Basements can get uncomfortable fast if the humidity is high, so choosing the Best Dehumidifier for your Basement & Crawl Space is a big deal, especially if you spend a lot of time in your basement. There’s a lot to consider when purchasing a dehumidifier, which is why we’ve put together this guide for you.
Let’s have a look at some of the top selling dehumidifiers and in learning how to make your basement and crawl space comfortable.
Table of Contents...
- 1 Best Dehumidifier for Basement & Crawl Space
- 1.1 Review : Frigidaire FFAD7033R1
- 1.2 Review : AlorAir Sentinel HD55
- 1.3 Keystone KSTAD957PA
- 1.4 Frigidaire FFAP7033T1
- 1.5 Friedrich D70BPA
- 1.6 Emerson Quiet Kool EAD70E1
- 1.7 Tjernlund V2D
- 1.8 Dri-Eaz F413 Revolution
- 1.9 Dri-Eaz LGR 7000Xli
- 1.10 Frigidaire FAD704DWD
- 1.11 Issues Related to Excessive Humidity
- 1.12 Degradation of Property
- 1.13 Benefits of Owning a Dehumidifier
- 1.14 Dehumidifier vs Air Purifier
- 1.15 The Air Purifier
- 1.16 Air Dehumidifier — Facts
- 1.17 Desiccative Dehumidifiers
- 1.18 Thermoelectric Dehumidifiers
- 1.19 Ionic Membrane Dehumidifiers
- 1.20 Humidity Management Tips for Homeowners
- 1.21 Gravity / Pump drainage
- 1.22 Energy Efficiency
- 1.23 Noise Output
- 1.24 Related posts:
What is a Dehumidifier?
As a species, we’ve enabled our lives to be almost completely indoors, if we choose. The problem is, when their is a massive disparity between outside and inside temperatures, and you have moisture in the air, due to a lack of airflow, problems begin to occur. Humidity is uncomfortable, and is defined as :
Humidity is the amount of water vapour present in air. Water vapour, the gaseous state of water, is generally invisible to the human eye. Humidity indicates the likelihood for precipitation, dew, or fog to be present. (Wikipedia)
The dehumidifier is one such device – it sucks away excess moisture from the air to increase comfort levels. But what does moisture have to do with discomfort? Well, if you have ever taken a walk outside during a scorching summer day, you probably know the answer to that question.
Warm air alone isn’t the reason your body feels so awkward – the humidity level of the surrounding air plays a key role in determining how quickly your body can dissipate heat from its core to the surrounding atmosphere. As you already know, the human body releases heat in the form of sweat – the sweat particles then evaporate into the surrounding air which causes loss of heat energy from your body and you feel cooler as a result.
Premium dehumidifier for your basement | AlorAir Sentinel HD55
The rate at which sweat evaporates depends on the humidity level of the surrounding air – air that is more humid will absorb the sweat at a slower rate, so your skin will feel itchy and sticky since the existing sweat is not evaporating fast enough and your body keeps on producing sweat to maintain a steady temperature. But if the relative humidity of the air is low, sweat evaporates faster and you feel much more comfortable since the skin is drier and cools faster.
Humidity is the main reason summers feel so treacherous in tropical areas – you feel as if you are wearing a sweater the whole time, and the body loses its water content at a faster rate. Mold, dust mites, and allergens thrive in damp atmospheres, and cause a whole bunch of health issues. Asthmatic people and kids are especially vulnerable to allergies and other health problems related to damp air. Too much moisture content in the air will also damage your home, and can significantly decrease the value of property if left unchecked.
Damp air will cause the wallpapers and paint to peel off, and mold will grow around damp areas such as the basement/ bathroom/ kitchen/ etc. Wooden floors will warp if they are exposed to moisture for prolonged periods of time, and furniture will begin to harbor mildew that causes them to smell musty and feel damp to the touch. There are several other issues caused by too much moisture in the air, which we shall discuss in the forthcoming section. For now, all you need to know is that a dehumidifier provides an easy and cost-effective solution to a multitude of serious health and property related issues that arise from excessive humidity in the air.
Storm LGR Extreme | Commercial-Grade Dehumidifier
This article is comprehensive, because choosing a dehumidifier really does matter and knowing what to look for will help you make the right decision.
We’ll look at owning a dehumidifier, types of dehumidifiers and how they work, differences between air purifiers and dehumidifiers, how to select the right dehumidifier based on your needs, as well as the differences between standard dehumidifiers and basement dehumidifiers. Our goal is to provide you with a complete understanding of the issues related to excessive humidity, and how a humidifier aids in resolving these problems to a certain degree.
There are several things you can do to maintain an appropriate level of humidity in your home, and a humidifier is only the first step towards that goal. It is not the complete answer to a comfortable and clean environment within the house, and it is important for you realize this fact. Everything that you learn in this article applies to all types and sizes of dehumidifiers, and doesn’t pertain exclusively to basement dehumidifiers. Basement dehumidifiers are simply dehumidifiers that are optimized to work in the extra cold and damp conditions found in basements.
