Dehumidifiers FAQ

Dehumidification is the process of removing excess moisture from the air in your home and is primarily accomplished through the use of a dehumidifier. Dehumidifiers work by combining three basic principles: cooling the air, adsorption, and absorption. Most home dehumidifiers--like Danby, Soleus, and Alen--work on the first principle. By using coolant, dehumidifiers cool the air below the dew point which causes the moisture in the air to condense.  The water is captured in a drain bucket. This same principle is also true for commercial/industrial dehumidifiers. Ebac dehumidifiers come equipped with larger fan motors, drain buckets, or internal condensate pumps to condense, collect and drain water away.

Smaller dehumidifiers, such as our Eva-Dry Dehumidifiers, work through adsorption. Adsorption is the process whereby chemicals, particles, or whatever you are trying to remove adheres to the outer surface of an adsorbent, generally called desiccant. A porous, odorless, non-toxic and safe silica gel will adsorb water up to 40% of its own mass. An indicator lets you know when to use these mini dehumidifiers. Via a small amount of electricity, heat reactivates the gel and returns its water adsorbing capability. The Dri-Eaz DriTec Pro 150 is a larger version of this principle. This model must be ducted to push the moisture collected by the desiccant out and away from the air you are drying. The last type of dehumidification is absorption. For home applications, this type of dehumidification is the least used. It involves an absorbent material such as calcium chloride which is hard to reactivate once it has absorbed moisture.

How will a dehumidifier help with my allergies?

Some of the most common allergens are directly effected by humidity levels in your home. Mold and dust mites flourish in more humid environments. According to the EPA and other sources, mold generally thrives in relative humidity levels as low as 60-65%. Dust mites live and breed at levels over 50%. For these reasons, our best advice is to keep your household relative humidity under 50% whenever possible. Dehumidifiers are a crucial component in keeping humidity levels low. Most of the models we sell have a built in humidistat that gives a relative humidity reading, but for use throughout the home you can use an Acu-Rite Digital Humidity Gauge. Overall, maintaining a relative humidity of less than 50% will greatly reduce or eliminate dust mites, mold, and other allergens.

Where does indoor moisture in the air come from?

Most of our everyday activities contribute to increased humidity in the home. Showering can add a 1/2 pint of water into the air. Simply preparing meals adds approximately 5 pints of water to indoor air for a family of four over course of a day. Washing your laundry, mopping, using the dishwasher and even indoor plants contribute moisture to indoor air. Our most basic activity of breathing can add 1/2 a pint of moisture to the air over four hours. In a home of 1000 square feet with constant temperature, four to six pints of water can increase relative humidity from 15% to as much as 60%. As you can see, the most basic activities have a growing impact on indoor humidity levels.  In a relatively short period of time, elevated humidity levels create a suitable environment for mold and dust mites to flourish.

What is relative humidity?

Relative humidity is a percentage showing how much water vapor is currently trapped in the air relative to the maximum amount of water vapor the air can hold at a given temperature. Imagine that you have a glass of water and begin to stir sugar into the water. When you get to point where you have put a full cup of sugar in the glass, you notice that the sugar no longer dissolves and that it begins accumulating at the bottom. At this point, the water is saturated with sugar and will hold no more. At the point where you have put only 1/2 a cup of sugar in the water, you are at 50% of the maximum the water can hold at the current temperature. Now, think of the air in your home as that glass of water and the moisture vapor in the air as the sugar. Your relative humidity level is the ratio of the current amount of water vapor in the air relative to the maximum amount of water vapor it will hold at a given temperature.

Where do I put a dehumidifier?

Most of our non-commercial dehumidifiers work best when placed in one room. There are several sizes available to fit any room in your house. Danby dehumidifiers range in size, from the Danby Premiere 70 Pint to the Danby 30 Pint. Additionally, our Soleus, Comfort-Aire, and Haier dehumidifiers come in multiple sizes. All of these models will work well in your basement, laundry room, living room, or bedroom. By far the most common area to place a unit is the basement or laundry room because these rooms tend to be on the lower levels of the home. These areas have constant contact with the moisture of the surrounding earth which makes them more susceptible to moisture problems. In reality, you can use a dehumidifier in any room where moisture and humidity levels lead to problems.  For your smallest applications, we suggest one of the Eva-Dry models, either the 1100 Petite or one of the Eva-Dry Mini Dehumidifiers. They are low maintenance and perfect for small spaces, i.e. in cabinets, in closets, and under sinks. On boats or in RV's where moisture is a concern, the slim Portable Air Dryr works well. Its low profile makes it ideal for tight quarters.

