Environmental assessment of thermal insulation composite material

Purpose

This paper presents life cycle assessment of planned mass production of the thermal insulation blocks (TIB) made of thermal insulation composite material (TICM) from secondary raw materials—glass and plastic. This material is being developed at Brno University of Technology, Faculty of Civil Engineering for use in structural details of (especially low energy or passive) buildings subjected to higher compressive loads. Two production modes depending on the quality of the input materials are compared.

Methods

The assessment is conducted using GaBi 4 software tool with inbuilt Ecoinvent database. The results of the assessment are presented in individual impact categories according to used characterization model (CML 2001—Dec. 07). All the necessary energy and material flows are specified in detail for the purpose of the assessment. Cut-off allocation method is used for allocating the environmental impacts of recycled materials. Part of the assessment is sensitivity analysis of one variable parameter—amount of TIB produced per year.

Results and discussion

The results of the assessment show decisive impact of used electricity source on the overall results—86.2 and 94.3 %, respectively, for both production modes. This is closely connected with quality of used secondary raw materials and design of the production line. Use of higher-quality materials, as well as changes of the designed production line can reduce the overall environmental impacts by almost 30 %.

Conclusions

The results show possible improvements in the planned mass production of the TIB. They also find that further investigation will be required before the start of mass production, especially in connection with improving the environmental impacts of used electricity sources.     

Studies on the thermal insulation effect of korean men''s folk clothes

1. 1. The purpose of this study was to obtain basic data necessary to design Korean folk clothes with comfortable thermal properties by carrying out the human wearing test under various ambient-temperature environments, by calculating the thermal insulation effect (TIE) of the Korean men's folk clothes (KMFC) on the basis of both material (silk, ramie and polyester) and season and by performing a comparative study with western style clothes.

2. 2. The results of this study can be summarized as follows: (i) the factor having an effect of the KMFC on the TIE is the air layer rather than the performance of materials, and (ii) the TIE of the Korean folk clothes confers a greater thermal resistance of the lower part of the body as compared with western style clothes.

Effect of air movement on the thermal insulation of avian nests

Capsule: Air movement over a nest increases the rate of cooling within the nest cup but the walls provide good thermal insulation.

Aims: This study compared nests of six bird species of the families Fringillidae and Motacillidae to investigate the insulative properties in still and moving air treatments. It was hypothesized that differences in nest size and moving air would differ between species and would have a significant effect on insulatory values of the nests.

Methods: Nest dimensions were measured for a total of 35 nests from six species. Thermal properties of the nests were recorded using temperature loggers within nests placed in a wind tunnel under still and moving air conditions.

Results: Insulatory values and internal nest cooling rates were significantly increased by moving air. There was no significant difference between species for the thermal properties of nests but nest mass correlated with greater insulatory values and a lower rate of cooling within the nest cup. Nest wall thickness had no significant effect on the thermal characteristics of the nests.

Conclusion: The use of a constructed nest mitigated the effects of air movement but the differences between species reflected difference in nest mass rather than wall thickness.     

Effect of pressure on thermal insulation in humans wearing wet suits

The present work was undertaken to determine the critical water temperature (Tcw), defined as the lowest water temperature a subject can tolerate at rest for 3 h without shivering, of wet-suited subjects during water immersion at different ambient pressures. Nine healthy males wearing neoprene wet suits (5 mm thick) were subjected to immersion to the neck in water at 1, 2, and 2.5 ATA while resting for 3 h. Continuous measurements of esophageal (T(es)) and skin (Tsk) temperatures and heat loss from the skin (Htissue) and wet suits (Hsuit) were recorded. Insulation of the tissue (Itissue), wet suits (Isuit), and overall total (Itotal) were calculated from the temperature gradient and the heat loss. The Tcw increased curvilinearly as the pressure increased, whereas the metabolic heat production during rest and immersion was identical over the range of pressure tested. During the 3rd h of immersion, Tes was identical under all atmospheric pressures; however, Tsk was significantly higher (P less than 0.05) at 2 and 2.5 ATA compared with 1 ATA. A 42 (P less than 0.001) and 50% (P less than 0.001), reduction in Isuit from the 1 ATA value was detected at 2 and 2.5 ATA, respectively. However, overall mean Itissue was maximal and independent of the pressure during immersion at Tcw. The Itotal was also significantly smaller in 2 and 2.5 ATA compared with 1 ATA. The Itissue provided most insulation in the extremities, such as the hand and foot, and the contribution of Isuit in these body parts was relatively small. On the other hand, Itissue of the trunk areas, such as the chest, back, and thigh, was not high compared with the extremities, and Isuit played a major role in the protection of heat drain from these body parts.     

Selection of building thermal insulation materials using robust optimization

The International Journal of Life Cycle Assessment - Life cycle assessment (LCA) is commonly used to analyze the environmental profile of a material and product. For example, the selection of...     

