What is the Ideal Indoor Humidity

The level of humidity in our homes is not something we normally pay attention to on a day-to-day basis, especially in terms of being harmful to our health and home. However, each year, many unfortunate Americans learn the hard way that humidity levels are something to which you need to pay close attention. What people are only beginning to realize are the adverse effects of high or low levels of humidity and how it affects the home and health of themselves and their family.

What is Humidity?

First and foremost, let us talk about what humidity is and why we should pay close attention to it. Humidity is the level of water vapor in the air. It is an integral part of our water cycle and increases the chances of rain, which aids in the growth of plants and trees on our planet. If there is a high level of humidity, the air will feel more wet. With lower levels of humidity, the air will feel more dry.

Humidity level can affect multiple things in our day to day lives. If the humidity levels are too high in our homes it can lead to mold and mildew and cause rot. This can lead to thousands of dollars worth of property damage. If humidity levels are too low, it can cause xerosis, or, as it is more commonly known, dry skin. Low humidity can also cause irritation of the eyes and/or sinuses.

What Is the Ideal Indoor Humidity?

Keeping Humidity levels at an ideal level in your home can be crucial to your overall comfort, health and wellbeing. It is recommended to keep the levels of humidity between 30%-50% at home. If the humidity levels are too high it can induce the formation of mold and mildew in our homes. Furthermore, low levels of humidity can contribute to damage to furniture, such as sofas, and decorations, like wallpaper. It can also cause xerosis on the skin.

How to Gauge indoor Humidity levels?

Perhaps you are blessed with the ability to detect when levels of humidity are getting too high or low, but for 99.9% of Americans this is not the case. Fortunately, there are many easy ways to detect levels of humidity for those unable to do so.

There are a variety of different methods that you can use detect humidity in the home, including the purchase of a retro thermo hygrometer, which works similar to a thermometer. However, instead of tracking temperature in the home it tracks humidity levels in the home. A more modern device would be a Bluetooth hygrometer which automatically sends notifications to your smart device when humidity levels are too high or low. If you are not technologically inclined, you can use the older method: the ice cube test.

The equipment needed for the ice cube test is relatively simple to put together. All that is needed are the daily household items listed below:

  • A clear glass
  • Three to four ice cubes
  • Water
  • The room you want to test the levels of humidity.

To carry out this test:

  1. Place the ice cubes inside the glass.
  2. Cover the ice cubes with water and give the glass a gentle stir.
  3. Place the Glass with the ice cubes and water in the room you have selected.
  4. Set a timer for four minutes and return to the room once the time is up.

The Results:

If you return to the room and the glass has formed water droplets or condensation the humidity is moderate to high. If you no condensation has formed the humidity may be low and you should consider buying a humidifier or taking other actions in your home to raise the humidity levels.


High levels of humidity lead to the expansion of water molecules due to the heat and a process called condensation, leaving water droplets on the outside of the glass. If humidity levels are low, the water molecules will not appear on the outside of the glass. In this case, the cold air removes water molecules from the air.

Please remember, do not use your bathroom or kitchen when you are testing the humidity levels, since these rooms consistently use water and will not provide as accurate of a result. Using either of these rooms for this experiment could lead to completely misjudging the precautions to take in mitigating the humidity levels of your home. You could end up raising humidity levels when they need to be lowered or lowering humidity levels when they need to be raised.

How the seasons can affect levels of humidity:

As the seasons change, not only does the weather get colder and the days get shorter, the levels of humidity change, as well. It is key to make take necessary steps to account for these changes as they affect all aspects of our lives.

Winter time can bring many new environmental changes as the levels of ice rise, snow falls, the world prepares for the festive season, temperatures drop and so drops the quantity of water vapor in the air. Throughout the winter months, you might have noticed the air is crisp and brittle. This is due to the low levels of humidity at this time of year.

If you were raised in a cold climate, you will have learned from experience the adverse effects low humidity can have on our bodies. Along with warm clothing, such as winter coats, gloves, undershirts and boots, moisturizer is essential to combat xerosis and other side effects of low humidity during this time of year. As cold air removes moisture from the air, it also dries out our skin, leading to the aforementioned xerosis. To prevent this it this important to regularly moisturize in the months with low levels of humidity.

