How Long Does a Humidifier Take to Work?

If you’ve ever wondered how long a humidifier takes to work, we’ve got the answer for you.

Once you set up your humidifier, you will notice a difference in your indoor environment within a few minutes. However, it may take an hour or so for a humidifier to reach its full potential.

How quickly a humidifier adds moisture to your space depends on the unit itself, the size of your room, and the dryness in the air.

This article will explain how humidifiers work, how long they take to moisten the air, and the factors affecting their performance, so you can pick the one that best suits you.

Let’s dive in!

Humidifiers: How Long Until They can Humidify An Area? 

Not every humidifier will start to produce mist the instant you turn it on. Most humidifiers take about 10-15 minutes to warm up and moisten the air in your space. Once that begins, you should feel the full effects of a humidifier within a few hours.

However, each humidifier performs differently depending on its model, the size of the room, and the dryness in the environment. Below, we have explained how these factors affect the performance of a humidifier.

How Humidifiers Perform In Different Spaces

Large-sized rooms typically take longer to be humidified, but you can speed up this process using a high-capacity humidifier. Similarly, a large humidifier would work faster to humidify a smaller area. Still, if kept running for too long, your space may over-humidify (we’ve explained how that happens down below).

Therefore, you should pick a humidifier that is best suited for the size of your room!

A compact, personal humidifier will work best for a small-sized room. In contrast, a large-capacity humidifier is recommended for medium and large-sized rooms to achieve the desired humidity level.

Rooms with moisture-absorbing surfaces, such as wood floors and furniture, also slow down the humidity process because they absorb the moisture generated from the humidifier. However, the surfaces stop absorbing moisture in the environment after a while, and the humidification becomes much quicker.

If you’re worried about moisture damaging your floors and furniture, you should invest in a humidifier with safety mechanisms, such as a timer to prevent oversaturation and a water filter to eliminate microbes.

Which Type Of Humidifier Should You Choose?

If you want quicker results, you should pick an evaporative humidifier such as the Vornado Evap, as it would only need a few minutes to boil water and release the mist. On the other hand, an ultrasonic humidifier such as HoMedics would take longer (approximately an hour) to reach the desired humidity level.

Out of the two, ultrasonic humidifiers are frequently recommended due to their high-tech features but if you want a seasonal humidifier for quick results, we suggest you go for the evaporative humidifiers.

So, there is no clear-cut answer to how long a humidifier would take to work. However, both evaporating and ultrasound humidifiers should ideally begin adding moisture to your indoor environment within 10-15 minutes and reach its full potential within a few hours.

How Do Humidifiers Work?

In the 18th century, people used to boil water and leave it to lay around an indoor space till it evaporated to increase the humidity levels. But this process was too slow and tedious, which led to the invention of a humidifier!

A humidifier works on the idea of artificially adding water vapor to the air to increase the amount of moisture in it. It breaks down water into tiny droplets and propels the mist into the air to increase its relative humidity.

These days, humidifiers come in various shapes and sizes with high-tech features such as dual ultrasonic technology, purification system, oil diffuser feature, etcetera, to fulfill all your humidifier-related needs.

Factors Affecting a Humidifier’s Performance

A humidifier’s effectiveness is determined by the humidifier itself and certain external factors. If you’re concerned about why your humidifier does not work as well as you’d expect, consider the following factors.

The Capacity of a Humidifier

A larger-capacity humidifier pushes more moisture into the air in a particular period. On the other hand, smaller units take longer to raise humidity levels in a room.

Evaporative and ultrasonic humidifiers release cool mist–combine this with a fan, and you can achieve the desired humidity level in a short period. Humidifiers that release warm mist to improve the humidity rather quickly are not a good option for summer.

To get the best of both worlds, we recommend you buy a humidifier with hybrid cool and warm mist technology best suited for your space’s size.

Room Size and Structure

The same humidifier will be more effective at increasing humidity levels if the room is smaller. However, in a bigger space, the water droplets per square will decrease, worsening the unit’s performance.

Windows and doors also negatively impact a humidifier’s performance as the outside air can seep through crevices. As a result, a humidifier would take longer to reach the desired humidity level.

Flooring and Furniture

Wooden floors, furniture, and carpets absorb moisture slowing down the humidification process. As a result, a humidifier would take longer to humidify a space.

Environmental Humidity

The dryness in the air affects the performance of your humidifier. For example, mornings are more humid than afternoons. So, your humidifier will reach desired humidity levels faster in the morning.

