Guide to Humidifiers

A Consumers Guide to Humidifiers

How Humidifiers Work:
Humidifiers are used both in homes and offices to increase the moisture level (i.e. the humidity level). The rule of thumb is to keep humidity levels at or below 50% to discourage the growth of dust mites and mold, which is especially important in the summer time. However, conversely there can be a number of problems, which occur in winter if the humidity falls too low. These problems include:

* Sinus headaches and other sinus related problems
* Warping of wood floors and cracking of furniture
* Wooden instruments such as pianos and guitars being ruined
* Nose bleeds
* Dry, itchy skin
* Bacterial and Viral infections that thrive in extra dry air
Different Kinds Of Humidifiers
There are different types of humidifiers including:

* Central humidifiers: These are built into the home heating and air-conditioning systems. They are the most effective since they humidify the entire house and are less likely to be the source of humidifier-associated problems if they are properly maintained. We have been trying out a new central humidifier this season and reports so far have been positive.
* Portable Humidifiers: There are two kinds of these. One kind is a console humidifier that is encased in a cabinet with wheels and is capable of doing more than one room up to about 1200 square feet. The second is a smaller unit that holds between 2 to 4 gallons and is designed to be used in a single room up to 600 square feet.

* Ultrasonic: These create a cool mist by means of ultrasonic sound vibrations. These use little electricity and are very quiet. The AIR-O-SWISS humidifier (priced at $135) is an interesting example of ultrasonic technology at its best because it both produces cool or warm mist- your choice. It also has conquered the drawbacks of other ultrasonic machines through an ionic stick which prevents the dispersion of fine mineral dust into the air. The AIR-O-SWISS also produces the most visible amount of mist.
* Air washers: These produce a cool mist by means of a high speed rotating disc. These are usually the ones that disperse the most microorganisms and minerals, and most often cannot control level of humidity achieved.

AIR-O-SWISS humidifier

* Evaporative: These units blow air through moistened materials such as a filter or a wick to put moisture into the air. Preferably choose one with a tank housing and wick that is antibacterial. The Hamilton Beach humidifier (priced at $69.95) is an example of a cool mist humidifier using evaporative technology. The Hunter humidifier (starting at $74.95) )has a patented anti bacterial wick which reduces the amount and frequency of cleaning which is required.

Slant Fin 2 gal Warm Mist Humidifier

* Vaporizer: These create steam by boiling water, which kills most microorganisms, but they can also be a hazard if put in a place where children or pets may knock them over and possibly burn themselves or others. For that reason, we do not sell them.
* Warm mist: This is a steam vaporizer that produces a warm mist for safety and feels the most comfortable, but they can use the most electricity. The SlantFin humidifiers (starting at $99.99) are the best of breed in the warm mist category.

Humidifier Maintenance
Clean your humidifier according to the manufacturer's instructions to prevent the growth of bacteria, mold, and scale. We suggest that you unplug any humidifier from the electrical socket before cleaning or emptying and refilling it.
The best water to use is distilled because it has had the minerals removed, but this could cost a small fortune. Be prepared if you are in an area with hard water to replace the mineral pads on your warm mist humidifier on a frequent basis. If your water has a high mineral content and the replacement of the demineralization pads becomes prohibitive, then using distilled water may be your only solution in which case you might consider producing your own distilled water. When using regular water in your humidifier, replace the filters with the frequency recommended by the manufacturer. You will need to do this if you want to prevent the dispersion of the white mineral dust that could penetrate your lungs and cause respiratory problems.
It is imperative that you clean your portable room humidifier religiously during the time that you are using it. Manufacturers differ as to the recommended frequency of their machines varying from daily cleaning to once per month. The most natural way to clean your humidifier is with a 50/50 solution of white vinegar and water. If you use household bleach to kill any mold that might have formed, you will need to rinse out the machine several times in order to avoid the toxins produced by the bleach.
End Of Season:
It is very important to thoroughly clean your humidifier at the end of the season by draining all of the water and cleaning the body and the filter with a 50/50 white vinegar and water solution. Put some water in the water tanks, add a few drops of bleach, swish the solution around, pour out the water, and rinse thoroughly with clean water. Allow all parts to dry and leave the caps off the water tanks so that they can dry inside.
If you have a central humidifier be sure to follow manufacturer's instructions for your unit and do not allow water to stand unused for long periods of time. Also drain and dry the tank at the end of the humidifier season.
Keep all humidifiers out of the reach of children and pets so that they can't pull them down on themselves or possibly burn themselves with the heated models.
If you place it on a table or bureau, make sure to run the electrical cord up the backside, so if the cord is pulled, the humidifier will be pulled into the wall and not off the fixture.

