Thermal comfort study of air-conditioned university laboratories

Sharma

2022

Hum Ftrs & Erg Mfg Svc

In an indoor kitchen environment, proper installation of supplying air system is essential for maintaining optimal human thermal comfort level. Current thermal comfort investigation has been accomplished during "various cooking periods (breakfast, lunch, snacks, dinner)" inside the air-conditioned kitchen environment of railway pantry car in India. The study goals to improve thermal comfort inside the pantry kitchen by implementing proper installation of the supply air system. A field experiment and computational fluid dynamics approach has been carried out during the summer season. Also, standard effective temperature (SET) index was utilized to determine the thermal comfort status. Three proposed design modified cases of pantry cars (based on supplying air system concepts) have been executed followed by validation and comparison with the existing case model. Results revealed modified Case III as a better design concept (indicating better air supply circulation and temperature decrease at the desired location) compared to the existing and other two proposed cases. Simultaneously, the SET index range was 26.5-28.6°C; indicating "comfortable thermal sensation throughout the cooking period." This study's outcomes suggest improvements in thermal comfort and energy savings of "airconditioned" pantry car kitchens in "Indian Railways" that could be referred directly.

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Investigating thermal environment inside the kitchen of air‐conditioned pantry car on Indian Railway using CFD

Sharma

2022

Hum Ftrs & Erg Mfg Svc

“…The comfortable range of MRT for official occupants 18°C-27°C, which varies on the person's clothing and activity level. Some researchers have used MRT to equal the mean dry-bulb air temperature in the buildings, kitchen environments, and others when calculating thermal comfort indices because of the difficulty in predicting MRT [97][98][99]. This will be considered keeping in mind the above-described conditions of MRT for the estimation of thermal comfort indices of occupants while working in the pantry car.…”

Section: Mean Radiant Temperaturementioning

confidence: 99%

Factors affecting on human thermal comfort inside the kitchen area of railway pantry car - a review

Journal of Thermal Engineering

2021

Railway transportation plays a significant contribution to carrying passengers in India. In which during the journey, pantry cars are involved to serves the food to all onboard passengers. The kitchen atmosphere of the pantry car gets very hot and humid during cooking which could affect occupants' thermal comfort. Therefore, the current research article describes a review of the factors affecting human thermal comfort inside the kitchen of the railway pantry car. The factors influencing of human thermal comfort inside pantry car kitchens are classified into two categories viz; environmental factors that include "air temperature, mean radiant temperature, relative humidity, air velocity" and personal or individual factors including "metabolic rate and clothing insulation". All these factors need to be considered in order to achieve the optimum level of thermal comfort inside the kitchen environment of the pantry car. With the assistance of all these factors, we can estimate the thermal comfort indices such as; SET "standard effective temperature, " PMV "predicted mean vote, " PPD "predicted the percentage of dissatisfied, " thereby recognizing the acceptable thermal sensation range for occupants' (chefs) in the pantry car kitchens during the work period. These kinds of parametric studies can cover a wide group of all pantry car chefs in evaluating thermal comfort. Furthermore, there is a need to apply all the consequences of this research to increase the chef 's thermal comfort inside the pantry car kitchen while working.

“…In the AC pantry car kitchen also, the total votes of chefs voted to the hot and warm side. Although there were also no chefs, who responded to feel cool inside the pantry car kitchen, as per the ASHRAE 55 standard [22] for thermal comfort requirements, the subjective responses should follow the central three categories (-1, 0, +1) votes [25]. But in the present research, the chefs' votes do not follow the central three categories of votes during the working hours inside both pantry car kitchen, which indicates a high thermal dissatisfaction rate of the working environment condition for workers.…”

Section: Subjective Evaluationmentioning

confidence: 99%

“…Both pantry car results indicated that chefs do not accept the existing environment scenario during the entire working time. According to ASHRAE (2004) standards, for thermal comfort, the percentage of thermal acceptability votes of occupants must exceed 80% in any hot and humid environment [25], [26], [27]. The subjective responses of chefs show that there is no difference between the two types of railway pantry car kitchen environments while preparing food.…”

Section: Subjective Evaluationmentioning

confidence: 99%

Appraisal of Thermal Comfort in Non-Air-conditioned and Air-conditioned Railway Pantry Car Kitchens

Muthiah

2020

IJIE

This study details the consequences of a thermal comfort survey conducted in N-AC "Non-Airconditioned" and AC "Airconditioned" pantry car kitchens in Indian Railways. The research was carried out on 6 railway pantry car kitchens in which 29 chefs participated. Field measurement and subjective evaluation techniques performed in this study during the working period of chefs. The aim of the present research to compare N-AC and AC railway pantry car kitchen. While the objective of the study was to determine the thermal comfort parameters "air temperature, mean radiant temperature, relative humidity and air velocity" of both pantry car kitchens and examine the subjective responses; and to evaluate the thermal comfort of both pantry car kitchens using the PMV "Predicted Mean Vote" and PPD "Predicted Percent Dissatisfied" indices and compare them with actual sensation votes. A result of this study revealed that all thermal comfort parameters do not comply with the recommended ASHRAE 55 Standard in both pantry car kitchens. There is no considerable difference between both pantry car kitchen based on the subjective assessment during the working period and all the chefs' votes were found to be outside the range of the ASHRAE 55 central three categories (-1, 0, +1) votes. Which indicates that the chefs are not satisfied with the current environment. While for N-AC pantry car, PMV and PPD value estimated were 3.10 and 99% respectively, with "hot" thermal sensation. Similarly, for AC pantry car, PMV and PPD value estimated were 2.21 and 85% respectively, with "warm" thermal sensation. The estimated values of PMV and PPD do not follow the ASHRAE-55 2017 and ISO 7730 standard. Therefore, PMV indices are not directly applicable for thermal comfort application in a pantry car kitchen environment due to high temperature. In both the pantry car kitchen, there is no difference between predicted and actual sensation votes. In further establish the other method and technique to identify the comfort temperature for better workmanship of chefs in a pantry car kitchen.