What is Relative Humidity?

The air we breathe contains different particles besides oxygen and nitrogen. These include water vapors and harmful impurities that affect our daily lives. Whether in your office, at home, or outside in nature, the air quality influences how you feel. If it is too dry, you may feel irritation, and if it is too humid you feel sticky and uncomfortable. 

So, it is important to understand the composition of the air around you. The external air is not in your control. However, there are ways to improve indoor air quality and comfort using tools, such as air purifiers, and dehumidifiers. 

One of the key elements of air composition is the humidity level. Relative humidity is a way to measure the humidity level in the air. Too low or too high relative humidity not only causes discomfort but can also pose health risks. 

Let's explore what relative humidity is, why it is important, and what can happen when it’s not in the ideal range.

What is Relative Humidity?

Relative humidity (RH) is the amount of water vapor the air contains at a particular temperature. It is expressed as a percentage, which indicates the amount of moisture the air holds compared to the maximum amount it can hold at that specific temperature.

It’s important to note that RH is strongly proportional to temperature and pressure. This means it changes as temperature and pressure fluctuate. When the temperature increases, the air can hold more moisture. So, the relative humidity decreases. Contrarily, if the temperature decreases, the air can hold less moisture. And the relative humidity decreases

Relative humidity (RH) remains stable if the indoor temperature stays constant. Pressure changes can also influence RH, which is often observed in controlled environments like laboratories and storage facilities. In everyday scenarios, temperature fluctuations are the primary factor affecting RH.

Why is relative humidity important?

Monitoring relative humidity is important for controlling the amount of moisture in a particular indoor setting. It helps you understand how much the air is occupied with water vapors compared to what it can hold. Extreme humidity levels—whether too high or too low—cause health risks and damage to products, goods, and property. When you know the exact humidity level in your space, you can opt for a suitable solution when it goes beyond the normal range. 

For instance, if you feel that the indoor air in your workplace is humid, you shouldn’t just run a heavy-duty dehumidifier in your workspace without knowing the actual humidity level. Otherwise, doing so may result in over-dehumidification, which can cause discomfort, health issues, or damage to materials sensitive to dryness, or lead to energy wastage. Therefore, you need to consider your indoor humidity conditions and the factors that affect them when choosing a solution such as a humidifier or dehumidifier. 

So, how can you measure the relative humidity? There are tools that can help you find the amount of moisture in your indoor air.

What Tool is Used to Measure Relative Humidity?

Typically, the tool used to measure relative humidity is a hygrometer. It is available in both digital and analog versions. Specially designed for humidity monitoring, it tells you the amount of water molecules in the air relative to the maximum amount that air can hold at a given temperature. 

Advanced hygrometers can also provide details about other indoor air quality factors such as temperature and dew points. Remember a hygrometer can measure temperature but it can’t function as a thermostat which can typically regulate and control temperature as well.

Besides, you can also find details about humidity using a dehumidifier with a humidity sensor. So, if you choose a dehumidifier with a built-in hygrometer, it will give you detailed information about humidity levels in your space. And you don’t need a separate hygrometer for it.

Relative vs Absolute Humidity: What’s the Difference?

Relative humidity and absolute humidity are two different ways of measuring moisture in the air. As we discussed, relative humidity represents the percentage or ratio of water vapor the air contains compared to the maximum amount of moisture the air can hold at a given temperature. It is temperature dependent and usually expressed in percentage (%).

Whereas, absolute humidity (AH) is the actual amount of water vapors a given volume of air contains regardless of temperature. It is generally measured in grams of water vapor per cubic meter of air (g/m³). It does not change with fluctuation in temperature as it tells you the exact water content in the air. For instance, if there are 15 grams of water vapor in 1 cubic meter of air, the AH is 15 g/m³, no matter what the temperature is.

What Causes High Indoor Humidity?

What causes humidity to rise in your house or building? There are different factors that add moisture to your indoor air. Some parts of the home such as basements, bathrooms, and kitchens are generally more humid as compared to living rooms and bedrooms.

Factors that cause high humidity include:

• Poor ventilation
• Rainwater intrusion
• Roof leakage
• Poor insulation
• Leaky doors and windows
• Overwatering houseplants
• Damp Basements
• Hot showers
• Cooking steam
• Poor insulation
• Humid climate

Moisture enters your indoor air from external sources, such as a humid climate, as well as from your indoor activities, such as cooking, taking showers, and doing laundry. One of the effective and easy solutions is to use a whole-home dehumidifier.

What Percentage is Considered High Humidity?

What percentage is considered high humidity? A humidity level greater than 50% is generally considered high, while levels below 30% are considered too low. The optimal humidity range is typically between 30% and 50%. 

It's important to keep your indoor humidity within this range to maintain comfort and avoid potential issues like mold growth or dryness.

What Happens If Relative Humidity is High?

If the relative humidity is high, it can cause various problems. These include discomfort, health risks, and potential damage to your goods and property. The sticky and musty indoor air makes your indoor environment highly uncomfortable and ideal for mold growth and other harmful microorganisms. 

The damage of long exposure to high humidity includes: 

• Musty odors 
• Mildew and mold growth 
• Rusting of metallic goods 
• Corrosion of equipment 
• Peeling of paint and walls 
• Water droplet stains on walls and ceilings 
• Warping of furniture and wooden materials 
• Damage to your building's structural integrity 

Besides, there are potential health risks. The moisture absorbs dust mites, which cause problems for those with allergies and asthma. Humid air contains more impurities such as VOCs (volatile organic compounds) and harmful microorganisms, which pose even bigger health risks such as eye irritation, respiratory problems, cancer, eczema, and nervous system issues.

What Happens If Relative Humidity is Low?

If your indoor air gets too dry, it can create various problems. 

These include: 

• Shrinking of furniture, windows, doors, and other wooden materials 
• Gaps and cracks between your building's structural units 
• Skin dryness, throat irritation, and other respiratory illnesses 

Long exposure to extreme humidity—either too low or too high—can cause severe problems. So, you need to address such issues in time. The easy and quick fix is to use relevant tools. For example, you can use a portable dehumidifier to remove excess moisture from your indoor air. To fix low humidity, you can use a humidifier. 

Read this if you don’t know whether you need a humidifier or a dehumidifier.

Conclusion

Achieving an optimal humidity level is important to make your indoor air comfortable and healthy. As we discussed above, both high and low humidity can pose potential risks to your health and property. 

As your indoor air quality is so important, you need to take steps to minimize airborne impurities and pollutants. One of the easiest ways to address extreme humidity levels is to use either a humidifier or a dehumidifier. Moreover, you can use an air purifier to remove other airborne contaminants. 

If you are confused about choosing the best dehumidifier or air purifier for your space, you can contact us right away. At Aloraircommercial, our dedicated team will help you find the best solution to your indoor air problems.