Harriet Meinander

Thermal manikin measurements--exact or not?

According to the European prestandard ENV 342:1998 [1], the thermal insulation of cold-protective clothing is measured with a thermal manikin. Systematic studies on the reproducibility of the values, measured with different types of clothing on the commonly used standing and walking manikins, have not been reported in the literature. Over 300 measurements were done in 8 different European laboratories. The reproducibility of the thermal insulation test results was good. The coefficient of variation was lower than 8%. The measured clothing should fit the manikin precisely, because poorly fitting clothing gave an error in the results. The correlation between parallel and serial insulation values was excellent and parallel values were about 20% lower than serial ones. The influence of ambient conditions was critical only in the case of air velocity. The reproducibility of thermal insulation test results in a single laboratory was good, and the variation was lower than 3%.

Heat and moisture transmission properties of clothing systems evaluated by using a sweating thermal manikin under different environmental conditions

Purpose – The paper aims to investigate thermal comfort properties, such as heat and moisture transmission through male business clothing systems, by using a sweating thermal manikin Coppelius that simulates heat and moisture production in a similar way to the human body and measures the influence of clothing on heat exchange in different environmental and sweating conditions.Design/methodology/approach – Ten different combination of male business clothing systems were measured using the sweating manikin, under three environmental conditions (10°C/50 per cent RH, 25°C/50 per cent RH and −5°C), and at 0 and 50 gm−2 h−1 sweating levels, in order to evaluate the influence of environmental and sweating conditions on thermal comfort properties of clothing systems.Findings – The results show how business clothing systems influence on the dry and evaporative heat loss between the manikin surface and environment in different environmental and sweating conditions.Practical implications – When using sweating therma...

Manikin measurements versus wear trials of cold protective clothing (Subzero project).

The thermal insulation properties of clothing systems can be defined through physical measurements using thermal manikins or through wear trials using human test subjects. One objective of the European Subzero project was to define the relationship between physically measured thermal insulation values of cold-protective clothing and the corresponding physiological reactions on human test subjects. Four cold-protective clothing ensembles, intended for use in temperatures between 0 and −50°C, were measured with manikins in eight European laboratories and on human test subjects in four of these laboratories. The results showed that reasonably good reproducible values from the manikin tests can be achieved (CV <8%); however, the fit of the clothing on the manikin is a critical factor. There were greater individual differences in the wear trial results. Comparing the results from the manikin and the wear trials, good agreement in the thermal insulation values was shown if the amount of accumulated sweat was low. In these situations, which are normal when using cold protective clothing, the thermal comfort can also be determined with good accuracy by means of mathematical models based on manikin results. Special situations, e.g. for highly perspiring wearers, strong wind, or high friction between garment layers, need specific modelling; some suggestions have been made as a result of the Subzero project, but further research is required.

Calculation of clothing insulation by serial and parallel methods: effects on clothing choice by IREQ and thermal responses in the cold.

Cold protective clothing was studied in 2 European Union projects. The objectives were (a) to examine different insulation calculation methods as measured on a manikin (serial or parallel), for the prediction of cold stress (IREQ); (b) to consider the effects of cold protective clothing on metabolic rate; (c) to evaluate the movement and wind correction of clothing insulation values. Tests were carried out on 8 subjects. The results showed the possibility of incorporating the effect of increases in metabolic rate values due to thick cold protective clothing into the IREQ model. Using the higher thermal insulation value from the serial method in the IREQ prediction, would lead to unacceptable cooling of the users. Thus, only the parallel insulation calculation method in EN 342:2004 should be used. The wind and motion correction equation (No. 2) gave realistic values for total resultant insulation; dynamic testing according to EN 342:2004 may be omitted.

Dry and wet heat transfer through clothing dependent on the clothing properties under cold conditions

The purpose of this study was to investigate the effect of moisture on the heat transfer through clothing in relation to the water vapour resistance, type of underwear, location of the moisture and climate. This forms part of the work performed for work package 2 of the European Union THERMPROTECT project. Thermal manikin results of dry and wet heat loss are presented from different laboratories for a range of 2-layer clothing with similar dry insulations but different water vapour permeabilities and absorptive properties. The results obtained from the different manikins are generally consistent with one another. For each climate, total wet heat loss is predominately dependent on the permeability of the outer layer. At 10 °C, the apparent evaporative heat loss is markedly higher than expected from evaporation alone (measured at 34 °C), which is attributed to condensation within the clothing and to increased conductivity of the wet clothing layers.

The Influence of Sweating on the Heat Transmission Properties of Cold Protective Clothing Studied With a Sweating Thermal Manikin

One of the objectives of the European SUBZERO project was to study the influence of sweat evaporation and condensation on the heat transmission properties of cold protective clothing. With the sweating thermal manikin Coppelius, water vapour transfer through and water condensation in the clothing can be determined simultaneously with the thermal insulation. In this study, 4 cold protective ensembles, intended for use temperatures between 0 and -50 °C, were measured with the dry manikin and at 2 different sweating rates. In addition, the ensembles were measured with non-sweating thermal manikins and in wear trials.

Heat Gain From Thermal Radiation Through Protective Clothing With Different Insulation, Reflectivity and Vapour Permeability

The heat transferred through protective clothing under long wave radiation compared to a reference condition without radiant stress was determined in thermal manikin experiments. The influence of clothing insulation and reflectivity, and the interaction with wind and wet underclothing were considered. Garments with different outer materials and colours and additionally an aluminised reflective suit were combined with different number and types of dry and pre-wetted underwear layers. Under radiant stress, whole body heat loss decreased, i.e., heat gain occurred compared to the reference. This heat gain increased with radiation intensity, and decreased with air velocity and clothing insulation. Except for the reflective outer layer that showed only minimal heat gain over the whole range of radiation intensities, the influence of the outer garments’ material and colour was small with dry clothing. Wetting the underclothing for simulating sweat accumulation, however, caused differing effects with higher heat gain in less permeable garments.

A study of the influence of different clothing materials on heat and moisture transmission through clothing materials, evaluated using a sweating cylinder

Purpose – The purpose of this study was to investigate the heat and moisture transmission through different types of textile materials or material combinations used for male business clothing.Design/methodology/approach – In this study, eight different material combinations, which simulate four‐layer male business clothing system were tested using the sweating cylinder under two environmental conditions (10°C/65% RH and 25°C/65% RH), and at two sweating levels (100 and 200 gm−2h−1), in order to evaluate the heat and moisture transmission properties of material combinations.Findings – The results show how combinations of clothing materials that simulate male business clothing system influence on the dry and evaporative heat loss between the cylinder surface and two different environment conditions as well as to different sweating levels.Practical implications – The sweating cylinder can be used for measuring the heat and moisture transmission through clothing materials or material combinations in order to ...

Haptic Sensing in Intelligent Textile Development

The haptic properties of textiles are of crucial importance in most application areas and particularly for skin contact garments. Extensive research work has therefore been done both in defining the mechanical textile properties, which influence the haptic sensations, in measuring these textile properties, in defining procedures for subjective evaluation of the haptics of textiles, and in simulation of the properties in a virtual environment. In the development of new smart or intelligent textiles it is particularly important to consider the haptic properties. The introduction of non-textile elements (e.g. sensors, transmitters) in the garments or other textile products easily cause impaired haptic or other comfort properties, which might not be accepted by the markets and the end-users. A primary application area for smart garments is in the health care, where tight fitting underwear garments for the monitoring of body functions (heart rate, ECG, temperature) have been developed. Good haptic properties are particularly important for unhealthy or elderly persons with very sensitive skin.