balance energy consumption and ventilation effectiveness

Inventive Principle:
Principle #15Dynamics

2Loss of energy

If the openable portion is opened to achieve energy saving, then energy consumption decreases, but security risk increases

Engineering Contradiction:
Improveenergy savingVSAvoidsecurity risk
Core Design Contradiction:
Loss of energyVSObject-affected harmful factors

Solution Approach 1:

The system incorporates security information as feedback to the control logic, which determines whether the openable portion should be opened based on both energy saving potential and security risk assessment, thereby resolving the contradiction between energy saving and security

Inventive Principle:
Principle #23Feedback

3Loss of energy

If the openable portion is opened to improve natural ventilation, then energy consumption decreases, but thermal comfort control precision worsens

Engineering Contradiction:
Improveenergy consumptionVSAvoidthermal comfort control precision
Core Design Contradiction:
Loss of energyVSManufacturing precision

Solution Approach 1:

The system dynamically switches between natural ventilation and mechanical ventilation modes based on environmental conditions, allowing precise control of thermal comfort through the air-conditioning device when needed, while saving energy when natural ventilation is sufficient

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the ventilation mode parameter based on PMV index comparisons, transitioning between natural and mechanical ventilation to maintain thermal comfort precision while optimizing energy consumption

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2985539B1Air-conditioning system
Publication Date: 2021.06.30 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • EP2985539B1 patent drawingFigure 1
  • EP2985539B1 patent drawingFigure 2A~2B
  • EP2985539B1 patent drawingFigure 3

AI summary

The air-conditioning system includes: an opening/closing device opening and closing an openable portion in an opening of a building;, an air-conditioning device performing air-conditioning inside the building by consuming energy for operation; a monitoring device monitoring environmental information regarding the inside and outside of the building; and a controller controlling the opening/closing device and the air-conditioning device based on the environmental information from the monitoring device, date and time information representing a current date and time, building information representing a location condition of the building, and draft information determined by parameters including an opening area and an opening shape in the openable portion. The controller opens the openable portion and stops the air-conditioning device when the outside is more favorable in air environment than the inside, and closes the openable portion and starts the air-conditioning device when the inside is more favorable in air environment than the outside.