Best Dehumidifier for Basement & Crawl Space
This next section we will review the top rated dehumidifiers for your basement and/or crawl space.
VIDEO | Dehumidifier buying guide from Consumer Reports
Review : Frigidaire FFAD7033R1
Best Dehumidifier for your Basement if you value peace and quiet.
- Dehumidification of up to 70 Pints per day
- Effectively dehumidifies a medium sized utility room with medium humidity level, proper sizing varies with room size, room location and conditions
- Washable filter keeps your air smelling fresh, plus, the dehumidifier prevents odors that result from mold, mildew and bacteria
- Effortless clean antibacterial filter reduces bacteria, room odors and other airborne particles for a cool, comfortable environment
- Effortless humidity control allows you to control the exact percentage of humidity in your room
- Ready-select controls make it easy to select options
- Effortless full tank alert system lets you know when your water tank nears capacity and it is time to empty the water bucket
- Unit shuts off automatically when the water tank is almost full
- Continuous drain operation option allows continuous dehumidification without having to empty a heavy water bucket
- Dehumidifier runs quietly at 51 dBA
- Water bucket is conveniently located in the front of the unit for easy access, while the carry handle and splash guard make emptying your bucket hassle-free
- Portable design with caster wheels and top and side handles makes it easy to move your unit from room to room
This model is considered to be the best portable residential dehumidifier on the market right now, and if you take a look at online reviews as well as buyer feedback, you will understand why. Not only is the Frigidaire FFAD7033R1 an extremely easy to use dehumidifier, but it performs like a true champ and is one of the quietest dehumidifiers we have ever tested. The major strengths of this dehumidifier are-
Removes more moisture per day than most other 70-pint models on the market
Energy efficiency rating is off the charts because of how quickly it removes moisture compared to the amount of electricity that it consumes
A very quiet dehumidifier if you consider its size class (70-pint dehumidifiers are some of the largest portable residential units that you can buy)
Almost no negative feedback from consumers regarding its build quality or reliability, an indication that this is a very sturdily built machine which should last long
So, we know that the Frigidaire FFAD7033R1 is fast at extracting moisture, runs silent, and consumes less energy than similarly sized competitors. We also know that this is a very well-built machine, and consumers rarely complain about it malfunctioning or breaking down. But surely, there is more to it than just that right? After all, performance and efficiency alone doesn’t make a particular dehumidifier the most preferred/ popular model.
The FFAD7033R1 was designed as a successor to the critically acclaimed FAD704DWD, which was one of the best dehumidifiers of 2014. The two largest improvements made to the older design were energy efficiency and noise suppression. While the older FAD704DWD consumes the exact same amount of power as the FFAD7033R1 under average humidity (50%), the newer model is much more efficient as humidity levels increase, meaning that it has a wider range of energy efficiency, and should result in you having to pay slightly less in terms of running costs. The FFAD7033R1 also removes moisture more quickly and efficiently than its predecessor, and is around 20% faster on average.
It also runs much quieter, thanks to the rear air intake and side-mounted exhaust ports. Unlike most models which suck humid air in through the front and expel fresh air through the back or topside, the FFAD7033R1 draws humid air through the back and expels fresh air from its sides. This, combined with efficient fan and compressor design results in reduced noise output. At close ranges, the FFAD7033R1 produces 61.2 dB of noise on “high” settings, and just 57.2 dB on “low” settings. The average noise output for most 70-pint dehumidifiers on high fan speed is 67.2 decibels, while on low fan speeds it is 63.4 decibels. Clearly, the FFAD7033R1 is anywhere between 30 to 40 percent less noisy than the average 70-pint dehumidifier. Not only that, but it is also an Energy Star rated model.
Some of the convenience features on the Frigidaire FFAD7033R1 are : automatic defrosting, gravity drainage, condensate pump drainage, extremely intuitive digital control panel, large 16.3-pint bucket, easily removable air filter, and portability (weighs 47 pounds and has an extendable top handle, along with 4 casters on the bottom). Finally, the Frigidaire FFAD7033R1 is capable of operating within a very wide temperature range (41°F to 90°F).
Review : AlorAir Sentinel HD55
Best heavy-duty dehumidifier for your Basement or Crawl Space.
- Moisture Removal Capacity: 55 Pint / 115V (80°F-60%) 60L(125 PPD) / 220V (30°C-80%)
- Power Supply: 115V / 60HZ, 220V / 50HZ
- Coverage Area: Up to 1300 sq.ft
- COP 2.4L/Kwh (115v/60Hz), 2.95L/Kwh (220v/50Hz) Energy Star Listed
- Hot Gas Valve Defrosting System
- Coated Coils with Stainless Side Plate
- Quick Access to Service
- HVAC Remote System
Optimized for heavy-duty dehumidification, the AlorAir Sentinel HD55 is a commercial grade dehumidifier which is integrated with unique features geared towards operation in crawlspaces and basements. It is extremely powerful, as well as highly efficient. Under AHAM conditions (80°F, 60% RH) this dehumidifier can extract 55 pints of moisture from the air per day, and can manage 125 pints per day (PPD) at 86°F and 80% relative humidity. It is also CE, ETL, and Energy Star approved.
