How Does a Humidifier Work?

Lower humidity levels in the winter air can be quite uncomfortable for humans; this is true even when we are in warm indoor spaces. We need certain air humidity levels to stay comfortable.  It’s normal for indoor humiditylevels to dip in the wintertime and that just dries out your mucous membranes and skin.

Lower humidity levels also make the indoor spaces feel colder than they already are. The dryness in the air tends to dry out wooden features in your home like the floors and walls. The shrinkage in the wood results in cracks in the plastering and drywall and you will notice that the floorboards start to creak.

Here we talk about how installing a humidifier can help increase comfort levels in your home. It can also reduce the wear and tear on your home, as it adds moisture to the air. You will be surprised to see how much of a difference a little bit of water makes to the indoor environment in your home. Before we discuss the working of a humidifier, we need to understand a little bit about what relative humidity is.

Relative Humidity

The air’s relative humidity impacts how comfortable you feel. Humidity is typically defined as the levels of moisture in the air. When you stand a while in the bathroom after taking a shower, you are able to see the steam all around you. If you are outdoors after heavy rainfall, you would be able to feel the humidity in the air.  Contrastingly, if you are standing in a desert area that hasn’t experienced any rain for a few months; you would be in an environment with low humidity levels.

The air has certain amounts of water vapor. The total amount of water vapor that a certain air mass can hold is dependent on the air’s temperature. If the air is warm, it would be able to hold more water. Low relative humiditylevels mean the air has a lot of dryness in it and that it has the capacity to hold much more moisture at that particular temperature.

For example, 68 ° F, the maximum amount of water that a cubic meter of air is able to hold is 18 grams. At 77° F, the same amount of air is able to hold 22 gms of water. If the temperature is 68 ° F and 1cubic-meter of air has 22 gms of water, the relative humidity becomes 100%. If that amount of air has 11 grams of water, then the relative humidity is 50%. If it has 0 gms of water, then the relative humidity is 0%.

Types of Humidifiers

If the relative humidity levels in your home are very low in the winter, these can be raised by installing a humidifier in the space. There are a number of different types of humidifiers; this is how they work:

1. Evaporative Humidifier

This is the most common type of humidifier. It’s an extremely simple device that is largely self-regulating. The cold water is held in a reservoir, which gets dispensed into a basin. The system has a wicking filter that absorbs the water that’s been dispensed in the basin. A fan blows air right through the wet filter. When the air moves through the filter, some of the water there gets evaporated.

If the relative humidity in the space is higher, it becomes more difficult   for the water to evaporate from the filter; this is why the humidifier has a self-regulating function. With a rise in humidity, the water vapor output of the humidifier decreases.

At times, the evaporative humidifier is connected to the home or building’s heating & cooling system. These systems function in a similar manner. The metal screen/mesh that’s situated in the duct that comes from the AC/furnace; water from the home’s pipes flows vertically down this screen. As the air that’s coming from the duct moves across the screen, it lifts that moisture and transfers it into the indoor spaces.

2. Steam Humidifier

This is also sometime referred to as a vaporizer. This system boils water and the warm steam gets released into the room. This is the simplest type of humidifier and so the least expensive as well when it comes to adding moisture to the indoor air. Stores carry some very basic impeller models that are available at less than $10. The other benefit of this particular technology is that you are also able to utilize a medical inhalant with this unit; this helps reduce coughs.

3. Impeller Humidifier

This system has a rotating disc that flings water towards a diffuser that looks very much like a comb. This diffuser breaks the water down into very fine droplets, which float in the air. Typically, you will be able to see a cool fog emitting from the humidifier; this adds to the humidity levels in the air.

4. Ultrasonic Humidifier


The unit has a metal diaphragm that vibrates at ultrasonic frequencies, somewhat like the manner in which a high-frequency speaker vibrates; this vibration is what creates the water droplets. This type of humidifier has a quiet operation and produces very cool fog.

Some Aspects to Keep in Mind

When you are weighing the pros and cons of various technologies, there are certain things you would have to keep in view:

    • Steam vaporizers aren’t the best solution if you have kids or pets in your home, as the vapor can cause burns.  These systems also have very high-energy costs, but you don’t have to worry about any mineral or bacterial contaminations with these systems. The ultrasonic and impeller systems use less power but raise certain other concerns. Since they blow stagnant water into your home, the air can contain bacteria. Cleaning the tank with regularity and refilling it with fresh water is one way to overcome this problem. The more advanced models of these units have antibacterial features built into them. Aside from this, ultrasonic and impeller designs send minerals into the air, especially if the water in your region has a lot of minerals; these minerals are visible as dust. The EPA recommends that you use distilled water in these



You have the option to install humidifiers as single portable units in different rooms; alternatively, if you want full-house humidity control through a single system, you can integrate them into your home’s furnace. You can track your home’s humidity levels by using a hygrometer. It will indicate what the relative humidity in your house is and will help you decide whether you need to get a humidifier installed.