Thermal manikin

Over the years these were improved upon by various companies and individuals employing new technologies and techniques as understanding of thermal comfort increased.

In the mid-1960s, seated and multi-segmented thermal manikins were developed, and digital regulation was employed, allowing for much more accurate power application and measurement.

Over time breathing, sneezing, moving (such as continuous walking or biking motions) and sweating were all employed in the manikins, in addition to male, female, and child sizes depending on the application.

The exterior skin of the manikin may be made of fiberglass, polyester, carbon fiber, or other heat conducting materials, within which are temperature sensors in each measurement zone.

Additionally, manikins may be fitted with supplemental devices that mimic human actions such as breathing, walking, or sweating.

This requires that the system know several basic facts about the manikin (surface area, hypothesized metabolic rate) while experimental factors must be input by the user (clothing insulation, Wet Bulb Globe Temperature).

The third method is that the skin temperature of the manikin is maintained constant at a user-specified value, while the power increases or decreases depending on the environmental conditions.

A good system to achieve this is to have the manikin seated in an open chair (allowing air movement to pass through), with its feet propped up off the ground.

At each temperature set point the manikin will need to remain in the room for 3 to 6 hours in order to come to steady state conditions.

To calculate the heat transfer coefficient (hcali) the following equation is used: hcali = ⁠Qsi/tski – teq⁠ where: This factor may then be used to calculate equivalent temperature during further experiments in which radiant temperature and air velocity are not controlled using the equation: teq = tski – ⁠Qsi/hcali⁠ Posture, positioning, and clothing affect the thermal manikin measurements.

Clothing reduces the effects of air velocity and changes the strength of the free convection flow around the body and face.