AlorAir recommends the Sentinel HD55 for usage in basements, offices, storage spaces, bars, museums, apartments, shops, factories, and pretty much any place where temperatures can vary between 35.6 °F and 90°F, functional humidity range of this machine is between 35 to 90% relative humidity. It is clearly much more rugged than a standard residential dehumidifier, and can operate across a wide range of temperature and humidity variance. You can use it in hot as well as cold climates, and there is a special “Hot Gas Valve” defrost system inside the unit which ensures quick and efficient ice removal from the coils at extremely low operating temperatures.
VIDEO Overview | AlorAir Sentinel HD55
It is preassembled, and features an external condensate removal point as well as remote humidistat support. Dimensions are 300 x 450 x 300 mm, and it weighs 59 pounds. The compact design means you can easily fit this into tiny crawlspaces, and there are two carry handles on the top for portability. The fan can generate an airflow rate of 240 CFM at full speed, but what is surprising is that the entire system generates only about 45 dB(A) of noise on average (at moderate fan speeds of course).
It comes with optional duct mounting flanges and has automatic humidistat control, along with memory starting. The shell is designed to prevent water from seeping in, and the usage of a rotary compressor results in higher extraction rates along with lower energy consumption. You can install an external condensate drainage system, it comes with gravity drainage as the default option.
A good option for dehumidifying a basement up to 6000 sq.ft.
- Room dehumidifier with built-in pump for continuous upward drainage
- Removes up to 95 pints of moisture from the air per day
- Dehumidifies a room up to 6000 square feet
- Electronic controls with LED Display and 24-hour timer
- Auto-restart saves your settings during a power outage
- Note: The filter is located under the rear grill
Capable of servicing areas as large as 6000 sq. feet, the Keystone KSTAD957PA is a portable 95-pint refrigerant dehumidifier. It features 3 drainage options – manual (20-pint bucket), gravity drain, and a built-in condensate pump. There are 2 fan speeds – Normal, and Turbo. Auto defrost ensures that the coils never collect ice when the unit is working at temperatures below 65°F, and there is an LED alert which goes off whenever the condensate bin gets filled with water.
On the front, there is a transparent water level indicator. Four highly durable omni-directional caster wheels are attached to the base so that you can easily push this dehumidifier around the house or office space. In case of a power outage, the auto-restart function will resume operation as soon as power is back. This ensures that no time is wasted, and if you are not around to switch it on, it will just start itself. Excellent feature to have in certain places like storage rooms, unoccupied basements, and crawlspaces.
There is a 24-hour timer, and a very easy to use LED display control panel. One of the features that could potentially prove to be very useful, is the clean-filter alert that notifies you through a blinking LED light whenever the filter needs to be cleaned or replaced. The filter is extremely easy to clean, and is washable too. The giant 20-gallon condensate tank comes in handy, if you plan to use the unit inside a room with no nearby windows or floor drains. For basements, you should use the included 16.4-foot hose to pump out water.
Also, it has a condensate pump that can easily flush out accumulated water into an overhead sink or out through a nearby window. There are pocket handles on either side if you want to carry the unit around, and it is extremely energy efficient for its size thanks to an Energy Star 2016 rating. It is slightly heavier than most other portable dehumidifiers, at nearly 60 pounds. Measurements – 18.8” x 14.2” x 24.60”.
Best dehumidifier to keep your basement dry and free o mold and mildew.
- 70 pints per day dehumidifier uses standard 115-Volt electrical outlet
Built-in pump allows unit to continuously discharge water in an upward direction into a sink or out of a window
- Protects your home from mold and mildew caused by excess moisture
- Helps eliminate bacteria in the air that can make breathing difficult
- Low temperature operation saves energy and money (41°)
- Ready-Select electronic controls with digital humidity readout, 24-hour on/off timer and control lock
- Effortless humidity control allows you to control the exact percentage of humidity in your room
- Effortless full tank alert system with auto shut-off
- Front, pull-out 13.1-pint tank with handle and splash guard
- Rear-access washable mesh filter reduces bacteria, room odors and other airborne particles
- SpaceWise design includes top handle, integrated side handles and caster wheels
- Extra long 6.2 ft. 3-prong power cord with cord wrap makes extension cords unnecessary
- Easy Mobility: Four rolling casters and two side-grip carry handles make it easy to transport this portable dehumidifier from room to room.
- Reusable Filter: The Friedrich 70-Pint D70BPA Dehumidifier includes a washable air filter that easily slides out of the front panel.
- Electronic Controls: The digital screens display the timer and temperature settings, so you can monitor the humidity level in your space and maintain a comfortable room temperature.
