Effects of athletic T-shirt designs on natural ventilation

2016 ◽  
Vol 20 (2) ◽  
pp. 112-123 ◽  
Author(s):  
Chupo Ho ◽  
Jintu Fan ◽  
Edward Newton ◽  
Raymond Au
Keyword(s):  
Thermal Insulation ◽  
Moisture Transfer ◽  
Design Method ◽  
Air Gap ◽  
Thermal Manikin ◽  
Heat And Moisture Transfer ◽  
Content Type ◽  
Heat And Moisture ◽  
Air Circulation ◽  
Moisture Vapour

Purpose Maintaining air circulation between the wearer and garment layer is crucial for activating heat and moisture transfer from the body. If an air gap is trapped, air circulation may become ineffective and the ventilation of the garment is, thus, hindered. To maintain and extend the air gap, this study aims to propose a design method that involves placing spacer blocks underneath the garment to prevent the fabric from clinging directly to the skin. Design/methodology/approach To study the application of this design method, a series of T-shirts were produced and tested using a thermal manikin in standing and walking postures. All the T-shirts were made of fabric ostensibly manufactured to have high air permeability. Porous mesh fabric was used to construct the vented panels on the T-shirts. The test was conducted in a chamber with controlled temperature, relative humidity and wind velocity. Total thermal insulation (Rt) and moisture vapour resistance (Ret) were measured. Findings The test results showed that extension of the air gap between wearer and fabric provided higher ventilation to the wearer if the vented panels were also present on the T-shirts. Different placements of the vented panels on the T-shirts also affected the heat and moisture transfer from the thermal manikin. Research limitations/implications Due to limited resources, the evaluation of total thermal insulation and moisture vapour resistance was based on the testing result from a thermal manikin instead of any subjective wearer trial. Practical implications This research can contribute to the clothing designer who is developing function wear for a better ventilation. Social implications This research can contribute to the clothing designer who is developing function wear for a better ventilation. Originality/value This study aimed to further develop a new design concept in T-shirt design by improving the construction of the spacer blocks. Fabric with higher air and water vapour permeability was used to determine to what extent this design method is applicable to higher performance on heat and moisture transfer.

Experimental study of heat and moisture transfer in vertical air gap under protective clothing against dry and wet heat exposures

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yun Su ◽  
Miao Tian ◽  
Yunyi Wang ◽  
Xianghui Zhang ◽  
Jun Li
Keyword(s):  
Natural Convection ◽  
Protective Clothing ◽  
Moisture Transfer ◽  
Heat Exposure ◽  
Air Gap ◽  
Gap Size ◽  
Heat And Moisture Transfer ◽  
Content Type ◽  
Wet Heat ◽  
Heat And Moisture

PurposeThe purpose of this paper is to study heat and steam transfer in a vertical air gap and improve thermal protective performance of protective clothing under thermal radiation and hot steam.Design/methodology/approachAn experiment-based model was introduced to analyze heat and moisture transfer in the vertical air gap between the protective clothing and human body. A developed test apparatus was used to simulate different air gap sizes (3, 6, 9, 12, 15, 18, 21 and 24 mm). The protective clothing with different air gap sizes was subjected to dry and wet heat exposures.FindingsThe increase of the air gap size reduced the heat and moisture transfer from the protective clothing to the skin surface under both heat exposures. The minimum air gap size for the initiation of natural convection in the dry heat exposure was between 6 and 9 mm, while the air gap size for the occurrence of natural convection was increased in the wet heat exposure. In addition, the steam mass flux presented a sharp decrease with the rising of the air gap size, followed by a stable state, mainly depending on the molecular diffusion and the convection mass transfer.Originality/valueThis research provides a better understanding of the optimum air gap under the protective clothing, which contributes to the design of optimum air gap size that provided higher thermal protection against dry and wet heat exposures.

Design of polyester-elastane-cotton plated knitted components for hot and dry environment

2018 ◽  
Vol 30 (5) ◽  
pp. 657-667
Author(s):  
Varadaraju Ramakrishnan ◽  
Srinivasan Jagannathan
Keyword(s):  
Outer Layer ◽  
Linear Density ◽  
Moisture Transfer ◽  
Contact Layer ◽  
Cotton Yarn ◽  
Heat And Moisture Transfer ◽  
Polyester Yarn ◽  
Content Type ◽  
Skin Contact ◽  
Heat And Moisture

