Dehumidifier Buying Guide

Dehumidifiers are your first line of prevention and defense against overly humid conditions in your home. Too much moisture in your indoor environment can start off as a small musty-smelling problem, but left untreated, it can morph into a full-on mold issue. Taking action at the first sign of a problem is ideal, but regardless of if you just realized you have a problem or you have known about if for some time, investing in a dehumidifier will solve your moisture issues.

When deciding to invest in a dehumidifier, it is important to really get a feel for these units and what they are capable of. The following guidelines will help you to make a knowledgeable decision in choosing a unit that will serve your current needs and be a reliable resource for years to come. If you still have questions or need further clarification beyond this information, please contact our product experts toll-free at (800) 934-9194.

For easy accessibility to the topics in this article, use the list provided below:

About Dehumidifiers
Why Dehumidify
Types of Dehumidifiers
Cost and Considerations
Size and Efficiency
Energy Efficiency
Capacity At AHAM vs Saturation
Maintenance
Ducting
Eliminating Collected Water
Noise Level
Electrical Outlet Requirements
Special Features

About Dehumidifiers

Dehumidifiers work by absorbing excess moisture from the air. Most units function in the same way: they pull air into the unit through a vent, cool it down rapidly, which causes the moisture to condense, and then a fan pushes the dehumidified air back out the unit's ventilation system. The water that is collected from the air inside the unit drains into a receptacle or out through a gravity tube (most units feature both).

Dehumidifiers are most often placed in areas that experience excess moisture such as:

Basements
Crawl spaces
Kitchens
Bedrooms
Bathrooms
Spa or pool rooms
Warehouses
Workshops

Why Dehumidify

Beyond keeping your home, office, indoor pool areas, or warehouse comfortably dry, dehumidifiers also offer the following benefits:

Supplement Air Conditioning: Feeling cool requires two things: cool enough air (temperature) and dry enough air (humidity). Many times, people run their air conditioner for longer periods of time simply because the air is too moist, resulting in a hot, sticky feeling. You can easily combat this situation by investing in a dehumidifier to supplement your AC system. This will ensure a cool and dry environment, which is especially important in those hot summer months.
Energy Savings: Along with keeping you comfortable, maintaining dry enough air can easily save you money on your cooling bills. If the surrounding air is simply less humid, you can actually feel cool enough even with a warmer air temperature.
Mold Prevention: It is important to keep the air dry to control mold and mildew growth. In a home, basements, bathrooms, and kitchens are three areas which are especially susceptible to mold formation year-round due to the high humidity often found there, so the addition of a dehumidifier can drastically reduce the likelihood of mold formation. Keeping mold from forming is particularly beneficial to allergy sufferers, as mold is a common allergy trigger.
Maintaining Structural Integrity: Keeping the humidity level balanced, particularly in crawl spaces and basements, will ensure the structural integrity of your home. Excess moisture in these areas can lead to rotting support beams, buckling floor boards, and damage to hard woods, all of which can be very costly to repair. Prevention is always less expensive than repairs.

Types of Dehumidifiers

There are several types of dehumidifiers on the market, and they are categorized by their functionality. They can be classified most generally as residential, commercial, and industrial. In order to figure out which grade of system you will need, there are a few elements to consider:

Size - Size definitely matters when it comes to choosing the right unit for your space. Dehumidifiers are designed to remove a specified amount of water out of the air per day. Unfortunately, it is sometimes difficult to estimate how many pints of water per day need to be dehumidified, so many customers find it easier to consider the size of the area to be dried. Fortunately, this rule of thumb is roughly accurate, as size generally correlates to the amount of water that needs to be removed from the air. Square foot recommendations though are only a rule of thumb. A room in humid South Florida would need more dehumidification than a room in dry Arizona.

Another point to consider is if the size of your space is approaching the end-point of the size range for a particular dehumidifier. If it is, then you should consider moving up to next larger capacity model to ensure efficient dehumidification. To this suggestion, many people ask, "Why do I need to go larger?" The answer is simple: the closer you are to the cut-off range, the harder your unit will have to work to keep the air free of moisture, which over time will diminish the effectiveness and longevity of the system. Also, getting a unit that is too small to handle your humidity issue will cost you more in energy, as a smaller unit will run more and possibly freeze up under the additional strain.

