How Do Certain Fabrics Hold Warmth?

Wool fabrics are a popular choice for holding warmth.
••• David De Lossy/Photodisc/Getty Images

A fabric's capacity to hold warmth is referred to as its "thermal effusivity." Two factors affect how well a fabric can hold warmth: its ability to store heat (i.e., heat capacity) and its ability to transport heat (i.e., heat conductivity).

A Fabric's Chemical and Physical Makeup

The chemical and physical makeup of a fabric determine its heat capacity and its heat conductivity. For example, the natural fibers of cotton absorb water more readily than the synthetic material used to make polyester. This is important in retaining heat because water near the skin can evaporate and cool the wearer. Additionally, if a piece of fabric is thick and loosely woven, it will hold more air than a more tightly-woven piece of fabric. This is helpful in retaining warmth because air, a poor thermal conductor, is itself an insulator. Also, the surface area of a fabric should be as small as possible to hold warmth, because more area means a greater surface for heat loss.

Related Articles

Uses of PVC Plastic
Properties of Thermal Insulators
Why Is Styrofoam a Good Insulator?
The Effects of High Temperature on Epoxy
Physical Properties of Styrofoam
What Are Insulators?
Does Neoprene Stretch?
How to Shrink Rubber Bands
The Properties of Insulators
What Is Melamine Formaldehyde?
What Is the Difference Between Permeable & Impermeable?
What Is Vermiculite?
Properties of Polyester Fabrics
Properties of Natural & Synthetic Rubber
How to Mix Calcium Chloride and Water
Thermal Conductivity: Definition, Units, Equation &...
The Best Insulators to Keep Water Hot
How Does a Suction Cup Work?
How Does Water Stabilize Temperature?