The sensation of feeling cool or warm is influenced by a combination of factors, including the ambient temperature, relative humidity, and our body's thermoregulation mechanisms. The perception of temperature is subjective and can vary from person to person. However, there are a few key reasons why we may feel cool in a room with air conditioning set to 23 degrees Celsius in summer and warm in a room with heating set to the same temperature in winter:
Temperature gradient: Our bodies exchange heat with the surrounding environment. In summer, when the air conditioning is set to a cooler temperature (e.g., 23 degrees Celsius), there is a significant temperature difference between the room and our body. Heat flows from our warmer body to the cooler room, resulting in a cooling sensation. In winter, when the heating is set to the same temperature, there is less of a temperature difference, so heat loss from our body to the room is reduced, resulting in a warmer sensation.
Thermal comfort: Thermal comfort is influenced by factors such as air movement, humidity, and personal clothing. In summer, air conditioning not only cools the air but also reduces humidity and provides air circulation, which helps evaporate moisture from our skin, enhancing the cooling effect. In winter, heating systems primarily aim to increase the ambient temperature, but they may not address humidity or air movement to the same extent, leading to a relatively drier and stagnant environment that may feel warmer.
Seasonal acclimatization: Our bodies can acclimate to different weather conditions over time. During summer, we tend to adapt to higher temperatures and become more tolerant of warmth, so a room set to 23 degrees Celsius with air conditioning feels cool and comfortable. In contrast, during winter, our bodies adjust to colder temperatures, making a room set to 23 degrees Celsius with heating feel warm, especially when we are bundled up in layers of clothing.
It's important to note that individual preferences, clothing choices, and activity levels can also affect how we perceive temperature. Additionally, personal comfort may vary based on factors such as age, health conditions, and metabolic rate.