Dehumidifiers

What dehumidifiers do

Humid indoor air is uncomfortable, causes damage to your home and possessions, and promotes the growth of mold and dust mites. Humidity is usually defined in terms of relative humidity, which is the amount of water vapor present in the air compared to the greatest amount of water the air can hold at a given temperature. The optimal relative humidity indoors is 30 percent to 50 percent in the summer, and 30 percent to 40 percent in cool weather. Dehumidifiers can maintain the indoor relative humidity at the desired level, controlling musty odors and protecting furniture from water damage.

Dehumidifiers remove excess moisture by using built-in fans to blow the humid air over a refrigeration system with cold and warm coils. This causes condensation, which then drips into a collection bucket. The remaining dry, warm air is blown back into the room. Dehumidifiers actually slightly raise the air temperature, as opposed to air conditioners that dehumidify air as they cool it. Many dehumidifier models are now made to vent out the back of the unit so warm air isn't blown directly into the living environment when you'd least want it -- on hot summer days.

Experts say dehumidifiers are most useful down to an indoor temperature of 65° F; temperatures below that cause some units to ice up, in addition to simply working less efficiently and wasting money. If you need dehumidification at lower temperatures, look for a model that's Energy Star certified down to 42° or 44° Fahrenheit and has an auto-defrost function that prevents ice formation by shutting the unit off below that temperature.

Dehumidifier sizing is based on the condition of the area before dehumidification, as well as on room size. The most popular size is a model with a capacity of 30 to 50 pints (see sizing chart below).

Best general-purpose dehumidifiers

Despite some complaints about customer service, we found the best owner reviews for the Soleus CFM-40E (*est. $215) , which can operate in temperatures down to 36° Fahrenheit, though it is not Energy Star rated. The unit includes an automatic defrost feature to keep it from icing up. It can remove up to 40 pints of moisture every 24 hours and allows for discharging moisture through a drainage port or for collection in the tank, which can hold up to 11.5 pints of water. The Soleus CFM-40E automatically shuts off when the tank is full. Because the tank is on the small side, the Soleus wouldn't be the best choice for a basement unless you set it up for continuous drainage because the small tank would fill up too fast.

The Soleus dehumidifier has three fan settings and three humidity settings, the lowest of which is 50 percent. Most reviewers say that the Soleus is significantly quieter than other dehumidifiers they've tried. This 40-pint dehumidifier is compact and weighs about 30 pounds. Note that this unit doesn't actually have a humidity readout on the display, but it does have a washable filter. Note that this unit will not turn back on automatically if there is a power fluctuation or outage.

Despite this drawback, this dehumifidier and the smaller Soleus Air CFM-25E 25-Pint Dehumidifier with Humidistat (*est. $150) are standouts in the number of user comments they receive at Amazon.com. Both have nearly two hundred user reviews and both maintain rankings just over 4 stars. Most users praise these models for their overall functionality and durability. However, there are over a dozen comments for each complaining about the customer service given by this company as well as durability issues.

LG is also in the dehumidifier business. Its 45-pint, Energy Star rated LG LHD45EL (*est. $180) receives positive marks from the pros but almost no consumer feedback. This dehumidifier has electronic controls, two fan speeds and can operate at temperatures down to 42 degrees. This model also has an external drain connector and a washable filter. Without referencing consumer feedback, however, we hesitate to recommend it solely based on professional tests.

GE also makes some smaller capacity dehumidifiers. However, there weren't any professional reviews available and there were only a few -- albeit inconsistent -- user reviews available. The GE AHK30LK (*est. $260) is a 30-pint/small capacity unit that earns just one enthusiastic review at Amazon.com. GE's 40-pint model doesn't do as well, with complaints about usability.

We did see some reviews for Haier dehumidifiers, including the 30-pint Haier HDN305 (*est. $160) and 40-pint Haier HDN455E (*est. $170). Features are similar to others. Both are low-temperature dehumidifiers, and both are Energy Star rated. The difference here is that these two models have a mechanical dial instead of digital controls. The Haier HD306 earns some good comments in expert testing but only a few scattered comments from users. Though most at Amazon.com are positive, there are still far too few user reviews to conclude users are as satisfied as the pros. Considering what huge splits there have been between users and experts over some dehumidifier models, we'd like to see a far greater number of owner-written reviews before recommending this unit.

