Whole House Humidifiers: Your Options
Drum, Flow-through and Spray Mist Humidifiers
Whole house humidifiers are normally units that are connected to an HVAC system in a home and they use the airflow and ductwork of these systems to humidify and circulate air throughout the house.
Some whole house humidifiers have built-in fans that are used to move air through the humidifier to absorb moisture. It is possible to find portable humidifiers that are capable of humidifying an entire house but these tend to be large and noisy.
There are three main types of whole house humidifiers:
Drum systems use belts made from foam or fabric that rotate through a water reservoir. Air from the HVAC system is blown over the wet belt, absorbing moisture and carrying it throughout the house. Drum system whole house humidifiers tend to be the least expensive but can be high maintenance as they require frequent cleaning to prevent mold forming in the reservoir.
Instead of using a belt, flow-through systems use a foam or aluminum pad to humidify the home. These systems are connected to their own water supply instead of using a reservoir which does mean there is no need to worry about refilling it. Water is slowly passed through the pad to soak it and air from the HVAC system is then passed through the pad to absorb moisture. One draw-back with a flow-through whole house humidifier is that it produces excess water that needs to be drained away via a floor drain.
Both drum and flow-through humidifiers are also known as evaporative humidifiers.
Spray mist humidifiers
Spray mist systems use a mister to physically spray water vapor into the air which is then carried through the HVAC ductwork into the house. Spray mist whole house humidifiers come in three different types:
Warm mist humidifiers – use a heating system, such as a furnace, to carry warmed water vapor into the house. Some steam humidifiers cool the steam slightly before it is released and these are sometimes referred to as warm mist humidifiers.
Steam vaporizers – these use heating elements, normally two, to heat water in the reservoir and produce steam. Steam vaporizers carry a small risk of burning so it is not recommended for those with young children.
Cool mist humidifiers – cool mist systems work the same way as warm mist humidifiers except that they produce cooler mist. This is usually done by either just spraying water into the air without the aid of a heating system or it is used in conjunction with the air conditioning.