Attic Airflow Control for Multi-Unit Air Conditioning Efficiency

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Solution Overview

Problem

Existing air conditioning systems face inefficiencies in energy consumption and heat exchange due to the structure of buildings and the arrangement of unitary air conditioners, where the common space, such as a roof space, acts as a heat-insulating air flow path, making it difficult to achieve efficient air conditioning operations.

Innovation Solution

An air conditioning system that includes multiple air conditioners with changeable airflow ventilation fans and a control device that adjusts airflow based on the temperature of the common space, using sensors to detect actual temperatures and processing loads to optimize heat exchange efficiency and reduce energy consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the common space is used as a heat-insulating air flow path with fixed ventilation, then the structure is simple, but the air conditioning efficiency deteriorates due to inability to adapt to varying thermal loads

Engineering Contradiction:
Improveair conditioning efficiencyVSAvoidventilation control system complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent implements dynamic control of the ventilation fan's airflow volume based on real-time temperature detection in the common space. The control device adjusts the fan operation according to detected temperature values, transforming the static ventilation system into a dynamic one that adapts to varying thermal conditions, thereby improving air conditioning efficiency without requiring overly complex infrastructure

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent employs a feedback mechanism where temperature sensors continuously monitor the common space temperature and transmit this information to the control device. The control device processes this feedback and adjusts the ventilation fan's airflow volume accordingly, creating a closed-loop control system that optimizes heat exchange efficiency while maintaining system simplicity

Inventive Principle:
Principle #23Feedback

2Loss of energy

If multiple air conditioners share the common space for heat exchange, then energy consumption is reduced, but heat exchange efficiency deteriorates due to temperature fluctuations in the common space

Engineering Contradiction:
Improveenergy consumptionVSAvoidheat exchange efficiency
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The control device receives temperature information from sensors in the common space and uses this feedback to dynamically adjust the ventilation fan's airflow volume. This ensures that even when multiple air conditioners are operating simultaneously, the common space temperature is maintained within an optimal range for heat exchange, preserving efficiency while enabling energy-saving shared operation

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent changes the operational parameters of the ventilation fan based on detected temperature conditions. By adjusting the airflow volume parameter in response to temperature variations caused by multiple air conditioners, the system maintains optimal heat exchange efficiency while allowing multiple units to operate concurrently, thus reducing overall energy consumption

Inventive Principle:
Principle #35Parameter changes

3Reliability

If the ventilation fan operates at high airflow volume to maintain common space temperature, then heat exchange efficiency is improved, but energy consumption increases

Engineering Contradiction:
Improveheat exchange efficiencyVSAvoidventilation fan energy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The ventilation fan operates dynamically with variable airflow volume rather than at constant high speed. The control device adjusts the fan's operation based on real-time temperature detection, increasing airflow only when necessary to maintain heat exchange efficiency and reducing airflow when temperature conditions are favorable, thereby optimizing the balance between efficiency and energy consumption

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent dynamically changes the airflow volume parameter of the ventilation fan based on detected temperature conditions. By adjusting this parameter in response to actual thermal conditions rather than maintaining a fixed high setting, the system preserves heat exchange efficiency while minimizing unnecessary energy consumption by the ventilation fan

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The system effectively suppresses energy consumption by optimizing airflow in the common space, improving the overall efficiency of the air conditioning system while maintaining stable and efficient heat exchange operations.

Implementation Method 1

a heat source-side heat exchanger configured to carry out heat transfer to and from the usage-side heat exchanger

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Implementation Method 2

The ventilation fan is disposed near an intake port through which air in an outdoor area is taken in the common space and/or an exhaust port through which air is discharged from the common space toward the outdoor area

Methodology Applied
Scientific EffectForced convection: Forced Convection

Implementation Method 3

a heat source-side fan configured to feed air from the common space to the heat source-side heat exchanger and to blow the air into the common space

Methodology Applied
Scientific EffectForced convection: Forced Convection

Data Source

PatentEP3553405B1Air conditioning system
Publication Date: 2022.06.01 DAIKIN INDUSTRIES LTD
  • EP3553405B1 patent drawingFigure 1
  • EP3553405B1 patent drawingFigure 2
  • EP3553405B1 patent drawingFigure 3

AI summary

Provided is an air conditioning system capable of suppressing energy consumption by efficient shared use of air in a common space that is not subjected to air conditioning in an indoor area, among a plurality of air conditioners for the purpose of heat exchange. A plurality of air conditioners (21 to 25) each include: a usage-side heat exchanger configured to carry out heat exchange with air in an air-conditioning target space; a heat source-side heat exchanger configured to carry out heat transfer to and from the usage-side heat exchanger; and a heat source-side fan configured to feed air from an attic (AT) to the heat source-side heat exchanger and to blow the air into the common space. The heat source-side heat exchangers of the air conditioners (21 to 25) are disposed in the attic (AT). A first ventilation fan (46) whose airflow volume is changeable is disposed near an exhaust port (43) through which air is discharged from the attic (AT) toward an outdoor area (99). A controller (30) changes the airflow volume of the ventilation fan, based on information relating to an air temperature of the attic (AT).