To ensure comfort and your overall health in these months, a portable humidifier is a good, and relatively cheap, investment. Increasing the levels of humidity in the air reduces the risk of xerosis and other minor health problems. These can include sinus problems, chapped lips and dry and irritated eyes. Furthermore, a humidifier is great at increasing your overall comfort during these months.

How can low levels of humidity affect your health and home?

Decreased levels of humidity can lead to dry skin, sore throat, respiratory problems and nose bleeds. These issues, without proper treatments, can lead to more pressing issues such as chest infections, continuous nosebleeds and long term sinus problems.

In our homes low levels of humidity lead to increased amounts of static electricity. It causes millwork to split or crack and can damage electronic devices such phones, tablets, televisions, and desktops or laptops. If you do not fix these problems early on it will incur huge repair costs and the problems will only get worse.

High levels of humidity can cause major damage to our health, as well. It can lead to heat stroke, increased levels of perspiration and increased risk of asthma attacks. High humidity activates nerves in your lungs that make you airways restrict and become narrow, increasing potential respiratory complications.

Higher levels of humidity in our homes increase condensation on windows and glass surfaces. Moisture can accumulate and a damp smell can engulf the house. Before you know water spots will begin to form on your ceiling and walls, usually near plumbing pipes.

There are many different methods to combat less than ideal levels of water vapor in the home. They are relatively simple.

To decrease humidity:

  • Purchase a dehumidifier from your local Walmart
  • Start using exhaust fan whilst cooking
  • Increase the number of cold showers (not only can this be good for your health but also your home)
  • Avoid bringing water to boiling point when cooking
  • Leave windows open in your home to vent steam and humid air out of the home

To increase the levels of humidity:

  • purchase a humidifier from your local Walmart
  • increase the number of plants you have in your home
  • Increase the number of hot showers or baths you take or leave the door open when doing this
  • Allow bath water to cool before draining it if possible, to allow the steam to raise the humidity levels in your home
  • hang your laundry indoors to dry as the moisture from the clothes will evaporate, raising the moisture in the air

House plants, as mentioned in the bullet list above, are a great addition to the home to increase humidity. The best plants to invest in for increasing humidity at home are as follows:

  • jade plant
  • areca palm
  • Boston fern
  • peace lily
  • lady palm
  • spider plant

When these plants photosynthesize and respire they release water molecules into the air, increasing the humidity.

Although all the above listed house plants are well suited for increasing water vapor in the air, there is one plant in particular from the list that has proven to be more effective than the all others. A study by NASA in 2018 found that chlorophytum, or the spider plant as it is more commonly known, not only increases humidity but it also has air purifying properties. The study found that the plant removed around ninety percent of formaldehyde, a potentially cancer causing chemical, from the air. If you are a plant lover or generally concerned about your health you should consider purchasing a spider plant for your home.

When trying to raise the levels of moisture in the air please be aware of small children. Leaving baths full, hot showers running or leaving boiling kettles or pots unattended could be hazards for young kids and may result in serious accidents such as drowning in the bathtub or high degree burns to the body from boiling hot water.

When lowering the humidity levels it is also important to keep a close eye on young children in your household. Leaving windows or doors open during the day could result in young children wandering out into the street and being struck by a moving vehicle. When taking such actions of leaving doors and windows open to lower the levels of water vapor in the air, be mindful of the potential dangers and consequences that they pose to your children.

Humidity levels can affect all people in all stages of life and, much like the current covid-19 pandemic the world is facing, the effects high or low levels of humidity do not discriminate. They can potentially affect everyone. Neglecting the humidity levels in our home can not only lead to serious health problems, it also has the ability to cause damage to your home incurring huge repair costs. It is vital that people pay closer attention to the humidity levels in their homes to decrease the risk of serious health problems for themselves and their loved ones as well as ensuring your home stands the test of time with minimal damage to the structure or foundations.

Microsoft word- David Donnelly- Humidity effects-David




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