By Ryo Govila
Abstract:
Humans working in hot environments require suitable methods to stay comfortable while engaging in strenuous activity. These methods include wearing clothing optimized for permitting the dissipation of heat from the body, methods of active cooling using supplied power to run fans, and the ability for evaporation of sweat from the skin to take place. Using information from various research articles, this paper aims to determine the most suitable methods for ensuring thermal comfort in hot environments. It also explores quantitative methods of determining how comfortable certain methods and materials are to the wearer.
Introduction:
Blends of various textiles, alongside certain design guidelines, and various active cooling methods are employed to keep workers comfortable in hot environments. Proper clothing design can help prevent heatstroke, dehydration, and heat exhaustion, not only improving performance but preventing injury.
With more extreme climates predicted across the world due to global warming, and the popularity of real estate development in hot regions of the world such as the Middle East, the issue of clothing design for usage by construction workers in addition to other types of laborers is more important than ever.
This research analyzes the factors affecting comfort of certain aspects of clothing in these environments, the general guidelines to be used while designing articles of clothing for this method of usage, and the effects these aspects have on the comfort of the wearers.
Despite the fact multiple approaches to clothing design have been proposed, this research advocates for a variety of design principles, such as the clothing permitting the evaporation of sweat, the circulation of air within the clothing, and the permeability of the fabric. Textiles used should prevent the absorption of heat energy from the sun and be permeable by sweat to prevent wetness of the skin. All of these methods are used to ensure comfort.
Body:
Design Principles for Clothing
Active Cooling Methods
Following an analysis comparing 4 different design styles of personal cooling clothing, the effectiveness of different active cooling systems was researched. System one consisted of a hybrid cooling system which includes active ventilation and phase change materials. System 2 consisted of a variant of system one except with additional insulation. System 3 consisted of only phase change materials. System 4 consisted of a variant of system 3 except with additional insulation. System 1 was proven to be the most effective, with the lowest core temperature recorded between all trials after 90 minutes of exercise. (Udayraj et al., 2019)
This analysis demonstrates the effectiveness of active cooling during periods of elevated temperature. This may be adapted to add devices such as fans to future clothing designs.
General Design Insights
A paper aiming to develop a new uniform for construction workers in Hong Kong analyzed the suitability of 30 different fabrics alongside what design strategies should be implemented. Their findings found that the most suitable materials for thermal comfort include those which have a high permeability, and are able to keep the skin dry by permitting evaporation. It should also have sufficient UV blocking capabilities. In addition, clothing should be breathable and loose-fitting, while also being flexible. The color chosen should preferably be light. (Albert P.C et al., 2015)
These general design goals provide designers with methods of improving the thermal comfort of garments designed by them, and creates a design philosophy to be followed.
Common Difficulties and Trade-offs
During the design process, several challenges are faced while trying to optimize thermal comfort. Materials that are thin while reflecting heat have low thermal reflective ratios, making them inefficient. In addition, designers face challenges while trying to balance different functional aspects such as comfort and breathability, flexibility, and ability to absorb moisture in thin clothing.
Other challenges faced involve the complexity in the manufacturing process of the advanced materials used in thermal regulation clothing. To add to this, there are insufficient standardized scientific methods which can be used to objectively compare the suitability of different materials, making it difficult to directly compare different ones. (Peng et al., 2019)
Conclusion:
While designing clothing for thermal comfort, several methods may be employed to achieve this goal. Unique methods such as active cooling systems utilizing power may be used. In addition, choices have to be made such as the type of material used and what characteristics are desirable in said textiles. Clothing should also be loose fitting and lightly colored. Multiple challenges are faced while balancing these requirements, such as thin fabrics permitting thermal convection and radiation however with the downside of reflecting very little heat. There are also insufficient scientific methods to objectively compare multiple fabrics.
References:
Chan, A. P., Guo, Y. P., Wong, F. K., Li, Y., Sun, S., & Han, X. (2015). The development of anti-heat stress clothing for construction workers in hot and humid weather. Ergonomics, 59(4), 479–495. https://doi.org/10.1080/00140139.2015.1098733
Udayraj, Wang, F., Song, W., Ke, Y., Xu, P., Chow, C. S., & Noor, N. (2019a). Performance enhancement of hybrid personal cooling clothing in a hot environment: PCM Cooling Energy Management with additional insulation. Ergonomics, 62(7), 928–939. https://doi.org/10.1080/00140139.2019.1596318
Peng, L., Su, B., Yu, A., & Jiang, X. (2019). Review of clothing for thermal management with Advanced Materials. Cellulose, 26(11), 6415–6448. https://doi.org/10.1007/s10570-019-02534-6
