The cold season is upon us. We’ll soon see people scrambling to find a reliable humidifier to help them weather the dry conditions of the cold months. If you’re one of those planning to buy a new humidifier in the next few weeks, you should consider top-fill models.

Top-fill humidifiers aren’t very different from other humidifier types. They function the same way and output moisture just like other units. The difference is that they fill from the top of the unit. This is different from humidifiers that fill from the side. Though either option is okay, filling your humidifier from the top is a tad more convenient – a benefit you cannot overlook.

Read on to find out more about top-fill humidifiers. How exactly are they beneficial? What are the options at your disposal? What other factors do you need to consider during shopping?

Buying Guide

The following are some of the tips and considerations to keep in mind when shopping for a top-fill humidifier.

What’s a Top-Fill Humidifier?

As the name suggests, a top-fill humidifier is a portable humidifying appliance that fills from the top as opposed to alternative models that fill from the side/bottom.

There are two broad categories of humidifiers – furnace and portable. Furnace humidifiers are installed on the furnace of the home’s heating system. It is permanently installed in such a way that it draws water directly from the home’s plumbing system. As such, there’s no water tank and no need to worry about water refills.

However, on the other end, portable humidifiers don’t connect to the home’s water supply system. These units still need water to work, though. So, they come with a tank (or you may need to purchase the tank separately). This tank needs to be replenished with water regularly to provide the water necessary to produce moisture.

Humidifier manufacturers employ two broad refilling strategies – top and side (bottom filling is one of the side-fill options);

Top filling: Top filling refers to filling the tank from the uppermost part of the humidifier. Typically, the humidifier will have a lid that you can lift/remove to fill the tank. Once you’ve refilled the unit, you’re required to return and (where applicable) tighten the lid.
Side filling: Side filling means filling the humidifier from any location on the sides. The majority of side fill humidifiers feature a base-tank design where the tank is concealed in the base construction. The rest of the humidifier rests on this base. Bottom fill models are the most popular type of side fill humidifiers. They fill through an opening close to the bottom of the unit.

Advantages and Disadvantages of Top Fill Humidifiers

The filling method has a direct impact on the ease of use of the humidifier. The following are some of the strengths and challenges associated with top-fill units.

Top-fill Humidifier Advantages

Easy to refill: This is the most significant advantage of top fill humidifiers. They are far easier to refill compared to side (and bottom)-fill models. Typically, it takes just a few seconds to complete the refill process. Better still, there’s a lower risk of the water spilling as you attempt to refill the tank.
Flexible refilling options: The majority of side-fill humidifiers require that you carry the humidifier to the sink or use special equipment when refilling. Imagine the inconvenience! Top-fill models remove those barriers, allowing you to fill the tank as you wish. You can carry it to the sink or fill it right next to the bed with a cup.
Easier to clean: Most top-fill humidifiers feature large lids that can be removed or flipped for ease cleaning. You can use the large opening to access and thoroughly clean the inside of the tank. In contrast, side-fill humidifiers take a lot more effort, especially when cleaning the tank.
You don’t need to remove the tank to clean it: Side and bottom fill humidifiers are also designed in such a manner that you must remove the tank to clean it. This is another inconvenience that top-fill models eliminate. The large lids allow you to access every corner of the tank without removing it from the humidifier.

Top-fill Humidifier Cons

Not all top-fill humidifiers have large lids: You’ll easily come across several top-fill humidifiers with narrow openings. Where this is the case, refilling and cleaning are just as challenging as side and bottom fill humidifiers.
The lid may harbor mold and bacteria: That large lid, though incredibly convenient during refilling and cleaning, presents a risk of mold and bacteria growth. The water drops left on the lid can harbor other harmful microorganisms. This necessitates more frequent cleaning.

Top-Fill Humidifier Types

Top-fill humidifiers can be categorized in two ways – by operation mechanism and by mist temperature (cool or warm-mist).

Types by Operating Mechanism

Top-fill humidifiers are available in all the four operating mechanisms – ultrasonic, impeller, evaporative, and steam.

Ultrasonic humidifiers: Ultrasonic humidifiers rely on sound vibrations moving at ultrasonic speed to break water particles into a mist stream.
Impeller humidifiers: Impeller humidifiers employ a rotating disc to fling water at a diffuser, breaking down water particles into fine moisture.
Evaporative humidifiers: These units use wick filters to break down water into vapor. Air drawn from the room is forced through a soaked wick filter, breaking the water particles into fine moisture.
Steam humidifiers: As the name suggests, steam humidifiers boil water into steam. The steam is then forced out of the humidifier and dispersed throughout the room.

