Whole-House Humidifier

Types of whole-house humidifiers and how they work

Bypass humidifiers use the furnace blower to push air through a wet evaporator pad, borrowing airflow between the supply and return ducts. Fan-powered models add their own small fan to drive more air across the pad, so they deliver more moisture without depending on a bypass duct. Steam humidifiers heat water electrically and inject steam directly into the supply air, producing the most output and working independently of furnace run time. All three are governed by a humidistat, and the pad-style units need their water panel replaced regularly, typically each heating season, to prevent mineral buildup and keep output up.

Why winter air gets so dry in Southeastern Pennsylvania homes

Cold outdoor air holds little moisture, and once a furnace heats it, the relative humidity indoors can plummet. The symptoms are familiar in the region's long heating season: static shocks, dry skin and sinuses, creaking hardwood floors, and gaps opening in woodwork. Keeping winter humidity roughly in the 30 to 40 percent range restores comfort without fogging windows, though leakier older homes may need to aim lower in deep cold to avoid condensation. A whole-house unit treats every room and refills itself from the plumbing, which is why many homeowners graduate to one after a winter of hauling water to portable humidifiers. PJ MAC HVAC installs and services humidifiers as part of its indoor air quality work.