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How Does a Whole House Humidifier Work

Portable humidifiers are the most common and easily identifiable humidifiers on the market. You plug the device into your outlet and watch as humidity levels increase in a particular room of your house. Portable humidifiers are great for your bedside table, children’s room, or nursery.

But, what if you need to increase the humidity levels of your entire home? 

In this blog we examine whole house humidifiers including their function, how exactly they work, and how much maintenance is required to keep your device in tip-top shape. 

What is a Whole House Humidifier?

A whole house humidifier is a unit that attaches to your HVAC (Heating, Ventilation, and Air Conditioning) system and elevates the moisture levels throughout your home. 

Whole house humidifiers can humidify spaces with 1,000 square feet or higher depending on the device output. Comparatively, a portable humidifier generally humidifies spaces between 300 and 600 square feet.  

How Does a Whole House Humidifier Work?

A whole house humidifier seems like a complex device, but the process is really quite simple. The whole house humidifier is attached directly to your HVAC system and connected to your water supply. When your humidifier is on, the air drawn into the HVAC system flows into the humidifier passing through a foam pad moistened by the water supply. The moistened air is then pushed through the furnace and dispersed into your home through the ventilation system. 

Types of Whole House Humidifiers

There are three primary categories of whole house humidifiers: bypass humidifiers, fan humidifiers, and vaporizers. Each of these humidifiers effectively increases the level of humidity in your home, though the method by which they humidify is slightly different. 

Bypass Humidifiers

Bypass humidifiers work by drawing warm air from inside the home, passing it through a moistened delivery system (a tray or a pad) and distributing this hydrated air through the furnace. 

Fan Humidifiers

A whole house fan humidifier operates exactly like a bypass humidifier with one difference: a fan humidifier uses a fan to accelerate the evaporation process. The additional evaporation from a fan humidifier creates higher levels of humidity compared to a bypass humidifier. 


A vaporizer is the most efficient way to humidify your whole home. Steam vaporizers boil water and push the resulting vapor through the ventilation system.  

How much maintenance does a whole house humidifier need? 

A whole house humidifier is a low maintenance home appliance. Once you install your whole home humidifier, you can virtually forget about the device between scheduled cleaning. 

When you switch your whole house humidifier off, the water is drained from the device so you need not worry about sitting water developing mold and bacteria. When caring for your whole house humidifier, you need to replace the tray or pad yearly to ensure a safely operated machine. You may also want to deep clean your device with a water and distilled white vinegar solution once per year to keep your machine running smoothly. 

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