There are many reasons to purchase a dehumidifier. It could be that you are looking to air out and remove that damp smell from your basement or laundry room. It could be that you are having trouble with condensation building up on your windows. Or, it could be that you, or someone in your family, are suffering from allergies or even asthma.

If parts of your home, or your entire home, have excess humidity a variety of things can happen. Firstly, you will notice it by the feeling of the room. The higher the humidity the more uncomfortable the room will be during the hot days of summer. It’s not just that though, a home with excess humidity can be a prime candidate for dust mites, mildew, fungi, and even mold. In some cases the mold can begin growing on the walls or your curtains. In extreme cases the mold could begin to grow on your bed sheets and even on your clothes. This mold, mildew, and dust can wreak havoc on allergies. They could result in itchy or water eyes, sneezing, coughing, or even a skin rash. If you are an asthma sufferer then things could get much worse.

Adding a dehumidifier to your home will not only increase the comfort level for your family but it will also make your home less hospitable for these allergens to grow. The question though is what to look for when purchasing a dehumidifier? There are a variety of sizes, considerations, and product features that should all be taken into consideration. In this article we’re going to look at everything you ever need to know before purchasing your dehumidifier. Let’s dive in and take a look:

Sizing

First you will need to determine what you intend to use the dehumidifier for. Are you going to be using it in a damp basement? Your master bedroom? Or, perhaps, in your kitchen/living room combination area? Knowing what room you will be using the appliance is key as you will have to purchase the right sized dehumidifier to ensure that the correct amount of moisture is removed from the air.

Once you have room chosen you now need to measure the square footage of said room. The square footage number will help you in determining just what size dehumidifier that you need. To find the square footage you need to measure the width and the length of the room. Let’s say for example you are measuring for a bedroom that measures ten feet long and twelve feet wide. Ten times twelve equals one-hundred and twenty square feet.

These square footage measurements will aid you in picking a portable dehumidifier. However, if you are looking to dehumidify your entire home then you may look at a whole home dehumidifier. These units can actually be attached to your central air conditioner and be routed through your central duct work. While the cost may be expensive at first you will end up seeing monthly savings on your energy bill and a longer life from your central air conditioner due to the dehumidifier taking some of the work off of the AC. These whole system dehumidifiers can work on homes up to three-thousand square feet.

Determining Dampness

Before you purchase you should keep in mind that once you determine the minimum capacity you need for your room that you should always go up slightly. By going up in capacity, say from a twelve pint to a twenty pint, you are able to increase the overall efficiency of your dehumidifier. This is because the larger unit will not have to work as hard as a unit that was right at the minimum level. Also, while there are all different varying pint sizes required the most common dehumidifier sizes are twenty, thirty, and fifty pints.

When you have your square footage determined you next need to figure out how damp the room is that you are trying to dehumidify. There are a few different dampness ratings that we can assign to your room. Knowing these will allow us to guide you on what kind of dehumidifier to purchase.

Moderately Damp – When you enter the room you may notice that the air feels clammy or even damp. There may also be a musty odor when the weather is humid outside. This may be a lot of your basements. The recommend capacity for a moderately damp room is between ten to twenty-six pints, or between five to twelve liters.

• • A five-hundred square feet area that is moderately damp will require a dehumidifier with a capacity of ten pints or four point seven liters.
  • A one-thousand square foot area that is moderately damp will require a dehumidifier with a capacity of fourteen pints or six point six liters.
  • A fifteen-hundred square foot area that is moderately damp will require a dehumidifier with a capacity of eighteen pints or eight point five liters.
  • A two-thousand square foot area that is moderately damp will require a dehumidifier with a capacity of twenty-two pints or ten liters.
  • A twenty-five-hundred square foot area that is moderately damp will require a dehumidifier with a capacity of twenty-six pints or twelve liters.

Very Damp – When you enter this room you may notice that it always smells musty and the air feels clammy or damp. You may even notice damp spots on the floor, walls, or windows.  The recommend capacity for a very damp area is between twelve to thirty-two pints, or between five point seven to fifteen point one liters.

