Multi-Layer Duct Insulation for Fire Resistance in Tight Spaces

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Solution Overview

Problem

Current fire and heat protection systems for ventilation air ducts require excessive insulation, complex penetration details, and intensive site supervision, leading to high energy consumption and inefficiencies in installation and redesign processes.

Innovation Solution

A fire and heat protection system comprising at least two layers of materials arranged around ventilation air ducts, where the first layer is made of low thermal conductivity insulation material with crystallized water particles, and the second layer is flexible, impervious to water, and undergoes an endothermic reaction to retain water vapor and condensed water, thereby controlling temperature rise.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If heavy gauge metal ducts with thick insulation are used to achieve 120 minutes of fire resistance, then fire protection performance is improved, but the space requirement increases by 278 mm

Engineering Contradiction:
Improvefire protection performanceVSAvoidspace requirement
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The patent applies composite materials by combining a reflective barrier layer (metalized film) with a foam insulation layer. This composite structure achieves 120 minutes of fire resistance while reducing the insulation thickness from 278 mm to significantly less, as the reflective barrier provides thermal resistance without adding substantial thickness, thereby resolving the contradiction between fire protection performance and space requirement

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent changes the thermal parameters of the insulation system by introducing a reflective barrier with high reflectivity. This barrier reflects radiant heat, changing the heat transfer mechanism from purely conductive to a combination of reflective and insulative effects, thereby achieving the same fire resistance with reduced material thickness

Inventive Principle:
Principle #35Parameter changes

2Reliability

If chemical solutions are applied to seal duct joints for fire resistance, then fire protection is improved, but the complexity of installation and supervision increases

Engineering Contradiction:
Improvefire protectionVSAvoidinstallation complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the sealing function from the chemical solution application process and integrates it into the mechanical assembly of the duct system. The reflective barrier and foam insulation layers are mechanically attached to provide both insulation and sealing, eliminating the need for separate chemical sealing operations and reducing installation complexity while maintaining fire protection

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent merges the sealing function with the insulation function by using the same foam insulation material to both insulate the duct and seal the joints. This integration eliminates the need for separate chemical sealing operations, reducing installation complexity and supervision requirements while maintaining fire protection integrity

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If extensive insulation is applied to ventilation ducts to control heat propagation, then fire resistance is improved, but energy consumption during installation increases

Engineering Contradiction:
Improvefire resistanceVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent changes the thermal parameters of the insulation system by introducing a reflective barrier that reflects radiant heat. This reduces the amount of insulating material needed, thereby reducing the energy consumed during material production, transportation, and installation, while maintaining the same fire resistance level

Inventive Principle:
Principle #35Parameter changes

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 effectively reduces the propagation of fire and heat through ventilation air ducts, improves fire resistance, and simplifies installation by minimizing the need for excessive insulation and complex penetration details, while also reducing energy consumption and site supervision requirements.

Implementation Method 1

the insulation material of the first layer comprises crystallized water particles that - when subjected to heat - are vapourised and released as water vapour

Methodology Applied
Scientific EffectVaporization: Evaporation

Implementation Method 2

which second layer is made of a material making the second layer flexible enabling the second layer to be wrapped over and around the first layer and the ventilation duct(s), wherein the material of the second layer is impervious to liquid water and water vapour and configured to - when subjected to heat - undergo an endothermic reaction process

Methodology Applied
Scientific EffectEndothermic reaction: Endothermic Reaction

Implementation Method 3

the water vapour impervious second layer retains water vapour and any condensed water between the second layer and the air-proof casing and inside the fire and heat protection system

Methodology Applied
Scientific EffectCondensation: Condensation

Implementation Method 4

which first layer comprises an insulation material with a low thermal conductivity

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Data Source

PatentEP4556778A1A metal ventilation duct to prevent the spread of fire, smoke and heat
Publication Date: 2025.05.21 SMOFIR TRADING LTD
  • EP4556778A1 patent drawingFigure 1
  • EP4556778A1 patent drawingFigure 2A~2B
  • EP4556778A1 patent drawingFigure 3~4

AI summary

The disclosure relates to a fire and heat protection system (100) for covering one or more ventilation air ducts (1) made of sheet metal, the fire and heat protection system comprising at least two layers (110, 120) of materials arranged around the ventilation air duct as insulation. The at least two layers (110, 120) are made by different materials or made by different compositions of the same material, wherein one or more first layers (110) and/or one or more second layers (120) encapsulate the ventilation air duct (1). The first layer (110) comprises insulation material. The second layer (120) is arranged in close proximity with or in contact with the first layer (110). The second layer (120) is made of a material making it flexible enabling it to be wrapped over and around the first layer (110) and the ventilation duct (1).