Phoenix indoor air runs drier than almost anywhere in the country. A whole-home humidifier fixes it at the system instead of one room at a time.
into your existing system
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A whole house humidifier installs into your ductwork and adds moisture to the air as the heating system runs, so it treats the whole house rather than one bedroom. It is one of the more worthwhile pieces of comfort equipment you can put in a Phoenix home, and one of the least discussed.
The reason is the number. Comfortable indoor relative humidity sits somewhere around 30 to 50 percent. Phoenix indoor air in winter routinely drops below 20 percent, and heating it drops it further, because warming air lowers its relative humidity without adding any water to it. Most people here live with the results without connecting them to the air.
CMI-AIR installs whole-home humidifiers across Phoenix and the Valley, fitted to the system you already have.
The most common reason people call about this. Air below 20 percent relative humidity pulls moisture out of skin and out of the mucous membranes in your nose and throat. That last part is why dry air leaves people with a scratchy throat and a stuffy nose that has nothing to do with being ill.
Overnight is when it shows up most, because you are breathing the same dry air for eight hours without drinking anything. Recurrent winter nosebleeds, particularly in children, are a common symptom of very dry indoor air.
Static builds in dry air and dissipates in humid air. If you are getting shocked by door handles and the car every winter, and your clothes cling coming out of the dryer, the humidity in the house is low. It is a nuisance rather than a problem, but it is a reliable indicator.
This is the expensive one. Wood gives up moisture to dry air and shrinks doing it. Hardwood floors develop gaps between boards, solid wood furniture develops splits, cabinet doors and trim move, and musical instruments go out of tune and stay there. Replacing a hardwood floor costs many times what a humidifier costs.
Dry air feels colder than humid air at the same temperature, because moisture on your skin evaporates faster and evaporation cools. People respond by turning the heat up, which dries the air further, which makes it feel colder still. Correcting the humidity often means the same comfort at a lower thermostat setting.
For a few weeks in late summer Phoenix gets genuinely humid, and some homes get clammy because an oversized air conditioner satisfies the thermostat too fast to pull moisture out. That is a dehumidification problem, not a humidification one, and it is usually a sizing or staging issue rather than something a piece of add-on equipment fixes. We will tell you which one you have.
Three types get installed in homes, and the differences matter more here than in most markets because our water is hard and our air is very dry.
The simplest and least expensive. A bypass duct routes some warm air from the supply across a water panel and back into the return. No electricity beyond the control, and no fan of its own. The limitation is capacity, and it only works while the furnace is running.
The same idea with a fan of its own, which increases output and means it does not depend on the furnace blower being on. A good middle option, and it handles a larger house than a bypass unit will.
These boil water and inject steam into the duct. The highest output by a wide margin, independent of whether the heating is running, and the most accurate control. They cost more, they use meaningful electricity, and they need more maintenance. For a large or very dry house, or where the humidity has to hold a specific range for wood floors or instruments, this is the one that will actually do it.
Which one fits depends on your square footage, how leaky the house is, your ductwork, whether you have a drain nearby, and how much water hardness you are dealing with. Phoenix water is hard, and hard water is the main thing that shortens the life of any of these, so scale management is part of the recommendation rather than an afterthought.
We measure the indoor relative humidity, look at the square footage and the construction, check the ductwork at the air handler for space, and find the nearest water supply and drain. Hard water is assessed at the same time, because it drives which unit makes sense.
Humidifier capacity is rated in gallons per day and it is matched to the volume of the house and how much air the house leaks. Undersized is the common error here, and an undersized unit runs constantly and never reaches the setpoint.
The unit mounts to the supply or return plenum. A water line is run and a saddle valve or proper tee fitted, a drain line is routed where the unit needs one, and the humidistat is wired in and mounted where it reads the house rather than the duct.
The humidistat is set, output is verified, and we check that the added moisture is not condensing anywhere it should not, which is the one thing to get right on a humidifier install.
This takes five minutes and it is the step most installers skip. Where to set it, what to expect in different weather, when to change the water panel, and how to shut it down for summer.
A whole-home humidifier is seasonal equipment in Phoenix. It works from roughly [November through March] and it should be off the rest of the year.
Leaving one running into the summer is the mistake to avoid. Adding moisture to a house that the air conditioner is working to dehumidify wastes energy and can leave you with condensation problems. Most units have a summer shutoff on the water supply, and it is worth using it rather than relying on the humidistat.
Maintenance is one visit a year. The water panel or evaporator pad gets replaced, the unit gets descaled, and the drain gets cleared. With Phoenix water, skipping the descaling is what kills these units.
Call (602) 437-0066 or use the form. If you are also dealing with dust or allergies, mention it, because filtration and humidity are separate fixes and it is worth looking at both on one visit.
If your indoor humidity is dropping below 20 percent in winter and you are dealing with dry skin, sinus irritation, static or wood furniture and flooring drying out, then yes. Phoenix is one of the strongest cases for one anywhere in the country, precisely because our air is so dry. A cheap hygrometer will tell you your actual number before you spend anything.
Somewhere in the 30 to 40 percent range for most Phoenix homes. Higher than that is more comfortable but risks condensation on windows and inside walls on cold nights, and condensation inside a wall is a much worse problem than dry air. If you have hardwood floors or instruments, the flooring or instrument manufacturer usually specifies a range, and that range wins.
In favour: it treats the whole house, it needs no daily filling, it runs off the humidistat without you thinking about it, and it protects wood floors and furniture. Against: it is a fitted appliance with a water line and a drain, it needs annual maintenance, and with hard water it needs descaling or it scales up and stops working properly.
A portable unit humidifies the room it is in, needs filling by hand, and needs cleaning often or it grows things. A whole-home unit is plumbed in, treats every room the ductwork reaches, and runs automatically. If you only care about one bedroom, a portable is fine. If the whole house is dry, it is the wrong tool.
Marginally, and it can go the other way. A bypass humidifier uses almost no energy of its own. A steam unit uses a real amount. Against that, humid air feels warmer, so most people end up running the thermostat a degree or two lower and the net difference is small.
Half a day for most bypass and fan-powered units. Longer for a steam humidifier, and longer again if a water line has to be run any distance or a drain has to be added.
It scales it up, which reduces output and eventually stops the unit working. Phoenix water is hard, so this is a real consideration rather than a footnote. It is managed with annual descaling, choosing a unit that tolerates hard water, or feeding it from a softened supply if the house has a softener.
No, it would make it worse. That is a dehumidification problem and the usual cause is an air conditioner oversized for the house, which cools the air fast and shuts off before it has run long enough to remove moisture. The fix is on the cooling side, and it is worth diagnosing properly rather than adding equipment.
CMI-AIR is the residential division of Consolidated Mechanical, a local, family-owned commercial air conditioning company with more than 30 years of experience.
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