Heated Sorption Filter Element for Cabin CO2 and Moisture Removal

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Solution Overview

Problem

In electrically powered vehicles, recirculating air for air conditioning can lead to water and carbon dioxide accumulation in the passenger compartment, causing fogging and health issues, which existing sorption filter devices fail to adequately address.

Innovation Solution

A sorption filter element with a heater and sorption filter bodies that adsorb and absorb water and carbon dioxide, featuring a frame with a separating wall and end cap for easy replacement, and a desorption mode using heated regeneration air to regenerate the sorption filter bodies.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If air recirculation mode is used to save energy, then energy consumption is reduced, but water and carbon dioxide accumulate in the passenger compartment

Engineering Contradiction:
Improveenergy consumptionVSAvoidwater and carbon dioxide accumulation
Core Design Contradiction:
Use of energy by moving objectVSObject-affected harmful factors

Solution Approach 1:

The air treatment system is segmented into multiple functional components: a sorption filter element with sorbent material for removing water and carbon dioxide, a heater for regenerating the sorbent, and a control system. This segmentation allows the system to maintain recirculation mode for energy savings while adding targeted functionality to address moisture and CO2 accumulation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A sorbent material acts as an intermediary substance that selectively absorbs water vapor and carbon dioxide from the recirculated air. The sorbent material captures these harmful substances, allowing the system to maintain energy-efficient recirculation while preventing accumulation of moisture and CO2 in the passenger compartment.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If dehumidifying effect is used in evaporator, then water is removed from air, but this effect cannot be utilized during recirculation mode

Engineering Contradiction:
Improvewater removal capabilityVSAvoidoperational flexibility
Core Design Contradiction:
Object-affected harmful factorsVSAdaptability or versatility

Solution Approach 1:

The sorbent material provides self-service dehumidification by passively absorbing water vapor and carbon dioxide from the recirculated air without requiring the evaporator to operate. This allows the system to maintain dehumidifying capability during recirculation mode without the energy penalty of running the evaporator, as the sorbent continuously removes moisture and CO2 through adsorption.

Inventive Principle:
Principle #25Self-service

3Ease of repair

If sorption filter bodies are made replaceable, then maintenance ease is improved, but device complexity increases

Engineering Contradiction:
Improvemaintenance easeVSAvoiddevice complexity
Core Design Contradiction:
Ease of repairVSDevice complexity

Solution Approach 1:

The sorption filter element is designed as a segmented, modular component that can be independently removed and replaced. The filter element includes a frame, separating wall, and sorption filter bodies that are structured to allow easy extraction from the housing through guide tracks, enabling maintenance without disassembling the entire device.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The sorption filter bodies are designed to be extractable from the housing through guide tracks and movable separating walls. This extraction capability allows users to remove and replace the sorption filter bodies independently, simplifying maintenance while the guide tracks and frame structure minimize the complexity increase by providing straightforward removal paths.

Inventive Principle:
Principle #2Taking out (Extraction)

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

Effectively reduces water and carbon dioxide levels in the passenger compartment, preventing fogging and health risks while allowing easy maintenance and cost-effective operation.

Implementation Method 1

The heater is configured to heat regeneration air within the intermediate space

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 2

one or more sorption filter bodies comprising at least one sorbent, the one or more sorption filter bodies being configured to remove carbon dioxide and/or water from raw air

Methodology Applied
Scientific EffectAdsorption: Adsorption

Implementation Method 3

The sorption filter element or the sorption filter bodies are suitable for adsorbing and/or absorbing carbon dioxide and water

Methodology Applied
Scientific EffectAbsorption: Absorption (physical)

Implementation Method 4

By applying heat to the sorbent, the adsorbed and/or absorbed substances can be released from the sorbent. Desorption thus generally represents the reverse process of sorption

Methodology Applied
Scientific EffectDesorption: Desorption

Data Source

PatentEP4491255B1Sorption filter element and sorption filter device
Publication Date: 2026.04.01 MANN HUMMEL GMBH
  • EP4491255B1 patent drawingFigure 1
  • EP4491255B1 patent drawingFigure 2
  • EP4491255B1 patent drawingFigure 3

AI summary

A sorption filter element (16) for a sorption filter device (5) includes a heater (11), and a frame (37) enclosing an intermediate space (58) and comprising a separating wall (40) running through the intermediate space (58), the separating wall (40) being configured to receive the heater (11).The heater (11) is configured to heat regeneration air (R1) within the intermediate space (58), and comprises a heater grid (78) through which the regeneration air (R1) flows. The sorption filter element (16) further includes one or more sorption filter bodies (52, 53, 54, 55) comprising at least one sorbent (8, 9), the one or more sorption filter bodies (52, 53, 54, 55) being configured to remove carbon dioxide (CO2) and/or water (H2O) from raw air (RO) to turn the raw air (RO) into clean air (RL).