Lessons About Humidity You Should Know This Winter

humidity newport kentucky greater comfort

Have you ever wondered why humidity is lower in the winter? Recall that humidity is a measure of water vapor that’s in the air.

It’s a fact that colder air can hold less water vapor (or moisture) than warm air, and as a result, the colder the air, usually the lower the outdoor humidity as well. That’s why we sweat more in the summer, in part. And, unless you control the humidity in your house, it will typically come to equal the low outdoor humidity (1).

Let’s take a deeper dive and examine what you need to know about humidity.

What’s Relative Humidity?

What is relative humidity? First, it’s a term that’s used by weather scientists. For those of us dealing with issues related to comfort, this is what matters! Relative humidity can be defined as the percentage of water vapor in the air, compared to the maximum amount of water vapor that the air could hold at the current temperature.

Our bodies use evaporation from the skin as the main way to control our temperature, and it’s relative humidity that governs how fast evaporation occurs (1).

So what are the risks of low humidity? We know that there are lots of downsides to high humidity—but common problems that can come with low humidity include itchy skin, irritated throat and sinuses, and even a bloody nose, in some cases!

Longer term, you can become susceptible to cold, flu and other respiratory infections, because the lining of your mucus membrane can become inflamed (2, 3, 4, 7).

Damage to Your Home?

Besides health risks that can occur, and just plain old discomfort, overly-dry air can cause damage to assets in your house. Things like furniture, anything made of wood, wine bottles (the corks may shrink and crack); bookshelves, electronics and much more can be affected over time. Walls, cabinets and floors can even show cracks or splits due to extremely low levels of moisture in the air over time (2, 4, 6).

Besides the idea of relative humidity there is also ideal relative humidity. There’s no single percentage that is ideal for everyone, within every climate, but most people feel discomfort at humidity below 25 percent or above 60 percent, which shows just how much range there can be (3, 7).

The American Society of Heating, Refrigeration and Air-Conditioning Engineers (ASHRAE) reports that 45-55 percent is best for health reasons, but since this can cause water to condense on your windows and doors, humidity as low as 35 percent is often acceptable. Generally speaking, when temperatures are mild, 45 percent is a level that can keep your family—and your houses’ assets—in good shape (1).

How To Measure Humidity

How do I measure humidity? It’s smart to have at least one “hygrometer,” as humidity sensors are called. They come in digital or mechanical models. The mechanical devices are cheaper, but the digital ones can measure humidity faster (3, 4, 6, 7).

Humidity will increase if you are using water indoors, such as for cooking in the kitchen or showering in the bathroom. (You’d be surprised how much moisture this can add to the air in your home.) So you should move your portable hygrometer to different parts of the house from time to time, to get an overall picture of the humidity levels (3, 4, 5, 6).

How To Better Manage Humidity

So you want to feel cool and comfortable during the summer, and you want to feel warm and cozy in the winter? Of course you do!

We are actually very sensitive to humidity, we just often feel the discomfort or see the signs more in the summer or spring. When you have forced air heating, furnaces use combustion to create hot air. This can contribute even further to the problem within the home (3, 4, 5, 6).

Recall that humidifiers work through a reservoir that holds water. With cool mist humidifiers, air passes through the filter and evaporates some of the water into the room. Warm mist humidifiers work to heat water, and then disperse it into the air.

A whole house humidifier integrated with your heating and air conditioning system is by far the most complete way to control humidity. The humidifier will have a wall-mounted control similar to a furnace’s, which you can easily set and monitor. If a whole-house humidifier is not practical, you can buy room humidifiers, which you fill with water that is heated so that it evaporates. These are also useful if someone in the family has respiratory problems that need higher humidity, such as a sinus infection or sore throat. Call us at 859-491-4915 if you have questions for what is right for your home or business (3, 4, 5, 6).

Know More About Your Indoor Humidity Levels

Ask us to help you see what your indoor humidity levels are, and how you can track your level on an ongoing basis. In these winter months, if you notice more static electricity than normal, dried paint, or millwork that has cracked, let us know.


  1. http://www.centralhtg.com/blog/managing-home-humidity-for-maximum-comfort
  2. http://www.thermastor.com/information/relative-humidity-and-your-home.aspx
  3. http://www.startribune.com/fixit-what-is-the-ideal-winter-indoor-humidity-level/11468916/
  4. http://healthliving.today/physical-health/low-humidity-and-your-health/
  5. https://www.thisoldhouse.com/ideas/9-things-your-homes-low-humidity-ruining
  6. http://articles.chicagotribune.com/1999-12-12/news/9912120409_1_good-quality-furniture-wood-furniture-moisture
  7. http://www.criticalcactus.com/ideal-home-humidity-levels/