Have you ever woken up sweating in the middle of the night or felt frozen with the air conditioner on in the evening? Thanks to our metabolic cycle, our body prefers different temperature settings throughout the day.
The main problem with traditional ACs is that they only allow setting a single temperature, foregoing other crucial factors that may significantly affect how we feel. According to ASHRAE (American Society of Heating, Refrigerating and Air-Conditioning Engineers), aside from temperature, all of these components make up our thermal comfort: Indoor Humidity, Thermal Radiation (Sunlight) and Time of Day. Another super important factor that isn't on ASHRAE's list but is definitely a big player, is Outdoor Weather. Different combinations and levels of each factor create a shift in our environment, and ultimately in how we feel.
To make things a bit easier to understand, we’ve created the Factor Series – focusing today on one that many of us feel but can’t quite put our finger on: Time of Day.
How does time of day and our routine govern how we feel?
After living on earth for millenniums, humankind has developed a certain routine called the Circadian Rhythm, which basically means our body follows the schedule set by the sun - keeping us awake and active during the day and sleepy when night falls. However, aside from this basic primitive schedule, each person now has a unique routine based on when and what they eat, their activity level, hours of rest or excitement and general lifestyle; how we feel is still individual, creating a need to understand how time of day affects our body temperature, energy levels and degrees of comfort.
Why is time of day crucial when it comes to our comfort?
Our body temperature correlates with our energy level, which fluctuates throughout the day. Your home environment, level of activity, predisposed genetic characteristics and basically anything in your daily routine will cause your energy levels to fluctuate at different times and under different conditions. For example, we typically have a higher body temperature during the day and in the afternoon since our body needs to perform and be alert, and we have a lower body temperature in the late evening because we are generally less active towards bedtime.
When trying to compensate for these fluctuations by using the AC, many will find that they need to constantly adjust the temperature and other settings in order to maintain an acceptable environment and stay comfortable, which turns out to be quite the task!
What are some comfort problems we may face?
Each person has different temperature preferences throughout the day because of unique metabolic rates and various habits; activities like having a meal, working out or walking back home from work each night will either raise or lower our body temperature. Thus, some may like a warmer temperature at home since they take cold showers in the morning, and some like to turn the AC temp down after they’ve eaten lunch around the same time each day.
These contrasting habits will determine the different room temperature we need throughout the day in order to optimize our comfort and will require our AC to “behave” and fill the gap so that we’re not left too cold or too hot.
Another comfort problem we face is the peak and trough of our body temperature. According to the US National Institute of Health, our body temperature is the highest around 6pm and drops to the lowest around two hours before we wake up.
Because traditional air conditioners aren’t able to auto-adjust based on time of day or our routine, major comfort problems arise. These could include being too hot in the afternoon or early evening, not feeling comfortable throughout the night or waking up super cold with an AC that has been set to the same low temperature all night and wastes a lot of energy overcooling us and our home!
What can I do to make sure my air conditioner performs and efficiently keeps me comfortable throughout the day?
There are a few things you can try to do to minimize energy waste and the discomfort that comes from the gap between the fluctuation of our body temperature and our AC’s limited capabilities:
- Turn off the air conditioner and use a fan instead
- Keep adjusting your AC whenever you feel warmer or cooler
- Purchase different blankets for different seasons, or one that’s good for all four
- Try setting the air conditioner at a higher temperature and see how you feel
Seems that the methods above aren’t foolproof; how can I improve my air conditioner so that it takes time of day into account?
Since a traditional air conditioner can’t really auto-adjust and consider our routine, habits, daily schedule and lifestyle to provide the optimal temperature and humidity conditions, either we’re left with clumsy and bothersome solutions, or we can choose to upgrade our existing AC and make it smarter.
Doing this could be fairly easy with a smart AC controller that would take time of day and other factors into account - including sunlight, humidity and outdoor weather - and optimize your air conditioner. When choosing a smart controller, your ideal choice would be one that learns from your feedback and adapts to your unique patterns, accounting for your daily and hourly preferences and allowing you to always sleep like a baby and be comfortable at any given time.