Humidity Level - The level of humidity under which your dehumidifier will work will directly impact the unit's effectiveness. If your humidity is high, then of course the unit will have to work harder, run longer, etc. So, if you are trying to dehumidify a large basement, and you live in a humid climate, then you will want to get a stronger, commercial-size (or possibly even industrial-grade) basement dehumidifier that can effectively combat that level of moisture. There are high-capacity units on the market that are well equipped to handle heavy moisture loads. There are dehumidifiers designed for specific areas in your home, such as basements, crawl spaces, indoor pool or spa areas, etc., so you can match your specific needs to the most appropriate unit. Additionally, industrial warehouse dehumidifiers are designed and built to dehumidify large commercial areas efficiently and effectively.
Temperature- You will want to consider the temperature where you will be placing the unit. Many dehumidifiers are simply not equipped to handle colder temperatures and will freeze up, causing the unit to work less effectively or to shut down completely. However, there are many units on the market that can easily handle cold temperatures. Typically, the colder months of the year are associated with lower levels of absolute humidity, so dehumidifiers are not needed as frequently. However, if you live by a large body of water, such as the ocean or a lake, or in a low-level setting where water collects, you may need a very low-temperature dehumidifier.

Cost and Considerations

The price of a dehumidifier can range from less than $200 to more than $1,000. Deciding whether to choose the low-end or high-end model can be confusing. Dehumidifiers generally operate in the same way, meaning air is pulled into the unit, water is extracted, and then blown out. However, the logistics of how this is done (meaning the internal design of the unit) and the quality and quantity (pints per hour) of dehumidification is the basis of how each unit is different from one another. The key to deciphering which unit is best for you is to discover the real differences in models and then matching the right features to your specific needs.

Answering the questions below is a useful, time-saving method that will help you narrow down the dehumidifier choices by honing in on your needs (and expectations) for a dehumidifier. After you have answered the questions, refer to our dehumidifier listings where units are listed by brand with detailed product descriptions that include: capacity, special features, warranty, etc.

What is the square footage of the space I am trying to dehumidify?
Is my space more than 1,000 square feet?
How tall are my ceilings?
Is this a finished space?
Is this a crawl space?
Do I have a musty smell in my space?
Do I have a mold problem?
Do I live in a high-humidity climate?
Do I live in a low-temperature environment?
How long do I expect the unit to last?
What kind of financial investment do I want to make in this unit? Consider upfront cost versus the lifespan and quality of the unit.
If I had a dehumidifier previously, did that unit solve my problem when it was working?

Additionally, Sylvane offers product experts who can guide you through the buying process at (800) 934-9194.

Size and Efficiency

Dehumidifiers are designed in many sizes and configurations and are usually categorized by their pint-per-day capacity. Knowing the pints-per-day capacity is valuable information for choosing between units; however, many customers find it difficult to accurately estimate how many pints of water per day they need dehumidified. To forgo this issue, customers find it easier to consider the size of the area to be dried, as size generally correlates to the amount of water that needs to be removed from the air. It is crucial to note though, this correlation is only a rule of thumb and should be used as only a starting point for picking out the right dehumidifier for your space. You will want to also consider other factors such as your humidity level, temperature, etc.

When considering a dehumidifier's efficiency, going larger isn't bad, but going too small is. For example, buying a unit that has a maximum capacity of 1,000 sq ft for a 900 sq ft space isn't a good choice. The unit will run longer and probably wear out faster. Additionally, constantly running the unit to maintain the desired level of dehumidification for this size space will result in higher energy costs. It is best in these situations to simply upgrade to the next level of dehumidifier. The unit will work better and the overall results will be improved, including the life-span of the unit, energy savings, and efficiency of dehumidification.

Energy Efficiency

Another consideration when choosing a dehumidifier is energy efficiency.

Go Larger: A general rule of thumb is the larger and stronger the unit, the more energy efficient it is in terms of capacity. This is true because a larger unit doesn't have to work as hard to dehumidify a space as a smaller unit. It isn't overwhelmed by the high-moisture load. Energy efficiency can be achieved most easily by being realistic (and accurate) about the size of your space and level of humidity you are trying to balance.
Think Bigger: Some people try to dehumidify a large space with several small units, rather than a more expensive larger unit, thinking this is a more economical choice. In reality, you may save money on the purchase of the units up front, but the units will run longer, cost more in energy consumption, and simply wear out faster. Your best bet is always to buy the unit that best fits your size space. In the long run this choice will pay for itself with energy-saving results and peace of mind. Sylvane offers many units that are Energy Star rated, as well as units that lead the industry in energy efficiency.

