Humidifier vs Dehumidifier – Which One Do You Need?

humidifier vs dehumidifier

Keeping the humidity in your home at a comfortable level can be challenging at times. Depending on the humidity in the air, and the time of year, you may find yourself faced with the decision on whether you need a humidifier or dehumidifier.

In this article, we will look at what each of these appliances is, how they work, the different types, the main difference between them, and what to look for when shopping for either.

Humidifier vs Dehumidifier – The Difference

The difference between humidifier vs dehumidifier is quite simple to understand.

A humidifier adds moisture to the air and is effective in raising the humidity when it is too low. Dry conditions are common with low humidity in your home. This can be an itchy throat, dry skin irritations, and even cracking wood on floors.

A dehumidifier works in much the opposite way. It removes excess moisture from the air to bring the humidity down to a safe level. High humidity can result in the development of mold and mildew. It can cause wood floors to warp and sag.

How Does Dehumidifier Work

A compressor-style dehumidifier pulls in moist air and passes it over two different types of coils. The first one is an evaporator coil and the second is a condenser coil. The moisture that forms on these coils in the form of water droplets eventually falls to a bucket in the bottom of the machine. The dehumidified air is then released back into the room.

A desiccant-style dehumidifier uses a compound that absorbs moisture from within the air. This moisture is extracted from the compound and collected in a bucket.

Once the collector bucket is full, it can be emptied.

Other models permit continuous drainage with the assistance of a drain hose.

How Does Humidifier Work

A humidifier is a machine that uses a water reservoir and releases moisture into the air.

Warm air, in the form of steam, is the delivery method in warm air humidifiers. Cool air humidifiers mist the room.

As there is a bucket of water constantly sitting inside a humidifier, it requires regular cleaning to prevent bacteria growth. Humidifiers are commonly used in a nursery to help the baby in their nighttime breathing.

The Different Types of Dehumidifiers

There are five different types of dehumidifiers:


This is the most common of the dehumidifiers. It uses a small fan to pull moist air across and refrigerated coil. Condensation collects on the coil in the form of water droplets that fall to a collection bucket below.


A desiccant is a material that absorbs moisture in much the same way as a sponge mops up water. The desiccant is sometimes on a rotor that is heated and draws the moisture out of the absorbing material. Other desiccant models collect the water within the moisture-absorbing compound or below it in a reservoir.


A Peltier heat pump is used in this type of dehumidifier that creates a cool surface where condensation forms. There are no moving parts to this type of dehumidifier so it is very quiet, but not very efficient.

Ionic Membrane

Specialized ionic membranes are used to remove water from the environment at the molecular level. The membranes pull the water out of a sealed environment where water may not be visibly produced. This type of dehumidifier is used in water filtering, chemical engineering, and fuel cells.


An air conditioner works like a mechanical/refrigerative dehumidifier if the design of the model used releases accumulated condensation outside of where it was collected while heating it up.

The Different Types of Humidifiers

There are two different types of humidifiers:

Warm Mist Humidifiers

This type of humidifier, also known as a steam humidifier, is the most common. It warms the water and releases steam into the room.

Cool Mist Humidifier

There are three different types of cool mist humidifiers.

The Wick/Evaporative Humidifier uses a cloth wick to absorb water from a storage container. A fan blows over the wick surface, evaporating the water.

An Impeller Humidifier creates a fine mist from a rotating disc that throws water onto a diffuser. The diffuser converts the water into tiny droplets and sends them into the air.

An Ultrasound Humidifier uses a diaphragm that vibrates at an ultrasonic range. This breaks water down into tiny water droplets that a fan blows into the room like a mist.

What To Look For When Buying A Humidifier Vs Dehumidifier

The capacity rating and area served are two main points to look for when shopping for either of these appliances.

A humidifier will have an output capacity which may be measured as gallons of moisture per day. The higher the tank capacity, the less often it will require the addition of more water.

Dehumidifiers have a capacity rating that is described as the number of pints of water removed per day. For example, a 50-pint model can remove up to 50 pints of water per day from the air. The higher the capacity, the larger an area a dehumidifier can operate within.

If you are unsure if you need a humidifier or a dehumidifier, it may be worth measuring the humidity in the different areas of your home. You can do this with a hygrometer. Read more about hygrometers here.

Other Considerations

Another consideration is noise levels. Sound is measured in decibels (dB) and the average humidifier or dehumidifier operates under 50 dB.

Energy consumption should be another consideration. A humidifier uses less energy than a dehumidifier but to find an energy-efficient model is easy – as a starting point, just look for the ones that are EnergyStar rated. These units have been tested and passed the strict EnergyStar guidelines.

Finally, easy-to-read and operate controls are a must. One item the control panel or display should have, especially on dehumidifiers, is a measurement of relative humidity. This will tell you the moisture content in the area you are using the appliance.


Although both humidifiers and dehumidifiers have something to do with the regulation of humidity levels, they are two different pieces of equipment working on two different ends of the humidity scale.

While you may require the assistance of both appliances, they work under exclusive conditions to either raise or lower the humidity in your home, depending on the appliance in use.

If you need more information on the difference between humidifier vs dehumidifier, see this article and this article respectively.

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