What are "commercial" dehumidifiers?

Our most popular commercial dehumidifiers are manufactured by Ebac. These heavy duty units are constructed primarily of steel instead of the abs plastic commonly found in typical home dehumidifiers. Many come with built in condensate pumps, operate in temperatures as low as 33° F, and offer higher water extraction rates than typical home dehumidifiers. These units are generally more expensive, shipped via truck freight (as opposed to parcel service), and built for the rigors of crawlspaces, restoration sites, construction sites, and industrial settings. These units are equipped to operate in settings where the moisture being extracted could be contaminated with harmful or noxious substances. We offer an Ebac Comparison Chart to give a simple breakdown of each model's features and specifications. To see a sample listing of the various uses of our commercial Ebac dehumidifiers, visit our A to Z Guide of Uses for Ebac Dehumidifiers.

The other large commercial units we offer are Dri-Eaze. These units are constructed of a dent-resistant, nearly unbreakable plastic. They are primarily used for restoration and water damage projects where maximum drying in a rugged or contaminated environment is a necessity. Most are stackable so that you can use more than in any area while utilizing vertical space. Ideal for the cleanup of "gray water" Dri-Eaz has a dehumidifier for nearly any restoration or water damage project.

What do the terms "capacity," "pints per day," and "CFM" mean?

These are three different terms commonly used when describing the extraction capabilities of a dehumidifier. "Capacity" is the amount of water the drain bucket will hold before having to be emptied. This will vary strictly by size. While larger capacity dehumidifiers will hold more water and mean less frequent trips outdoors or to the drain to empty them, they also mean that the full bucket will be heavier. If you are porting your dehumidifier, the capacity is not nearly the concern that the pints per day is.

"Pints per day" (or PPD) refers to the maximum number of pints of water a particular dehumidifier will remove from the air during a 24 hour period. If you have a 70 pint dehumidifier that means under ideal conditions, this unit will remove up to 70 pints of water per day. This depends on whether or not there is actually that much water in the air to remove, and if you are to be sure the tank is not sitting full, or if you have the unit ported. In the average home, it is not uncommon to remove 3-7 pints of water a day from the air. This number will vary widely depending on how many people live in the home, geographic location, temperature, climate, and other variables.

"CFM" or Cubic Feet per Minute is the same measurement used in many air purifiers. This number represents the amount of air the fan will move in any particular appliance. The greater the CFM the more air that is cycled through a dehumifier for moisture removal. Commercial models built for more rugged applications typically have a higher CFM than home/room models.

What about AHAM ratings and saturation?

AHAM rates apply not only to air purifiers but also dehumidifiers. In regards to dehumidifiers, AHAM certifies that the PPD that a manufacturer claims their product will remove is accurate. AHAM also certifies that power consumption for a given model is in line with manufacturer stated specifications. With PPD, AHAM will test a dehumidifier in a controlled environment that has a temperature of 80° F and relative humidity of 60%. Then, under these conditioners a dehumidifier is tested for 24 hours to determine whether or not the actual amount of moisture removed from the air is what the manufacturer claims.

With our Ebac and Dri-Eaze dehumidifiers, you will find not only a PPD rating but also another number given for another set of conditions. "Saturation" is best described as an extreme condition where the amount of moisture in the air is so much that the dehumidifier will run constantly over a 24 hour period. Some examples are a flooded basement, clean up site after a natural disaster, or an industrial environment that continually saturates the air with moisture. Instead of the controlled environment of AHAM testing, the extraction rate provided at saturation or under extreme conditions will far exceed typical dehumidifier results.

How do I know what size is right for me?

There really is no easy answer to this question, and deciding which model and size is right for you will depend on several factors. You need to ask yourself several questions before purchasing.

• How severe is my moisture problem?
• How large is the room/location where the dehumidifier will be used?
• Under what conditions will my dehumidifier typically operate?
• Is energy consumption a primary concern?
• Will I port the unit or empty the drain bucket?
• How much do I want to spend?

• Use a 30-40 pint model for small (8'x10') to medium (15'x15') rooms with moderate levels of humidity (45-55%)
• Use a 50 pint model for small to large (20'x20') rooms with moderate to high humidity levels (50-75%)
• Use 65-70 pint models for large to extra large rooms (20'x30') or rooms with high humidity (75% and above)

What is Porting?

