Whole house humidifier installation in West Orange and Essex County, NJ

HomeGuide puts a whole-house humidifier at $400 to $1,200 installed, with a national average of $750. Carrier estimates $400 to $800 installed for a bypass unit and $1,200 to $2,500 for a steam unit. A steam unit that needs a new circuit costs more; HomeGuide puts a dedicated circuit at $250 to $900. These are published national ranges, not MDL prices.

A bypass humidifier uses the furnace blower to push warm air through a wet water panel, with a small bypass duct between the supply and return ducts. A fan-powered (power) humidifier has its own fan, so it needs no bypass duct. Carrier rates its large bypass and fan-powered models at up to 18 gallons a day, and its small bypass at 12. HomeGuide says bypass units are cheaper and quieter, and fan-powered units suit larger homes.

On the ductwork next to the furnace. HomeGuide says bypass models can go on the return or the supply duct, and fan-powered units usually go on the supply duct. A steam unit sends steam into the ductwork. The humidistat is mounted separately; HomeGuide says at least 6 inches from the humidifier.

Yes, if the house has a forced-air furnace and ducts. HomeGuide says a humidifier is easiest to add during a furnace replacement but can be added to an existing furnace, and puts the labor at $100 to $900. Carrier says older systems may need duct or electrical changes, which add labor.

HomeGuide calls it a complex job best left to a professional: the duct is cut, a water line is tapped, a drain is run, and the humidistat and water valve are wired. It warns that skipping the manufacturer's instructions can cause leaks, flooding or electrical problems, and says most manufacturers require a licensed HVAC installer for the warranty.

Low enough that the windows stay dry. The EPA says to keep indoor humidity below 60%, ideally between 30% and 50%. University of Minnesota Extension says 25% in winter to 50% in summer, and NDSU Extension says to aim for about 40% in winter. Turn it down on very cold nights or when windows start to sweat.

On during the heating season, set to a level that keeps the windows dry, and lower on the coldest nights. Carrier recommends a spring shutdown that follows your owner's manual and a fresh water panel before the next heating season. Bypass units also have a damper with a seasonal setting; Carrier's startup checklist covers it.

Too much moisture, if it is set too high. The EPA lists condensation on windows, walls or pipes as a sign of high humidity, and University of Minnesota Extension says moisture problems may start above 50%. Other downsides: a water panel to replace every year, a water line and drain that can leak if neglected, and, for steam units, a dedicated circuit and a higher running cost ($150 to $480 a year, HomeGuide).

Static shocks, dry skin and chapped lips in winter, and wood floors, trim or furniture that crack (HomeGuide, Carrier). A hygrometer settles it; HomeGuide puts one at $10 to $70. If it reads below 30% on a winter day, the air is drier than the EPA's 30% to 50% range.

It boils water with electricity and sends the steam into the ductwork, so it does not depend on warm furnace air (Carrier). Carrier's steam model makes up to 34 gallons a day. HomeGuide says steam units need a dedicated electrical circuit and take 4 to 6 hours to install, against 2 to 3 hours for bypass and fan-powered units.

Maybe, and the type matters. HomeGuide says heat pump air is not hot enough for a drum or flow-through humidifier to work well, and recommends steam. Carrier names its fan-powered humidifier as the preferred type for homes with heat pumps. HomeGuide also says low humidity in a heat pump home can come from air leaking in around windows and doors.

Not the duct-mounted kind, because it needs forced air. AprilAire sells a steam humidifier with a wall-mounted fan pack, the Model 865, for homes without ducted air systems. Otherwise, portable humidifiers work room by room; the EPA says to clean them every third day. Ask MDL what fits your house.

Once a year, before the heating season, on evaporative (bypass and fan-powered) units, per Carrier, and sooner with hard water. HomeGuide puts replacement pads at $10 to $20. Carrier says paper or mesh water panels cannot be cleaned and must be replaced. Steam units use a canister that is replaced when the unit calls for it.

It depends on the work and your town. Maplewood's construction office lists new wiring and new ductwork as work that needs a construction permit, and replacing duct work and repairing furnace equipment as work that does not. A humidifier is not named on either list. Ask your town's construction office before the work starts.

Call 973.809.2339 or send the form on this page. Include your town, whether you have a furnace with ducts or a boiler with radiators, the furnace model if you can read it, and roughly how big the house is. MDL holds a New Jersey master HVACR contractor license (19HC00308200) and a New Jersey electrical contractor license (34EI01606200).