Vehicle HVAC Defrost Vent Split Flow for Head Overheat Control

Solution Overview

Problem

In vehicle air conditioners with horizontally-disposed heat exchangers, hot air is directly discharged to the defrost vent in floor or mix modes, causing discomfort due to inadequate temperature control and vertical temperature differences.

Innovation Solution

The air conditioner features a defogging outlet separator with a partition wall and hot air guide baffle, which directs hot air passing through the heating heat exchanger to be discharged through a separate path, preventing direct discharge to the defrost vent and allowing for smoother mixing with cooling air, thereby improving temperature distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If hot air is discharged directly through the defrost vent in floor or mix modes, then the heating effect is strong and rapid, but the occupant's head overheats and vertical temperature difference increases causing discomfort

Engineering Contradiction:

Improveheating effectVSAvoidoverheating at head

Core Design Contradiction:

TemperatureVSObject-affected harmful factors

Solution Approach 1:

The defrost vent is divided into two separate flow paths: a first flow path for hot air from the heating heat exchanger and a second flow path for mixed air from both cooling and heating heat exchangers. This segmentation allows selective discharge of appropriately temperature-adjusted air to different regions, preventing direct discharge of hot air to the occupant's head while maintaining effective heating at the floor level.

Inventive Principle:

Principle #1Segmentation

2Device complexity

If hot air is discharged directly through the defrost vent, then the structure is simple, but temperature control is inadequate and air distribution is poor

Engineering Contradiction:

ImprovestructureVSAvoidtemperature control

Core Design Contradiction:

Device complexityVSEase of operation

Solution Approach 1:

The defrost vent is divided into two separate flow paths: a first flow path for hot air from the heating heat exchanger and a second flow path for mixed air from both cooling and heating heat exchangers. This segmentation allows selective discharge of appropriately temperature-adjusted air to different regions, preventing direct discharge of hot air to the occupant's head while maintaining effective heating at the floor level.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A mixing chamber is introduced as an intermediary component where air from both the cooling and heating heat exchangers can mix before being discharged through the second flow path. This intermediary structure enables better temperature control and air distribution by allowing thermal exchange between the air streams before discharge.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Device complexity

If a single flow path is used for the defrost vent, then the device complexity is low, but the vertical temperature difference is large causing discomfort

Engineering Contradiction:

Improveflow path structureVSAvoidvertical temperature difference

Core Design Contradiction:

Device complexityVSStability of the object's composition

Solution Approach 1:

The defrost vent is divided into two separate flow paths: a first flow path for hot air from the heating heat exchanger and a second flow path for mixed air from both cooling and heating heat exchangers. This segmentation allows selective discharge of appropriately temperature-adjusted air to different regions, preventing direct discharge of hot air to the occupant's head while maintaining effective heating at the floor level.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the vehicle interior receive air with different temperature characteristics appropriate to their specific needs: the floor area receives warmer air through the first flow path for effective heating, while the upper region near the occupant's head receives mixed and cooled air through the second flow path, creating locally optimized thermal comfort conditions.

Inventive Principle:

Principle #3Local quality

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

This configuration enhances indoor comfort by reducing the vertical temperature difference, preventing the occupant's head from overheating and improving air distribution in vehicle air conditioning systems.

Implementation Method 1

a cooling heat exchanger and a heating heat exchanger provided sequentially on the air flow path of the air conditioning case in an airflow direction

Methodology Applied

Scientific EffectHeat exchange: Heat Exchanger

Data Source

PatentUS20240174045A1Air conditioner for vehicle

Publication Date: 2024.05.30 HYUNDAI MOTOR CO LTD

AI summary

An air conditioner for a vehicle with an improved structure so that hot air is not directly discharged to a defrost vent in a floor mode or a mix mode, includes an air conditioning case in which an air flow path is formed, and a cooling heat exchanger and a heating heat exchanger provided sequentially on the air flow path of the air conditioning case in an airflow direction, wherein a defrost vent, a face vent, and a floor vent are formed on the air conditioning case, wherein the defrost vent includes a first defogging flow path allowing air passing through the heating heat exchanger to be discharged directly, and a second defogging flow path allowing air passing through the cooling heat exchanger or the heating heat exchanger to be mixed and discharged therethrough.