Hygrometer -measures temperature and indoor humidity

We recommend that you use a hygrometer to measure the humidity in the rooms. If you see any condensation on a window or dampness on fabrics like upholstery or drapes, this is a sign that you need to reduce the water vapor output from your humidifier. As we have mentioned before, some units do come with built in hygrometers.
We recommend keeping the humidity between 30% to 40%.
Remember that the manufacturers usually overstate their square foot coverage; so cut their suggested square footage in half or you won't be able to put enough humidity in the room to be of much benefit.


How to Choose an Air Purifier
Which One is Right For You?
By Richard Gerardi, Staff
Editor's note: Richard is one of our senior product specialists who helps our customers choose which air purifier is best for them. He has a way of making the complex very simple.

Choosing an air purifier can be a confusing task. With hundreds of different machines on the market, choosing one that's appropriate for your specific needs can be daunting to say the least. The technology that has developed over the past decade has produced some impressive machines and some not so impressive, and a few are propelled by very misleading marketing. Let's start by asking a few simple questions, and then we'll familiarize you with the basic terminology.
The first step is to think about what you would like to accomplish. Since air purifiers are designed for different needs, selecting one should be specific to you and not because your uncle Bob uses one and thinks it's great.
Let's narrow down our search by breaking air purifiers down into three different categories.

IQAir Hepa Air Purifiers
* Allergens (particulates) - Mold, pollen, dust, dust mite allergens and pet dander. Basically the stuff most of us have reactions to at some level.

* Smoke, Gas & Odor Control - Cigarette smoke, chemicals from the outside such as air pollution or a nearby pollution source such as a factory or a gas station. Also chemicals inside,
such as cleaning fluids, formaldehyde from carpets, new furniture, food odors, and pets.

* Bacteria & Viruses - Some air purifiers will actually remove bacteria and viruses. These are appropriate for people with compromised immune systems, serious health issues or conditions such as asthma or bronchitis.
Where to put it?
The second step is to determine how large a space you want to purify. Something to understand is that most air purifiers are room specific. While a manufacturer may say their unit can clean 1500 square feet, it would have to be totally open space, because you can't circulate air around corners, or up a flight of stairs, or suck air out of a room down a hallway. The manufacturers that make machines with fans don't claim to clean multiple rooms, so how is it that the ones without fans do! Use your common sense. Remember the old saying "If it sounds too good to be true, it probably is."
Generally speaking, the most important rooms in your home to purify are your bedrooms, followed by your main living space. Square footage is based on an 8 foot ceiling, so a 12 x 10 foot bedroom with an 8 foot ceiling would be 120 square feet. The square footage listed by the machine's manufacturer is on high speed. You should choose an air purifier with about double your desired capacity in square footage, because of fan noise and increased air circulation. The best way to run most machines is on high speed when you're away from the room and reduce to a comfortable listening level when you are actually in the room.
CADR Ratings
CADR - the Clean Air Delivery Rate - is an efficiency standard established by AHAM in conjunction with the product manufacturers. This rate determines how well an air cleaner reduces pollutants such as tobacco smoke, pollen and dust. By using CADR, the recommended maximum room size for each unit can also be determined. While useful, many of the manufacturers of the higher end machines on the market do not belong to AHAM because of the cost and the limited nature of AHAM testing. These air purifiers are not available to purchase in your local outlet store, so don't eliminate automatically a machine because it does not have an AHAM rating. Many of the air purifiers not rated by AHAM are many more times efficient then the top rated AHAM machines.
Types of Air Purifiers
HEPA filters are time tested and we feel are the most effective air purifiers. HEPA filters are made out of finely pleated paper and only allow clean air through the tiny holes in the paper. They trap the particles that are drawn into the air purifier. Some air purifiers like the IQAir machines which use hepa filtration can actually filter out bacteria and even viruses as well. These kinds of air purifiers are particularly safe and recommended because they do not produce ozone. Just like any type of product, some air purifiers are better than others. A good machine will filter 90% or more of the air going through it. A poorly constructed air purifier will allow air to pass around the filter because it is not sealed well.