Bionaire dehumidifiers are typically a bit more expensive, but we found good reviews for the 40-pint Bionaire BDQ25-UC (*est. $230), which earns praise from pro and consumer reviewers alike, along with the smaller 20-pint Bionaire BDQ24-UC (*est. $150) . There are some critical remarks from users about noise and reliability on both of these models, but the positive comments outnumber the negatives by quite a bit. Features are similar to others, with electronic controls, a full-bucket indicator and adjustable humidity. These units are not Energy Star rated. One unique feature is that in addition to a washable particle filter, these units include a carbon filter, helpful for reducing odors. They are a little nicer-looking than most other dehumidifiers, which might make a difference to you.

Basement dehumidifiers

If you plan to place a dehumidifier in a less-used space like a basement or an attic, you might prefer a larger unit that can collect more water before being emptied. Most of these so-called basement dehumidifiers also have a drain, so you can run a hose to floor drain.

Of the larger capacity models, we only found a large number of reviews for the GoldStar DH504E 50 Pint DH504EL (*est. $200). At Walmart.com, this model -- which is priced anywhere from $100 to $200 less than more expensive, similar products -- receives largely positive reviews for its overall usability and effectiveness. The GoldStar dehumidifier has a humidity setting that can be selected within a range of 35 percent to 70 percent in increments of five, along with an auto-restart function that restores operation after a power outage to the previous settings. The GoldStar dehumidifier has a hose connection if you'd rather run condensate to a floor drain. That said, experiences did vary, with some users reporting issues with durability and customer service (this model comes with a one-year warranty.) We found some noise complaints as well, but if this unit is to be used in a basement, that issue might not be as important to you.

Kenmore, as mentioned earlier in this report, also makes a 70-pint dehumidifier, but user reviews gave us pause.

The Danby DDR606 (*est. $250) is another model with praise in professional reviews and few -- if any -- consumer reviews out there for comparison. One review at Epinions raves, but the other says this 60-pint model is difficult to operate. Though this dehumidifier is Energy Star compliant and operational down to 44 degrees, we're not including it in ConsumerSearch Fast Answers due to the small number of owner reviews.

Recently, the GE AHK65LK (*est. $335) -- a 65-pint large capacity unit -- earned a positive nod from one professional review. Unfortunately, this model has been discontinued and replaced by the GE AHR65LL (*est. $240), which has a 66-pint capacity, and it's unclear at this point whether performance is comparable. We haven't found any user ratings yet.

Mini dehumidifier

If you need a dehumidifier for a bathroom or closet, we found some reviews for the widely available Eva-Dry EDV-1100 Electric Petite Dehumidifier (*est. $55) . At Amazon.com -- where there are over a hundred user comments for this model -- many users are pleased that this dehumidifier does exactly what they want it to do, and say that it works well in smaller rooms such as bathrooms. There are also those who mention living in damp climates -- near the ocean -- and using this model to their full satisfaction. Though the majority are happy with this item's performance, there are also several complaints that the item has a short lifespan.

Important Features: Dehumidifiers

Experts say you should consider the following when choosing a dehumidifier:

• Determine the dehumidifier capacity you need. See the recommendations by AHAM (Association of Home Appliance Manufacturers) in the chart below. Experts recommend buying a larger dehumidifier, as it will work more quickly and efficiently.

• Get an Energy Star model. These save on energy costs in the long term. Most models larger than 40 pints are Energy Star rated.

• Storage tank capacity. All dehumidifiers include a collection tank for the condensed water. Unless you've hooked up a hose for continuous drainage, you'll need to empty the tank periodically. The size of the container varies a lot, however. If you want to use the dehumidifier in a remote location and continuous drainage isn't an option, look for a tank of 15 pints or more. Collection containers can be hooked up to a hose for continuous drainage through a floor drain or sump pump, pumped through water pipes or emptied manually. Many dehumidifiers are made to accommodate all of these options.

• An automatic shutoff prevents overfilling when the storage tank is full. Most dehumidifiers have this feature.

• An adjustable humidistat controls the relative humidity level. If you choose a model that doesn't have this option, you can buy a separate hygrometer to hang next to the dehumidifier that indicates the relative humidity level in the air, but you still have to turn the dehumidifier on and off. Mechanical hygrometers cost less than $10; electronic models cost $35 to $60.