Porting is the process of using an exterior drain line to continuously drain your dehumidifier. As mentioned above, most of the dehumidifiers we offer come with a port where a plastic or rubber hose can be attached to drain the water collected from the unit. A suitable type and length of hose can be purchased from your local hardware store. Porting is a fairly simple process and works best when gravity is on your side. The dehumidifier needs to be placed in a higher position than the receptacle where you want the water to drain into. If this is not possible due to a grade or a lack of a nearby drain, you can still port your dehumidifier, but you will require a condensate pump to push the water longer distance.

Do I need a condensate pump?

A condensate pump is a simple pump device that pushes fluids much in the same way a sump pump works. The only difference is a condensate pump is built mainly for the purpose of moving moisture removed by dehumidification. This small pump attaches to the dehumidifier the same as if you were simply porting it. The hose runs from the dehumidifier to the condensate pump and then a separate line runs from the pump to your drain. A condensate pump allows for continuous drainage of your dehumidifier and eliminates the hassle of emptying a heavy water bucket. This is a simple and inexpensive solution to use when there are no drain lines readily available for your dehumidifier, or when gravity is working against you. The condensate pump pictured is for use with home dehumidifiers. In situations where the air may be contaminated with chemical vapor or other noxious substances, an Ebac dehumidifier with a condensate pump directly into the unit is a better option. For most "gray water" situations, a Dri-Eaz dehumidifier will likely fit the bill.

How long will my dehumidifier last?

If your unit does not run every day or 24 hours a day, it will inevitably last longer. Most of the units we carry are durable from 5 to 15 years though most have warranties that are shorter than that time frame. As long as your unit is not running constantly, the only thing that will shorten your dehumidifier's lifespan is freezing temperatures. Some have features that will prevent the unit from running in low temperatures, and other dehumidifiers have de-icing capabilities to thaw frozen coils. In low temperatures, the coils will freeze, but the unit will often continue to run. You waste electricity as well as the wear and tear on the motor, while getting no dehumidification results. To protect the unit and prevent wasting energy, some units have automatic shutoff points at low temperatures.

What do I do when my dehumidifier stops working?

Your first step would be to reference the user manual to check any simple troubleshooting measures. While a dehumidifier is a simple appliance, it does have several things that could go wrong with it. From sensors and a humidistat to heating and cooling coils there are several aspects of a dehumidifier that could be malfunctioning. Some have filters that need to be changed, other times a certain feature has stopped working such as a faulty humidistat causing the dehumidifier to run constantly. In most instances you will want to locate your closest servicing dealer. Contact the manufacturer and they can point you in the right direction. With Ebac dehumidifiers you can often order replacement parts for a DIY repair. If the dehumidifier is under warranty the repairs likely will cost little if anything at all. If your unit is beyond its warranty, you may find it less expensive to purchase a new dehumidifier rather than repair your current one. If this is the case, contact the manufacturer or a local organization about recycling options. As with all of our products should you have a problem with a dehumidifier you purchased from us at AchooAllergy.com, contact customer service, toll-free, at 800-339-7123 for an exchange of a defective or malfunctioning dehumidifier.

Should I keep the box?

Should a dehumidifier you purchase from us encounter problems due to no fault of your own within 60 days of purchase, you can contact customer service to obtain a Return Authorization number and exchange the unit. For this reason, we recommend you keep the box your dehumidifier arrived in for at least 60 days. If you have the storage space you may want to keep the box for as long as the manufacturers warranty time period.

How do I maintain my dehumidifier?

There is very little regular maintenance required for dehumidifiers. For most models, including Danby, Soleus, Comfort-Aire, and Haier, you simply unpack them and plug them in. The primary maintenance with these units is disposing of the water collected in the drip tanks. Most come with convenient built in handles so after you slide the bucket out of the unit you can easily carry it outside or to your drain to dump. A more convenient option is to port your dehumidifier. Nearly all of these units come with a small port toward the bottom on the unit. From this port you run a small hose to an existing drain. Some people find it best to tie this drain line into your existing HVAC drain line (for moisture produced by your air conditioner) or possibly to a basement drain. From time to time you may want to check the tank and make sure it is clean and check the drain line (if ported) for blockage. If the unit has a removable cover you should check and clean the condensing coils annually.