Electrostatic air purifiers draw the air into a small ionizing chamber that puts a very small charge on the particles only to make them stick to a positively charged filter about 12 inches away. It is similar to trying to pass iron filings past a huge magnet. The Blueair air purifier uses both mechanical and electrostatic filtration that emits no ozone externally and can remove particles as small as .1 microns.

Blueair Air Purifiers
Ultra Violet Light machines are generally effective when used in conjunction with a good filtration system. In a water purifier that utilizes ultraviolet light, the water is in contact with the ultraviolet light for a long enough time for it to be effective. With an air purifier, the air is moving very fast through the machine and generally on its own will not affect a majority of the particles going through it. If you are interested in an air purifier that utilizes hepa filters and ultra violet light together well, we highly recommend the NQ Clarifier Commercial and Medical units.
Ozone/Ionic air purifiers produce electrical charges that can go through walls just like a portable phone does. They cause the particles to be sticky and those sticking together will be pulled downward by gravity. However, these sticky particles will also stick to walls, furniture, window blinds, your lungs, and some will even make it back to the machine itself. Basically they turn your house into inside-out Scotch Tape. When inhaled, ozone can damage the lungs. Relatively low amounts can cause chest pain, coughing, shortness of breath, and, throat irritation. Ozone may also worsen chronic respiratory diseases such as asthma and compromise the ability of the body to fight respiratory infections. Manufacturers and vendors of ozone devices often use misleading terms to describe ozone. Terms such as "energized oxygen" "plasma" or "pure air" suggest that ozone is a healthy kind of oxygen. Ozone is a potentially dangerous gas with a different molecular structure. does not recommend machines that emit ozone.
You can read more about the potential harm that ozone can do by typing in OZONE in the search field of these two web sites. The Environmental Protection Agency and the American Lung Association
Don't be misled by false advertising!
* Contrary to what you may be led to believe, the technologies used in portable air purifiers are not used on submarines or in the Pentagon as some web sites claim. Don't be sold on claims that cannot be verified.
* Don't be overly impressed by a seal of approval on an air purifier. When you see a seal by a national health agency on a machine, most agencies are not endorsing that product. They are saying that the machine does take some particles out of the air, and are often paid millions of dollars for that seal to be used. The electrostatic charge from your television takes particles out of the air as can bee seen by the dust that accumulates to its screen, but it does not benefit your health.
* Remember when a manufacturer claims that their air purifier will make the air in your home smell clean or fresh, ask yourself this question: What is that smell? Since air has no smell, the machine is most likely producing harmful ozone.
As a final note, remember that you are purchasing an air purifier that is going to affect your health and the health of your family. Be careful where you purchase it. Your first stop should not be the local mall. Buy from a company that gives you information that makes sense. After you read the information on our web site, you may want to call one of our well-trained product specialists so that they can confirm you are picking the appropriate unit. We are more than happy to assist you.

Pets as Carriers for Mold Spores
by Thad Godish Ph.D.

