Thermal comfort along the aging process

Dive into age-specific thermal comfort needs, gender differences, and energy-efficient HVAC solutions for inclusive and sustainable indoor environments.

How does age impact our thermal comfort needs?


As people age, their needs for maintaining thermal comfort subtly change. Generally, newborns and babies are more vulnerable to subtle temperature changes, while older adults may require consistent warmer ambient temperatures.


Additionally, aging impacts various other aspects like muscle strength, sweating capacity, and reduced ability to move heat from a person’s core to skin, influencing how the body regulates its temperature. Studies show that we perceive temperature differently at different stages of life and depending on different circumstances and scenarios, making it clear that age plays a significant role in determining what constitutes a comfortable thermal environment.


In this article, we look at the link between age and thermal comfort during certain stages of life.


Defining Thermal Comfort: Thermal environment and human perception


Before we do, how is thermal comfort defined? Within indoor environments, it’s understanding how our bodies perceive and react to temperature, humidity, and air movement. This balance is influenced by both the physical conditions of our surroundings and our personal attributes. While standard measurements of thermal comfort exist, each person's response to temperature varies based on their physiology and psychology, and how it makes them feel or act.


Importance of optimal indoor thermal comfort for health and well-being 


Maintaining a comfortable indoor temperature is key for our health and, therefore, our feeling of well-being. When the temperature is just right, which, according to ASHRAE, can range between approximately 20 and 27ºC, people tend to feel better, more comfortable, and are more productive at home or in the workplace. The ideal indoor temperature will vary depending on outside conditions, the building, who’s in it and their activity level.


There are instances where your own thermal comfort may need to be compromised in order to help meet the thermal comfort needs of others. Luckily, simple things like changing what we wear, using a fan, air conditioning, or opening a window can help us adjust and meet in the middle.


Aging: One of the main factors affecting thermal comfort   


A blend of environmental and personal attributes contribute to the factors affecting thermal comfort. Among these, age plays a significant role. It subtly impacts our thermal comfort needs as we grow and change. But how? Let’s find out.


Unique Aspects of Thermoregulation in babies and toddlers           


Babies and toddlers have unique needs when it comes to maintaining their body temperature, differing notably from adults. Foremost, is that they don’t have the capability to adjust the environment around them or the know-how to add or remove layers to improve their own thermal comfort. Their body structure, with a larger surface area relative to weight, makes them more vulnerable to temperature changes. This aspect of thermoregulation is particularly significant in newborns.


Thermal comfort requirements for toddlers and babies 


Thermal comfort requirements for toddlers and babies involves keeping them at a temperature that is neither too hot nor too cold. Since babies lose heat faster than adults, don’t have the skills to regulate their own temperature, they find it harder adjusting to temperature changes. Though there are many studies, generally a baby will start to regulate their own body temperature from 9 - 12 months old, however even then it's important that a steady temperature is maintained around them. This is because it’s not just about comfort, it’s about their safety.


Too hot and a baby can overheat leading to uncomfort and grave issues, too cold and they are at the risk of developing hypothermia.

Kids enjoying and jumping on a couch at home.

How do HVAC and thermal conditions affect babies' and toddlers' sleep


HVAC systems and thermal conditions have a noticeable effect on babies' and toddlers' sleep. They find it harder to keep their body temperature steady, so they need a room that stays between 20ºC to 22ºC helps. If it's too warm, they might not wake up easily; if it's too cool, their sleep might not be as deep. Using residential AC and their latest functions help keep a room's temperature more consistent. In places where the weather changes a lot causing fluctuations in indoor temperatures, making sure the room’s thermal conditions stay the same can help babies and toddlers sleep better, and safely.


Thermal comfort factors for children and teenagers       


In everyday life, thermal comfort factors affect children and teenagers in different ways. At home or while playing outside, the right temperature makes a big difference in how they feel and act.