Studies on the thermal insulation effect of the Korean women's folk clothes

The purpose of this study is to examine the basic data useful for more comfortable folk clothes of Korean women, with respect to their thermal insulation effect. The result of this study is summarized as follows, by comparing the calculated thermal insulation effect of Korean women's folk clothes with that of the western style clothes. 1. The thermal insulation effect of the Korean women's folk clothes showed that summer clothes accounted for 0.67-0.93 Clo, while spring and autumn clothes showed 1.09-1.20 Clo. 2. Air layer had more effect on the thermal insulation of the Korean women's folk clothes than one of their material properties. 3. The thermal insulation of the Korean women's folk clothes features higher effect in the lower part of the body as compared with one the western style clothes, which act as an important factor in the thermal insulation.     

Effects of sea water on thermal insulation of the otter, Lutra lutra

Otters Lutra lutra L. which feed in the sea in Scotland frequently wash in fresh water. Experiments were carried out with otter pelts and with captive otters, to study the biological function of this behaviour. In vitro , the fur of otters lost much of its thermal insulation after five soakings in sea water and subsequent drying. Otters were fed in sea water or fresh water, with or without simultaneous access to alternative fresh water. When fed in sea water, otters used the alternative fresh water much more than when fed in fresh water, they were more reluctant to enter sea water if no alternative fresh water was present, and without this alternative fresh water they showed signs of hypothermia. After swimming in sea water the animals spent more time grooming and rolling. Without fresh water present the otters' fur lost its capacity for retaining air under water. These observations suggest an explanation for the restricted distribution of otters living along the coast, and for the lack of use of marine habitats by small mammals in general.     

The effects of nest size and insulation on thermal properties of tree swallow nests

The nest environment can have important influences on incubation behavior and nestling development in birds. Nest thermal properties, particularly nest composition and size, can have a major influence on heat loss. To examine the role of nest size and insulation on clutch cooling rates, we collected tree swallow Tachycineta bicolor nests and measured the cooling rate of eggs in a controlled thermal environment. We also examined the thermal benefits of nest feathers by comparing the cooling rates of nests with and without feathers. Nests with more feather insulation and heavier, deeper cupped nests cooled at slower rates. In addition, nests with feathers cooled at much slower rates than did the same nests without feathers. Our results show that nest insulation and size play important roles in nest cooling rates, which may ultimately affect incubation costs and thus reproductive performance.     

Changes in thermal insulation during underwater exercise in Korean female wet-suit divers

The present work was undertaken to examine the effect of wet suits on the pattern of heat exchange during immersion in cold water. Four Korean women divers wearing wet suits were immersed to the neck in water of critical temperature (Tcw) while resting for 3 h or exercising (2-3 met on a bicycle ergometer) for 2 h. During immersion both rectal (Tre) and skin temperatures and O2 consumption (VO2) were measured, from which heat production (M = 4.83 VO2), skin heat loss (Hsk = 0.92 M +/- heat store change based on delta Tre), and thermal insulation were calculated. The average Tcw of the subjects with wet suits was 16.5 +/- 1.2 degrees C (SE), which was 12.3 degrees C lower than that of the same subjects with swim suits (28.8 +/- 0.4 degrees C). During the 3rd h of immersion, Tre and mean skin temperatures (Tsk) averaged 37.3 +/- 0.1 and 28.0 +/- 0.5 degrees C, and skin heat loss per unit surface area 42.3 +/- 2.66 kcal X m-2 X h. The calculated body insulation [Ibody = Tre - Tsk/Hsk] and the total shell insulation [Itotal = (Tre - TW)/Hsk] were 0.23 +/- 0.02 and 0.5 +/- 0.04 degrees C X kcal-1 X m2 X h, respectively. During immersion exercise, both Itotal and Ibody declined exponentially as the exercise intensity increased. Surprisingly, the insulation due to wet suit (Isuit = Itotal - Ibody) also decreased with exercise intensity, from 0.28 degrees C X kcal-1 X m2 X h at rest to 0.12 degrees C X kcal-1 X m2 X h at exercise levels of 2-3 met.(ABSTRACT TRUNCATED AT 250 WORDS)     

Thermal insulation and body temperature wearing a thermal swimsuit during water immersion

