Window Sill Airflow Channel for Heat-Loss Reduction

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Solution Overview

Problem

Existing window sill systems fail to effectively reduce heat loss and condensation, leading to mold and damp formation due to thermal insulation gaps between glazed units and building walls, with retrofitting high-performance glazing units being costly and disruptive.

Innovation Solution

A window sill system with an internal sill featuring an airflow channel that diverts warm air from radiators towards the glazed unit, enhancing thermal efficiency and reducing condensation through computational simulations and experimental data.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If triple glazed window units are installed to reduce thermal transmittance, then heat loss resistance is improved, but replacement cost and installation disruption increase

Engineering Contradiction:
Improveheat lossVSAvoidinstallation complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent introduces an intermediary thermal insulation system consisting of rigid insulation boards installed in the cavity between the glazed unit and the interior sill. This mediator provides thermal insulation without requiring replacement of the entire window assembly, thereby reducing heat loss while avoiding the complexity and disruption of full window replacement.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention segments the thermal insulation function into a separate modular component (rigid insulation board) that can be independently installed in the cavity space, rather than integrating insulation into the entire glazed unit assembly. This allows targeted insulation enhancement without replacing the whole window system.

Inventive Principle:
Principle #1Segmentation

2Loss of energy

If curtains and shutters are closed to provide insulating barrier, then thermal insulation is improved, but visibility is blocked

Engineering Contradiction:
Improveheat lossVSAvoidvisibility
Core Design Contradiction:
Loss of energyVSIllumination intensity

Solution Approach 1:

The rigid insulation board acts as a permanent intermediary thermal barrier in the cavity, providing continuous insulation without obstructing the visual field. Unlike curtains and shutters that block visibility when closed, this fixed insulation layer maintains both thermal performance and visual transparency simultaneously.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Shape

If interior sill is installed to provide aesthetic covering, then appearance is improved, but thermal insulation effect is insufficient to prevent condensation

Engineering Contradiction:
Improveaesthetic appearanceVSAvoidthermal insulation
Core Design Contradiction:
ShapeVSLoss of energy

Solution Approach 1:

The patent creates a composite thermal insulation structure by combining rigid insulation boards with the interior sill assembly. This composite system integrates both aesthetic functionality (through the decorated interior sill) and thermal insulation functionality (through the rigid insulation layer), achieving superior thermal performance that prevents condensation while maintaining aesthetic appearance.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The system combines multiple materials with different properties: rigid insulation boards for thermal resistance, interior sill for aesthetics and structural support, and adhesive bonding for integration. This composite construction achieves both aesthetic and thermal performance requirements that neither component could achieve alone.

Inventive Principle:
Principle #40Composite materials

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 system improves thermal resistance, reduces heat loss, and minimizes condensation, thereby increasing room temperature and preventing mold formation, while being retrofittable and adaptable to various wall configurations.

Implementation Method 1

an airflow channel extending between the air inlet and air outlet... configured to direct a stream of air across at least a portion of the surface of the glazed unit

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP4172449B1Window sill system
Publication Date: 2025.09.10 KSR CONSULTANCY (NW) LIMITED
  • EP4172449B1 patent drawingFigure 1~2
  • EP4172449B1 patent drawingFigure 3
  • EP4172449B1 patent drawingFigure 4(a)~4(c)

AI summary

A window sill system is provided comprising a body that is configured to be arranged adjacent a bottom edge of the window. The body comprises an air input to draw in air, an air output to direct a stream of air across at least a portion of the surface of the window, and an air flow channel extending between the air input and air output. A heat source is arranged to heat the air within the body. For instance a heating element may be arranged to be mounted within the air flow channel.