Cool vs. Warm-Mist Top-Fill Humidifiers

Essentially, cool mist humidifiers generate moisture at room temperature while warm mist models deliver warm air generated from a heating process. All steam humidifiers are warm mist humidifiers. Ultrasonic, impeller, and evaporative humidifiers, meanwhile, can be cool mist or warm mist. A few models, known as hybrid humidifiers, can generate cool or warm moisture, depending on the setting.

Cool-mist humidifier pros and cons: A key advantage of cool mist humidifiers is their inherent safety. Since both the mist and humidifier parts remain cool throughout, you don’t need to worry about scalding. This is especially important in homes with pets or kids. The downside, however, is that you need to take additional steps to prevent mold and bacteria.
Warm-mist humidifier pros and cons: Warm mist humidifiers add supplemental heat to the home, thus cutting heating costs. The heating process also kills any mold, mildew, and other harmful microorganisms – hence no need for chemicals. However, on the flip side, they are more costly to run and pose a significant burn risk.

What Size Humidifier Do I Need?

Humidifier sizing is a delicate but crucial process because over-humidification is just as bad as under-humidification. If you add less humidity than necessary, the low-humidity issues will persist. These may include cold and flu symptoms, allergies and asthma, dry skin and scalp, and snoring problems.

Over-humidification comes with just as many downsides. The excess humidity can cause foggy windows, destroy wallpaper/paint, and cause dampness all over the house. It may even comprise the building’s structural integrity.

So, how do you determine the right humidifier size? You’ll need to keep the following in mind when making your calculations;

The size of your room/home

What’s the size of the room you’re looking to humidify? Or, are you shopping for a humidifier for the whole house? Whichever the case, calculate the total area (length x width) of the space. For the whole house, add the figures for all the rooms in the house.

The relative humidity in your area

Your relative humidity will determine the degree by which you need to raise the moisture levels in your home. The greater the difference between the existing humidity levels and desired levels, the greater moisture you need to add to the room/house per hour.

How you intend to use the humidifier

Do you intend to use it for year-round humidification? Or are you shopping for a humidifier for the cold season only? It’s also possible to buy a humidifier specifically for the kid’s bedroom or supplemental use (alongside the central/furnace humidifier). All these factors will determine the humidifier size that best fits your situation.

Picking the right humidifier size

After considering the above factors, you can now start looking at humidifier sizes. The following three points should help you make the right pick;

Check the humidifier’s recommended coverage

Most manufacturers indicate the recommended coverage on the product label to help consumers with decision making. Usually, the coverage is given as a range, say 300-400 square feet. You want to make sure that the size of your room/home calculated above is within the humidifier’s recommended coverage.

Consider the mist output rate/hour

Many shoppers don’t even look at this rating. But, it’s very important if you want to take home the right size humidifier. The mist rate/hour will determine whether the humidifier can keep up with your moisture needs. Also, check if the humidifier has different moisture rates/speeds.

Consider moisture output per day

This especially applies to larger humidifiers. On average, you need about a gallon of moisture for every 300 square feet every 24 hours, equating to 10 gallons for a 3,000 square-foot home. Does the humidifier you’re looking at have the capacity to deliver on that requirement?

Is the tank large enough?

Finally, tank size usually has a direct or indirect impact on all three factors above. Therefore, you need to pick a humidifier with a sufficiently large tank. Humidifier tank capacities are measured in gallons or liters. In general, the larger the tank, the larger the area it can effectively humidify.

Other Things to Consider When Choosing a Top-Fill Humidifier

Size, type (by working mechanism), and type (by moisture temperature) are some of the top factors to consider when shopping for a top-fill humidifier. But they aren’t the only ones. Consider the following as well;

Noise

All models make a few sounds when operating. But that doesn’t mean you shouldn’t try to find the quietest humidifiers. Ultrasonic models are arguably the quietest, followed by steam and then evaporative models. Impeller humidifiers tend to be a bit noisy. For room humidifiers, anything under 40 decibels is great. As for whole-house humidifiers, try not to go past 65 decibels.

Ease of cleaning

Top-fill humidifiers, in general, are easy to clean, which is great news. But, some models are even easier to clean. A few even implement self-cleaning technologies. What you want to look for is a unit with a large lid. Ease of disassembly is also essential. If you can find one made with easy-clean material, then that would be excellent.

Intended use

Are you buying the right humidifier for the right purpose? For instance, some humidifiers are designed for bedroom use, others for whole-house use, and some for the kitchen. These units are labeled this way because extra effort is made to make them ideal for those rooms or specific conditions. It wouldn’t be a great idea to buy a kitchen humidifier for the kid’s bedroom.