Q. What is your professional opinion on pets being carriers/ transporters of mold spores to the inside of the home?

- Patricia, Georgia

A. There is, of course, no direct scientific evidence to confirm that pets can and do bring mold spores into homes. However, it is quite likely since pets like humans track dirt into a house on their paws (our shoes and feet).

Soil contains large quantities of mold (because the organic matter present is a good source of food). The more organic matter (leaf/grass debris, etc.) the more mold will be present (It is mold's job to decompose dead plant and animal matter).
Outdoor air has during the summer and especially the fall very high levels of mold spores. These spores land on surfaces including people and pets who/which can bring them indoors where they are incorporated into house dust. They can become airborne when such house dust is disturbed. Of course mold spores come into houses through open windows affecting dust mold levels and airborne mold numbers for months after entry.

Indirect evidence for pet transport of mold/mold spores comes from studies of lead-based paint and childhood lead exposures. Pets and children are known to carry lead contaminated soil indoors from contaminated soil around building exteriors and thus cause increased indoor lead levels as well as exposures to children.

The question that I think you have implied is "Do pets carry mold into our houses and if so, how significant a problem/concern is it?"

I have answered the first part of your question. Now here is the second. In the average house it is very doubtful that pets significantly increase indoor mold levels as a consequence of their going outdoors and then coming back in (certainly not more so than their masters).

However, it has been my experience that very active pets can cause mold spores in house dust to become re-suspended and produce significant short-term increases in airborne mold levels (I saw this once with two large dogs which in their excitement in a very small space caused a significant spike in airborne mold levels.

Previously I made reference to the fact that people can bring mold in from the outdoors and thus cause increased airborne mold levels. I have seen significant increases in airborne mold in school classrooms during occupied hours as compared to those sampled after hours. It is likely that a good part of the increased levels during occupied hours is due to student activity. It is also likely that some of it is due to the fact that students are bringing mold in. In some classrooms I have actually smelled mold on some students' coats or jackets.

(2004), Thad Godish Ph.D., C.I.H

Moldy Mattresses
by Thad Godish Ph.D.

Q. Can mold grow in mattresses? If so, how can I get rid of the mold?

- Anon.

A. Indeed mold can grow in mattresses and box springs as well. How do I know? Well, it happened in my own home, in the bed, bedroom of my oldest daughter. That was about 20 years ago.

It occurred shortly after we moved into what was then our new house. About the time we noticed our daughter having respiratory problems at night, we also noticed that her comforter smelled musty. We responded by washing the comforter and bedding including the pillow (on which one could see tiny black mold colonies). The washing took away the mold odor and her symptoms improved. With time both the mold odor and symptoms returned. We responded in a similar manner multiple times (this was at a time that my research on mold in buildings had not yet begun) and each time the odor and symptoms returned. Finally, I examined the bed and to my (then) surprise both the mattress and box springs smelled musty. This was quite surprising since the bed had been purchased but 2 years before and was not in a particularly moist location.

I was a much younger faculty member at that time and purchasing a new bed seemed like a costly, drastic move. As a consequence, I started to look for information on how to remove mold from beds and box springs. It may not have been an uncommon problem at one time as the USDA extension service actually had a pamphlet that advised putting mattresses out in the bright sunshine. I did that a couple of days and it did in fact work to some degree, but the mold odor always came back. The ultraviolet light in sunshine can kill mold, but it could not penetrate through the depth of the mattress and box springs.

We got rid of the "moldy mattresses and box springs" replacing them with new ones. Her respiratory symptoms disappeared over night and did not reoccur until she went on to college where unfortunately a carpet fragment once stored in an unheated space re-exposed her to a mold source.

In recollecting events it is likely that mold made its way into the mattress and box springs was through her pillow. At that time she wore her hair long, and I suspect that on showering and going to bed her hair was not completely dry. A somewhat wet head, became a somewhat wet pillow, that then began to grow mold which subsequently infested the mattress and box springs.
If one has a moldy mattress or box springs, what do you do with it? Get rid of it (put it out as trash) and replace it with a new one (even if you think you cannot afford to).