As outdoor temperatures change, so do humidity levels. Relative humidity is a way to measure the amount of moisture in the air. For optimum comfort, your home’s relative humidity should at or near 40 percent. The weather outside can affect the relative humidity in your home, as well as your HVAC system.

During the chilly winter months, outdoor humidity decreases. This drop in relative humidity can cause problems for some people with sensitivities. When the air is dry outside, it can cause the humidity inside to drop, too, affecting your indoor air quality. When indoor air dries out, you may notice your skin may become dry, your nose may run, and you may feel unusually thirsty.

Causes of Dry Indoor Air

When the weather starts to become cooler, the air contracts which lowers its ability to hold moisture. When outdoor temperatures drop, dry air blows in through open doors and windows, causing your home’s relative humidity to fall.

Indoor habits can also affect relative humidity and indoor air quality. Turning on your HVAC system forces the drier air outside into your home’s interior. This, in return, lowers the moisture levels in your home.

How Dry Air Affects Your Health

Bacteria, viruses, and certain allergens spread more easily in dry conditions. Since most people spend more than 80 percent of their lives indoors, it’s important for your health to know when indoor air is too dry.

Your respiratory system, including your nose, throat, and lungs, is covered in mucus, a fluid designed to protect your body from potentially dangerous airborne particles. When you breathe dry air, it causes this protective fluid to thin, lessening its protective quality. This makes it easier for your airways to become irritated or swollen and increases your risk of infection.

Since cold air also causes your body to produce histamines, the combination of cold air and low humidity can have several adverse effects. These include:

• Cough
• Runny nose
• Wheezing
• Sore throat
• Nosebleeds
• Dry skin
• Nasal congestion
• Thirst
• Fatigue
• Increased asthma symptoms

These are also common cold and flu symptoms, so dry air may not be the only cause. However, if you start noticing these symptoms every time the weather cools down or only when you are indoors, dry indoor air may be the culprit. Also, since dry air makes it easier for the flu and colds to spread, paying attention to indoor humidity levels in important.

Preventing Dry Air Problems

There are steps you can take to help protect yourself from the adverse effects of dry air. Implement some of these actions to improve your indoor air quality and help you find relief.

1. Monitor the humidity level in your home. This lets you know when the indoor relative humidity is too high or too low.
2. Use your HVAC system and a humidifier. Keeping the relative humidity at or around 40 percent is optimum. You can use a standalone humidifier or a whole house humidifier to help you maintain comfortable moisture levels.
3. Turn fans on low. As air circulates it can dry out the air and your respiratory system’s protective mucous. To help prevent this, turn fans on low or completely off, especially when you are sleeping.

Dry air can cause some uncomfortable problems. However, by implementing these actions, you can help keep the humidity inside your home at a comfortable level.