- Temperature Selector: This Friedrich dehumidifier allows you to choose between Celsius and
- Fahrenheit temperature display.
- Multiple Fan Speeds: This portable dehumidifier is equipped with a two-speed fan.
- Adjustable Humidity: A built-in humidistat allows you to set your ideal humidity level from 30% to 90% relative humidity in increments of 5%.
The Friedrich D70BPA is a 70-pint portable air dehumidifier, designed to be efficient and versatile enough for both living room and basement applications. It features one of the best digital control panels of any residential dehumidifier on the market, and there are LED indicators which notify you whenever the bucket is full or the dehumidifier is in defrosting mode. Controls are intuitive, and the digital display shows room temperature as well as relative humidity very accurately. You can switch between 3 different drainage options – manual, gravity, and pump drainage.
This Friedrich model is very easy to use, all you have to do is hook up the included 16.5-foot-long drain hose to the rear outlet, and switch the dehumidifier into continuous drainage mode. The pump generates enough pressure to push the condensate vertically up to a height of 15 feet. You can easily move the D70BPA around thanks to 4 ultra-durable omnidirectional casters which are attached to the base in order to facilitate swift and easy short-range transportation. You can also lift up this 44-pound dehumidifier using the pocket handles on either side. It is Energy Star certified, and draws a maximum of 840 watts.
The cool thing about this particular dehumidifier is that the fan switches off automatically whenever the machine goes into defrost mode, in order to reduce power consumption and noise output. It is not the only dehumidifier with this feature, but the drawback is that defrosting will take slightly longer whenever the fan switches off. Most dehumidifiers keep the fan running during defrost mode to speed up the deicing process.
There are two different fan speeds – normal and high. Lowest operating temperature of this unit is 41°F, and it allows you to set desired humidity level between 30 to 90%. For most refrigerant based models, 35% humidity is the lowest point, but we are glad to see the D70BPA go one step further in this aspect. No, it is not applicable in residential scenarios since 30% is below the comfort level of human beings and can induce sensations of dryness in the skin. But it is super useful for storage or equipment rooms. The front panel contains a washable air filter which slides out conveniently for easy cleaning. The D70BPA is UL – certified and uses environmentally friendly R-410A refrigerant.
- Up to 4499 sq. ft. capacity
- 70 pints/day dehumidification : Reduces moisture in the air, making your living environment a healthy place to be.
- Drain hose connection allows you to run continuously.
- Adjustable humidistat allows you to choose a comfortable moisture level for you and your family.
- Full bucket indicator with auto shut-off : Turns the unit off when the bucket is full. Indicator light lets you know when to empty the bucket.
- Water splashing and frost protections.
- Timer For preset operation and reduced energy consumption.
- Electronic controls and digital display
- 3-speed fan gives you more control.
- Caster wheels make it easy to move the dehumidifier from room to room.
- 1.7 gal. water tank
- ENERGY STAR certified
Capable of covering up to 4500 sq. feet of area, the Emerson Quiet Kool EAD70E1 is a compact and lightweight dehumidifier suited for both living rooms as well as basements. It comes with 2 preset modes, and features a digital display along with a 24-hr timer, 3 fan speeds, and automatic defrost. Featuring a sleek and straightforward design, this dehumidifier should fit right in with the rest of the home decor. It should also be very easy to move around, thanks to the 4 casters on the bottom as well as the side mounted handles. The controls are fairly easy to understand, and there are 3 drainage options for maximum versatility.
While it is not Energy Star certified, customers who purchased this dehumidifier reported that they didn’t notice any significant spike in power consumption on their bills. It is just as efficient as any other 70-pint model out there, except for a select few like the Frigidaire ones. Noise output is between 55 to 68 decibels depending on the fan speed setting, which is considered to be average for a dehumidifier of this capacity.
VIDEO | Features of the Emerson Quiet Kool Dehumidifiers
One thing worth mentioning, is that the air intake is located at the back – so you shouldn’t place the unit too close to a wall or else it will not be able to dehumidify air efficiently. Placing it in the center of the room will definitely not be an issue, since it is so compact and sleek looking (measures 15 x 12 x 25.2 inches). Also, there is a built-in condensate pump which means that waste disposal should be an effortless process. Simply attach a hose to the rear end and point it out of a window or into a sink. Accessing the air filter is extremely easy, and there is a clean-filter indicator which lights up whenever too much dust accumulates on the intake filter. This dehumidifier has an operational humidity range of 35% to 80%, and includes a defrost mode for functioning in cold temperatures (as low as 41°F).
UnderAire Crawl Space Fan Ventilator
Applications / Uses:
- Fan powered crawl space ventilation quickly reduces moisture helping to protect both home and occupants.
- Ventilates excess moisture, the cause of mold, mildew and wood rot. Increases air circulation to fight condensation.
- Constant operation helps vent radon, treated wood off-gassing and odors that might otherwise migrate into living areas.
