Effects of Layering on Thermal Insulation and Vapor Permeability

Abstract

Introduction: Thermal insulation of clothing depends largely on the air trapped between the skin and the clothing layers. Textile from clothing layers and the air between layers provide insulation. The purpose of this work is to examine the effects of layers and air gaps on thermal insulation and vapor permeability. Methods: Standard tests for the thermal and evaporative resistances (Rct and Ret) were conducted (ASTM F1291-16 and ASTM F2370-16) for eight military ensembles within climate controlled environmental chambers. Each of the eight ensembles varied in the types of material and number of layers (2 - 5 layers); while one included a 6th layer in the form of ballistic armor. Results: Thermal insulation (clo) ranged from 1.30 2.71 (1.87 0.57), vapor permeability (im) 0.32 0.55 (0.41 0.08), and evaporative potential (im/clo) ranged from 0.14 0.40 (0.24 0.09). Conclusion: This work provides some quantitative evidence that the thermal insulation is highly dependent on the addition of air layers within clothing ensembles.

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Document Details

Document Type
Technical Report
Publication Date
Nov 01, 2019
Accession Number
AD1092367

Entities

People

  • Adam W Potter
  • Daniel R. Suey
  • Julio A. Gonalez
  • Julio A. Gonzalez
  • Michael P. Castellani

Organizations

  • United States Army Research Institute of Environmental Medicine

Tags

DTIC Thesaurus Topics

  • Air Gaps
  • Armor
  • Body Armor
  • Clothing
  • Contracts
  • Department Of Defense
  • Heat Transfer
  • Instructions
  • Insulation
  • Materials
  • Permeability
  • Resistance
  • Test Methods
  • Textiles
  • Thermal Insulation
  • Thermal Resistance
  • Vapor Pressure

Readers

  • Materials Science
  • Ocean-Atmosphere Mesoscale Modeling, Data Assimilation, and Flux Boundary Layers
  • Thermal Physics or Thermal Science.

Technology Areas

  • Microelectronics
  • Microelectronics - Graphene