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Residential HVAC

Dry Air, Indoor Air Quality & Your Health

Dry air, IAQ and health

We tend to think about high humidity as a problem that impacts both our health and our comfort. However, dry air (caused by low indoor humidity) can cause just as much discomfort as humid air. In fact, recent research suggests that prolonged exposure to excessively dry air can even cause elevated stress levels.

Dry air may also compound the impacts of other indoor air quality problems. Some studies have shown that dry air increases the negative effects of high levels of particulate matter and VOCs. 

It’s worth paying attention to the relative humidity levels of the air you breathe, especially since most buildings are not monitored or controlled for humidity levels that are too low. There isn’t even consensus on what constitutes air that’s too dry, but many experts recommend optimal humidity levels between 35 and 60 percent.

Here are some health symptoms you may experience as a result of dry air in your indoor environment, plus steps you can take to fix the problem and feel better.

Physical effects from dry air indoors

Respiratory symptoms and infections

Your respiratory system often bears the brunt of the impacts from dry air. The mucus membranes in your nose, sinus passages, and bronchial passages get dried out when fluids evaporate. That leaves them more susceptible to irritation and infection. 

When people spend a lot of time in excessively dry air, they are more likely to experience symptoms of asthma, bronchitis, sinusitis, and even nosebleeds. 

Dry air also increases your risk of respiratory infections such as colds, the flu, or even Covid-19. Experts say that viruses can survive longer in dry air, and also dehydrated mucus membranes decrease your body’s ability to fight off infection.


It’s not only your respiratory system that gets dehydrated with long exposure to air with low humidity. Your eyes, skin and throat also feel the effects:

Eye irritation. Dry indoor air can cause dehydration of the tear film that protects your eyes, leading to irritation, dry eyes, itching, problems with contact lenses, and increased susceptibility to other eye conditions.

Throat irritation. Dehydrated tissues in the throat can lead to difficulty swallowing, throat pain and inflammation, as well as hoarseness and thickened mucus in the throat.

Skin irritation. Loss of moisture in the skin can cause not only discomfort, but also skin rashes and infections, such as eczema.

Increased stress response & decreased sleep quality

Did you know that dry air and poor indoor air quality can increase your body’s stress response? A US GSA Wellbuilt for Wellbeing study found that office workers exposed to dry air (with relative humidity levels below 30 percent) experienced 25 percent higher stress levels, as measured by cardiac activity. (Workers in environments with too much humidity also showed higher stress levels, but the effects were less pronounced.) Other studies have found a correlation between exposure to dry air and production of higher levels of the stress hormone cortisol.

The Wellbuilt for Wellbeing study also revealed an indirect link between dry air and sleep quality, since the workers that experienced more cardiac stress also showed reduced quality of sleep.

How to combat dry air in summer and winter

Add moisture to the air in winter

In the winter, air gets dry indoors because of heating systems that pump warm, dry air into the space. It can be challenging to make up for the lost moisture. If your heating system can accommodate it, you may benefit from installing a central humidification system that monitors the amount of moisture in the air and maintains the optimal humidity level in your space.

When the air is uncomfortably dry, the humidifier adds moisture (water vapor) to the air circulating throughout your space via your HVAC system. The central air or central heating humidifier, which is connected to your furnace and HVAC ductwork and also hooked up to your plumbing system, produces humidity by using water and heat from your furnace.

Learn more: The Inside Scoop on the Central Air Humidifier

Keep your AC from removing too much moisture in summer

Air conditioners cool the air by removing humidity from the air. Which, ideally, should leave you with moderate and comfortable humidity levels in your space. 

However, if your air conditioner is oversized for your space, or it has problems that are causing it to run constantly, you can easily end up with dry air in your space even in summer.

If you suspect that’s the case, have your air conditioning system inspected and maintained by qualified HVAC experts. They may be able to make adjustments or repairs that can better control humidity levels, improve your comfort, and even improve your health.

If you’re in the NYC metro area, Arista is here to help. Contact us today!