- Deluxe two-fan ventilator
- Built-in dehumidistat
- Freeze protection thermostat
- Sealed bearing motors for long life
- Mounts into ventilation openings in block foundations
- ower ventilate musty, damp crawl spaces through existing passive vents
- Faceplate is sized for ventilation openings through standard block foundations
- 220 CFM, 40 watt maintenance free exhaust fans
- Includes adjustable dehumidistat, freeze protection limit and 6 foot grounded power cord
- Faceplate can be trimmed to match non-standard foundation openings
The Tjernlund V2D is a crawlspace ventilation fan that is designed to pull moist air out of an encapsulated crawlspace, thus reducing the chances of mold formation and dampness in the crawlspace floor or walls. You can use it in open crawlspaces as well, just make sure to seal all but one opening so that negative pressure is created within the crawlspace which results in humid air moving outside. The V2D consists of 2 maintenance-free, 40-watt exhaust fans mounted onto a metal faceplate that can be cut in order to fit a crawlspace vent or tile.
The combined airflow from both of these fans is 220 CFM, and the unit also comes with a built-in thermostat + humidistat module which monitors temperatures and humidity levels in order to maintain a healthy atmosphere in the crawlspace. You should be able to cover a crawlspace area of up to 3000 sq. feet with this particular model. If you are wondering how to know the ventilation requirements for your particular crawlspace, it is pretty easy – take the volume of your crawlspace (length x width x height), and divide that by 15 to get the CFM value. The CFM value corresponds to the amount of airflow that is necessary to successfully keep the crawlspace dry and mold-free.
VIDEO | Learn more about the Tjernlund V2D Crawl Space Dehumidifier
We also recommend that you install a plastic vapor barrier on the floor of your crawlspace, especially if your home is sitting on a wet foundation. If soil is damp, up to 20 gallons of water can evaporate into a 1400 sq. foot crawlspace within 24 hours. Some crawl spaces tend to attract moisture during the summer, because all the heating systems and ventilation ducts going through the crawlspace are cold during summer, so warm and humid air from outside gets into the crawlspace and condenses on the cold metal pipes. Gradually, your crawlspace will begin to get infested with mold and let off a musty smell. The wooden support beams and floor panels will rot away, weakening the structural integrity of your floors. To prevent all this from happening, you just have to install a dehumidifier or ventilation fan inside the crawlspace.
The mounting bar is much cheaper than most dehumidifiers and will get the job done for much less power (it’s just two 40-watt fans). The humidistat has a range of 20 to 80% relative humidity, we recommend that you set it between 50 to 60% in order to enjoy a mold-free crawlspace. The thermostat will deactivate the fans as soon as temps hit 40°F or below. This is to prevent formation of frost. The galvanized steel face plate (9” x18”) can be trimmed to fit cinder blocks or existing passive louvers. Comes with a 6” power cord attached. Mounting hardware is included.
Visit the Tjernlund site to lean more.
- Dehumidifies areas up to 7,000 square feet
- Built-in humidistat, plus displays temperature and humidity conditions
- Easy to transport; Multiple units can be moved on a standard dolly
- Fast access for cleaning and maintenance
Fits into small spaces such as stairwells and bathrooms; Stacks and stores completely
At first glance, you are going to say “wow, this is such a small dehumidifier!”. Then when you learn that the Dri-Eaz F413 is a commercial grade model capable of extracting 80 pints of moisture per day under AHAM conditions, you will be shocked. That’s right – it is capable of competing with dehumidifiers that are nearly twice as big, and the best part is that it will even outperform them. The F413 is loaded with some of the most advanced technology that you will ever see in any machine designed to draw moisture out of the air.
VIDEO | Learn More — Dri-Eaz F413 Revolution
There are microprocessors and advanced weather sensors built into this dehumidifier, it can detect air temperature and humidity in real time, and adapt accordingly to perform as efficiently as possible under a certain set of conditions. Most conventional dehumidifiers are designed with one specific operating condition in mind, which is usually the AHAM condition – 80°F, 60% relative humidity. Yes, they include functions for multiple fan speeds and come with automatic hygrostats that control performance based on humidity levels, but the truth is that residential dehumidifiers simply aren’t advanced enough to properly cope with wide temperature and humidity ranges.
Even if the manufacturer tells you that model “X” has an operational temperature range of 41°F to 90°F, what they actually mean is – “this is the temperature range in which our machine can perform without malfunctioning”. They don’t state the efficiency of the dehumidifier under different conditions, because we all know that it will drop drastically with a decrease in temperature. But, the F413 is a commercial grade model and comes with parts that are designed frowhich is m the ground up to perform under all foreseeable temperature and relative humidity ranges.
VIDEO | Durability Test — Dri-Eaz F413 Revolution
What’s really interesting about the Dri-Eaz F413, is how it adapts to changing conditions in real time without the need for any user input. There is a digital control panel on the top-front area, and underneath this panel lies a microprocessor chip which is essentially a tiny computer that takes input from the various sensors located on the unit’s body. There is a sensor located on the intake grill which measures the temperature and humidity of incoming air, and there is a sensor on the exhaust grill which does the exact same thing.
