In short, the 20-degree rule of air conditioning states that you should always keep your AC unit at no more than 20 degrees lower than the outside temperature. It means that, if the outdoor conditions are at 95 degrees, you should set your thermostat at no less than 75 degrees.
You may have heard someone mention “the 20 degree rule” when it comes to your air conditioning unit. But what does that mean? Simply put, it means you should never set your thermostat for a temperature more than 20 degrees cooler than the outside air.
It is up to you!
Some will say 21-23 degrees is the best setting for ultimate comfort but at the end of the day it comes down to personal preference. It is important to keep in mind that some people tend to feel cold more than others.
Most air conditioning units are designed to go as low as 17°C, but do note that air conditioners are designed to achieve an inside temperature that is up to 11°C lower than the outside temperature.
According to the Department of Energy1, 78° Fahrenheit is the sweet spot for air conditioners to balance energy savings and comfort when people are at home and need cooling.
Technical analysis indicates that, in order to achieve the desired comfort level at a steady state, the temperature setting can be 24-25 degree celsius.
The Ideal Air Conditioner Temperature Setting Is 22-26°C
Most people find that a temperature range of 22-26°C is the ideal indoor temperature during the summer. Not too hot, not too cold, but just right. Studies have shown that for each degree you raise your thermostat, you can save 3-5% on cooling costs.
A recent article published by Canstar Blue suggests that the standard air conditioner's temperature should be set to 25 to 27 degrees for cooling in summer, and around 18 to 20 degrees for heating in winter. This is to ensure maximum energy efficiency from your unit.
How cold is too cold? Below 13° - If your home is this cold, it may increase your blood pressure and risk of cardiovascular disease. 14-15° - If your home is this cold, you may be diminishing your resistance to respiratory diseases. 18° - This is the recommended night time bedroom temperature.
If you're setting your air conditioner in cooling mode, doing so at lower than 21C will normally be regarded as too cold to have much impact and is generally wasteful of electricity.
A standard air conditioner's temperature should be set to 25 to 27 degrees for cooling in summer, and around 18 to 20 degrees for heating in winter. This is to ensure maximum energy efficiency from your unit.
On average, the best air conditioner temperature setting for summer in Australia is around 23℃ – 24℃ for comfort or 25℃ – 27℃ for maximum energy savings. In winter, reverse cycle heating should be set to around 18℃ – 20℃.
Everyone is different but from our experience 22°C for either cooling or heating modes is the consensus norm. There is no one correct answer, instead, it's best to consider everyone and find a balance between those who like it cooler and those who want some extra warmth.
You might be low on refrigerant or have a worn out motor or a dirty evaporator coil. Not all AC problems demonstrate themselves with loud sounds or funny odors coming from your system. Some of them simply reduce the AC's ability to run, and all you notice is less cool air in the house.
Wether you measure degrees Celsius or Fahrenheit: the lower the figure, the colder it gets. Minus 24 is lower than minus 16. If you convert to absolute temperature in Kelvin, you always get a positive number.
Without enough refrigerant, the evaporator coil inside your air conditioner gets too cold. As condensation forms, the cold evaporator coil turns this condensation into ice. That's why one of the biggest manifestations of a frozen AC unit is an evaporator coil that's turned into a block of solid ice.
For example, the ideal temperature of a living room should be around 20 to 22 degrees. This is a room for relaxing in, and where you sit for long periods of time, meaning it should be on the warmer side. Meanwhile, the best temperature for a bathroom or child's bedroom should be warmer too at 22 to 24 degrees.
Your house could be cold due to an old air filter, a faulty furnace, improper insulation, or leaky ductwork. The simple fixes, like replacing an air filter, are relatively easy to complete. However, if the heater itself needs repairs, it's best to call in a professional to take a look and determine the problem.
The recommended thermostat setting during winter depends on the time of day, and whether you are at home or not. The ideal healthy home temperature should be no higher than 20 degrees Celsius or 68 degrees Fahrenheit. When you're at home during the day, you'll be quite comfortable at this temperature.
What's the 20-Degree Rule? In short, the 20-degree rule of air conditioning states that you should always keep your AC unit at no more than 20 degrees lower than the outside temperature.
Answer: It is recommended that you set the temperature at about 25°C or higher. For every degree raised, you can save about $13 a year. Refer to this link for more energy saving tips.
Most experts recommend 18-20°C as the ideal temperature to set your air conditioner's thermostat in winter and throughout the year. This temperature is the most efficient in terms of energy.
As per the 18-page guideline, the temperature of the home-run AC should be between 24-30 degrees Celcius and the humidity should be between 40-70 per cent.
Choose the right temperature
People often think that setting the AC at 16 degrees will provide better cooling, but that's not really the case. As per the Bureau of Energy Efficiency (BEE), the ideal temperature for the human body is 24 and any AC will take less load to achieve that target.
According to the Department of Energy1, 78° Fahrenheit is the sweet spot for air conditioners to balance energy savings and comfort when people are at home and need cooling.