How Do Humidifiers Work?

Two years ago, the Washington Post reported that nearly 82 per cent of the United States was seeing abnormally dry conditions.

Dry air can aggravate medical conditions, including asthma and allergies, and exacerbate the discomfort of conditions like a dry mouth, nose, or throat. Dry skin is also a fairly common complaint and can become very painful, particularly if the skin cracks or splits, leaving it open to infection as well as being sore. This is something that will only become more of an issue as we grow older. A humidifier can make the air less dry, thus fielding off some of the conditions listed above – we take a look at how humidifiers work.

What does a humidifier do?

Humidifiers increase the amount of moisture in the air in your home, enhancing the air quality, and making it more comfortable, especially during dry seasons or in regions with low humidity. This can be quite a salve to those who suffer from the conditions we mentioned earlier.

Francis J. Dietz is vice president of public affairs at the Air-Conditioning, Heating, and Refrigeration Institute in Arlington, Virginia. He explains: “A whole-house humidifier adds moisture to the air. Your thermostat sets the appropriate moisture level based on humidity already in the air and also outside. It is an add-on to your system, mounted near the air handler, usually in the basement where the furnace, air handler, and water heater are located.”

Another option would be a portable humidifier, one which is designed to add moisture to specific smaller areas. Which one is right for you will largely be driven by your space and budget.

How do different types of humidifiers work?

There are different options for humidifying your home and they work slightly differently.

Whole-house humidifiers

A whole-house humidifier will automatically respond to changes in the relative humidity in your home by using a humidistat to measure the amount of water vapor in your air and then using a fan to circulate humidified air, usually via your furnace’s duct system.

The humidified air is usually produced by distributing water over an evaporative media filter. Hot air moves through the filter, evaporating the water, and the fans blow this air through your home. Of course, to ensure your humidifier keeps working as it should, you need to replace the filter according to that particular model’s instructions.

Portable humidifiers

More compact, portable humidifiers are also really popular. These will humidify specific, smaller spaces.

An evaporative humidifier has a wicking filter and a fan. The fan blows air through the moistened filter. One of the simplest models you can buy, they can be quiet and relatively cheap but they need to be cleaned frequently to prevent growth of mold and bacteria.

An impeller humidifier uses a high-speed fan to send water droplets at a diffuser mesh that distributes droplets as a fine mist into the air. These cool mist humidifiers can be noisier than other types.

An ultrasonic humidifier will also produce a cool mist but it does so by using either a metal diaphragm or ceramic plates vibrating at ultrasonic frequency. This creates the water droplets that the machine then releases into the air as a mist. These humidifiers are effective and very quiet, but they may send dust into the air, which can affect allergies.

A steam humidifier uses a heating element to vaporize water, creating steam, which is then released into the air. This type of humidifier comes with the caveat that they can get very hot – and the steam they produce will also often be hot – so they might not be suitable for families with young children.

All humidifier models will require a degree of maintenance including replacing filters to stop bacteria growing, though some do have UV lights integrated to mitigate this.

Why might you want a humidifier?

We have touched on the health benefits of a humidifier before but, as Dietz explains, they have other advantages. He told us: “Adding moisture reduces or eliminates static electricity, such as that which causes small shocks when touching objects or people after, for example, walking on carpet.”

He also says: “Adding moisture to an appropriate level is a vital part of overall indoor air quality, joining ventilation and filtration.”

Some experts will also add that humidifiers can save money on heating bills – humidified air feels warmer, so homeowners can turn down their thermostats.

READ NEXT: Best Air-Quality Monitors

How do you decide on the best model for your space?

Dietz suggests taking advice from a professional if you are considering installing a whole-house humidifier. ”These are installed by reputable contractors, who will know what model is best for your home, taking into account factors such as house size and common relative humidity in your geographic area”, he says.

If a whole-house solution is outside your budget, he adds: “Portable humidifiers can be bought from most big box stores or home centers.” Bear in mind that you will need to measure your space and match it with a humidifier that has the correct capacity and range.

So, whether you are looking at buying a humidifier for health reasons or for the general comfort of your home, research what models are available. Think about your requirements but also consider how much time you can devote to maintenance and cleaning. You will find there is a model to fit your needs.