Dual Comfort Cool + Warm Mist Humidifier with Humidistat, HWC778

Dual Comfort Cool + Warm Mist Humidifier with Humidistat, HWC778

The Dual Comfort Cool + Warm Mist Humidifier with Fusion Mist technology fills your air with refreshing moisture to help relieve dry air discomforts and also lets you choose and customize your comfort. It is a cool mist humidifier and a warm mist humidifier, giving you the flexibility to choose your temperature based on personal preference or as weather changes. Fusion Mist Technology boils water and fuses it with cool mist to generate the ideal warm mist temperature. During cold and flu season or when the air is simply just dry, you can rely on this humidifier for your entire family. 

  • 3 mist settings each for cool and warm
  • 2-direction mist outlet
  • Enviracaire® digital humidistat
  • essential oil cup (oils not included)
  • no filter to change
  • up to 36 hour run time

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Product details

Details & Dimensions

Both cool and warm mist temperatures add necessary moisture to the air, and help ensure proper humidity levels in your home. Indoor humidity levels between 40-60% can help relieve cough and congestion, keep throat and nasal passages hydrated, temporarily relieve dry air discomfort, protect furniture, reduce static electricity and even keep plants healthier.

Honeywell has been keeping families comfortable in their homes for over 100 years with our full line of humidifiers, filters and more.

Tank Size: 1.5 gallons
Room Size: Large
Run Time: Up to 36 hours
Dimensions: W 10.12″ x H 14.65″

Owner's Manual & FAQs

HWC775/HWC778 Dual Comfort Cool + Warm Mist Humidifier Owner’s Manual

Question: How do I clean my Honeywell Ultra Plus Ultrasonic Cool Mist Humidifier?

Answer: To keep your humidifier running efficiently, clean it regularly. Weekly cleaning is recommended. All maintenance should be done in the kitchen or bathroom on a water-resistant surface near a faucet.

To properly clean your humidifier, we recommend the separate processes of Scale Removal and Disinfecting.

These two processes must be performed separately. See product support page for step by step cleaning instructions.

Question: Why is there white dust?

Answer: With an ultrasonic humidifier, a built-in nebulizer vibrates the water at ultrasonic frequency which causes the water droplets to break into a fine, cool mist that you can see. Naturally occurring minerals in your water get projected out with the mist and can settle around the unit in the form of white dust. In hard water areas, we recommend using demineralization cartridges with your ultrasonic humidifier to capture minerals in the water and to help reduce white dust on surfaces. You can also dilute tap water with distilled water to minimize white dust.

Question: Why does it sound different on warm mist setting than cool mist setting? ?

Answer: The sound may increase on warm mist setting as the heating element warms up to boil water. Wait up to 5 minutes for water to boil then sound should decrease; sound will be slightly higher on warm mist setting.

For additional FAQs or post-purchase support, please visit our support page.

Videos & Support

Product Features
Honeywell Dual Comfort Cool + Warm Mist Humidifier HWC778 – Product Features


Dual Direction Mist Outlet
Direct Mist in two directions

Essential Oil Cup
Add essential oil for extra comfort
(oil not included).

Choose Your Comfort
Both cool and warm mist provide temporary relief from dry air discomforts. Dual options give you the flexibility to choose your temperature based on your personal preference or as seasons change