When it's too hot or too cold, they might become restless or unable to focus on tasks, especially when inside. Comfortable temperatures help them to be more relaxed and engaged in activities. For example, during a family movie night or while doing homework, being in a room with a pleasant temperature can make the experience more enjoyable, aiding concentration. It’s about creating the right environment where they can learn, play, and rest without the distraction of feeling too warm or too cool.


Understanding Growing Bodies: What role does growth have in children's and teen's thermal comfort?


Aging influences how children and teens react to thermal comfort factors. As their bodies develop, their metabolism and surface area-to-volume ratio changes. This means they may feel colder or warmer at different stages compared to adults.


For instance, younger children might get chilly more quickly due to less muscle mass, which affects heat production, and teen’s that are more developed may have more thus feeling warmer more easily. Also, puberty can cause increased sensitivity to cold or heat, making it more difficult to identify the optimal indoor temperature.


It's useful to consider these changes when thinking about their comfort. Simple adjustments in clothing or room temperature can help in maintaining their comfort, especially in environments where concentration is required, like school.


School Environments and Thermal Comfort: Enhancing Learning Experiences  

School environments greatly benefit from optimal thermal comfort and air quality achieved by balancing the factors previously mentioned: temperature, humidity, and airflow. It helps students concentrate and improves the overall learning environment.


Uncomfortable temperatures can distract and impede learning. Similarly, good indoor air quality does help increase and facilitate studying. Beyond thermal comfort, it prevents health issues like eye irritation or asthma.


Simple measures, like proper ventilation and efficient air conditioning, can create healthier, more comfortable learning spaces. According to ASHRAE, in locations with defined seasons, classrooms should have a minimum temperature of 22ºC (72ºF) in winter and 24ºC (75ºF) in summer, and relative humidity between 40%-60%. What’s more, a secondary result of correct temperature and ventilation is improved efficiency. In essence, a well-managed school environment enhances student well-being, learning outcomes and efficiency.



Comfort temperature for adults: challenges and considerations


Maintaining a comfortable temperature for adults is important, especially as aging affects the body's ability to regulate heat. Adults typically maintain a body temperature around 37°C (98.6°F), but aging reduces the effectiveness of natural cooling and heating mechanisms. As we get older, we are less active, slowing down our metabolic rate. 


That said, adults, similar to teens react to different temperatures and act in different ways. Too hot anxiety and stress levels increase, too cold generally we become more lethargic. This in some situations can create tensions. Just take the workplace, for example.

 Couple sitting on sofa drinking coffee and looking at digital tablet

Thermal comfort in the workplace: Balancing Individual Preferences and Office AC Solutions


Adjusting the temperature in a workspace is important for both comfort and productivity. It's not just about the air temperature; it's also about how this temperature affects our bodies and minds. When it's too cold or too hot, it can be harder to concentrate and complete tasks efficiently. This can impact not only work but also our social interactions and overall mood.


In the workplace, the recommended temperature range varies with the season, ASHRAE suggests 21°C to 24°C in winter (70ºF to 75ºF) and 24°C to 27°C in summer (75ºF to 80ºF). Regular ventilation is also key for maintaining a healthy and energy-efficient environment. Modern technology, like advanced air conditioning systems, can help create a comfortable atmosphere that enhances productivity and well-being​​​​​​​​.


But one person’s thermal comfort can be different to that of another, with many factors at play, including gender.


Male vs female body temperature: How to get a balance in HVAC settings


In workplaces, balancing male and female temperature preferences is a challenge. AC zoning allows different areas of a workplace to have customized temperature settings. It enhances energy efficiency by allowing specific control over each zone and optimizes energy based on occupancy. This system also improves indoor air quality, benefiting health and productivity. It addresses the diverse comfort needs of employees, improving their well-being and productivity by reducing temperature-related stress and health risks. In summary, a zoned AC system can be an effective solution to the issue in workplaces, offering different temperatures to different areas.


But what is that makes men more susceptible to warmer temperatures?


Why are men warmer than women?

This question touches on a common observation: men often feel warmer compared to women in the same environment. A key reason lies in the metabolic rate.


