Room Humidifiers vs. HVAC Humidifiers

Price

• Portable, small room humidifiers cost less than the large models used to maintain humidity in the whole house at once, according to Allergy Buyer's Club. A humidifier installed in the HVAC system also requires the entire system to be modified. This comes with serious installation fees. However, consider how many rooms you need a higher humidity in. Buying and running a room humidifier for each room may be just as expensive as installing a whole house system.

Humidity Control

• While some room humidifiers have monitoring equipment that shuts them off when a certain air humidity level is reached, most don't. Whole house humidifiers come with more sophisticated monitors. Too much moisture causes water to gather on the walls or items in the room and leads to mildew and mold growth, says Air Assurance. Using a whole house humidifier eliminates the need to constantly turn a small unit on and off to reach a certain moisture level.

Cleaning

• The water tank on a room humidifier isn't sealed and requires refilling on a daily or weekly basis. You'll also need to clean the appliance regularly, in some cases daily, to prevent mold and bacteria from breeding in the water and causing serious illness, according to Sanders Home Services. Water comes from a sealed tank that is constantly refilled in an HVAC humidifier. The occasional air or water filter change is the only cleaning a whole house system needs.

Sound

• Both room and HVAC system humidifiers use blowers to circulate the mist or steam created into the air supply. Portable systems have the blower in the unit, while HVAC humidifiers hide it in the wall, attic or basement. This drastically lowers the noise produced by a whole house appliance. The amount of noise produced by room humidifiers vary by brand and model, but most will be noisier than a permanently installed system.