• Look for automatic reset capability after power failure and when the storage tank has been emptied. Some say this is a nice convenience feature if your power supply is unreliable.

• Consider a low-temp dehumidifier. If there's any chance your dehumidifier will be working in temperatures less than 65° Fahrenheit, it's best to get a model that's rated to operate down to 42º or 44° F, with an auto-defrost feature to prevent ice formation. Some models come with anti-frost sensors that automatically shut off the unit when air temperatures drop below a certain point.

• Check for clearance around the unit. Dehumidifiers must have good air circulation all around them. For a unit with a top exhaust, you need eight or ten inches on all sides -- so it shouldn't be placed flat against a wall. If you choose a dehumidifier that exhausts out the back, you'll need even more space.

• Casters allow the unit to be moved easily.

• Look for reusable, washable air filters. Many models have a filter to protect the coils from dust. Being able to wipe this clean periodically makes for easy maintenance without the need to buy replacement filters.

Choosing a size

When choosing a dehumidifier, first determine room size. Dehumidifier sizing is based on the amount of moisture extracted from the air in 24 hours, measured in pints. Experts recommend buying a larger-capacity model over a smaller one unless the room with the moisture problem is very small, such as a bathroom or closet. Large-capacity dehumidifiers can handle a room in a shorter time. A small-capacity model in a large room might run continuously and still not lower the humidity to an acceptable level.

After considering size, you'll need to think about the room's current conditions (see the chart below), and consider issues that might further affect humidity, such as whether you use the room to dry clothing, or if you're running a dishwasher in the room.

Dehumidifiers that meet energy-efficiency criteria set by the U.S. Environmental Protection Agency and Department of Energy earn Energy Star status. Efficiency is measured in terms of the "energy factor"; the higher the number, the more efficient the machine. These models remove the same amount of moisture as standard models, but they use ten to 23 percent less energy, meaning significant energy-cost savings. Most models that remove 40 pints or more of water per day are Energy Star certified. You can view the entire product list on the Energy Star website.

AHAM Dehumidifier Sizing Guide - Match room or area size to current humidity conditions to find minimum size rating in pints.
Condition without dehumidification	500 sq. ft.	1,000 sq. ft.	1,500 sq. ft.	2,000 sq. ft.	2,500 sq. ft.
Moderately damp: Feels damp and has musty odor only in humid weather.	10 pints	14 pints	18 pints	22 pints	26 pints
Very damp: Always feels damp and has musty odor. Damp spots show on walls and floor.	12 pints	17 pints	22 pints	27 pints	32 pints
Wet: Feels and smells wet. Walls or floor "sweat," or seepage is present.	14 pints	20 pints	26 pints	32 pints	38 pints
Extremely wet: Laundry drying, wet floor, high-load conditions.	16 pints	23 pints	30 pints	37 pints	44 pints

Our Consensus Report shows how many times products are top-ranked by reviewers included in our
All The Reviews Reviewed chart.

# of Picks	Model (with Retailer Links)	Details from Amazon.com
2	Soleus CFM-40E (*est. $215)	details
2	Kenmore 54701 (*est. $200)	-
1 each	Danby DDR606, LG LHD45EBL, Soleus Air CFM-25E 25-Pint Dehumidifier with Humidistat , NewAir ADS-300 , Windchaser Compact Dehumidifier , GoldStar 50 Pint Dehumidifier with Electronic Controls, GoldStar DH4010B (discontinued), Santa Fe Rx Whole Home Dehumidifier , Comfort-Aire 130 Whole House Dehumidifer , Comfort Plus 300, Comfort Dry 400, Haier HD306 , Whirlpool AD70USS Gold Dehumidifier, GE AHK65LK , Eva-dry EDV-1100 Electric Petite Dehumidifier

We found very few professional reviews for dehumidifiers. However, we did find a large number of owner-written ratings for dehumidifiers. Some expert reviewers recommend buying virtually any dehumidifier based on size and efficiency, but we found notable differences in owner-written reviews when it comes to durability and customer service. The chart above includes picks in professional testing; we corroborated these results with user reviews at Amazon.com, Sears.com, Walmart.com and Epinions.

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