Guardian Technologies is an Ohio-based manufacturer of home appliances that employs cutting-edge technologies. Despite being a relatively new enterprise, Guardian Technologies has been able to secure their position as one of the top brands in the home appliance industry. Their extensive line of products all seek the singular goal of providing affordable solutions to common household problems like poor indoor air quality.

They’re best known for their line of GermGuardian air purifiers but also offer an equally impressive line of ultrasonic humidifiers under the brand name, PureGuardian. PureGuardian humidifiers are cost-effective, high-quality ultrasonic humidifiers that have gained unrivaled popularity among users. In this article, we’ll be comparing 7 of the best-selling PureGuardian ultrasonic humidifiers in the hopes that it’ll help you make an informed decision when picking out a humidifier for your home.

  • Cool mist, ultrasonic humidifier
  • Covers up to 400 sq. ft.
  • 1.5-gallon tank capacity
  • Silver Clean Protection fights the growth of mold and mildew on the surface of the water tank
  • 12-hour timer
  • 3-year warranty

  • Cool mist, ultrasonic humidifier
  • Covers up to 250 sq. ft.
  • 1-gallon tank capacity
  • Silver Clean Protection fights the growth of mold and mildew on the surface of the water tank
  • Automatic shut off
  • 3-year warranty

  • Cool Mist, ultrasonic humidifier
  • Best for small rooms
  • 0.5-gallon tank capacity
  • Silver Clean Protection fights the growth of mold and mildew on the surface of the water tank
  • 2 output levels
  • 1-year warranty

  • Dual mist capability
  • Large room coverage and tank capacity
  • High daily humidity output
  • 12-hour timer
  • Runs quietly
  • Silver Clean Protection prevents growth of bacteria, molds, and mildew
  • No filters to replace
  • Affordable

  • Cool mist, ultrasonic water bottle humidifier
  • Best for small rooms
  • Variable mist output
  • Adapter for conventional water bottles
  • Night light
  • 1-Year warranty

  • Warm and Cool mist, ultrasonic humidifier
  • Covers up to 300 sq. ft.
  • 1.32-gallon tank capacity
  • Smart Mist Technology automatically monitors humidity levels and adjusts mist output
  • 12-hour timer
  • 3-year warranty

  • Cool mist, ultrasonic humidifier
  • Covers medium-sized rooms
  • 1.5-gallon tank capacity
  • Aroma tray for essential oils
  • Variable mist output
  • 3-year warranty


If you’re looking for a sleek humidifier that’s both powerful and easy on the eyes, then look no further than the H3200WCA. It’s a tower-type cool mist humidifier that can easily be placed anywhere in the house without taking too much space.

Rated to cover up to 400 sq. ft. of space, the H3200WCA is considered a large room humidifier. It has large tank that can hold 1.5 gallons of water, which allows the H3200WCA to run for a whopping 100 hours on each filling. This high-end humidifier also features PureGuardian’s signature Silver Clean Protection antimicrobial treatment to keep mold growth to a minimum.

Unfortunately, the H3200WCA is not without flaws. First of all, it’s designed in such a way that makes it difficult to refill it. The H3200WCA also faces the same leaking complaints that the previous models had. This is very disappointing, especially considering how expensive the H3200WCA is. Overall, the H3200WCA remains a premium cool mist humidifier that is powerful, elegantly-designed, and feature-packed.

Pros

  • Large room coverage
  • Large tank capacity
  • Long runtime (up to 100 hours)
  • 12-hour timer
  • Silver Clean Protection prevents growth of bacteria, molds, and mildew
  • Space-saving tower design

Cons

  • Expensive
  • Difficult to fill
  • Leaking problems

The H965 from PureGuardian is a mid-range cool mist ultrasonic humidifier with a modest price tag. Although it is only rated to cover small rooms, the H965 doesn’t skimp on power and performance: it’s able to run continuously for up to 70 hours on each filling and has a high daily humidity output of 3.17 gallons.

Unfortunately, one of the biggest complaints users have about the H965 is that it’s incredibly mold-prone despite having Silver Clean antimicrobial treatment on the water tank. In addition to this, many users report their H965 suddenly stops working after a few months of use. While all these may be isolated issues, it’s best to keep them in mind.