Purpose The purpose of this paper is to optimize the linear densities of polyester yarn and filament for inner layer and elastane for middle layer with cotton yarn outer layer in plain knitted plated structure for hot and dry environment clothing. Design/methodology/approach Three levels of polyester yarn linear densities (11.1, 8.4 and 5.6 Tex), filament linear densities (0.8, 1.55 and 2.3 Decitex) and elastane (0, 4 and 8 percent) with 14.75 Tex cotton yarn have been used to knit 15 single jersey plated fabrics based on Box and Benhens experimental design with same loop length. Three cotton–elastane core-spun fabrics were also produced. All the fabrics were analyzed for moisture and ergonomic comfort properties and wet fabric coefficient of friction. Findings The increase in elastane content and yarn linear density decreases water vapor and air permeability; the increase in filament linear density decreases wicking rate and water absorbency. The optimum solution is 5.55 Tex polyester yarn of 0.8 Decitex filament as inner layer and 14.75 Tex cotton yarn as outer layer which gives good heat and moisture transfer without stickiness. Research limitations/implications The implication of this paper is to study thinner polyester, polypropylene and polyethylene fabrics with more micro pores as skin contact layer for quicker heat and moisture transfer. Practical implications Outward wickability of sweat from the skin is the prime requirement of all skin contact layer fabrics. Social implications It shifts the social attitude of most comfortable fabric to polyester–cotton plated for hot and dry climate. Originality/value This paper employs a more practical method for the selection of fabric.

Effect of Different Initial Moisture Contents on the Characteristics of Coupled Heat and Moisture Transfer of a Reinforced Concrete-EPS Thermal Insulation Composite Wall in Harbin

2011 ◽  
Vol 250-253 ◽  
pp. 3044-3049
Author(s):  
Yu Gong Xu ◽  
Mei Lu ◽  
Zi Le Jia
Keyword(s):  
Reinforced Concrete ◽  
Thermal Insulation ◽  
Moisture Transfer ◽  
Heat And Moisture Transfer ◽  
Moisture Contents ◽  
Composite Wall ◽  
Condensed Water ◽  
Coupled Heat And Moisture ◽  
Heat And Moisture ◽  
The Heat Transfer Coefficient

This paper investigated the effect of different initial moisture contents on the characteristics of coupled heat and moisture transfer of a reinforced concrete-EPS thermal insulation composite wall in Harbin. The change of the moisture content with time and the change of the heat transfer coefficient with time of the reinforced concrete-EPS thermal insulation composite wall at different initial moisture contents in Harbin were numerically simulated. The relative humidity and the quantity of condensed water in the air layer of the reinforced concrete-EPS thermal insulation composite wall were also calculated. The paper provides a scientific proof for the influence of the process of construction of a reinforced concrete-EPS thermal insulation composite wall on the energy-saving of buildings.

Coupled transient heat and moisture transfer investigation of facade panel connections

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Bahram Abediniangerabi ◽  
Mohsen Shahandashti ◽  
Atefe Makhmalbaf
Keyword(s):  
Moisture Transfer ◽  
The Other ◽  
Heat Transfer Analysis ◽  
Thermal Resistivity ◽  
Heat And Moisture Transfer ◽  
Maximum Heat ◽  
Content Type ◽  
Hygrothermal Performance ◽  
Coupled Heat And Moisture ◽  
Heat And Moisture

Purpose The purpose of this study is to investigate the effect of panel connections on the hygrothermal performance of facade panels using a coupled, transient heat and moisture transfer analysis. Design/methodology/approach A coupled, transient heat and moisture transfer analysis has been conducted to investigate the effect of panel connections in the hygrothermal behavior of facade panels. Governing partial differential equations for the coupled heat and moisture transfer were formulated. Four panel connections proposed by pre-cast/pre-stressed concrete institute were modeled for the ultra-high performance fiber-reinforced concrete facade panel as illustrations and a finite element method was used to solve the numerical models. Findings The results of heat transfer analysis showed that steel connections could significantly reduce the thermal resistivity of facade panels by converging heat fluxes and acting as thermal bridges within facade panels. The results also showed that the maximum heat flux in the steel connector of the panel to foundation connection was 10 times higher compared to the other connections. Also, the results of moisture transfer showed that air gaps between the panels had higher moisture flux compared to the other layers in the models. The results show the significant importance of panel connections in the energy performance analysis of facade systems. They also highlight the importance of devising novel connection designs and materials that consider the transient, coupled heat and moisture transfer in the connections to effectively exploit the potential opportunities provided by innovative facade systems to improve building energy efficiency. Originality/value This paper, for the first time, investigates the effect of panel connections in the hygrothermal performance of building facade systems using a coupled, transient heat and moisture transfer analysis.

