Roof Window Vacuum-Insulated Glass Unit With Overlapping Gap

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Solution Overview

Problem

Existing roof windows face challenges in achieving optimal heat insulation, reducing cold bridges, and providing aesthetically appealing solutions while maintaining mechanical robustness, especially when using vacuum insulated glass units.

Innovation Solution

A roof window design incorporating a vacuum insulated glass unit with a further insulating gap that overlaps the edge seal, combined with heat insulation material and a lamination layer, to enhance thermal performance and structural integrity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If a vacuum insulated glass unit is used in the roof window, then heat insulation performance is improved, but cold bridges form at the edge seal area causing reduced thermal performance

Engineering Contradiction:
Improveheat insulation performanceVSAvoidcold bridge formation at edge seal
Core Design Contradiction:
Loss of energyVSTemperature

Solution Approach 1:

An intermediary insulating gap is introduced between the vacuum insulated glass unit and the frame. This gap acts as a thermal mediator that breaks the direct thermal path (cold bridge) between the interior and exterior through the frame, while allowing the vacuum insulated glass unit to maintain its high insulation performance. The gap is positioned to overlap the edge seal area where cold bridges typically form.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If the vacuum insulated glass unit is positioned close to the frame for structural compactness, then device complexity is reduced, but heat insulation performance deteriorates due to increased thermal bridging

Engineering Contradiction:
Improvestructural compactnessVSAvoidheat insulation performance
Core Design Contradiction:
Device complexityVSLoss of energy

Solution Approach 1:

The solution moves the insulation strategy from a two-dimensional planar approach to a three-dimensional spatial arrangement. By introducing the insulating gap that extends in the depth direction (overlapping the edge seal), the design creates a thermal barrier volume rather than just a surface barrier, achieving better insulation without increasing the visible profile complexity.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Reliability

If the edge seal is made rigid to maintain vacuum integrity, then reliability is improved, but thermal conductivity increases creating cold bridges

Engineering Contradiction:
Improvevacuum seal integrityVSAvoidthermal conductivity at edge seal
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The harmful thermal conduction path is extracted or removed from the system by positioning the insulating gap to overlap the edge seal area. This creates a discontinuity in the thermal path, effectively taking out the cold bridge effect while allowing the rigid edge seal to maintain its vacuum integrity function without the detrimental thermal side effect.

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

The design provides improved heat insulation, reduces cold bridges, and offers a more robust and aesthetically pleasing solution with enhanced noise reduction and weather resistance.

Implementation Method 1

an insulating, evacuated gap is placed between the first glass sheet and the second glass sheet

Methodology Applied
Scientific EffectVacuum insulation: Vacuum

Implementation Method 2

a further insulating gap arranged between a first major surface of a third glass sheet facing the further insulating gap and a major surface of the first glass sheet

Methodology Applied
Scientific EffectGas insulation: Thermal Insulation

Data Source

PatentEP4617450A1Roof window with a vacuum insulated glass unit comprising an overlapping further gap
Publication Date: 2025.09.17 VKR HOLDING AS
  • EP4617450A1 patent drawingFigure 1
  • EP4617450A1 patent drawingFigure 2A~2B
  • EP4617450A1 patent drawingFigure 3~4

AI summary

The present disclosure relates to a roof window (1) for installation in a roof structure 50 of a building. The roof window (1) comprises a frame (2, 2a, 2b) and a vacuum insulated glass unit (3) supported by the frame (2). The vacuum insulated glass unit (3) comprises an evacuated gap (4) which is enclosed by a first edge seal (9). Moreover, the vacuum insulated glass unit (3) comprises a further insulating gap (7) arranged between a first major surface (3d1) of a third glass sheet (3d) facing the further insulating gap (7) and a major surface (3a2) of a first glass sheet (3a) which faces the further insulating gap (7). The first glass sheet (3a) is arranged between the evacuated gap (4) and the further insulating gap (7). The third glass sheet (3d) is configured to be the exterior glass sheet (EGS) of the roof window, and comprises an exterior major surface (3d2) configured to face towards the exterior (EXT) of the building when the roof window is installed in the roof structure (50). The further insulating gap 7 is configured to be arranged between the evacuated gap (4) and the exterior glass sheet (EGS) when the roof window is installed in the roof structure (50). A part (7b) of the further insulating gap (7) partly or fully overlaps the width of the first seal (9).