Vehicle HVAC Blower Coaxial Flaps for Warm-Up and Defogging

Solution Overview

Problem

Existing motor vehicle HVAC systems face challenges in quickly warming the passenger compartment while avoiding windshield fogging, as recirculated air is more humid and requires efficient separation of air flows to achieve thermal comfort.

Innovation Solution

A suction blower with coaxial flaps, where the central flap is larger than the side flaps, allowing for greater proportions of recirculated air to be introduced initially to accelerate warming and directing outside air towards the windshield to prevent fogging.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If recirculated air is used for heating the passenger compartment, then the warm-up speed is improved, but windshield fogging occurs due to high humidity

Engineering Contradiction:

Improvewarm-up timeVSAvoidwindshield fogging

Core Design Contradiction:

Loss of timeVSObject-affected harmful factors

Solution Approach 1:

The air inlet housing is segmented into multiple independent air inlets: a first air inlet for recirculated air and a second air inlet for outside air. This segmentation allows the system to selectively control the proportion of each air type entering the blower, enabling rapid warm-up using recirculated air while preventing windshield fogging by introducing outside air to reduce humidity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the air inlet housing are assigned different functions: the first air inlet (configured with a larger cross-sectional area) is optimized for recirculated air intake to maximize heating efficiency, while the second air inlet is optimized for outside air intake to control moisture. This local differentiation of air inlet properties enables simultaneous achievement of fast warm-up and fog prevention.

Inventive Principle:

Principle #3Local quality

2Object-affected harmful factors

If outside air is used for heating, then windshield fogging is prevented, but the warm-up speed decreases

Engineering Contradiction:

Improvewindshield foggingVSAvoidwarm-up time

Core Design Contradiction:

Object-affected harmful factorsVSLoss of time

Solution Approach 1:

The air inlet housing is segmented into multiple independent air inlets: a first air inlet for recirculated air and a second air inlet for outside air. This segmentation allows the system to selectively control the proportion of each air type entering the blower, enabling rapid warm-up using recirculated air while preventing windshield fogging by introducing outside air to reduce humidity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system dynamically adjusts the proportion of recirculated air to outside air based on operating conditions. The first air inlet is configured with a larger cross-sectional area to allow greater recirculated air flow for fast warm-up, while the second air inlet provides outside air to control humidity and prevent fogging, achieving optimal balance between heating speed and fog prevention.

Inventive Principle:

Principle #35Parameter changes

3Device complexity

If a single air inlet is used, then the device complexity is reduced, but the ability to separate airflows and control thermal conditioning is limited

Engineering Contradiction:

Improveair inlet structureVSAvoidairflow separation capability

Core Design Contradiction:

Device complexityVSAdaptability or versatility

Solution Approach 1:

The air inlet housing is segmented into multiple independent air inlets: a first air inlet for recirculated air and a second air inlet for outside air. This segmentation allows the system to selectively control the proportion of each air type entering the blower, enabling rapid warm-up using recirculated air while preventing windshield fogging by introducing outside air to reduce humidity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The air inlet housing with multiple air inlets serves multiple functions simultaneously: it separates recirculated air and outside air streams, enables thermal conditioning of both air types, controls humidity levels, and provides adaptability for different operating modes (heating, ventilation, air conditioning). This multi-functionality is achieved within a relatively simple integrated housing structure.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentEP3856552B1Blower for a heating, ventilation and/or air conditioning device of a vehicle

Publication Date: 2024.10.16 VALEO SYST THERMIQUES SAS

Figure 1~2
Figure 3~4
Figure 5a~5c

AI summary

The invention relates to an air intake housing (21), in particular for a heating, ventilation and/or air conditioning device, comprising: - at least two distinct air inlets (24, 26), and - air guiding members (27, 28, 30) configured to direct at least one air flow that is intended to be admitted into the air intake housing (21). According to the invention, the air guiding members comprise at least three flaps (27, 28, 30), one of these being a central flap (27) and two lateral flaps (28, 30) arranged one on each side of the central flap (27), said flaps (27, 28, 30) being positioned between the said two distinct air inlets (24, 26) of the air intake housing (21) so as to be able to move about a single axis of pivoting (33). The invention also relates to a suction blower (1) comprising such an air intake housing (21) and to a corresponding heating, ventilation and/or air conditioning device.