Vehicle HVAC System Firewall Mounting and Axial Alignment

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Solution Overview

Problem

Existing vehicle HVAC systems are inefficient in space utilization and noise management, with potential water leakage and noise propagation into the passenger cabin due to their conventional mounting configurations.

Innovation Solution

The HVAC system is designed with an airflow inlet case mounted on the engine side of the firewall, featuring a blower case that connects to a heater case, including an evaporator and filter aligned with the blower's axis of rotation, allowing for a compact and quiet operation by separating noise sources and water management from the passenger cabin.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of repair

If the HVAC system is mounted on the passenger cabin side of the firewall, then the system is easier to access for maintenance, but noise and potential water leakage propagate into the passenger cabin

Engineering Contradiction:

Improvemaintenance accessibilityVSAvoidnoise propagation and water leakage

Core Design Contradiction:

Ease of repairVSObject-affected harmful factors

Solution Approach 1:

The HVAC system is divided into separate functional modules: the evaporator assembly is mounted on the engine side of the firewall while the heater case and air distribution components are positioned on the passenger cabin side. This segmentation isolates noise-generating and water-prone components from the passenger cabin, reducing noise propagation and water leakage risks while maintaining system functionality

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The evaporator and associated airflow inlet case are extracted from the traditional passenger cabin mounting location and repositioned on the engine side of the firewall. This extraction removes the primary noise source and water leakage risk from the passenger cabin environment, while the heater case remains accessible for maintenance purposes

Inventive Principle:

Principle #2Taking out (Extraction)

2Ease of operation

If the evaporator and heater are positioned away from the blower axis, then airflow distribution is improved, but the system occupies more space

Engineering Contradiction:

Improveairflow distributionVSAvoidsystem space occupation

Core Design Contradiction:

Ease of operationVSVolume of stationary object

Solution Approach 1:

The evaporator and heater are arranged in a linear configuration along the blower's axis of rotation, utilizing the axial dimension rather than radial or lateral space. This one-dimensional alignment allows all components to be positioned collinearly with the blower, optimizing airflow distribution while minimizing the overall footprint of the HVAC system

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Ease of operation

If the recirculation air inlet is positioned away from the firewall, then airflow mixing is improved, but the system becomes more complex

Engineering Contradiction:

Improveairflow mixingVSAvoidsystem configuration

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The recirculation air inlet is merged with the heater case structure, with the inlet positioned to face the heater case directly. This integration allows recirculated air to be drawn in and immediately directed through the heater core, achieving effective airflow mixing and thermal processing while maintaining a compact, simplified system configuration

Inventive Principle:

Principle #5Merging (Combining)

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 maximizes passenger cabin space, reduces noise, and simplifies water management by isolating the evaporator's noise and potential water leakage from the cabin, resulting in a more compact and quieter HVAC system.

Implementation Method 1

a blower configured to draw airflow through the airflow inlet case into a heater case

Methodology Applied

Scientific EffectPressure difference: Pressure Gradient

Implementation Method 2

The airflow inlet case includes an evaporator and a filter both aligned with an axis of rotation of a blower

Methodology Applied

Scientific EffectHeat transfer: Heat Exchanger

Implementation Method 3

The heater case includes a heater aligned with the axis of rotation of the blower

Methodology Applied

Scientific EffectHeat transfer: Heat Exchanger

Data Source

PatentUS11186143B2Vehicle HVAC system

Publication Date: 2021.11.30 DENSO INTERNATIONAL AMERICA INC

AI summary

A heating, ventilation, and air conditioning (HVAC) system for a vehicle. The HVAC system includes an airflow inlet case defining a fresh air inlet and a recirculation air inlet. The airflow inlet case includes an evaporator and a filter both aligned with an axis of rotation of a blower configured to draw airflow through the airflow inlet case into a heater case. The recirculation air inlet faces the heater case. The airflow inlet case is configured to be mounted on an engine side of a vehicle firewall such that the recirculation air inlet is at the firewall.