I am not a lover of humidifiers on furnaces .
They are a great place for bacteria to grow as most seldom get any cleaning .
They can rust out the Furnace and can also add a lot of moisture into the home when it is not needed.
Most homes now have HRV units .
Even if the water is shut of if the damper is not closed about 15% on the air goes in circle when the furnace/AC fan is in operation .


I have seen them overused and caused severe mould in homes.

Humidifiers can be useful to increase comfort levels within the home during the Winter months but MUST be managed and maintained well to avoid window condensation and other concerns.

I explain to my clients their proper use and maintenance.

I simply tell my clients to divide their homes total sq/ft by 1,500 and that is the number of days per week they need to make pasta for dinner. The steam rising from the boiling water will be more than sufficient to stabilize the homes RH. During the hot summer months, they can only make Lasagna using the ‘dry noodle’ method.


True Michael but the debate is what Roy’s picture points out and my experience too. They are never maintained well enough to not grow bacteria.
I even question the newer ones because when doing some training on this I was enlightened to the fact that if you have one they need to be cleaned almost every day. Some say they do this by draining the wick pad and water from the pan.

The unit in roys pic is old, has been poorly maintained and should have been replaced with the furnace 15 years ago.

My humble opinion of course.

This is what to think about when weighing the cost of one.
Humidifiers Aid Comfort, Not Health

Published: January 02, 1988

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The Consumer Product Safety Commission is looking into the health risks of humidifiers.
Over the years, other studies have shown that humidifiers that are not cleaned diligently and often become contaminated with microorganisms that grow in the water reservoirs. These microorganisms, or bits of them or their byproducts, can cause illness when spewed into the air and inhaled, especially by allergy-prone people.
The study by the commission, a Federal agency that looks into the hazards of products used in the home, is comparing the growth of microbes in the water tanks of different humidifiers and the number of organisms discharged into the air, according to Dr. Richard Tyndall, a researcher. The results of the study, the most wide ranging of its kind, will be available in about two months.
Well over half a million consumers bought portable humidifiers last year to put moisture into heated indoor air, which can be drier than the Sahara’s 30 percent humidity. It parches the nose and throat, and can leave the skin feeling taut. It also takes its toll on furniture, plants and paintings. The moisture that humidifiers add to air makes people feel more comfortable, perks up plants and helps keep furniture and paintings from cracking.

But even though moister air may make people feel more comfortable, experts say there are** no health reasons to use humidifiers**. The nasal and oral passages are the body’s natural humidifiers, and air reaching the lungs is thus always moistened to some degree. A Source of Molds and Bacteria
If the water reservoirs of humidifiers are not cleaned regularly, molds and bacteria can breed in them. Humidifier fever, a relatively rare pneumonia like allergic condition, has been caused by breathing air that is contaminated with microorganisms from humidifiers.
‘‘People live very nicely in the middle of the desert without adding humidity to their air,’’ said Dr. Harriet Burge. She is a research scientist at the University of Michigan School of Medicine who was a consultant to the study and has done extensive research on indoor air quality and humidifier contamination.
Dr. Burge said no reliable research supports the idea that adding moisture to the air prevents colds or even brings relief to those with asthma or croup. Humidifier manufacturers agree. ‘‘They make the air moist and more comfortable, but there are no health benefits,’’ said Michael Murphy, marketing product manager for Toshiba, a manufacturer of humidifiers.
In the past several years, humidifier technology has changed significantly. The new ultrasonic units, which range in price from about $40 to $400, are quiet and lightweight. In these, the inaudible vibrations of a dime-sized ‘‘nebulizer’’ that oscillates 1.7 million times a second break water into a fine mist.
Ultrasonic units are compact. Evaporative units that add moisture to air by fanning it through a water-soaked pad are more cumbersome; they can weigh 100 pounds when filled with water. An ultrasonic unit filled to capacity weighs only about 20 pounds. More compact still are the inexpensive cool-mist vaporizers, which use a mechanical impeller to propel coarse droplets of water into the air. Ultrasonic Units Have Fewer Hazards
In recent years studies by Consumers Union, a private, nonprofit organization, have found that ultrasonic humidifiers pose less of a health hazard than other types because they kill molds and bacteria. The reports theorize that this happens because the high-speed vibrations fragment microbes. But one report noted that ‘‘an ultrasonic humidifier may still spew bits and pieces of mold and bacteria,’’ which can affect people with allergies.

Well kevin since that article was written some 25 years ago…

What did they decide?

I know that the decision is final as of today. No you do not need a humidifier. The person mentioned in the article still teaches this info along with many IAQ issues. What is still being debated is how much humidity is good for you. Not something easy to determine as in my experience some comfort issues occur when people are subject to low levels of moisture in Homes. 25-30%
On the scale for Indoor Air Humidity 38%-58% is indicated as best. Over 50% and dust mites thrive under 30% you are asking for the other spectrum of problems. You need to strike a balance no matter where you live.
HRV’s and ERV’s are the answer to this.

This is three years old .

Looks like it says the same thing.

Kevin please stop trying to support your view with outdated incomplete articles.
As long as humidifiers are properly maintained they are not a health risk.**

They are very effective in reducing dry skin, nasal bleeding while increasing comfort levels at lower temperatures.

Michael this is not my own view!
But I do appreciate that you did give the article on InterNachi.
Not all will agree with the Doctor and the only thing I am going to say is not always are we going to agree.
Not always am I going to agree with InterNachi articles, but when I don’t I make sure I inform Nick about it.

Is there anything wrong with what I have stated?

Anything at all?

No Michael, thanks! I can’t always just dig up training on the fly so the internet is my friend.
BTW the chart is directly from HRAI guidelines.
This is some light reading for some to understand ERV and HRV applications.

If you take no issue with what I said then why keep posting?

Correction to this
Kevin please stop trying to support your view with outdated incomplete articles.

Who said they helped colds. :roll: