Window Frame External Layer Thermal Bridge Reduction
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Solution Overview
Problem
Compound frames for windows and doors, composed of different materials, face challenges in thermal bridging due to differing mechanical and chemical characteristics, leading to significant thermal energy loss.
Innovation Solution
The external layers of the frames are made of insulation foam with a uniform or non-uniform density covered by aluminum, using plastic profiles and bond elements for connection, creating an air space for additional insulation and water drainage through the aluminum cover, rather than filling the entire frame with foam.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If aluminum profiles filled with insulation foam are used for external layers, then thermal insulation properties are improved, but thermal bridges are created at connection points to internal base carrier layers
Solution Approach 1:
The external layer is segmented into multiple aluminum profiles rather than a continuous solid structure. This segmentation creates discrete thermal pathways, breaking up thermal bridges and reducing overall heat transfer through the frame assembly.
Solution Approach 2:
Insulation foam acts as an intermediary material between the aluminum profiles and the internal base carrier layers. This foam layer interrupts direct thermal contact, reducing thermal bridge formation at connection points while maintaining structural integrity.
2Strength
If insulation foam is used to connect aluminum profiles to internal base carrier layers, then connection strength is improved, but manufacturing complexity increases due to material compatibility issues
Solution Approach 1:
The frame assembly uses a composite structure combining aluminum profiles, insulation foam, and internal base carrier layers. This multi-material approach optimizes each component for its specific function while creating a unified assembly that balances connection strength with manufacturing feasibility.
Solution Approach 2:
Different materials are applied locally to specific regions where needed - aluminum profiles provide structural rigidity where required, while insulation foam provides bonding and thermal insulation at connection points. This localized material application optimizes performance without unnecessarily complicating manufacturing.
3Loss of energy
If entire frame is filled with insulation foam, then thermal insulation is maximized, but water drainage capability is reduced
Solution Approach 1:
The insulation foam used in the frame assembly has porous characteristics that allow for controlled moisture management. These pores enable water vapor to pass through and condensation to drain properly, preventing water accumulation while maintaining effective thermal insulation properties.
Solution Approach 2:
The frame structure is segmented to include dedicated drainage pathways separate from the insulation zones. This segmentation allows water to be channeled away from critical areas through specific drainage channels while insulation foam fills the remaining spaces for thermal protection.
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 enhances thermo-insulation properties, reduces thermal bridges, and improves mechanical durability, making the frames more energy-efficient and effective.
Implementation Method 1
The external layer of the frame exposed to thermal, light and weather influences protects the frame against all the mentioned influences in order to provide it with better thermo-dynamic properties
Implementation Method 2
This air-space closed by the movable or by the fixed frame of wing forms, in terms of thermo-dynamics, an insulation layer, which serves, at the same time, as the canal for collecting and draining condensed water
Data Source
Figure 1
Figure 2
AI summary
The external layer of compound frames for windows and doors serves to protect fixed frames, as well as movable and fixed frames of wings against thermal, light and weather influences. The external layer of the fixed frame, shown in Figure 1, consists of insulation layer (2), of uniform density, the external surface of which is covered by vertical aluminum cover (3), which is by plastic profile (8) and plastic bond elements (14) connected to carrier part (1) of the fixed frame by means of snap joints. In the upper part of aluminum cover (3) an air space is made which serves to collect and drain condensed water through openings (7) made on aluminum cover (3). The external layer of the movable frame of wing consists of an insulation layer, which is fastened to the external surface of carrier part (17) of the movable frame of wing by means of adhesive, and aluminum cover (19). The insulation layer consists of surface layer (18a) of a higher density, and internal part (18b) of a lower density, the external parts of which are covered by aluminum cover (19), which is fastened by means of permanently resilient adhesive. Thermo- insulation and mechanical properties of frames with the described external layers are significantly improved in comparison to those of the already known frames for windows and doors.