Whole House Humidifier Cost

• A standard (non-steam) central humidifier unit costs about $100 -$250, depending on capacity; although some higher-end models can run $300 -$500. Options to look for include an adjustable humidistat or a bypass gate to block the humidifier in the summer (if you're attaching it to a heat pump or central air conditioning). Although some models are reasonably easy to install, the process does require electrical wiring, plumbing and sheet metal skills. (However, one manufacturer estimates that about 80 percent of its customers self-install a central humidifier without professional assistance.) Professional installation runs about $100 -$300 or more (depending on your heating system configuration and local rates), bringing the total installed cost to $200 -$550 for an average unit and $500 -$1,050 for higher-end models.
• For more precise control, steam humidifiers -- which are connected to your home's ductwork but can operate independently of the heating/cooling system -- cost $300 -$1,100 or more (depending on capacity and options such as an automatic humidistat that adjusts to changes in outdoor temperatures). Steam humidifiers generally require professional installation which can bump the total cost up to $600 -$1,600 or more, depending on configuration and local rates. Note: many steam ductwork humidifiers use an electric heating element, which make them costly to operate. Because of the cost, steam humidifiers are more likely to be used in commercial buildings than in a residential setting.

• Most central humidifiers (a box or drum plus hoses/ductwork) are mounted on the ductwork near the blower of your heating system, whether it's a furnace or a heat pump. Most central humidifiers cannot be added to a house that is heated by hot water or electricity, or one without ductwork ThisOldHouse.com says a typical professional installation takes 4-6 hours, and provides a video illustrating the process.
• Standard (non-steam) central humidifiers pass air from forced-air system across a humidifying surface, so humidification takes place only when your forced-air system is running. Drum systems use foam or fabric belts to move moisture into the air; disc wheel humidifiers are similar to drum systems but uses plastic discs instead of a foam or fabric drum; and flow-through models use a rectangular foam or expanded aluminum pad to transfer moisture to the air. There are also spray mist systems, which spray water vapor into the heated air in the ductwork. CornerHardware.com provides an overview, including installation details.
• Steam humidifiers heat water until it evaporates, then inject the resulting steam into the ductwork of your forced-air system. These humidifiers operate independently from your forced-air system, so you don't need to turn on the heat to add moisture to the air.

• Humidity levels over 50 percent can promote dust mites and mold spore growth, so It's important to monitor humidity levels when using a central humidifier. Recommended winter humidity levels are 30-40 percent. You can get a hygrometer (humidity gauge) for $15 -$80.

• A less-expensive alternative to a central humidifier is to weatherstrip your home to keep more moisture inside, or use other methods of moisture control.

• When choosing a central humidifier, make sure it can be installed relatively easily with the existing configuration of your forced-air heating system.
• Central humidifiers are sold by most home improvement stores or heating equipment dealers. Major manufacturers include Aprilaire, Honeywell, Lennox and Skuttle.

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