Determination of clothing microclimate volume

Human heat transfer depends on the amount of ventilation between the skin and the clothing layers, which in turn depends on the microclimate volume (7). This volume is hard to quantify. The traditional method, developed by Crockford et al. (4) and further in Birnbaum and Crockford (1) and Sullivan et al. (10) utilises a vacuum oversuit to evacuate and measure the quantity of air trapped in the microenvironment. This method is cumbersome and an alternative may be found in a model approach or using 3D whole body scans. Lee and Hong (8) endeavoured to ascertain the relationship between the insulation value of the clothing ensemble and the air volume measured by using phase-shifting moiré topography. They determined the microclimate volume between a manikin and a T-shirt. This technique was time efficient and accurate, but it was not reported if this technique could be used on humans and how the results compared to the traditional technique of microclimate volume measurement. A third technique to estimate the microclimate volume assumes that the body is represented by a series of cylinders. The circumference of each segment is measured with and without clothing, allowing the volume of each to be calculated. The method was adopted from Lotens and Havenith (9) and is fast and simple. It is the purpose of this study to compare the reliability and reproducibility of the vacuum suit method, scanning method and cylinder model to determine microclimate volume.