Development and trial of athletic T-shirt using spacer blocks to enhance ventilation

2017 ◽  
Vol 29 (5) ◽  
pp. 706-715
Author(s):  
Chu Po Ho ◽  
Jintu Fan ◽  
Edward Newton ◽  
Raymond Au
Keyword(s):  
Skin Surface ◽  
Air Gap ◽  
Comfort Level ◽  
Treadmill Running ◽  
Thermal Manikin ◽  
Design Development ◽  
Content Type ◽  
Air Ventilation ◽  
Ventilation Performance ◽  
Moisture Vapour

Purpose In previous studies, enlarging the air gap between fabric and the skin through the placement of spacer blocks has been proven to improve air ventilation, particularly when the pumping effect is activated during movement. These studies evaluated only the total thermal insulation (Rt) and moisture vapour resistance (Ret) by using a fabric thermal manikin. The purpose of this paper is to report the experience, perceived comfort level, and ventilation effect of two designed T-shirts in a wearer trial. Design/methodology/approach An athletic T-shirt (Vented Design) was designed by attaching spacer blocks to the underside of the fabric to enlarge the air gap. Eight subjects participated in the wearer trial, which comprised 30 min treadmill running, followed by 10 min of rest. At different points during the 40 min test period, subjects rated their body coolness, skin dryness, and overall comfort of the designed T-shirt. The testing was repeated with participants wearing the same T-shirt but without spacer blocks, which served as a control garment. The mean skin temperature of each subject was also measured to support survey findings. Findings The data were evaluated using independent t-tests. The T-shirt with spacer blocks provided higher ventilation than the control T-shirt after 10 min of running. Research limitations – because of limited resources, only eight subjects were recruited to this study. In addition, more T-shirt designs should be tested in the future to elucidate how T-shirt design affects ventilation performance. Originality/value This study investigated a T-shirt design wherein the air gap between the skin surface and fabric was increased. The results of the wearer trial showed that this design could be adopted as a design brief for further design development of related clothing. This study has implications for clothing designers developing functional clothing with improved ventilation.

Effects of hip protective clothing on thermal wear comfort of clothing ensembles

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Wiah Wardiningsih ◽  
Olga Troynikov
Keyword(s):  
Thermal Comfort ◽  
Thermal Insulation ◽  
Protective Clothing ◽  
Thermal Manikin ◽  
Content Type ◽  
Wear Comfort ◽  
Ensemble Performance ◽  
Clothing Style ◽  
Thermal Wear ◽  
Moisture Vapour

Purpose This paper aims to examine the influence of hip protective clothing on ensemble performance attributes related to thermal comfort. It also explores the effect on protective pads of various materials and the arrangements of material. The thermal comfort characteristics are thermal insulation and moisture vapour resistance. Design/methodology/approach For this research, four ensembles of clothing were used: one ensemble without hip protective clothing and three ensembles with hip protective clothing. A thermal manikin was used to test the thermal insulation and moisture vapour resistance of the ensembles. Findings The findings revealed that incorporating hip protective clothing into the clothing ensembles influenced the thermal resistance and moisture vapour resistance of the ensemble. In the “all zones group,” the influence of the hip protective clothing depended on clothing style, with hipster-style clothing producing insignificant changes. In the “hip zones group” and “stomach and hip zones group,” hip protective clothing strongly influenced the thermal comfort attributes of ensembles. Pad material and volume play important roles in these changes in thermal comfort attributes. Originality/value These outcomes are useful for the design and engineering of hip protective clothing, where maximizing protection while minimizing thermal and moisture vapour resistance is critical for wear comfort and adherence in warm or hot conditions. The designer should consider that material, volume and thickness of protective pad affect the overall thermal comfort attributes of the hip protective clothing.

scholarly journals The interaction of clothing ventilation with dry and evaporative heat transfer of jackets

2016 ◽  
Vol 28 (5) ◽  
pp. 570-581 ◽  
Author(s):  
Xiao-Qun Dai ◽  
George Havenith
Keyword(s):  
Heat Transfer ◽  
Forced Convection ◽  
Moisture Transfer ◽  
Heat Diffusion ◽  
Vapor Permeability ◽  
Heat And Moisture Transfer ◽  
Content Type ◽  
Dry Heat ◽  
Evaporative Heat Transfer ◽  
Heat And Moisture

Purpose The purpose of this paper is to investigate the effect of air and vapor permeability of jacket materials on ventilation, heat and moisture transfer. Design/methodology/approach Clothing ventilation (V), thermal insulation (I) and vapor resistance (R e ) of three jackets made of different materials (normal textile, PVC and “breathable” membrane coated textile), worn on an articulated thermal manikin in a controlled climate chamber, were measured under various conditions, respectively. The various conditions of microenvironment ventilation were created by making the manikin stand and walk, combined with three wind speeds of <0.2, 0.4 and 2.0 m/s, respectively. Findings In the condition without any forced convection, the air permeability makes no big difference to dry and evaporative heat transfer among the jackets, while the vapor permeability plays a big role in the evaporative heat loss. In the condition with forced convection, the dry heat diffusion is strongly coupled to the evaporative heat transfer in air and vapor permeable textile material. Research limitations/implications The effects of ventilation on heat and moisture transfer varies because of different ways of ventilation arising: penetration through the fabric is proven to be the most effective way in vapor transfer although it does not seem as helpful for dry heat diffusion. Originality/value The achievements in this paper deepens the understanding of the process of the dry and evaporative heat transfer through clothing, provides clothing designer guidance to choose proper materials for a garment, especially work clothing.

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