Capacity at AHAM vs Saturation

When comparing capacity of dehumidifiers, especially commercial grade vs. residential grade, be careful to compare apples-to-apples. AHAM vs. saturation is a commonly confused issue when it comes to dehumidifiers and their capacities. Some manufacturers rate their dehumidifiers at AHAM and some at saturation. The concept is that a dehumidifier takes out a lot less water in a dry environment (e.g., desert) than it would in a moist environment (e.g., rainforest). If a manufacturer states the capacity of their unit, or how much water it can take out of the air per day, they should also state under what conditions.

Unfortunately, manufacturers are not always completely clear about their unit's true capacity. In fact, most off-the-shelf appliance-grade dehumidifiers rate their pint-per-day dehumidification capacities at saturation, meaning at 100% relative humidity, which gives you a false perception of their true capacity to eliminate moisture. What the manufacturer isn't telling you is that the unit's performance drops significantly at cooler temperatures, which are typically found in basements and crawl spaces, and at more realistic humidity levels. A better estimate of what a unit is capable of under more realistic conditions is AHAM (80 degrees F, 60% RH). If a manufacturer only gives you saturation or does not state the conditions at which their capacity is rated, halve the capacity stated and you will have an estimate of the AHAM capacity. At Sylvane, we offer you realistic estimates of performance at AHAM and saturation. If you have specific questions about the capacity of a unit, please contact us at (800) 934-9194 for more information.

Maintenance

Properly maintaining your dehumidifier is simple and requires minimal effort. After proper setup, most units work as a "turn it on and forget it" appliance. However, to get the most out of your investment, you must keep up on general maintenance:

Clean air filters as needed (Usually every 6 months).
Drain your unit before storing it away.
Consult a professional for any necessary repairs (Check your warranty for more specific information on parts/services covered).

Properly maintaining your unit will ensure that it has a long life span. Dehumidifiers can last anywhere from 3-15 years depending on the model.

Ducting

Many units allow for ducting. This can be particularly beneficial if you would like to dehumidify multiple spaces simultaneously, or if you are interested in hiding the unit away in a closet or separate room. You can easily:

duct multiple rooms for air to flow simultaneously;
duct one room and have it to blow the air into the next room or vice versa; and
run ductwork to the far ends of a crawl space to force air circulation.

Please note that model configurations vary. Some units are not designed for ducting, while other units that are ductable require the addition of a remote humidistat. See specific product pages or call our product experts at (800) 934-9194 for more information.

Eliminating Collected Water

Dehumidifiers extract moisture from the air. This collected water must then be eliminated. There are many different ways that various models deal with this condensate water.

Buckets: The simplest units have an internal container that needs to be drained regularly (as frequently as every day to as infrequently as once a month, depending on your conditions). Units will automatically shut off when their containers are full, until emptied.

Gravity Drain: All units support the option of a permanent water drain hose connection, which allows for water to continuously drain out via gravity. This water can then be directed to a floor drain, outside, or to another drain point.
Condensate Pumps: Condensate pumps are also available to help pump collected water through a drain hose. They can move water in an upwards direction if needed. The hose can then be directed outside or to an inside drain point. These pumps are energy efficient as well and work with a flow switch that allows the pump to run only when needed.

Noise Level

You cannot find a silent dehumidifier because these units work by physically moving air through them, which is accomplished by a motorized fan. In addition, they have a compressor in them (similar to a refrigerator) that compresses the refrigerant inside. Even though dehumidifiers are not silent, the amount of sound they produce varies from unit to unit. Most dehumidifier manufacturers will list a dehumidifier's noise level in decibels. Look for this information in the product specifications. For easy reference, use the comparison chart below to get an idea for the level of sound a dehumidifier will make based on its decibel measurement.

0 dB	Hearing Threshold
10 dB	Breathing
20 dB	Falling Leaves
30 dB	Whisper
40 dB	Raindrops
50 dB	Average Home
60 dB	Normal Conversation
70 dB	Vacuum Cleaner

Electrical Outlet/Requirements

Most units use typical household 110-120 volt power and require no special wiring or outlets. Of course, some dehumidifiers can draw a significant amount of energy, so caution must be taken not to overload a circuit with multiple high-energy consumption devices (e.g., placing a refrigerator or portable air conditioner on the same circuit). Some of the industrial or commercial-grade units may or may not require special outlets/wiring, such as 220 volt wiring. Please see product descriptions for more information. Energy consumption will vary depending on the model and your environmental conditions.

Special Features

Many dehumidifiers on the market offer special features that add convenience to your life and allow you to optimize your unit to best fit your needs. Some of the special features to consider when shopping are: