Best Dehumidifier for Mold: How to Choose the Best Dehumidifier?

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As you start to look into purchasing a dehumidifier for your home, it will seem like all the models available are almost identical with each other with the exception on the size of the unit. And for the most part this can be somewhat true. There are a number of standard features that come on just about every dehumidifier, such as casters, automatic shut off features and digital humidistats. However, these aren’t all the considerations you need to take into account when looking for unit for your home.

Our goal here is to provide you with all the dehumidifier advice that you need to be able to choose the perfect equipment for your situation. We will be looking at the important things to look for, the features that are nice to have and some general tips on getting the most out of your new system. We’ll start off by looking at some of the important factors to consider, starting with the size.

Best Dehumidifier Size:

Size is the most important factor to consider when looking for a new dehumidifier. If you end up with a unit that is too big for your space, you are essentially paying too much for what you need. However at the other end, if you buy too small of a unit, then it will end up running all the time but never bringing the humidity level down to where it needs to be. So be sure to accurately calculate the space that you need to control and we would recommend buying a unit that is slightly larger than what you need.

Ideally the target range is to hit a humidity level of 50% or lower, since molds won’t start to grow until you reach a humidity level of 55%. The EPA recommends that you maintain a humidity level between 30-60% to decrease mold growth in your home. Depending on where you live, this may be difficult to maintain. Most dehumidifiers are rated based on ideal conditions. If you live somewhere humid, like in Florida, the outside humidity will make it more difficult to reduce the levels inside the home. So a more realistic target would be in the 45% to 50% range.

58131-large_size_image-frigidaire-50-pint-dehumidifier-bucket-lgWhen looking at individual dehumidifiers, you will see that they are rated by pints of water, such as 30-pint, 50-pint and 70-pint. This number is an indicator of how much water the unit is able to remove from the air over a period of 24 hours. Again it’s important to remember that this is in ideal conditions, and as it is often said, your mileage may vary. Note that this DOES NOT talk about the size of the reservoir. Typically the size of the bucket that is included with the unit is around 16 pints. So if a unit can remove 50 pints of water and has a 16 pint bucket, you will have to empty the bucket 3-4 times a day as the dehumidifier runs if the room is very humid.

In summary, be sure to measure your space so that you can get the properly sized unit for your home. Keep the area where you live in mind when looking at the specifications on the device. And if emptying the bucket isn’t something you look forward to doing you might consider a dehumidifier with a hose attachment.


Another major factor to consider when trying to properly choose the best device for your home is the temperature in the room where you are using it. To fully understand the interaction between temperature and humidity let’s look at how they relate more closely.

WarningWater can exist in three different states: solid, liquid and vapor. The only difference between the states is the amount of space between the molecules. As a solid, the molecules are close together and as a vapor they are far apart. What causes these molecules to spread apart or come together is temperature. When the molecules are far apart and move around a lot, as in a vapor, they become invisible. As the temperature goes down, they stop moving as much and start to stick together, becoming visible. They can appear as a cloud, steam or even raindrops. If it continues to get colder, they eventually become a solid, ice.
If the temperature is warm, the atmosphere has a greater capacity to hold water in its vaporous state than if it were cold. It’s also important to note that vapor can change into visible water in another way. If vapor molecules get closer together they will transform into water. For any specific temperature there is a certain capacity for water vapor. If you exceed that level, then the extra will ‘spill’ out as excess water.

The best way to visualize this is to consider a glass on a table. If the glass is full of water and you pour more in, it’s going to spill over the edges. In the atmosphere, this happens when you have more water vapor than what the air can contain OR by lowering the temperature. When you lower the temperature, the air will then be able to hold less vapor which then turns to water. So as the air reaches its capacity of water vapor, the excess will spill out as liquid water.

The relative humidity is the ratio between the actual amounts of water vapor present to the capacity at that moment. So if the glass is half full, the relative humidity would be 50%. The relative humidity depends on how full the glass is and how tall the glass is. The relative humidity will increase if more vapor collects in the atmosphere (the glass fills up) or if the temperature is lowered (the glass becomes smaller). If the water vapor level stays the same and the temperature goes up (the glass gets bigger) then the humidity level will decrease. If the temperature goes down (the glass gets smaller) the relative humidity will go up.If your room or basement is colder, then using the example above, the glass is smaller and cannot hold as much water vapor. So it becomes much more difficult to affect the humidity levels. It’s much easier to reduce the humidity in a room that is 80 degrees than it would be in a room that is 60 degrees. Learn more about humidity at

What does this have to do with dehumidifier advice? Understanding the science behind what is occurring in your house will help you to properly choose the best dehumidifier. The science above is why some units will only function at temperatures above 65 degrees. “Low temperature” dehumidifiers are usually more effective in basements due to the lower temperatures that are often found there.

The equipment that is designed to work in low temperature conditions will typically have “frost guards” or “freeze guards” which turn off the compressor when freezing is detected while leaving the fan on to blow warm air over the coils. If you are going to be using a dehumidifier in a cold environment, be sure to choose a unit that has auto defrost features.

In general, at 80 degrees you should be able to lower the humidity to about 40%, at 70 degrees you should be able to reach about 45% humidity and at 60 degrees you might not be able to get it much below 60%.