These sensors continuously pass information to the microprocessor which then decides how fast the blower should spin, how hard the compressor must work, etc. The result is an advanced dehumidification system that is capable of working at extremely high efficiencies within a wide range of temperatures (33°F to 100°F). Of course, it also includes all the convenience features found in most modern units such as : timer, auto shutoff and startup, automatic defrosting, etc.
The F413 can extract 80 pints of moisture per day under AHAM conditions, and 139 pints per day at 90°F, and 90% relative humidity. It measures just 12.5” (W) × 17.6” (D) × 21.5” (H), and weighs 65 pounds. There are dual carry handles on the top, and the side contains holding mechanisms for both the power cord as well as included water hose (which is 60 feet long).
If you want to learn more, visit the Dri-Eaz site.
Best dehumidifier for basements. Compact and powerful.
- Auto Defrost – In very cold temperatures, the dehumidifier automatically warms frost build-up on the coil and transforms it into condensation.
- Digital Control Panel – The Dri-Eaz 7000XLi control panel boasts a digital display and touchpad displaying English system messages, no confusing codes.
- High Airflow Filter –A vacuum-able 3M High Airflow Air Filter protects internal components from damage due to dust and other particles, ensures efficient operation, and catches allergens.
- Pump Purge Switch –Easily purge collected water in preparation for transport.
- Hour Meter – Tracks job hours and total life hours for task management.
- Rotomolded Housing – The 7000XLi is constructed with Dri-Eaz’s legendary rotomolded polyethylene housing, which resists dents and scratches.
- Semi-Pneumatic Tires – These tires are puncture-proof, lightweight, and rugged for easy transport and a long service life.
- Integrated Handle – Along with semi-pneumatic tires, the sturdy handle makes transport from job to job a breeze.
- Detachable Power Cord – The cord measures 25 feet for usage flexibility.
- Storage Pockets – Store the drain hose and electrical cord neatly in pockets located on the side of the unit.
The Dri-Eaz LGR 7000Xli is the big daddy of extra-large dehumidifiers, designed for serious work such as post-flood restoration projects, dehumidifying storage rooms, or for dehumidification of newly constructed basements/ crawlspaces. It is a LGR (Low Grain Refrigerant) dehumidifier, which basically means that this dehumidifier will perform much better across a broad range of temperature/ humidity conditions, compared to a standard refrigerant dehumidifier.
The compressor, fan motor, and fan itself, are all designed specifically for heavy duty workloads across a wide range of conditions. Just like the F413, this model also features advanced microprocessor control and sensors on either side that monitor incoming and outgoing air characteristics in real time. The microprocessor analyzes the temperature and humidity of air passing through the blower, and adjusts the fan speed and compressor pressure accordingly to ensure maximum efficiency.
Under AHAM conditions, this 107-pound beast will extract 80 pints of moisture per day. Under saturation conditions (90°F and 90% RH), it will remove 235 pints (111 liters) of moisture per day. Operating range is 33°F to 100°F, and tests have proven that the 7000Xli is 40% more efficient than other Extra Large LGR dehumidifiers from competing brands. A 40% performance difference is not something you see every day, that too between models of the same size class. The unit is heavy, but still quite portable because of the trolley style frame design – there is a handle on the top and large wheels on the bottom that allow you to roll it around quite easily.
The shell is constructed from rotomolded polyethylene for maximum toughness, and the built-in pump basin is infused with antimicrobial protection to prevent growth of bacteria or mildew. The fully-sealed large capacity pump basin is designed to contain the water from an unintended defrost that might occur in the event of a power outage or accidental shutdown. There is a detachable 25-foot long power cord, and storage pockets which allow you to store the drain hose and power cord for easy transportation. The wheels are equipped with semi-pneumatic tires for puncture resistance.
The high-airflow industrial grade air filter protects internal components from flying debris, dust particles etc., and is vacuumable for easy maintenance. There is a built-in condensate pump which automatically removes collected water through the 40-foot hose that is included along with the 7000Xli. The Dri-Eaz 7000Xli LGR dehumidifier is meant for industrial or commercial use, but you can definitely buy it for your basement or as a whole-home dehumidifier. It will efficiently and quickly dry wet carpets, floors, walls, etc. Perfect for restoration work or renovation jobs after floods/ leaks.
**Not in stock at the time of this writing. Browse these other Frigidaire dehumidifiers for alternatives.
- 70 pt. per day dehumidifier uses standard 115-Volt electrical outlet
- Protects your home from mold and mildew caused by excess moisture
- Helps eliminate bacteria in the air that can make breathing difficult
- For a room up to 2000 sq. ft.