Are dehumidifiers heavy?

The larger the unit means the heavier it will be. Though medium to large home units weigh between 35 and 55 pounds most come equipped with casters, so on hard surfaces, moving them is not difficult. The smaller units (20 to 35 pounds), usually have hand holds built into the sides and some of these units have casters as well. For our commercial/industrial Ebac dehumidifiers the weight can range from 50 lbs. to as much as 353 lbs. The all steel construction of most of these dehumidifiers lends itself not only to their heavy duty nature, but also to their increased weight. The weight for each dehumidifier we sell is listed in the specifications section on each product's webpage as well as our Dehumidifier Comparison Chart.

How loud is a dehumidifier?

As with any appliance that has a fan, the higher the fan setting increases the noise these units will make. Honestly, for those who have owned older dehumidifiers, you likely will find that many of the home or room models we offer are much quieter than what you are used to. For those who have never owned a dehumidifier, the sound may seem loud. To give you some comparison, the noise equivalent for most of these models is that of a basic air purifier. On higher settings the noise may keep you up at night if the unit is in your room, but on the lower settings, the noise is comparable to white noise which actually helps many people sleep. With the commercial models we offer, the noise is greater, but these units are typically used in crawlspaces, basements, outdoors, industrial settings, and often locations where noise is not a primary concern.

Can I safely recycle the water my dehumidifier produces?

This is a "yes, but" answer. If you are not porting water away from your dehumidifier, there are many things you can do with the condensate that your dehumidifier produces. Keep in mind that the water produced by air conditioners and dehumidifiers is not meant for human consumption. While it will often initially be free of pathogens, it can stagnate quickly.  If the tank is not kept clean, the water could become contaminated if fungi or other organisms begin to grow in your tank. What also makes it unfit for human consumption is that dehumidifier water often lacks the mineral and inorganic substances that make water potable. This also means you should not use the water to fill your pet's water dish.

The best use is for watering your plants or gardens. Here in Georgia, where water seems to be at a premium due to this prolonged drought, you can use your dehumidifier water to water your indoor plants or use it outside for a vegetable garden, flowers, or other landscaping you may have. While you cannot drink the water, it still can be put to good use.

Depending on the environment you this same advice will hold true for our commercial/industrial dehumidifiers. The exception would be while using a dehumidifier in an environment where there is toxic and harmful chemicals in the air. In these instances the condensate produced may contain these substances and should be handled accordingly.

How will using a dehumidifier impact my power bill?

The majority of the home/room dehumidifiers we offer are Energy Star compliant. Looking for dehumidifiers with the Energy Start logo will help to ensure that your purchase is not wasting electricity. Differences in your power bill will vary according to size and how often the unit runs during an average month, but you can probably expect that with daily usage your cost to run will range from $5 to an additional $10-$15 per month. Again, this will vary depending on the model you choose and how often it is used. As a final note, you will find that often the larger dehumidifiers are Energy Star compliant while many smaller ones will lack this designation.

With our commercial dehumidifiers power consumption will vary greatly with use. Some are built for extremely large or damp environments and actually run on 220V instead of the 110V found in most home receptacles. The larger motors and fans found in these units also lend themselves to greater power consumption.

What are other ways I can reduce moisture in my home?

There are several other things you can do, in conjunction with the use of a dehumidifier, to help reduce the level of humidity in your home. First, make sure there are no leaks or seepage in and around your home. Improper landscaping, leaking pipes, faulty gutters and clogged drains can all increase the amount of water and moisture in and around your home. Next, use your dryer. Some of us like to allow certain articles of clothing to air dry for fear of shrinkage in the dryer. By allowing laundry to air dry in your home, you are increasing the overall humidity levels. Always remember to use exhaust fans whenever possible. While using the dryer helps, inspect the vent to make sure it is actually vented to the exterior of your home and inspect the hose for cracks or leaks. In the bathroom and kitchen exhaust fans can quickly remove excess moisture out of your home. By keeping doors open in your home you can allow air to circulate from room to room. By allowing heat to circulate, you can bring warm air to colder places where moisture is likely to condense. Lastly, it always helps to air our your home from time to time.

Am I forgetting anything?

If you have any questions about dehumidification, dehumidifiers, humidity and allergies, prices, or our policies, please call our customer services representatives at 1-800-339-7123 or you can reach us via email at cs@achooallergy.com.

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