Aromas and essential oils

Beware – not all humidifiers are designed for use with essential oils. Indeed, in some cases, using essential oils in the humidifier may damage it or even void the product warranty. Therefore, if you’d wish to use essential oils in your humidifier, find a model listed as an essential oil diffuser.

Convenience features

Convenience features may include multiple fan speeds, numerous mist settings, remote control, and smart control. A few modern humidifiers, for instance, are compatible with Amazon Alexa and Google Home devices. Imagine the convenience! The presence of a humidistat can also make a massive difference.

Warranty

Finally, all great humidifiers are backed by solid warranties. If the one you’re looking at has no warranty, consider other options. Focus, especially on the length of the warranty and range of parts/situations covered.

Frequently Asked Questions

How Often Do You Need To Change Water in a Humidifier?

Ideally, you need to change humidifier water every 24 hours. However, for models that have made significant efforts to prevent mold and bacteria growth, you may be allowed to change the water every two or three days.

Do I Need to Unplug the Humidifier Each Time I Refill the Tank?

Yes. Ensure to switch off the humidifier and plug it out. The reason is to prevent electric shocks and potential electrocution. Water can accidentally spill on the socket or wires during refilling. Unplugging the unit reduces the risk of electrocution in such circumstances.

How Should I Clean and Maintain a Top Fill Humidifier?

The same way you would clean any other humidifier. Begin by switching it off and unplugging it from the electrical outlet. Then, disassemble the unit and soak the base and parts in vinegar solution and tank in bleaching agent solution. Soak for at least 30 minutes in both cases, then scrub the base, parts, and tank gently with a soft brush. Once done, rinse with fresh water and leave to dry. Then, reassemble the pieces. Your humidifier is now clean and ready for use.

Can You Use Tap Water in a Top Fill Humidifier?

Yes, you can. However, it’s discouraged. Tap water contains a lot of minerals. These minerals pose a health hazard when breathed into the body. They also tend to cause “white dust,” which can make your home untidy. Instead, you should use distilled or demineralized water.

Can You Use Essential Oils in a Top Fill Humidifier?

It depends on whether the humidifier is designed for essential oil use. The good news is that manufacturers make it very clear whether or not you can use essential oils in the humidifier. Where essential oils use is prohibited, do not add them to the humidifier. They could damage the unit.

Do You Put Hot or Cold Water in a Humidifier?

You should only refill your humidifier with cold water. Though tempting, hot water may damage some of the elements inside the unit and compromise the functioning of the humidifier. If you desire warm humidification, consider investing in a warm-mist humidifier.

Product Reviews

Before we discuss the shopping tips, though, here’s a look at some of the best top-fill humidifiers to consider;

Honeywell HWM-340WC 700 Square-Foot Top fill warm Mist Humidifier

Pros

Easy-fill technology
No costly filters
Adjustable humidity control
Dishwasher friendly
3-year warranty

Cons

Few digital controls
No smart controls

Cons The Honeywell 340WC is a low-maintenance warm-mist humidifier. It boils water to produce vapor, which also eliminates 95% of all airborne bacteria in the water. This unit holds 1.3 gallons of water. When full, the tank can run continuously for 24 hours.

What makes it unique, though, is the ease of refilling. A filling area at the top allows you to pour water into the tank with ease. What’s more, you don’t need to take the tank out for refilling. Just pour water while the tank is inside the unit. The unit is also very easy to clean. Unlike most other humidifiers, it’s dishwasher friendly. The HWM 340WC features several safety features, including an auto-shutoff function that automatically turns the unit off when the tank runs dry.

The humidifier is recommended for large rooms, up to 700 square feet. It comes with adjustable humidity control for maximum comfort and includes a medicine cup for use with liquid inhalants. A 3-year warranty backs it.

Honeywell Model HUL570B Top Fill Cool Mist Humidifier with Auto Shutoff

Pros

Ultra-quiet operation
Auto-shutoff when empty
No filters required
Variable mist output
2-year warranty

Cons

Ideal for smaller spaces up to 300 Sq. Ft.
Essential oil use strongly prohibited

The Model HUL570B is another Honeywell on the list, but a cool-mist model this time. It features a 1.25-gallon tank that runs for 36 continuous hours when full. The unit automatically shuts down when the tank runs empty. It’s also a filter-free humidifier, so you don’t need to worry about the related expenses.

This unit too fills from the top and is very easy to refill. The tank comes off effortlessly and can be refilled at the sink or with a water pitcher. It’s also very easy to clean since the parts disassemble without much effort. You may want to know that the HUL570B is a visible-mist humidifier.

