Humidifiers vs. Dehumidifiers: How They Work and What You Need

It’s so humid. It’s so dry. Chances are you’ve said one of those things to yourself (and recently), and that’s why you’re interested in humidifiers and/or dehumidifiers. If the outside of your home is stuffy or barren, you may also be curious about what you need to better equip the inside of your home to compensate. Here we look at the differences between humidifiers and dehumidifiers, when to choose one or the other, which type works best in which conditions and whether you need one at all.

Humidifiers vs. dehumidifiers: the big (and small) differences

On the surface, it’s not hard to figure out the difference between a humidifier and a home dehumidifier and what they do: the benefits of a humidifier include adding moisture to the local environment, and the purposes of a dehumidifier include removing of it, but the machines are not complete opposites. . This is how you can access them all:

Humidifiers release water

Humidifiers require a tank filled with water to deliver to your home, although some advanced humidifiers may use a hose supply. There are several mechanisms for absorbing the water and dispersing it as vapor into the air (we’ll discuss a few below), but they all work faster and “better” than evaporation.

Keep in mind that humidifiers can release things other than liquids. It is not uncommon for humidifiers to also be advertised as aromatherapy machines for dispensing essential oils.

Dehumidifiers collect water

The process of dehumidification can essentially be divided into four major steps:

1. Moist air is sucked into the machine and cooled.
2. The moisture from the cooled air begins to condense, like water on the outside of a glass of ice water.
3. This water is collected in a reservoir or pumped away.
4. The drier air is reheated and released back into the room.

Water storage or drainage becomes important. Almost all dehumidifiers have tanks in which the water produced is collected. Many also have the option of adding a feeder or some type of hose that allows the removed water to drip into a drain or sink.

Design Considerations for Humidifiers vs. Dehumidifiers

Based on these differences, there are quite a few things you can expect to be different (or want to be different) between your humidifier and your dehumidifier. Here are just a few:

Automatic shutdown: One of the most common features of humidifiers and dehumidifiers is the auto shut-off feature, or something similar. With dehumidifiers, this is usually activated when the water tank becomes filled to a certain level, should you be using it. Humidifiers typically activate their automatic shut-off when their tank becomes empty. Both dehumidifiers and humidifiers can also have a shut-off associated with a certain humidity level being reached (via a humidistat), but you’re more likely to want this feature on a humidifier due to the harmful effects of too much humidity in your home.

Water tanks: The water tanks of humidifiers and dehumidifiers serve incredibly different purposes and as such you can expect differences from their designs. Because humidifiers need to be filled, you can count on a smooth internal water tank in an easily accessible place. Dehumidifiers, on the other hand, will often require manual dumping. This means that the water tank must be removable, have at least one sturdy handle and possibly have breakwaters.

Filtration and cleanliness: While you don’t want your humidifier or dehumidifier to be involved dirty, cleanliness is much more important when it comes to humidifiers. As we collectively learned from COVID-19, tiny water droplets containing bacteria and other toxins can lead to illness serious conditions. For this reason, Health Guidelines for EPA Humidifiers recommends the use of distilled water, especially in ultrasonic humidifiers and impeller humidifiers. Look for easy-to-clean humidifiers with built-in filtration systems. Keep in mind that many humidifiers are advertised as being BPA-free. Plus, some air purifiers double as a humidifier – and it’s a great combination, because you can’t expect your houseplants to do all the work when it comes to air quality (although they can help).

Loudness, strengths and planning: Operating machines makes noise. Sometimes that sound is acceptable and sometimes it is not. For example, a very powerful humidifier or dehumidifier can be so loud that you cannot sleep well or have a good conversation. For this reason, many of these devices have different strength settings and even schedules. While you may want to schedule a dehumidifier to turn off at night, if you need a humidifier for nighttime comfort, look for one with a night mode.

Which one do you need?

The simple advice is that if your air is humid, you need a dehumidifier; if it is too dry, you should use a humidifier. In reality, it’s not that easy to say, so here’s how to decide whether you need a humidifier or dehumidifier.

With low humidity you will probably feel the effects immediately. According to the Mayo Clinic, health conditions associated with low humidity include itchy eyes and dry skin – not exactly killing you, but not comfortable either.

On the other hand, a dehumidifier might be better for you if your home shows it signs of high humidity. While common problems, such as mold growth or even peeling paint, may lead you to address the moisture problem in your home, they may not be the most obvious. An easy to spot, but often misdiagnosed sign of dampness is condensation from windows in winter.

If you’re still not sure what you need in your home, consider purchasing a hygrometer. This is especially true if you have some, but not all, of your humidity or dry air problems… or a combination of dry air and humidity problems. After all, effective hygrometers are much cheaper than humidifiers or dehumidifiers, and a reliable hygrometer should get you under $10.

Still interested in something bigger? Read on for the different types and top choices when it comes to humidifiers and dehumidifiers.

Types of humidifiers

There are actually many different types of humidifiers when you think about it on a mechanical level. While there is occasionally a bit of overlap between one category and the next (many manufacturers use “cool mist” and “warm mist” very loosely), the following types of humidifiers represent the most common types:

Ultrasonic: This type of humidifier uses intense vibrations to “rattle” water into a kind of mist or mist. Despite what it sounds like, these humidifiers can be quite quiet due to the use of ultrasonic sound waves.

Evaporation effect: Oddly enough, evaporative humidifiers use much of the same technology as wick-based hydroponic systems. Essentially, a wick is dipped into water, which then rises. The water is then spread into the air, possibly by a fan. Since this process is a somewhat gentle way of getting water into the air, it is easy to find examples of fog-free humidifiers in this category because you are unlikely to see a visible fog trail.

Fan: Also known as “cool mist” humidifiers, these humidifiers use rapidly rotating discs to create a mist in the air.

Atomizer: Also known as “warm mist” humidifiers, these humidifiers use heat to produce steam. Think of an appliance that’s similar to a kettle, but focuses more on the steam coming out of the spout than the water inside.

You can also consider humidifiers that come in two broad categories of form factors: central humidifiers And portable humidifiers. A central humidification system, just like central heating and air, is part of the total air exchange system in your home. They are whole house humidifiers. Chances are if you’re looking to buy a humidifier, you’ll want a portable humidifier.

Since most humidifiers you’ll come across while shopping online are portable humidifiers, most won’t explicitly label themselves as such, and if they do, it probably means that the humidifier in question is quite small or has a handle . In other words, there is no point in explicitly looking for a portable humidifier.

Types of dehumidifiers

Dehumidifiers are less robust in their design philosophy. Instead, the biggest variation in dehumidifiers will be usage scenarios and form factors.

For example, small dehumidifiers are quite good for small rooms and bedrooms. Their low profile and (usually) lower sound output make them ideal for your room. However, more intensive jobs require heavier humidifiers, such as these dehumidifiers for basements. These heavier dehumidifiers are also likely to come with pumps that can feed into your sink or bathtub.

Frequently Asked Questions