This study evaluated the effects of a thermal swimsuit on body temperatures, thermoregulatory responses and thermal insulation during 60 min water immersion at rest. Ten healthy male subjects wearing either thermal swimsuits or normal swimsuits were immersed in water (26 degrees C or 29 degrees C). Esophageal temperature, skin temperatures and oxygen consumption were measured during the experiments. Metabolic heat production was calculated from oxygen consumption. Heat loss from skin to the water was calculated from the metabolic heat production and the change in mean body temperature during water immersion. Total insulation and tissue insulation were estimated by dividing the temperature difference between the esophagus and the water or the esophagus and the skin with heat loss from the skin. Esophageal temperature with a thermal swimsuit was higher than that with a normal swimsuit at the end of immersion in both water temperature conditions (p<0.05). Oxygen consumption, metabolic heat production and heat loss from the skin were less with the thermal swimsuit than with a normal swimsuit in both water temperatures (p<0.05). Total insulation with the thermal swimsuit was higher than that with a normal swimsuit due to insulation of the suit at both water temperatures (p<0.05). Tissue insulation was similar in all four conditions, but significantly higher with the thermal swimsuit in both water temperature conditions (p<0.05), perhaps due to of the attenuation of shivering during immersion with a thermal swimsuit. A thermal swimsuit can increase total insulation and reduce heat loss from the skin. Therefore, subjects with thermal swimsuits can maintain higher body temperatures than with a normal swimsuit and reduce shivering thermo-genesis.     

Comparison of thermal insulation performance of fibrous materials for the advanced space suit

The current multi-layer insulation used in the extravehicular mobility unit (EMU) will not be effective in the atmosphere of Mars due to the presence of interstitial gases. Alternative thermal insulation means have been subjected to preliminary evaluation by NASA to attempt to identify a material that will meet the target conductivity of 0.005 W/m-K. This study analyzes numerically the thermal conductivity performance for three of these candidate insulating fiber materials in terms of various denier (size), interstitial void fractions, interstitial void media, and orientations to the applied temperature gradient to evaluate their applicability for the new Mars suit insulation. The results demonstrate that the best conductive insulation is achieved for a high-void-fraction configuration with a grooved fiber cross section, aerogel void medium, and the fibers oriented normal to the heat flux vector. However, this configuration still exceeds the target thermal conductivity by a factor of 1.5.     

Morphological and thermal properties of mammalian insulation: the evolution of fur for aquatic living

Carnivora includes three independent evolutionary transitions to the marine environment: pinnipeds (seals, sea lions, and walruses), sea otters, and polar bears. All three lineages must contend with the thermal challenges of submersion in the marine environment. In the present study, we investigated changes in the fur associated with the transition from a terrestrial to an aquatic lifestyle, comparing fur characteristics among these lineages with those of semi‐aquatic and strictly terrestrial carnivores. Characteristics included gross morphology (hair cuticle shape, circularity, length, and density) and thermal conductivity. We found consistent trends in hair morphology associated with aquatic living, such that marine carnivores have significantly flatter (P < 0.001), shorter (P < 0.001), and denser hairs (P < 0.001) than terrestrial carnivores. However, sea lions, phocids, and walrus, which have thicker blubber layers than fur seals, have lower fur densities than fur seals (P < 0.001). Species utilizing fur for insulation in water also showed an elongation of hair cuticle scales compared to terrestrial species and marine species relying on blubber for insulation (P < 0.001). By testing pelts under hydrostatic pressure, we determined that flattening of the hairs, cuticular scale elongation, and increased fur density are critical characteristics for maintaining an insulating air layer within the fur during submersion. Overall, these results indicate consistent evolutionary modifications to the fur associated with the transition to aquatic living, as well as a decrease in fur function associated with a greater reliance on blubber in some groups. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, ?? , ??–??.     

Morphological and thermal properties of mammalian insulation: the evolutionary transition to blubber in pinnipeds

Carnivora includes three independent evolutionary transitions to the marine environment: pinnipeds (seals, sea lions, and walruses), sea otters, and polar bears. Among these, only the pinnipeds have retained two forms of insulation, an external fur layer and an internal blubber layer for keeping warm in water. In this study we investigated key factors associated with the transition to the use of blubber, by comparing blubber characteristics among the pinnipeds. Characteristics included gross morphology (blubber thickness), fat composition (fatty acid profiles, percentage lipid, and water), and thermal conductivity. Sea lions, phocids, and walrus, which have lower fur densities than fur seals, have thicker blubber layers than fur seals (P < 0.001). Comparisons of lipid content, water content, and fatty acid composition indicated significant differences in the composition of the inner and outer regions of the blubber between groups (P < 0.001), consistent with the hypothesis that phocids and sea lions utilize the outer layer of their blubber primarily for thermal insulation, and the inner layer for energy storage. Fur seals, by contrast, rely more on their fur for thermal insulation, and utilize their blubber layer primarily for energy storage. Comparing across carnivore species, differences in total insulation (fur and/or blubber) are influenced substantially by body size and habitat, and to a lesser extent by latitudinal climate. Overall, these results indicate consistent evolutionary trends in the transition to blubber and evidence for convergent evolution of thermal traits across lineages. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, ??, ??–??.     

Effect of relative humidity on fungal colonization of fiberglass insulation.

Fiberglass duct liners and fiberglass duct boards from eight buildings whose occupants complained of unacceptable or moldy odors in the air were found to be heavily colonized by fungi, particularly by Aspergillus versicolor. Unused fiberglass was found to be susceptible to fungal colonization in environmental chambers dependent upon relative humidity. No colonization was observed at relative humidities below 50%.