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Honeywell Germ-Free Cool Mist Humidifier

The Honeywell HCM-350 UV Cool Moisture Germ Free Humidifier (Honeywell HCM-350-UV light bulb) is a popular choice for homeowners looking to improve air quality and humidity in medium-sized rooms.


As an owner of the Honeywell HCM-350 UV Cool Moisture Germ Free Humidifier, I am delighted to share my experience with this exceptional appliance.

This humidifier has been a game-changer in my home, effortlessly maintaining the perfect humidity level in medium-sized rooms for over 10 years!

Its innovative UV germ-killing technology and antimicrobial filters have given me peace of mind, knowing the air my family breathes is cleaner and healthier. The ease of use and maintenance of this unit is truly remarkable; its simple design and quiet operation make it a seamless addition to our daily lives.

With its consistent performance and elegant design, the Honeywell HCM-350 has not only improved our air quality but has also seamlessly blended into our home. This humidifier is an indispensable tool for anyone looking to enhance their living environment with pure, moisturized air.

Table of Contents

Size and Design

The Honeywell HCM-350 UV Cool Moisture Germ Free Humidifier is thoughtfully designed with dimensions that make it suitable for medium-sized rooms without being overly intrusive.

  • Dimensions: The humidifier measures 17.5 x 9.4 x 11.8 inches, making it suitable for medium-sized spaces.
  • Weight: It weighs 11.7 pounds, which is on the heavier side for humidifiers but still manageable.
  • Capacity: The unit has a 1-gallon tank and can operate for up to 24 hours on a single fill, making it convenient for daily use.
  • Room Coverage: It’s capable of effectively covering an area of up to 500 square feet.

Features and Operation

The Honeywell HCM-350 UV Cool Moisture Germ Free Humidifier boasts a range of features and operational aspects that enhance its performance and user experience. Firstly, its evaporative humidification method is both efficient and safe. It uses a wick filter to absorb water from its 1-gallon tank and a fan to distribute moisture evenly, covering up to 500 square feet. This method ensures no risk of burns from hot water, making it safe for homes with children.

In terms of health and safety, the humidifier excels with its UV technology, which kills germs and bacteria in the water, ensuring that the moisture added to the air is clean and healthy. Additionally, its antimicrobial filters inhibit the growth of mold and bacteria on the filter, further purifying the air.

User-friendliness is another key aspect of the HCM-350. It features a simple, intuitive control dial with three fan speed settings, allowing for easy adjustment of humidity levels. Despite its powerful operation, the humidifier operates quietly, making it suitable for use in bedrooms or other quiet spaces.

  • Humidification Method: This is an evaporative humidifier, which includes a reservoir, a wick to absorb and evaporate the water, and a fan to assist in the process.
  • Safety: The device utilizes ultraviolet rays to kill germs and bacteria in the water, coupled with an antimicrobial process in the filter to prevent germ and fungal growth.
  • User-Friendly: It features a simple rotating dial with three fan settings, making it straightforward to operate.
  • Noise Level: The unit functions with minimal noise, emitting a soft white noise that is less than many other evaporative humidifiers.


Maintaining the Honeywell HCM-350 UV Cool Moisture Germ Free Humidifier is a straightforward and user-friendly process, designed to ensure long-term efficiency and hygiene. The key component in its maintenance is the HAC-504 Humidifier Replacement Filter, which is specially treated with an antimicrobial process to prevent the growth of mold, fungus, and bacteria. This feature not only enhances the moisture output but also ensures that the air humidified is free from harmful microorganisms.

The humidifier’s design facilitates easy disassembly, allowing each part to be cleaned individually. This aspect of the design is particularly beneficial for regular maintenance, ensuring that all components are kept in optimal condition. The simple structure of the unit, without hard-to-reach parts, makes regular cleaning a hassle-free task, contributing to the overall durability and effectiveness of the humidifier.

Additionally, the use of Protec Antimicrobial Cleaning Cartridges is recommended to maintain the cleanliness and efficiency of the humidifier. These cartridges work in conjunction with the filters to provide an extra layer of protection against microbial growth, ensuring the unit remains clean and safe for extended periods.

Overall, the Honeywell HCM-350 is designed for ease of maintenance, making it a convenient choice for those who value both performance and hygiene in their home humidification solutions

  • Ease of Maintenance: The Honeywell HCM-350 is designed for easy cleaning and maintenance. It can be disassembled for cleaning individual parts, simplifying regular maintenance.
  • Filter Replacement: The unit uses the HAC-504 Humidifier Replacement Filter, optimized for enhanced moisture output and antimicrobial treatment.

Overall Assessment

The Honeywell HCM-350 is a solid choice for those seeking an efficient and safe evaporative humidifier for medium-sized rooms. Its ease of maintenance, coupled with its safety features like UV germ-killing technology and antimicrobial filters, make it a practical option. However, its size and lack of an automatic shut-off feature are potential drawbacks for some users.

  • Pros: Reliable for alleviating allergies and dry skin, safe with cool mist technology, user-friendly, easy to maintain, and relatively quiet operation.
  • Cons: The unit is somewhat bulky and lacks an auto shut-off feature, requiring manual monitoring of the water level.

Using distilled water and regular cleaning will help maintain its efficiency and longevity. Its quiet operation makes it suitable for bedrooms, nurseries, and living areas.

For more detailed information and maintenance procedures, it’s advisable to refer to the user manual and the manufacturer’s website.

Replacement Parts