- Low temperature operation saves energy and money
- Electronic controls with digital humidity readout
- Effortless humidity control allows you to control the exact percentage of humidity in your room
- 2 fan speeds for more flexibility
- Continuous operation is possible when unit is located near a suitable drain
- Effortless full tank alert system with auto shut-off
- Mesh filter reduces bacteria, room odors and other airborne particles
- Auto cool mode allows the fan to adjust speeds as the room temperature changes
Does almost everything that its successor is capable of, at a slightly lower price. Yes, you can still purchase this old workhorse which was released all the way back in 2014. It was considered to be one of the best 70-pint dehumidifiers of that year, and still holds up very well against the competition. It may be slightly slower and louder than the new FFAD7033R1, but there is no denying that the Frigidaire FAD704DWD is ahead of most 70-pint dehumidifiers on the market in terms of performance and efficiency.
Funnily enough, it is actually considered to be more portable than the newer FFAD7033R1, and the gravity drain port location on the FAD704DWD is more user-friendly since it is towards the bottom rear instead of the side. There are pocket handles along with an extendable top handle, while the new FFAD7033R1 only has an extendable top handle. After years of usage, the top handle might break or become loose, in which case the pocket handles come in handy (pun intended). One more thing worth mentioning – this model is slightly noisier than the new FFAD7033R1, but you have more freedom when it comes to positioning within a room. What does that mean?
Well, the FFAD7033R1 has air intakes on the rear and exhausts from the side. Which is why you shouldn’t place it close to a wall, since the tight space between the wall and intake could choke the unit and decrease efficiency. You must place it towards the center of your room in order to get the most out of it. However, there are no such restrictions on the old FAD704DW
D. It has intakes on the front and exhausts on the top – so no matter where you put it, as long as the front isn’t pointing towards the wall (why would you do that?), this model will suck air in from the center of the room.
Other than that, it includes most of the convenience features found on the FFAD7033R1 such as – automatic defrost, auto shutoff and start, timer, gravity and pump drain, digital display, dual fan speeds, and low temperature operation (up to 41°F). It is Energy Star certified, and includes a washable anti-bacterial air filter.
Learn more about Frigidaire products by visiting their site.
The problems caused by too much moisture in home air can range from mild to extreme, depending on the relative humidity of the air. The EPA (Environmental Protection Agency) recommends a relative humidity level between 30 to 50% for optimal comfort and good health. Anything above 60% is considered a threat to health and property, and you can tell that the air in your home is too humid based on certain signs.
For example, you may experience trouble while breathing because the indoor air feels too heavy or thick compared to outside, especially if you or someone in the family has respiratory tract problems. Your eyes might feel itchy at mornings or evenings, and your skin might crack or feel soggy. Excessive humidity also damages property, resulting in the formation of mold spores on the walls and black spots on the furniture/ wooden floors which harbor mildew. We have divided the problems caused by excess humidity into two categories for simplicity-
Difficulty in Breathing – High humidity levels in your home can cause several respiratory tract related issues, including sneezing, coughing, and trouble with breathing. The air becomes too thick and heavy, and it feels as if you are hiking through a tropical rainforest during a sizzling summer day. Even relatively unoccupied rooms can feel stuffy and overcrowded, leading to various health problems.
Allergies – Damp air is exactly what fungi need in order to breed successfully, which is why you will notice spores and mildew around humid parts of the house such as the basement, kitchen, bathroom, etc. Not only do spores and mildew look disgusting on your walls, they also let off a musty smell and pose several threats to the health of your family. Damp spaces with limited ventilation are breeding grounds for allergens and dust mites, and these microorganisms are notorious for spreading all kinds of allergies, especially in young children. Itchy/ watery eyes, sneezing, skin rashes, stuffy nose, etc. are some of the most common reactions to allergens. Not only do these microbes infest your home and cause all sorts of diseases, but they also fly around in the air and get into cereals, bread, etc., spoiling the food.
Dust Mites – Dust mites are microscopic insect like creatures which feed on dead skin cells. There are billions of these residing on our skin, feeding on dead skin tissue and producing waste particles which cause allergic reactions. Damp air is what these little mites love, so you are better off keeping the humidity levels low inside your home if you want to minimize the growth of these tiny pests.
Skin Rashes and General Irritation – Humid air prevents sweat droplets from evaporating effectively, and when droplets of sweat accumulate on your skin for extended periods of time, it begins to feel sticky and itchy. Sweat mixes with dust particles and pollutants from the air, resulting in a layer that covers the pores on your skin, and causes skin rashes.
Musty Smell – The mildew and spores which grow on walls/ ceilings produce waste materials that mix with the air, resulting in a foul odor. Not only is this smell disgusting, but it is also filed with toxins that cause allergies and various respiratory tract related issues. Neither your family, nor your guests will appreciate staying a room infested with spores and mildew.
Degradation of Property
Formation of spores on walls and ceilings – Spores and mildew breed on damp walls, and can eat through wooden furnishing or floors. This greatly depreciates the value of a certain house, and if you let it go unchecked, you might have to spend thousands of dollars on home renovation. In some extreme cases, homeowners have had to completely replace entire sections of floors, walls, and ceilings because of rampant mold growth across the home.