Other standout features of the unit include the visible water window, ultra-quiet operation, variable moisture output settings, and a rotating mist nozzle for directional moisture control. The humidifier comes with an optional demineralization cartridge.

Homasy Model HM510A Cool Mist Humidifier Diffuser, 2.5L Essential Oil Diffuser

Pros

Essential oils-compatible
Auto-shutoff for safety
Very quiet at 25 decibels
Convenient top-fill design

Cons

Best for small spaces (up to 300 Sq. Ft.)
No remote/smart controls

If you’re looking for a top-fill humidifier that you can use with essential oils, look no further than the Homesy model HM510A. First off, it’s a gorgeous compact humidifier that easily fits into any modern décor. Additionally, it’s a very safe humidifier, featuring auto-shutoff and a red LED light that comes on when water runs out.

What’s most impressive about the HM510A, however, is the range of convenience features. For one, the unit offers two mist levels and a Sleep Mode. A sensitive touch button allows you to change the modes conveniently. Secondly, it offers 360-degree humidification thanks to a rotating nozzle. Above all, it’s almost sound-free at just 25 decibels.

The unit allows you to add essential oils directly into the tank so you can enjoy the fragrance immediately.

Elechomes SH8830 Humidifier, 6.5L (1.72Gal) Top Fill Humidifier

Pros

Large room humidifier
Features set-and-forget mode
Remote controlled
Essential oils-compatible
18-month warranty

Cons

Remote buttons don’t light up at night

The Model SH8830 from Elchomes is a modern-looking ultrasonic humidifier. It’s one of the smart models, in case you desire more convenient indoor climate control. For instance, it features a built-in accurate humidistat and intelligent constant humidity system that constantly monitors and keeps humidity levels between 55% and 68%.

The unit is also large enough at 6.5 liters. This is sufficient for spaces up to 850 square feet. The tank runs for 72 hours when full (in the low mist level). The unit has six mist levels in total. A 360-degree rotating nozzle allows you to change moisture direction without moving the moisture. You’ll also love that it has a set-and-forget mode and is remote controlled.

The unit allows for the use of essential oils. But, you can’t drop the essential oils directly into the tank. Instead, you use a tray. The essential oil tray is included.

GENIANI Top Fill Cool Mist Humidifier for Bedroom and Essential Oil Diffuser

Pros

Easy to refill and clean
Features smart sensor
Sufficiently quiet at 38 decibels
Essential oils use allowed
2-year warranty

Cons

No remote control
Ideal for small rooms

This GENIANI humidifier has only been on the market for around a year but is already one of the most sought-after products. It has even won the coveted Red Dot Award. The unit is a smart humidifier that features an in-built sensor that consistently tracks indoor climatic conditions and adjusts humidity levels as appropriate to ensure optimal indoor climate.

This 4-liter (1.05 gallon) humidifier can run for 18 hours continuously on a full tank. An auto-shutoff function springs into action when the tank runs dry. The unit also features LED night lights that turn off whenever you wish. It has four mist settings and is recommended for spaces up to 220 square feet.

The humidifier easily fills from the top, thanks to a large opening. The large opening also makes cleaning a breeze. It’s backed by a two-year limited manufacturer warranty.

AirExpect Model STL-1802B Cool Mist Humidifier for Bedroom

Pros

Ultra-quiet at 28 decibels
3 mist modes – low/medium/high
2-8 hour timer
Advanced microporous carbon filter
Automatic shutoff
Lifetime customer support

Cons

The small tank is best for small rooms
Essential oils strongly prohibited

Finally, you may also want to take a look at this impressive unit from Air Expect. It’s a 3.5-liter (0.92-gallon) model, thus the smallest capacity humidifier on this list. However, it’s still one of the better performers, capable of running continuously for 24 hours on a single refill on the low setting. It features three mist settings in total.

The unit easily fills from the top. The unit is also very easy to clean. It features a 7-color LED mode and arrives with a cleaning brush, manual, and charger adapter. Buyers also get a lifetime customer support guarantee.

It’s important to note that the STL-1802B doesn’t allow for the use of essential oils. You may come across other reviews online that say it does. However, the manual states clearly that you must NOT add any essential oils as such oils can damage the appliance. Indeed, using essential oils in the STL-1802B instantly voids the warranty.

Summary

Humidifiers come in many shapes and designs – top-fill models are a great choice because they are easier to fill and clean. Easy refilling brings an extra degree of convenience while easier cleaning means you’re likely to have cleaner, healthier air in your home.

Nevertheless, make sure to pick a great unit. A great humidifier comes in the right size, has most of the features you desire and is backed by a reliable warranty.