Relative humidity of 30 to 50% is recommended for good health. This is challenging in extreme conditions such as dry heat or too much moisture. A humidifier is used to increase the level of humidity in the air and a dehumidifier reduces the humidity level of the air. A hygrometer can be used to measure the humidity of a particular area to decide whether a humidifier or dehumidifier is required.

Comparison chart

Dehumidifier versus Humidifier comparison chart
Edit this comparison chartDehumidifierHumidifier
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  • current rating is 3.44/5
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(77 ratings)
Purpose To reduce the moisture content in the surrounding area. To increase the moisture content in the surrounding area.
Usage During warm/humid climate in either a single room or basement or the entire house. During winter or when the air is cold and dry in either a single room or the entire house.
Application Recommended to alleviate allergy by eliminating mold, dust mites and mildew from the air. Suitable to moisten dry skin and nasal passages that dry up due to common cold. Humidifier works best in children’s room.
Humidity levels Used where humidity is greater than 50% Used where humidity is less than 35%
Types Mechanical /refrigerative, Air conditioners, Adsorption/desiccant, Electronic, Ionic membrane, Makeshift Warm mist and cool mist

What is a Humidifier?

Dry, itchy skin and chapped lips are common in areas with low humidity. Humidity levels over 50% result in the growth of mold spores, bacteria, and dust mites. 40% humidity is required for musical instruments to prevent finishes from crazing or cracking.

In the following video, Dr. Ari Brown explains the uses of a humidifier in a baby’s room.

What is a Dehumidifier?

A place with higher temperature and high relative humidity needs moisture to be pulled out of air. Moist air helps the growth of mold, dust mites and spores which aggravate allergies and asthma. A dehumidifier removes moisture from air and is suited for this climate.

Humidifier or Dehumidifier?

The relative humidity of a particular place is the deciding factor in selecting either a humidifier for dehumidifier. A healthy relative humidity level is 35 to 50%. Based on the humidity levels of a room, dehumidifiers and humidifiers help obtain these levels.

Optmimum humidity level

The flu virus thrives best when humidity is either over 98% or between zero and 50%. Because of this, Dr. Linsey Marr, a researcher at Virginia Tech, recommends keeping humidity levels around 50% to give the flu virus the least chance of survival.[1]


Types of Dehumidifiers

An eco-friendly air dehumidifier designed for dehumidifying small to medium-sized spaces
An eco-friendly air dehumidifier designed for dehumidifying small to medium-sized spaces

How to Choose a Dehumidifier

This video by Consumer Reports offers tips on how to select a dehumidifier.

Types of Humidifiers

How to Choose a Humidifier

Here is a buying guide for various types of humidifiers that outlines the symptoms, size and benefits:

Humidifier Buying Guide (click to enlarge)
Humidifier Buying Guide (click to enlarge)


Humidifiers and dehumidifiers require regular maintenance.

Maintaining a Humidifier

Maintaining a Dehumidifier

Capacity Rating

The output capacity of a humidifier is measured as gallons of moisture per day. A unit with higher tank capacity needs less frequent refilling. The capacity of dehumidifiers is measured as number of pints of water removed in a 24-hour period.

The energy consumption of a humidifier is lesser than that of a dehumidifier. Irrespective of energy efficiency, both these appliances are used under mutually exclusive conditions depending on the requirements.


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