• • A five-hundred square feet area that is very damp will require a dehumidifier with a capacity of twelve pints or five point seven liters.
  • A one-thousand square feet area that is very damp will require a dehumidifier with a capacity of seventeen pints or eight liters.
  • A fifteen-hundred square feet area that is very damp will require a dehumidifier with a capacity of twenty-two pints or ten liters.
  • A two-thousand square feet area that is very damp will require a dehumidifier with a capacity of twenty-seven pints or thirteen liters.
  • A twenty-five-hundred square feet area that is very damp will require a dehumidifier with a capacity of thirty-two pints or fifteen liters.

Wet – When you enter this room you may notice that it always smells musty and the air feels clammy or damp. You will also notice water beading on the floors, walls, windows, or elsewhere. You may also see moisture seeping at the edges of the room. The recommend capacity for a wet area is between fourteen to thirty-eight pints, or between six point six to eighteen liters.

• • A five-hundred square feet area that is wet will require a dehumidifier with a capacity of fourteen pints or six point six liters.
  • A one-thousand square feet area that is wet will require a dehumidifier with a capacity of twenty pints or nine point five liters.
  • A fifteen-hundred square feet area that is wet will require a dehumidifier with a capacity of twenty-six pints or twelve liters.
  • A two-thousand square feet area that is wet will require a dehumidifier with a capacity of thirty-two pints or fifteen liters.
  • A twenty-five-hundred square feet area that is wet will require a dehumidifier with a capacity of thirty-eight pints or eighteen liters.

Very Wet – When you enter this room you may notice that it always smells musty and the air feels clammy or damp. You will also notice water beading on the floors, walls, windows, or elsewhere. You may also see moisture seeping at the edges of the room. The difference here though between wet and very wet is that with the very wet section you will notice actual standing water on the floor. The recommend capacity for a very wet area is between sixteen to forty-four pints, or between seven point six to twenty point eight liters.

• • A five-hundred square feet area that is very wet will require a dehumidifier with a capacity of sixteen pints or seven point six liters.
  • A one-thousand square feet area that is very wet will require a dehumidifier with a capacity of twenty-three pints or eleven liters.
  • A fifteen-hundred square feet area that is very wet will require a dehumidifier with a capacity of thirty pints or fourteen liters.
  • A two-thousand square feet area that is very wet will require a dehumidifier with a capacity of thirty-seven pints or eighteen liters.
  • A twenty-five-hundred square feet area that is very wet will require a dehumidifier with a capacity of forty-four pints or twenty-one liters.

Now, you may have noticed that all of the products we mentioned above are NOT a central dehumidifier. These products we recommended above are strictly portable. If you are interested in a central system then it is best to schedule a consultation with your local HVAC contractor. It is always best to compare prices and quotes from various contractors to ensure you get the best price for your money. Also, you may also end up getting a deal if you purchase both an air conditioner and a central dehumidifier.

Considerations

Along with the choosing the right size there are other, more minor, factors that should be taken into consideration. The first is the overall portability of the appliance. If you are buying a dehumidifier for one of your rooms, or even your basement, how easy is it to move? Does it come with rollers, or does it have to be carried? Does it have handles to be carried? This may not mean much if you intend to set it and forget it in one room, but if you want the ability to move the dehumidifier around then portability definitely worth reviewing.

Another small factor is the overall size of the tank that will be holding the water that is removed from the air. Obviously, the larger the tank the less often you will have to empty it. This is just more of a convenience factor then anything though. The size of tanks can vary wildly from model to model. It’s not just the sizing though. How easy is it to empty the tank? Is it easily pulled out and dumped, or do you have to mess around with it for a bit?

You may also even find some units that come with a drainage hose that can be fed to your basement drain or even your sink. All of this is a matter of preference. Obviously the easiest solution is going with the hose option. There are also some models out there that come with a tank and an attachment for a drainage hose. This leaves the decision up to you on how you want to dispose of the water.

Something else to consider is what type of dehumidifier that you want for your home. There are two types of dehumidifiers: Refrigerant based and desiccant based. The desiccant models are more efficient then refrigerant models, especially in colder temperature areas. The down side is that these systems also have a smaller capacity rating.  The desiccant models are also quieter than their refrigerant counterpart. If you were looking to cool just a bedroom or two then you may look at the desiccant.

