Window Sash Frame with Segmented Thermal Insulation

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Solution Overview

Problem

Conventional window sashes face challenges in achieving low thermal conductivity (u-value) without increasing depth, as the sash frame's thermal conductivity is high due to cold bridges and air convection, and installation position affects the u-value, making it difficult to install modern windows in renovation settings with specified sash widths.

Innovation Solution

A window sash design with an inner shell connected to multiple glazing via a fine-pored, foamed plastic insulation that transfers weight directly to the inner shell, separating load-bearing and insulation functions, allowing for a shallow depth of less than 85 mm and maintaining low thermal conductivity by using a foamed, fine-pored plastic with specific compressive strength and thermal insulation properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the frame depth is increased to reduce thermal conductivity, then thermal insulation is improved, but the required minimum radius for opening increases and manufacturing complexity increases

Engineering Contradiction:
Improvethermal conductivityVSAvoidmanufacturing complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The sash frame is divided into an inner shell and an outer shell that are thermally separated by insulation, breaking the continuous thermal path while maintaining a compact overall depth

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

An insulating element is introduced as an intermediary component between the inner and outer shells to block thermal bridges and prevent air convection, achieving thermal insulation without increasing the sash frame depth

Inventive Principle:
Principle #24Intermediary (Mediator)

2Loss of energy

If the frame depth is increased to reduce thermal conductivity, then thermal insulation is improved, but the required minimum radius for opening increases

Engineering Contradiction:
Improvethermal conductivityVSAvoidminimum radius
Core Design Contradiction:
Loss of energyVSLength of moving object

Solution Approach 1:

The sash frame is divided into an inner shell and an outer shell that are thermally separated by insulation, breaking the continuous thermal path while maintaining a compact overall depth

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The thermal insulation is achieved by adding a dimensional layer between the inner and outer shells, allowing thermal separation without increasing the radial distance required for opening operation

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

3Ease of operation

If conventional sash frame design is used, then ease of installation is maintained, but thermal conductivity remains high due to cold bridges and air convection

Engineering Contradiction:
Improveease of installationVSAvoidthermal conductivity
Core Design Contradiction:
Ease of operationVSLoss of energy

Solution Approach 1:

The sash frame is divided into an inner shell and an outer shell that are thermally separated by insulation, breaking the continuous thermal path while maintaining a compact overall depth

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

An insulating element is introduced as an intermediary component between the inner and outer shells to block thermal bridges and prevent air convection, achieving thermal insulation without increasing the sash frame depth

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

This design achieves a consistent low u-value regardless of installation position and allows for the use of thinner profiles, making it suitable for renovations and reducing thermal conductivity while supporting the weight of the glazing effectively.

Implementation Method 1

The inner and outer shells are thermally separated from each other by insulation, i.e., by an area of low thermal conductivity, in order to largely prevent heat exchange between the environment and the building interior

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Implementation Method 2

The filling is connected to the inner shell by a positive-locking and/or material-locking connection, so that the inner shell is additionally stiffened by the filling. The weight is also thereby directly transferred through the inner shell

Methodology Applied
Scientific EffectMechanical support:

Data Source

PatentEP2642060B1Window or door leaves
Publication Date: 2020.07.08 HOCHULI METALLBAU AG
  • EP2642060B1 patent drawingFigure 1
  • EP2642060B1 patent drawingFigure 2
  • EP2642060B1 patent drawingFigure 3

AI summary

The leaf has a leaf frame with an inner shell and a selective outer shell. A filling part e.g. multi-shed glazing part or panel, is arranged at the inner shell that includes an insulation part. The filling part is connected with the inner shell by a form closure and/or a material closure connection unit, and an isolation of the inner shell is realized by an insulation body (19) with lambda value less than 0.08 W/m K preferably 0.04 W/m K. Compression strength of the inner shell is realized between 1 and 5 N/millimeter square preferably 1.4 and 2.3 N/millimeter square. An independent claim is also included for a profile for a door or wing frame.