The H965 easily makes up for these issues, by being an affordable but powerful humidifier that’s compact and features an optional night light. It’s incredibly easy to use and is quiet as a mouse while it’s running, which makes it perfect for people who are planning to use it on their bedside table.

Pros

  • Large tank capacity
  • Affordable
  • No filters to replace
  • Long runtime (up to 70 hours)
  • High daily humidity output (up to 3.17gal/day)
  • Optional night light
  • Small enough to place on desktop
  • Quiet and easy to use

Cons

  • Small room coverage
  • Releases white dust
  • Mold-prone
  • Durability issues


The PureGuardian H940 is a mini ultrasonic humidifier that’s small enough to place on your office desk or to bring with you when you’re traveling. Its sleek design allows it to easily find a place where space is at a premium. Because of its size, the H940 only has a small 0.5-gallon tank and is only capable of covering areas up to 210 sq. ft. in size. Aside from such limitations, the H940 is rumored to be a short-lived device which is probably why it’s only backed by a 1-year warranty.

On the bright side, the H940 still features the same Silver Clean Protection treatment in its water tank as well as a low water indicator. Surprisingly, it is able to run for up to 30 hours on each filling, which is quite a feat considering the small tank. Overall, the H940 is a good choice for people on a tight budget and looking to humidify small areas.

Pros

  • Affordable
  • Small enough for travel
  • Long runtime
  • Easy to use and maintain
  • Quiet
  • Silver Clean Protection prevents growth of bacteria, molds, and mildew
  • Low water indicator

Cons

  • Small room coverage
  • Small water tank
  • Durability issues
  • Releases white dust
  • Short warranty

 

One of PureGuardian’s pricier models is the H4810, a dual mist humidifier that is capable of servicing areas up to 650 sq. ft. in size. Being a large room humidifier, naturally the H4810 has a larger frame that weighs in at more than 7 pounds.

One of the drawbacks of owning this device is that maintenance can be difficult. There are several nooks and crannies to clean, and the tank opening is not as large as we’d like. In addition, an alarming number of people have complained that the H4810 has a wonky low water indicator that flashes on even when the tank is full.

The H4810 nevertheless has several redeeming qualities. Aside from having an enormous water tank, it also has a high daily humidity output of 2.5 gallons/day for either warm or cool mist. It also has a 12-hour timer and 3 output levels from which users can choose. Surprisingly, for such a powerful humidifier, the H4810 runs quietly enough for you to sleep soundly at night.

Pros

  • Dual mist capability
  • Large room coverage and tank capacity
  • High daily humidity output
  • 12-hour timer
  • Runs quietly
  • Silver Clean Protection prevents growth of bacteria, molds, and mildew
  • No filters to replace
  • Affordable

Cons

  • Expensive
  • Releases white dust
  • Hard to clean and fill
  • Bulky design
  • Problems with low water indicator

In PureGuardian’s line of humidifiers, the H500 is no doubt the smallest. It is the only water-bottle humidifier that Guardian Technologies offers, and it did not disappoint. Although we didn’t crown it as the best water-bottle humidifier, the H500 is still a pretty solid option for people who like to travel.

One of the biggest downsides of the H500 is that it lacks a few features that would’ve been useful, like a an automatic shut off feature and a low water indicator. Leaking is also a complaint that keeps popping up from users and while the cause for this is unknown, some users speculate that it’s a critical flaw in design.

With all things considered, the H500 is still a reliable water-bottle humidifier that’s quite modestly priced. It’s a very straightforward, no frills device that features a simple dial knob for adjusting mist output. It’s easy to use, easy to maintain, and easy on the wallet.

Pros

  • Compact, lightweight
  • Quiet and easy to use
  • Affordable
  • Easy to clean and maintain
  • Variable mist output
  • No filters to replace

Cons

  • Small room coverage
  • Leaking problems
  • No low water indicator and automatic shut off

Another premium dual mist humidifier from PureGuardian is the H7550, rated to cover areas around 300 sq. ft. in size. It boasts a large tank that can hold 1.32 gallons of water, allowing it to run for up to 90 hours on each filling.

Unfortunately, the H7550 is not without flaws. Some design issues include minor annoyances such as glaringly bright control panel lights and settings going to default every time you turn off the humidifier. And, like all the humidifiers on this list, this will release white dust when you use hard water.

