Vehicle Air Conditioner Intake Door Control for Fogging and Heating
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Solution Overview
Problem
Modern vehicle air conditioning systems face challenges in maintaining effective heating performance due to reduced engine coolant heat, leading to decreased indoor heating efficiency and increased risk of fogging on the windshield, which compromises driving safety.
Innovation Solution
A system that controls inside/outside air ratios in the air conditioner by using separate discharge passages and intake doors, adjusting their opening amounts based on heating load and humidity to maximize inside air circulation while preventing fogging, utilizing a control unit to manage the airflow ratios dynamically.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the amount of outside air introduced for ventilation is increased, then the fogging risk on windshield glass is reduced, but the heating performance of vehicle interior deteriorates due to heat loss
Solution Approach 1:
The air conditioning system is divided into separate upward and downward discharge passages, each with independent intake door control. The upward passage handles defrosting/ventilation functions while the downward passage handles heating, allowing independent optimization of each function without compromising the other
Solution Approach 2:
The control unit dynamically adjusts the opening amounts of first and second intake doors based on real-time heating load and interior humidity conditions. This dynamic control allows the system to optimize the balance between ventilation (preventing fogging) and heating performance according to actual operating conditions
2Use of energy by moving object
If the engine coolant temperature is reduced to improve engine efficiency, then fuel consumption is improved, but the heating capability of the air conditioner deteriorates
Solution Approach 1:
The control unit dynamically adjusts intake door opening amounts based on heating load requirements. When external temperature is low and heating demand is high, the system increases inside air circulation ratio to maximize heating efficiency without requiring higher coolant temperatures
Solution Approach 2:
The system changes the airflow parameters (inside air ratio, outside air ratio) based on heating load and humidity conditions. By optimizing these parameters, the system achieves effective heating with lower coolant temperatures, thereby maintaining engine efficiency
3Loss of energy
If the ratio of inside air circulation is increased to reduce heat loss, then heating performance is improved, but the risk of fogging on windshield glass increases
Solution Approach 1:
The system separates defrosting/ventilation functions (upward passage) from heating functions (downward passage). This segmentation allows inside air to be prioritized for heating while outside air is directed to defrosting, eliminating the need to choose between heating efficiency and fogging prevention
Solution Approach 2:
The control unit continuously monitors interior humidity and heating load conditions, and adjusts the intake door opening amounts accordingly. This feedback control ensures that the inside air ratio is optimized to prevent fogging while maintaining heating performance
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
Enhances indoor heating performance by increasing the ratio of inside air circulation without fogging on the windshield, reducing heat loss, and improving driving safety by effectively managing airflow ratios according to humidity and heating load.
Implementation Method 1
the air conditioner heats or cools outdoor air (outside air) introduced from the outside of the vehicle or indoor air (inside air) circulated in the interior of the vehicle
Data Source
AI summary
A system for controlling inside/outside air in air conditioner may include an air conditioner including an upward discharge passage, through which air is discharged toward a front glass of a vehicle, a downward discharge passage, through which air is discharged toward a floor of the vehicle, the upward discharge passage and the downward discharge passage being separated from each other, a first intake door, an opening amount of which is determined according to a ratio between inside air and outside air introduced into the upward discharge passage, and a second intake door, an opening amount of which is determined according to a ratio between inside air and outside air introduced into the downward discharge passage; and a control unit configured of controlling the opening amounts of the first and second intake doors according to a heating load of the air conditioner and a humidity of the interior of the vehicle.