Humidifier Placement

Ideally, a humidifier should be at a surface top in the middle of the room, so the mist outlet is above the ground and disperses evenly into a room. Putting your unit in a corner will humidify a space unevenly.

How To Tell a Humidifier is Working

The best way to check if a humidifier works effectively is by checking the relative humidity level when the unit is running.

For this purpose, some humidifiers have a built-in humidistat to monitor the humidity levels. If your humidifier does not have a humidistat, you can buy a humidity gauge to monitor your humidity levels.

Other methods include putting a hand over the output vent of the humidifier. If you feel a cool breeze on your hand, that means the humidifier is sending out mist into the air.

Our Favourite Humidifiers on the Market

Levoit OasisMist Smart Humidifier

The newly launched Levoit OasisMist Humidifier is designed to create a fresh and healthy vibe in your space. 

This unit offers dual mist technology to get the best of both worlds with warm mist to combat winter dryness and cool moisture for hot summer days.

It comes with a quick humidification technology that evenly disperses mist in every corner of your room and an auto mode to adjust the mist output depending on the humidity level. 

It includes a large 4.5-litre tank capacity with up to 45 hours of continuous runtime. Even using and cleaning the unit is pretty easy with its top-fill design. What a hassle-free user experience!

No wonder the OasisMist is a highly recommended, one-time investment!

HoMedics TotalComfort Ultrasonic Humidifier

The HoMedics Ultrasonic Humidifier is among the best portable humidifiers on the market. With its compact design, this humidifier can even fit in a car cup holder–making it easier to carry on the go.

It provides coverage up to 32 square feet with 10 hours of runtime that can last you the whole night. Pretty impressive for a unit that size!

With its auto shut-off feature, you don’t have to worry about the tank running empty. Plus, it’s whisper-quiet, so you can sleep without any disturbance.

The best part is that this unit comes with a Clean Tank Technology that protects that tank from mould and mildew. A premium choice if you need a humidifier around you constantly!  

ASAKUKI 2-in-1 Humidifier

The ASAKUKI 2-in-1 Humidifier, as the name suggests, performs two essential functions: It adds moisture to the air, and its oil diffuser feature eliminates any unpleasant smells in your space. Nothing’s better than having your home feel and smell fresh!

This unit has a 2.5-litre tank capacity and can run up to 30 hours straight without refilling. And thanks to its top-fill transparent design, filling it is absolutely hassle-free. This humidifier lives up to its ‘2-in-1’ name because it provides both ease and efficiency!

Even better, there are three settings for mist output that you can adjust to your liking, or you can just set a timer (between 2, 4, and 8 hours) if you wish to operate the device for a while.

You can’t go wrong with this unit in your home!

Frequently Asked Questions 

How long should you keep a humidifier running?

This depends on the settings of your humidifier–whether the unit is set to run on minimum or maximum power. On average, humidifiers run for 10-15 hours a day. Always check the water reservoir to ensure your unit is not running on an empty tank.

Can you over-humidify a room?

Yes, it is possible to over-humidify a room, causing a damp feeling in the room. If you keep a humidifier running past the recommended level of 60%, your room gets over-humidified. This can create the perfect environment for mould growth and foul odours. The ideal humidity levels should remain between 30% to 50%.

How can you improve the efficiency of your humidifier?

There are a number of ways you can improve the efficiency of your humidifier; you should regularly change the water to discourage the growth of waterborne microbes in the tank. You also need to thoroughly clean your humidifier to ensure that the mist output is clean and fresh.

Another thing you should do to discourage mould growth is to set the humidity levels between 30% to 50%. .

Wrap Up

A humidifier is an excellent addition to your home for health and wellness purposes. Most humidifiers only take a few minutes to make a noticeable difference to your indoor environment and reach their full potential in a few hours.

However, the exact time cannot be determined due to a shift in external factors. This is why you should buy a premium-quality humidifier best suited to your room’s specific dimensions.

Lastly, we recommend buying a smart-tech humidifier that is a bit larger than your room so you can achieve desired humidity with the option to monitor the humidity level.


Shawn Willis is all about humidifiers. After working for some of the biggest names in the industry, he started HumidifierGuys with Scott Dawson. Now, the dynamic duo helps others figure out what they need in their next humidifier.

Shawn is an avid sports fan, motorcycle enthusiast, and has two dogs named Whiskey and Boba.