However, these flaws can be easily overlooked, especially when you take into consideration the sheer power of the H7550. Its best features include an extended reach wand, which helps even out mist distribution in the room, as well as a smart mist sensor that automatically adjusts mist output to your preference. It’s undeniable that the H7550 is one of PureGuardian’s premium humidifiers that is big on power, performance, and durability.

Pros

  • Dual mist
  • Medium to large room coverage
  • Large tank capacity
  • Long runtime (up to 90 hours)
  • High daily humidity output (up to 3.3 gal/day)
  • 12-hour timer
  • Smart mist sensor automatically adjusts mist output
  • Features unique extended reach wand for even mist distribution

Cons

  • Expensive
  • Returns to default settings after turning off
  • Releases white dust
  • Bright control panel lights

The PureGuardian H1175 is another mid-range cool mist humidifier from PureGuardian that is rated to cover medium-sized rooms. One of its key features is its convenient, top-fill water tank which allows for easier refills.

Unfortunately, the PureGuardian H1175 is also prone to mold, based on several user complaints. Even with regular, weekly cleaning, the same problem persisted. This comes as a surprise, especially since the PureGuardian H1175 is also treated with Silver Clean Protection, which should minimize mold growth. Aside from that, users have also complained of durability issues and cleaning difficulty. Overall,  the PureGuardian H1175 is a robust humidifier that puts a premium on convenience and ease of use. As an added bonus, you get a scented pad slot in which you can diffuse essential oils as you humidify the room.

Pros

  • Medium room coverage
  • Large tank capacity
  • Convenient, top-fill tank design
  • Can be used with essential oil pads
  • Easy to use

Cons

  • Mold-prone
  • Difficult to clean
  • Durability issues
  • Releases white dust

FAQ

How do ultrasonic humidifiers work?

An ultrasonic humidifier uses a diaphragm that vibrates at an ultrasonic frequency to create water droplets that are released in the form of mist. These types of humidifiers can either emit warm mist only, cool mist only, or both.

Read also: https://www.howtohome.com/humidifier/best-dual-mist-ultrasonic-humidifiers/

How often should I clean my humidifier to prevent mold growth?

Generally, manufacturers will suggest thoroughly cleaning the humidifier once a week with white vinegar and bleach. The white vinegar is for descaling the humidifier and removing any mineral deposits that might have stuck to the walls of the water tank and other parts of the humidifier. The bleach is for disinfection, making sure that the humidifier is free from any bacteria or mold. For safety purposes, however, it’s important to rinse the humidifier parts after bleaching so that you don’t end up inhaling any harmful chemicals.

Why is there a puddle of water around my humidifier?

One of the most common causes for this is over-humidifying. It’s possible that your room is already quite humid. In this case, the mist no longer has anywhere to go and settles instead around the humidifier, causing the surrounding area to become wet. To address this problem, it’s best to turn off the humidifier and allow air to circulate in the room.

What is Silver Clean Protection and why is it used in my PureGuardian humidifier?

The antimicrobial activity of silver has long been known and has found a variety of applications in different industries. In PureGuardian humidifiers, the Silver Clean Protection technology pertains to small particles of silver which are embedded in the water tank to prevent the proliferation of mold and mildew.

How can I avoid the spread of white dust from my humidifier?

To prevent the spread of white dust, it’s best to use distilled or demineralized water for your humidifier. Unfortunately, this may add up to quite a hefty sum in the long run since distilled water is more expensive. Another option would be to purchase a demineralization cartridge for your humidifier that can trap minerals before they become airborne. Otherwise, you can opt for an evaporative humidifier which has a wick filter that removes minerals from water before releasing it into the room.

Final Thoughts

Guardian Technologies has been producing small appliance-based solutions to common indoor air quality problems since 2002. While relatively new to the home appliance industry, Guardian Technologies has repeatedly proved themselves a force to be reckoned with. Their range of PureGuardian humidifiers is wide and varied, all designed to suit different needs. After much consideration, we’ve decided that the best PureGuardian humidifier is the H3200WCA. Its sleek design, large tank capacity, and impressive runtime make it a powerful and robust humidifier worth every penny.

Further Reading