Thermal comfort
May 18, 2019
The fabric maintains and regulates the stability of the body temperature and the suitable humidity of the micro-environment between the human body and the environment.
Factors that determine the comfort of heat and humidity: micro-climate formed by the human body - fabric - environment
1. Microenvironmental climate
2. Boundary conditions
3. Relevant influencing factors
Environmental conditions for hot and humid comfort
It is generally considered that the human body feels comfortable in the range of the clothing temperature of 32 ± 1 ° C, the relative humidity of 50 ± 10%, and the air flow speed of 25 ± 15 cm / s.
Physical index evaluation
1. Thermal comfort physical indicators:
Thermal conductivity: When the temperature difference of the surface of the fabric is 1 °C, the heat flow through the fabric per unit area; the thermal conductivity of the fabric is small, and the fabric is warm.
Insulation rate T: the percentage of the difference between the amount of heat dissipated by the heat body when there is no fabric coating and the amount of heat dissipated by the heat of the fabric when the fabric is covered. The insulation rate is large and the fabric is warm.
Thermal resistance: When the temperature difference is 1 °C, when the thermal energy passes at a rate of 1 W/m2, it is a unit of thermal resistance. The fabric has a large thermal resistance and good thermal insulation.
Crow value (CLO): At room temperature of 21 ° C, relative humidity <50%, air flow rate <10 cm / s, the thermal resistance of the garment when the human body is sitting comfortably is called 1 cro. The value of the Kro is large and the fabric is warm.
2. Wet comfort physical indicators
Moisture permeability
Wetting and drying rate: The ability of the human body to absorb the sweat and the latent sweat on the outer surface of the fabric to release the drainage to the external environment.
Water retention rate: The percentage of moisture retained by the fabric under a certain preload, which is the weight of the dry fabric.
