Thermal comfort depends on more than insulation alone.
Even highly insulating materials can lose effectiveness if cold air moves freely through the product. Air movement removes the warm air trapped inside the insulation, increasing heat loss and reducing overall comfort.
For this reason, product developers often evaluate both thermal insulation and air permeability when selecting materials for cold-weather products.
Understanding how these properties work together is essential when designing gloves, footwear, workwear and outdoor apparel.
Air permeability describes how easily air passes through a textile material under controlled test conditions.
A material with high air permeability allows more air to pass through.
A material with low air permeability creates a greater barrier to airflow.
Neither is automatically better. The optimal level depends entirely on the intended application.
These two terms are often confused.
Air permeability measures the movement of air through a material.
Breathability normally refers to the movement of water vapour through a textile system.
A material can have low air permeability while still allowing moisture vapour to move through the product.
This distinction is particularly important in insulated clothing, where reducing cold airflow is often desirable without creating an uncomfortable microclimate.
Insulation works by trapping still air.
When external air passes through the insulation layer, part of this trapped warm air is replaced by colder air from the surrounding environment.
The greater the airflow, the greater the potential heat loss.
Reducing unnecessary air movement within the insulation therefore helps improve thermal comfort, particularly in cold and windy conditions.
Maximum wind resistance is not always the objective.
Different products require different levels of air permeability depending on their intended use.
For example:
High-activity sportswear may prioritise moisture transport.
Winter gloves may prioritise reduced airflow.
Safety footwear may require a balance between warmth and comfort.
Outdoor jackets often combine insulation with membranes and ventilation systems.
The insulation should always be selected as part of the complete product design.
The insulation itself is only one part of the finished product.
Overall airflow is influenced by:
For this reason, laboratory measurements should always be considered together with the complete product construction.
MEIDA Original combines superfine polypropylene microfibres with protective polypropylene fleece layers.
This construction creates a dense insulation structure that helps reduce air movement through the material while maintaining lightweight performance.
Internal testing has shown that the air permeability of MEIDA Original decreases as insulation weight increases, providing product developers with different options depending on the required balance between thermal performance and airflow resistance.
Rather than maximising airflow, the objective is to help maintain the layer of warm air that provides insulation.
When selecting insulation, developers often compare thermal values such as CLO or Rct.
However, products with similar thermal resistance can behave differently in real-world use if air movement through the insulation differs significantly.
Considering air permeability alongside thermal performance provides a more complete understanding of how an insulated product may perform in cold environments.
Air permeability measures how easily air passes through a textile material under controlled laboratory conditions.
No. Air permeability measures airflow, while breathability normally refers to water vapour transport.
Air movement can increase heat loss and reduce thermal comfort in insulated products.
Not always. Thermal comfort depends on insulation, moisture management, garment construction and intended use.
High airflow may increase heat loss because warm air trapped inside the insulation is replaced by colder surrounding air.
No. Every application requires its own balance between airflow, moisture management and thermal performance.
Fibre structure, material density, thickness, fabric construction and product design all influence air permeability.
Generally, thicker and denser insulation constructions reduce airflow more than lighter constructions, although material design also plays an important role.
Yes. The outer fabric is often one of the most important factors affecting the total airflow through the finished product.
Air permeability is measured according to recognised textile test methods by determining the amount of air passing through a material under controlled pressure conditions.
Yes. Controlling airflow can help maintain warmth while preserving comfort and dexterity.
Yes. Airflow influences both thermal comfort and moisture behaviour inside insulated footwear.
Yes. Different work environments require different balances between warmth, comfort and ventilation.
Both properties influence thermal comfort, but they measure different aspects of product performance.
MEIDA Original combines superfine polypropylene microfibres with protective PP fleece layers to create a dense insulation structure that helps reduce unnecessary air movement.
Yes. Air permeability data is available for selected MEIDA insulation constructions as part of the technical documentation.
Because thermal performance alone does not describe how a product behaves when exposed to wind and moving air.
Yes. Materials with similar thermal insulation values may perform differently if their resistance to airflow differs.
No. The optimal level depends on the product’s intended use, activity level and environmental conditions.
The best solution depends on the complete product design and the performance priorities of the finished application.
Whether you’re developing apparel, footwear, gloves or bedding, our specialists are ready to help.