 However, if you are having constant trouble with a part of your home that is hot and humid then you should be looking at the refrigerant models. A refrigerant based system will be more efficient in hotter temperatures. It all depends on temperature. If the area you are dehumidifying is below sixty-five degrees then you should go with the desiccant model and if your room is above sixty-five degrees then go with the refrigerant type model.

The ideal humidity setting in a room is between thirty to fifty percent. Most folks say fifty percent in summer and thirty percent in winter. In most cases the dehumidifier you chose will have a setting to allow you to customize the humidity within the room. You may have to play around with this setting until you find the exact number that works for you and your home.

Another point for consideration is the overall efficiency of the unit. The efficiency of a dehumidifier is measured by the amount of water the appliance can remove every hour compared to the amount of energy required to do so. What you want to look for here is the ‘Energy Star’ approval.  The Energy Star program was created and is run by the Environmental Protection Agency. Its goal is to set efficiency standards for appliances and to reward an ‘Energy Star’ if the appliance meets those goals.

Dehumidifiers that are Energy Star certified have been evaluated and tested to the rigorous efficiency standards of the Energy Star Program. In most cases you can see up to fifteen percent energy savings when using an Energy Star model.

The last consideration is how much noise the dehumidifier will produce. Most dehumidifiers are rated between forty to fifty decibels. This is about the equivalent of a running refrigerator. You will find some models go higher or lower then this number, so just keep that in mind when purchasing. I don’t hear very well in the first place so a higher decibel machine has never mattered much to me.

Product Features

Alright folks, so we have now looked at what size of machine to purchase and also what considerations should be taken in before purchasing. The next step in our buying guide is to look at the various product features that your dehumidifier could have.  These product features aren’t mandatory by any means. No, these are more quality of life enhancements.

The first to look for are user friendly controls. My favorite is the digital display options that allow you to easily set a humidity level and to change the speed of the fan. Some units also come with a built in timer setting. This allows you to run the dehumidifier at night or to have it turn off when you aren’t home. Along with a timer setting you may look for an auto shut-off feature that shuts the appliance down when the desired humidity level has been reached.

Whenever the power goes out I have to remember what appliances need to be reset. In my old house my air conditioner would reset to ‘Off.’ So, during a bad storm where we lost power I’d forget to turn the air conditioner back on and the house would be sweltering by morning. While it’s not the same situation with a dehumidifier it is good to have an auto-restart function on your appliances.

As far as maintenance and upkeep of your machine there are two functions that can help you out. The first is known as the auto-defrost. This feature stops your dehumidifier from freezing over during colder operation environments. (Remember, that dehumidifiers are very similar to air conditioners and can experience a lot of the same problems.) The other feature is a simple signal that alerts you that your filter needs to be cleaned.

I would be amiss if I didn’t mention this next section, but chances are you will be fine. There are some dehumidifiers out there that require a two-hundred and twenty or two-hundred and forty volt outlet. These are the types of outlets that you find when you plug in your oven or your clothes dryer. Occasionally your garage may be outfitted with these as well. (I have one for my air compressor.) More often than not though your dehumidifier will use the standard one-hundred and ten to one-hundred and twenty volt outlet. Keeping on the same topic of power, it is also best to look at how long the power cord of the appliance will be. If it’s six foot, will that be enough?

The last feature that I am going to mention is the fan setting. Yes, this may seem like such a minuscule thing but it is a legitimate option and I want to be as comprehensive as I can when making this guide.  There are two types of fan settings for dehumidifiers. There are the ones that run constantly even when the appliance is not removing humidity.  Then there is the fan that ONLY runs when the dehumidifier is running. The jury is still out on which model is more efficient. If the fan is running constantly though then there will always be noise even if the dehumidifier isn’t dehumidifying. The argument is that with the fan always on the dehumidifier is constantly checking the humidity levels in your room. If the level exceeds what you have set then the machine kicks on and begins dehumidifying.

Conclusion

There you have it folks. That is nearly everything I can think of to talk about when it comes to purchasing a dehumidifier. We have covered the sizing requirements, all of the considerations, and even a number of product features. After reading this article you should be well armed to purchase your dehumidifier.