Women generally have a lower metabolic rate, meaning they produce less heat than men. This is why women might feel colder and reach for a sweater more often. Men, with more muscle mass, generate more heat, creating their own 'heat islands'. This difference is even reflected in thermostat preferences: men might be comfortable at 22ºC degrees (72ºF), while women often prefer it around 25ºC degrees (77ºF).


Interestingly, these differences tend to even out as people age. After menopause, women's comfort with cooler temperatures returns, and as men lose muscle mass, they might start feeling colder in temperatures they once found comfortable​​.


How to achieve optimal indoor thermal comfort at home    


To achieve optimal indoor thermal comfort at home, consider these key points:

  • Set your AC between 20ºC - 23ºC (68ºF - 74ºF) in winter and 22ºC - 27ºC (72ºF - 80ºF) in summer.
  • For sleeping, aim for cooler temperatures around 18ºC (65ºF).
  • Keep humidity levels down, between 30% and 60% is ideal.
  • Use ventilation to enhance comfort without altering temperature, and remember that room occupancy and activities can affect warmth.


What is the ideal room temperature for an elderly person?           


Determining the ideal room temperature for an elderly person involves balancing comfort and safety. Research suggests that the safe temperature range for older adults is between 18ºC and 25,5ºC. It's important to consider individual comfort levels and adjust the temperature accordingly within this safe range​​.


Tips for the correct room temperature for elderly people      


Ensuring optimal room temperature and ambiance for elderly individuals requires careful attention:


  • Maintain Adequate Temperature: Keep indoor temperatures above 18°C, to avoid cold-related health risks.
  • Efficient Heat Retention: Use cost-effective methods, in locations where colder temperatures are common, like draft excluders, thick curtains, and heat-reflective foil behind radiators to improve room warmth.
  • Balance Room Temperature: Regularly monitor to ensure a consistent, moderate temperature using controllers for comfort and health.
  • Minimize Draughts: Seal drafts around windows and doors for warmth and energy efficiency.
  • Customize for Comfort: Adjust temperature based on the elderly person's individual preferences and comfort needs.


These are applicable for the home and care facilities for the elderly.


The right HVAC system can make maintaining the right temperature easier. Clean air is important too, so using good air filters and keeping up with regular maintenance can keep the air fresh. You can read about the role of air conditioning in healthcare facilities, here.


 Happy grandparents talking to their grandkids at dining table.


Role of HVAC Systems in Regulating Indoor Thermal Comfort           


HVAC systems control temperature and humidity, and many help reduce airborne dust and dirt, making our indoor spaces more comfortable in all manner of locations and weather conditions. Modern systems not only make it easier to create the ideal indoor ambiance but they have features and functions that mean maintaining this ambiance is more efficient.


Balancing comfort, efficiency, and cost-effectiveness with Hitachi residential AC's


Hitachi residential ACs put a variety of features at your disposal to help you achieve the optimal indoor thermal comfort, easily. Not only do they feature simple controls that make adjusting the temperature and operating mode effortless, some Hitachi residential AC’s come equipped with technology that takes care of your comfort for you.


One of these functions is the Smart Eco mode, designed to balance comfort and energy efficiency. This mode adjusts the temperature based on occupancy: when a room becomes vacant for over 20 minutes, it modifies the set temperature to a more energy efficient one. Then, when the room becomes occupied again, it returns to the set temperature, ensuring a pleasant environment without unnecessary energy use.


The SleepSense function, previously called "Air Sleep" or "iSense," is another feature that enhances comfort, particularly during sleep. It regulates the temperature of the system to match the natural drop in body temperature during sleep, promoting better rest.


Additionally, Hitachi offers the AirCloud Go app, allowing users to monitor and adjust their home temperature remotely, providing convenience and control over their indoor environment.


You can find out more about Hitachi residential AC and their functions, here.



Underlined References: Library/Technical Resources/Technical FAQs/TC-02.01-FAQ-92.pdf library/technical resources/free resources/design-guidance-for-education-facilities.pdf


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