Window Frame Thermal Bridge Reduction via Pane Insulation
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Solution Overview
Problem
The existing window frame assemblies cause an increase in the combined heat transfer coefficient (U-value) due to their higher U-value compared to thermally insulated glass panes, forming a thermal bridge and reducing energy efficiency.
Innovation Solution
The window frame assembly incorporates a thermal insulator where the pane itself serves as the insulator, with an outside perimeter larger than the inner perimeter of the window frame, and is attached to the sill and side frames using adhesives to prevent air leakage and ensure proper positioning, thereby determining the U-value of the assembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a traditional window frame assembly is used, then the window frame provides structural support and sealing, but it causes an increase in the U-value due to thermal bridges
Solution Approach 1:
The patent extracts the thermal insulation function from the window frame structure and assigns it to the glass pane itself. By making the pane the primary thermal insulator with a U-value lower than or equal to the window frame, the thermal bridge effect is eliminated. The pane is sized to extend beyond the window frame perimeter, ensuring that the thermal insulation performance is not compromised by the frame structure.
Solution Approach 2:
The glass pane serves multiple functions: it provides the primary thermal insulation (U-value determination), acts as the sealing surface against air leakage, and maintains the structural integrity of the window assembly. By making the pane multi-functional, the patent eliminates the need for separate insulation components within the frame structure.
2Reliability
If glass slats are used to hold the pane in place, then the pane is securely fixed, but the assembly becomes more complex and harder to install
Solution Approach 1:
The patent removes the glass slats from the assembly and replaces them with adhesives applied directly to the window frame. This simplifies the fixation mechanism while maintaining secure pane attachment. The adhesives are applied to the inner member and/or outer member to create a reliable bond with the pane without requiring additional mechanical fixation components.
Solution Approach 2:
The patent replaces the mechanical fixation system (glass slats) with a chemical bonding system (adhesives). The adhesives create a strong bond between the pane and the window frame members, eliminating the need for mechanical retention devices. This substitution simplifies the assembly process and reduces the number of components required.
3Loss of energy
If the pane perimeter is made larger than the window frame inner perimeter, then the U-value is optimized, but the pane placement becomes more challenging
Solution Approach 1:
The patent applies adhesives to the inner member and/or outer member before placing the pane. This preliminary action creates a ready-to-bond surface that facilitates easy pane placement. The adhesives are applied in a manner that accommodates the pane's larger perimeter, allowing the pane to be positioned correctly and then secured as it is pressed into place.
Solution Approach 2:
The adhesives act as an intermediary between the pane and the window frame members. They provide a bonding layer that accommodates the dimensional difference between the pane perimeter and frame perimeter, facilitating easy placement while ensuring secure attachment. The adhesives fill the gap between the pane and frame, creating a seamless transition.
4Object-generated harmful factors
If adhesives are used to attach the pane, then air leakage is prevented and installation is simplified, but the choice of adhesive becomes critical
Solution Approach 1:
The patent specifies particular parameters for the adhesive: it must be suitable for bonding to the inner member and/or outer member materials, and it must create an airtight seal. The adhesive is applied in a manner that ensures both mechanical bonding and air tightness. Specific adhesive types or formulations may be recommended based on the window frame materials used.
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 minimizes the U-value increase, maintains energy efficiency by reducing thermal bridges, and simplifies the installation process with improved airtight sealing and easier pane placement.
Implementation Method 1
The pane is attached to the lower sill, side frames and upper sill by means of adhesives. In addition the adhesives form an airtight barrier between the pane and the window frame, so that air cannot move itself via an opening between the pane and the inner member or outer member of the window frame.
Data Source
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AI summary
The invention relates to an assembly of a window frame and a pane of insulated glass for placement in an opening of a building. The assembly according to the preamble is known in the state of the art. The known assembly is applied to provide a building with one or more window frames. The window frame of the known assembly is placed for this purpose in the opening, after which the pane is placed in the window frame. The pane is held in place by glass slats. The combined heat transfer coefficient, the so-called U-value is expressed in W/m2K, of the known assembly is determined by the U-Value of the pane and the U-Value of the window frame, since the window frame is intended for placement between the pane and the opening. The window frame, which is produced from substantially wood, metal or plastic or a combination thereof, has, however, always a substantial higher U-Value then the pane, which is made of thermally insulated glass(such as HR.HR+ or HR++). The window frame in the known assembly causes as a result an increase of the U-Value of the assembly and thus forms a thermal bridge. It is the aim of the invention to provide an assembly according to the preamble, whereby the window frame does not cause an undesirable increase of the U-Value of the assembly.