Air Conditioner Overuse Can Make You Sick?

August 18, 2020

A dry environment

London, Ontario summers can be hot, and humid, especially without an air conditioner but air conditioner overuse is not only a bad habit, but it can potentially make you sick. While it is certainly nice to come home to a chilled space, overusing an air conditioner can affect your health through the constant drying of the air. 

Air Conditioner Overuse Can Lead to Dry Air

The main problem that arises as a result of air conditioner abuse is dry air. But what is so bad about dry air? The answer is revealed by common skin conditions and ailments familiar to all Canadian winters. 

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Similar to cold air in the winter, dry air is the absence of moisture in the air.
As a result, the depleted air will absorb any moisture near it. Commonly, dry air absorbs moisture from our nasal passages and skin, which results in the following ailments:

  • Nose bleeds
  • Dry, cracking skin
  • Respiratory problems like asthma, sinusitis, and bronchitis 

How Does Air Conditioner Overuse Dry Out Air?

By default, the cooling of air involves removing moisture from the air in your home via condensation. Further, condensation happens because of the coils inside your AC. 

Humid air collects around these coils while the refrigerant chemical inside is constantly condensing and evaporating. This process of transforming gas into a liquid and vice versa removes moisture from the air. As a result, the remaining air is cooler, and the removed moisture condenses around the coils. Lastly, cold air is blown into the home, while condensed water is evacuated outside of the house. More information regarding how air conditioners cool down air can be found in our article, here.

The rate at which air becomes dry depends on the climate of the area you live in. Areas with higher humidity will require extensive abuse of an air conditioner to dry out the indoor air completely. 

How Do You Know If The Air In Your House Is Dry?

Aside from the symptoms listed above, there are a few other clues that indicate the air within your home may be depleted of moisture. 

Increased static electricity is a sign of air that is too dry.
Dry air provides an environment that encourages static electricity, which means more opportunities for being zapped. According to Ron Kurtis, “Static electricity is formed much better when the air is dry, or the humidity is low. When the air is humid, water molecules can collect on the surface of various materials. This can prevent the build-up of electrical charges” (Kurtis 2017) 

In other words, dry air conducts electricity better because fewer water molecules interfere with the build-up of electric charges on surfaces. If you notice yourself getting shocked more often than average, it may not be the fault of having a carpeted floor. 

Feeling dehydrated is a sign it is too dry in your home.
Since dry air has a natural tendency to absorb moisture from humans, it is clear that constant exposure can lead to dehydration. Breathing in dry air will absorb moisture from our naturally wet nasal passages, leading to cracked and dry sinuses. The same occurs even further through the body, including the entire respiratory tract, throat, and skin. This causes people to feel mummified when they wake up, and like they need to drink water continually. 

How Do I Stop My Air Conditioner From Drying Out The Air? There are two main ways to counteract dry air. 

Turn the AC off. Run it only when you really need to.
Turn off the air conditioner and let the natural humidity build up once again. While it may seem obvious, this conclusion is only evident if a person already has prior knowledge of how these processes work. As a rule of thumb, it is wise only to run the AC for short bursts until the desired temperature is achieved. With proper insulation, there should be no problems with keeping the cold air from escaping. So, there is no need to run the AC to maintain a comfortable temperature continually. 

Use a Humidifier
The second option involves using a humidifier to boost air moisture levels. A humidifier is a device that creates moisture by blowing hot steam into the surrounding environment. The same effect is seen when taking a hot shower in an enclosed space. Humidifiers are a great way to counteract the problems associated with dry winter air and are especially useful for basements. 

Open a Window
Another simple solution available during the summer months is to crack open a window. While this may not apply to places with dry heat, Ontario has plenty of outdoor humid air. Letting some of that warm, humid air in will replenish the moisture that was lost from overuse. 

Can Cold Dry air make you sick?

It is clear that dry air can cause dehydration and cracked skin, but can long-term exposure make you sick? Abusing an AC system can contribute to the following problems, which can increase your chances of getting sick in some way. 

  • Dried out nasal passages
  • Worsened allergies
  • Circulation of indoor pollutants
  • Vulnerable to catching colds

When the mucus membranes inside your nose are depleted, the skin begins to crack. The resulting wounds indicate an opening for bacteria and other infections to pass through and cause additional irritation. Even irritation of the respiratory tract can cause, or aggravate conditions related to allergies, asthma, and bronchitis. In other words, yes, constant exposure to AC air can make you catch a cold in the middle of summer. 

Depending on your home state, constantly running an AC can also expose you to indoor pollutants like mould, dust, or bacteria. This is because the AC is continuously filtering stagnant indoor air, which may contain toxic particles. 

Air conditioner overuse can affect your lung health. The following are illnesses related to air conditioner overuse.


Pink tubes of legionella bacteria on a cyan background. Air conditoner overuse can breed illnesses like legionella

A high-quality image of Legionella Bacteria

Legionella is a disease that is caused by a bacterium that can sometimes grow in air conditioning units. Its effects on the respiratory system characterize it, “Legionnaires’ disease is a severe form of pneumonia or lung inflammation usually caused by the Legionella bacterium” (Government of Canada, 2018). Common symptoms of legionella are cough, fatigue, fever, muscle aches, and diarrhea. 

Air conditioners’ significance in relation to the disease is that the bacteria can be “transmitted to people through inhaled water droplets.” While an overactive air conditioner will not directly cause legionella to grow, it can certainly increase infection rates by propelling more droplets. 

AC Lung

Diagram of a human lung. Legionella caused by air conditioner overuse can affect your lung health

Also known as hypersensitivity Pnemonitius, AC lung occurs due to exposure to allergens like mould, dust, hay, and bird droppings. As mentioned earlier, continually running the AC will lead to a perpetual circulation of stagnant indoor air. If allergens are already present, then this circulation increases exposure. 

AC lung is not dangerous if it is caught and treated early. Additionally, symptoms may improve simply by avoiding irritating substances. 


An air conditioner is a luxury of the 21st century and has helped improve our quality of life. Despite this, there is always the possibility of over-indulging in a good thing, especially ignorance. 

Using your AC unit in short intervals will ensure high performance, while also preventing the above problems that come from overuse. If the utility bill does not persuade you, then at least know that running an AC 24/7 is a tremendous waste of energy contributing to developing dry sinuses. 

Please contact our friendly staff at Plumbhouse Plumbing Heating and Electrical to ask more about your air conditioner options.

Works Cited:
Kurtus, Ron. “Basics of Static Electricity.” Basics of Static Electricity by Ron Kurtus – Physics Lessons: School for Champions, 2017,,the%20buildup%20of%20electrical%20charges.

Canada, Employment and Social Development. “Government of Canada.” Legionella in Heating, Ventilating and Air Conditioning Systems –, 27 Mar. 2018,

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August 18, 2020 1:55 pm

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