International Research Journal of Engineering and Technology (IRJET)
e-ISSN: 2395-0056
Volume: 12 Issue: 01 | Jan 2025
p-ISSN: 2395-0072
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Heating, Ventilation and Air-Conditioning (HAVC) Systems: A Critical Review Ritik Singh Rawat1, Ankit Goyal1, Priyavrat Kumar1 1Department of Mechanical Engineering, Technocrats Institute of Technology and Science
Anand Nagar, BHEL Opposite Hathaikheda Dam, Bhopal, Madhya Pradesh 462021 ---------------------------------------------------------------------***---------------------------------------------------------------------
Abstract - HVAC (heating, ventilation, and air conditioning)
ASHRAE 55-2004 and ISO 7730 specify a "comfort zone" that takes into account both personal characteristics (clothing, activity level) and thermal components (radiant temperature, humidity, air temperature, and air velocity). Participants in controlled laboratory tests evaluated their level of comfort under static conditions, which served as the basis for these standards. Additionally, they set limits on the temperature differential between the neck and ankles; according to ASHRAE 55-2004, this difference cannot be greater than 5.4 degrees Fahrenheit [6].
Key Words:
The impact of different levels of thermal sensitivity on adaptive comfort models was investigated by Rupp et al. (2022) using information from the "ASHRAE Global Thermal Comfort Database II." They used five essential steps in their methodology: i) taking a pertinent subset out of Database II; ii) estimating the neutral temperature using conventional techniques.
systems are essential for maintaining comfort and good indoor air quality in a variety of environments, including homes and businesses. The HVAC industry is changing toward smart, sustainable, and energy-efficient solutions as a result of growing environmental concerns and technical advancements. With an emphasis on smart technology, energy-efficient designs, the incorporation of renewable energy sources, and advancements in air quality control, this article explores contemporary trends in HVAC. It also discusses the difficulties the industry faces and suggests possible avenues for further research.
HVAC (Heating, Ventilation, and AirConditioning), controllable environments.
1.INTRODUCTION Models of HVAC systems evaluate the electrical, heating, and cooling energy needs of their constituent parts using mass and energy conservation concepts. These three processes are combined in an HVAC system, which stands for heating, ventilation, and air conditioning [1–3]. It controls a building's ventilation, humidity, and quality. Room Temperature: Measuring devices that adapt to the needs of passengers are used to maintain the temperature in the passenger compartment [3]. Humidity: To keep passengers comfortable, the HVAC system regulates humidity levels [4]. Air Purification: The technology filters the air to get rid of dust and bacteria to improve passenger comfort. A key concept since the introduction of HVAC systems is "thermal comfort," which ASHRAE defines as a sense of contentment with the thermal environment. This comfort affects HVAC efficiency and is essential for health. According to Boyle's 1660s research, the average human body temperature is 37 degrees Celsius, with only a few exceptions. Excess body heat must be released via the skin to maintain a metabolic rate of 1 W/kg; during physical exercise, this rate can rise to 5 W/kg. This is equivalent to about 100 W during working hours for an average adult. When skin temperatures drop below 33 degrees Celsius, the body loses heat depending on a number of external conditions [5].
Griffiths' method consisted of the following steps: iii) iterating each step with new thermal sensitivity settings; iv) creating adaptive comfort models for both naturally ventilated and air-conditioned workplaces using data from Europe and the world; and v) assessing the different models created. The findings suggest that the temperature sensitivity of building occupants is influenced by various ventilation methods. In particular, office employees in naturally ventilated spaces were less sensitive to temperature fluctuations than those in climate-controlled spaces. One important conclusion is that geographic location and thermal sensitivity have a substantial impact on the "adaptive model relationship" between outdoor temperatures and inside neutral temperatures, with European occupants showing more sensitivity to temperature changes than those in other countries. Given that adaptive comfort standards are based on the adaptive model connection, this realization has significant ramifications for the planning and administration of naturally ventilated and mixed-mode buildings. As part of their investigation, [10] looked at a multi-person workplace with air-cooling equipment in Guangzhou, China. Researchers looked into the relationship between gender and different environmental variables and how these affected users' propensity to engage in adaptive behaviors. Using logistic regression, a probabilistic prediction study of
Air temperature is a crucial indicator of thermal comfort, but in order to properly evaluate heat stress, it must be considered in conjunction with other variables. In order to ensure at least 80% occupant comfort, current standards like
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