Studies on Tropical Conditions in Hot Sunny Days in India and Their Effects on Interior Temperature Rise in Truck Cabin

Abstract

Most of the tropical countries experience heat suffocations inside the commercial vehicles when soaked in sunny hot days. The solar heat radiation pass inside the vehicle cabin by convection, conduction, and radiation through roof, side panels, glass windows and windshield when all windows are kept closed. Even the heat dissipation to inside of cabin takes place from the engine compartment. The solar radiations are composed of IR, UV and visible rays which generate heat and is absorbed by the interiors to give rise of truck cabin temperature to as high as to 70–80 °C as stated in the review articles. This heat suffocation is injurious to human health and in particular to growing kids. There are many reported cases of children and pets dying due to suffocation of heat. In addition it also deteriorates durable life of interior components like seats, upholstery and dashboard. In India, the similar study, as done elsewhere in the world is required to understand the effects of hot weather conditions in different parts of the country and thus design for on i-cool system that is affordable for a common man to control interior cabin temperatures, other than use of air conditioning system. With this background to design an innovative i-cool system, the project was carried out to study temperature and humidity conditions in major metropolitan and hottest 15 cities in India to determine maximum temperatures during period of March to June interval. The mathematical modeling was used to determine peak temperature and total heat content that gets accumulated during 3 h from 10 am to 4 pm at intervals of 10, 20, 30, 60, 90, 120, 180 min of soaking of vehicle on the road respectively. CFD FLUENT software package was further used to determine temperature distribution inside the cabin at various locations such as dashboard, seats, roof and Windshield for soaking of vehicle for the duration of 30 min at peak temperature for the selected Metropolitan city, viz. Chennai because of the reasons that it is the second largest hottest and humid metropolitan city in India. Moreover, after Rajasthan and Gujarat, Tamil Nadu receives more solar radiations and also truck population is one of the highest in the country. The mathematical analysis was conducted and it show that the interiors of truck cabin reaches as high as to 56–78°C within 30 min of soaking of vehicle under the solar radiations during the peak summer days from ambient temperature of 40 and 47 °C respectively. The results are alarming and to design of system to control interior temperature to comfort zone, various i-Cool materials like—Phase Change Materials (PCM), Thermoelectric Materials (TEM), and Organic Dye Cell Materials (OCM) are required to be studied as a future work for their critical properties, availability and cost along with an innovative integration system.