Roof Window Ventilation Ducts for Rainproof Air Exchange

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Solution Overview

Problem

Roof windows in sloping roof structures are susceptible to rainwater intrusion when open and require constant supervision to prevent water entry, while maintaining ventilation is desirable.

Innovation Solution

A roof window design with ventilation air ducts integrated into the fixation frame, featuring a hinged wing that can be opened to allow air exchange while being rainproof, and a fixed insulating glass unit for enhanced daylight and thermal insulation, with insect screens and filters to manage airflow.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the roof window is opened to enable ventilation, then air exchange between interior and exterior is improved, but rainwater intrusion risk increases

Engineering Contradiction:
Improveventilation efficiencyVSAvoidrainwater intrusion
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The window assembly is segmented into multiple functional parts: a fixed insulating glass unit for weather protection, a separate hinged wing for ventilation control, and integrated ventilation air ducts. This segmentation allows the glass unit to remain closed (preventing rain intrusion) while the wing can be opened for ventilation, resolving the contradiction between ventilation efficiency and rain protection.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Ventilation air ducts are introduced as intermediary structures that provide dedicated ventilation pathways. These ducts allow air exchange to occur through controlled openings while being protected from direct rain exposure, acting as a mediator between the need for ventilation and the need for rain protection.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If a hinged wing is added to enable selective opening, then ventilation control is improved, but device complexity increases

Engineering Contradiction:
Improveventilation controlVSAvoidstructure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The hinged wing is merged with the ventilation air duct system, combining the ventilation function and the opening/closing mechanism into a single integrated assembly. This reduces overall device complexity compared to having separate ventilation structures and control mechanisms.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The hinged wing serves multiple functions: it acts as a protective cover when closed, provides ventilation access when opened, and integrates the ventilation air ducts. This multi-functionality reduces the need for additional separate components, thereby reducing overall device complexity while improving adaptability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Productivity

If ventilation openings are made larger to improve air exchange, then ventilation efficiency is improved, but rainproofing capability deteriorates

Engineering Contradiction:
Improveair exchange rateVSAvoidrainproofing
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The opening is segmented into two distinct zones: a fixed insulating glass unit that remains closed to maintain rainproofing, and a hinged wing that can be opened to provide ventilation. This segmentation allows large ventilation areas to be achieved without compromising the rainproofing function of the glass unit.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Ventilation air ducts serve as intermediary structures that channel air flow through protected pathways. These ducts allow large ventilation openings to be created while the duct structure itself protects against direct rain exposure, maintaining rainproofing capability despite larger opening areas.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Ensures effective ventilation with reduced manufacturing costs, improved thermal insulation, and easier cleaning access, while preventing rain ingress and particle entry.

Implementation Method 1

The exterior side opening of each ventilation opening is at a lower level that the interior side opening when the roof window is installed in a roof structure of a building

Methodology Applied
Scientific EffectGravity: Gravitation

Implementation Method 2

an insulating glass unit covering a first of the two openings

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Implementation Method 3

The ventilation air ducts are preferably provided with insect screens and/or filters for removing particles from the ventilation air entering the interior

Methodology Applied
Scientific EffectFiltration: Filter (physical)

Data Source

PatentEP4575129B1Roof window with ventilation arrangement
Publication Date: 2026.04.22 VKR HOLDING AS
  • EP4575129B1 patent drawingFigure 1~2
  • EP4575129B1 patent drawingFigure 3~4c
  • EP4575129B1 patent drawingFigure 5

AI summary

A roof window (1) is disclosed for being installed in a sloping roof structure of a building (16), the roof window (1) comprising a fixation frame (2) defining a fixation frame opening (7) and a division bar (8) dividing the fixation frame (2) opening (7) into two openings (9, 10), an insulating glass unit (11) covering a first (9) opening, and a wing (13), which is hinged to the fixation frame (2), which wing (13) in a closed position thereof covers at least a part of a second (10) opening, wherein the roof window (1) comprises ventilation air ducts (21), which provide ventilation passage through the second opening (10) of the roof window (1) while being rain proofed to prevent rain from entering from the exterior side (E) of the roof window (1) to the interior side (I) of the roof window (1) when the roof window (1) is installed in a roof structure of a building (16), the area of the ventilation passage covering at least 20% of the area of the second opening (10), such as at least 35% of the area of the second opening (10).