Whew, now that we’re past that topic, let’s look at noise levels. No matter which unit you choose, one thing you will have to understand is that dehumidifiers will make some noise. In general, the average noise level ranges anywhere from the noise of a street outside to a rather loud conversation. Additionally, what is acceptable is different for each person, so this area is going to depend on your preferences. Many of the more recent dehumidifiers on the market have found ways to dampen the noise levels to a point where the sound is just a low humming.

While we will do our best to indicate the noise levels when we discuss specific units, keep in mind that this area is very subjective to the individual’s tolerance levels.


And finally we look at reliability. As with many different appliances, it seems like nothing lasts as long as it did years ago. That’s where a good solid warranty comes into the picture. Making sure that you buy from a company who will stand behind their product is a smart buy. Companies like Danby, Delonghi, Frigidaire and Sunpentown.

Features to look for in Dehumidifier Reviews

When starting you start looking over our Dehumidifier Reviews, you want to be mindful of features that will be more important than others. We’ve listed a few of those important features below.

Digital Humidistat

delonghi dd50PThe digital humidistat has become almost a standard feature on most units, like in the Danby DDR50A2GP . In the past, most dehumidifiers only had an adjustable dial that turned the unit on and off at pre-selected moisture levels. It was a complete guessing game as to what the actual humidity levels were being selected. With the digital humidistat, you can select the desired humidity level accurately, thus preventing unwanted mold and dust mites from thriving.

Built in Hygrometers

A hygrometer is an instrument that is used to measure the amount of moisture in the air. You can purchase a separate hygrometer to place in the room so that you can keep an eye on the levels as the system works. But having one built into the dehumidifier eliminates the need for a secondary measurement.

Automatic Shut off

If you plan on leaving the dehumidifier running in a room without someone around to keep an eye on the water levels, it’s vital that you choose one that has a built in automatic shut off feature. When the bucket fills up completely, the auto shut off feature will turn off the system so that the water does not overflow the bucket, causing even more damage to your room.

Bucket with hose attachment

delonghi dd50p pumpThis feature is one of those nice to have features, especially if you are using the unit in a room that has easy access to a drain. Most of the buckets that come with your normal home system will hold around 16 pints of water. Once you reach that level, the system will shut down (if you have the automatic shut off feature mentioned earlier). Until you empty the bucket the system will remain off. If the unit comes with either a built in hose or an attachment for a hose, this will allow you to run the water over to a drain and out of the house using gravity. The Frigidaire FAD704DWD is a good example of this. If you need to push the water up a slope or into a sink, you might need to buy a unit with a pump or that can have one added to the system.

Built in Pumps

There aren’t a lot of models available that have pumps built into the system. As mentioned earlier, you can purchase a separate pump system that will connect to the system and allow you to push water up to a drain, a sink, out a window or even into your existing plumbing system. Some systems have an optional pump available to them.

Automatic Defrost

Most units use a refrigeration process to pull moisture from the air. One drawback to this system is that the compressor can have ice buildup on its coils. If you are going to be working with a system in a colder room, you will want to purchase one that has an automatic defrost feature. What this does is when it detects ice buildup on the coils, it will turn off the compressor and continue to blow warm air from the room over the coils. This will melt off any ice that is building up and then it can turn back on and continue working. This helps to avoid any potential damage to the unit.

Automatic Restart

Another feature that would be quite useful if you plan on leaving the system running unsupervised, is the auto restart feature. It’s also useful if you live in an area that might be subject to frequent power fluctuations. If this feature is enabled and the power goes off, when it power returns the unit will resume working where it left off.


Although these systems don’t get moved around a whole lot, when you do move them, you will be much happier if they have solid casters on the bottom. When you start looking at the individual units, notice how much each system weighs. Many of the systems can weigh between 30 lbs. – 60 lbs. Plus when loaded down with 16 pints of water, it can be difficult to move.

Energy Star Rated

energy-star-logoWe would be surprised if there were any units out there that were not already Energy Star Certified. Because dehumidifiers can use a lot of power over a very long period of time, it’s usually a good idea to pay a little more for a better unit. Some of these units can use more power than your normal refrigerator does. Making sure you have a frugal energy device will help you save money in the end.

Tips on usage

Make sure it’s properly sized

As we said at the beginning, properly sizing your dehumidifier for your specific space is one of the most important parts of this process. Knowing where you are going to use it, the size of the room, the temperature and conditions both inside and outside your home will help you make the best decision. It’s not just about buying the cheapest system.

Make note of its position

When setting up the system, keep in mind that it needs unobstructed airflow to work effectively. If you plan on setting it up near a wall, turn it sideways so that there is plenty of room in the front and back for airflow.

Clean the filter regularly

Just like your air conditioner system, you need to keep an eye on the air filter. If the filter becomes clogged, it can actually damage the system. The filter is designed to protect the system from having dust and other particles build up on the compressor coils. Especially consider that most units are used in places where the air isn’t particularly clean. This can lead to a premature death to your unit if not maintained.

Warranty coverage

And last bit of dehumidifier advice, is to look at the company who makes the unit. If they don’t stand behind it, why should you purchase it. Read the reviews from previous owners and make an informed decision.

Here is a good video from DeLonghi that will show you a little more information about dehumidifiers.


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