Peeling paint and wallpapers – Condensation on walls and ceilings will result in peeling wallpapers and black spots due to mold growth and contraction of the damp surface.
Damp and deformed wooden furniture – Damp wood tends to warp and deform, and you can notice this manifest in the form of doors that don’t close properly or make creaking sounds, rusty hinges, warped wooden floors that creak when you walk on them, etc. If the air in a room is too damp, it will cause the furniture in that room to rot, and rotten wood emits a soggy smell that is very unpleasant. Damp wood is also an open invitation to termites.
Rusting metal and damage to electronic equipment – Support beams, hinges, tools, and pretty much any exposed metal object in a damp environment is likely to rust over a period of time, and delicate electronic equipment can develop short circuits if exposed to excessive amounts of atmospheric moisture.
Pest infestations – You might own a few pets in your home, such as cats or dogs (maybe both). But damp environments can result in the entry of a few unwanted guests – centipedes, millipedes, cockroaches, termites, and some other very unpleasant creatures who you don’t want to see inside your home. Imagine waking up to one of these on your bed, or finding a bunch of them running around in the kitchen. Yep, not something we want to think of even in our dreams. So, it is better to be safe than sorry, investing in a dehumidifier sure sounds a lot better than hiring a pest extermination company.
Benefits of Owning a Dehumidifier
Now that we have told you all about the horrors of living in a damp and mold – infested house, let us take a brief look at the numerous benefits offered by a dehumidifier:
Dehumidifiers make the air more breathable and increase comfort levels by sucking away excess moisture – A dehumidifier will suck away excess moisture from the air and revert relative humidity levels to under 50%. Not only does this make the atmosphere inside the house feel less swampy and annoying, but it also improves the breathability of the air by making it feel much more like outdoors air, fresh and clean.
Dehumidifiers will significantly decrease the chances of mildew or mold developing inside your home – A dry atmosphere is a clean atmosphere – mildew and mold are much less likely to breed when humidity levels are under control. This will significantly increase the overall quality of life in your home, ensuring that allergens don’t spread across the home. It will also reduce the chances of family members developing asthma or other respiratory tract related issues.
Dehumidifiers get rid of that annoying musty smell – Damp air is the root cause of that annoying smell, which is a byproduct of the growth of mold and mildew on walls and furniture. Get rid of excessive moisture, and no more mold or mildew will breed inside your mouse. This directly results in fresh and clean smelling air.
Dehumidifiers also reduce the growth of dust mites – While it is nearly impossible to completely eradicate the growth of dust mites, we can reduce their numbers by more than half through the use of dehumidifiers and proper cleaning of the home (washing clothes and taking bathes, vacuuming the home regularly, etc.). These dust mites are one of the several species of microorganisms that exist on our skin, and they love damp air. By maintaining a low to moderate level of humidity in the air, you can greatly reduce the number of dust mites. These mites can cause allergic reactions if their numbers get out of control.
Dehumidifiers will reduce condensation – Although you might not notice the effects of condensation initially, over time it can result in peeling of paint and wallpapers as well as rotting and degradation of wood. Condensation is most likely to occur on bathroom and kitchen walls/ windows. A large – sized (70-pint capacity or more) dehumidifier will aid in controlling the moisture content of air in the entire house, and can significantly reduce the chances of damage to the walls or furniture.
Dehumidifiers can help dry your clothes – Well, this one is a little bit of a stretch as not all dehumidifiers are capable of sucking away moisture at a rate that will dry your clothes even remotely as fast as a tumble drier or dedicated clothes drying system. However, if you don’t own a tumble drier or clothes drier unit in your home (maybe you live in an apartment or rented space), then the dehumidifier will greatly help with indoor clothes drying. Let’s say, the weather outside is not suitable for line drying, then you can simply dry your clothes inside the home by turning up the dehumidifier to max speed. Some dehumidifiers even come with a dedicated “drying” mode for clothes.
Dehumidifiers increase the efficiency of air conditioning systems – An air conditioning system has to work harder to drop temperatures if the air is too humid, meaning that it will consume more electricity per degree of temperature reduced. A dehumidifier makes the ACs job easier by taking away excess moisture so that the cooling can be done more efficiently. Besides, your air conditioning system will also last longer if it operates in less humid air.
Dehumidifiers indirectly increase the shelf life of certain food materials – A damp atmosphere is going to result in the spread of various fungi, including molds and spores. These molds and spores fly around inside the home and land on exposed bread or cereal, greatly degrading food quality as well as life. Not just that, food is likely to spoil faster if you don’t store it in dry conditions. A dehumidifier takes care of all these issues, not only does it keep the air dry, but it also stops the growth of mildew, mold, mites, etc.
Dehumidifier vs Air Purifier
Although these two appliances differ fundamentally in how they work as well as what they do, customers often confuse one with the other. An air purifier is designed to remove particulate matter and pathogens from the air, but don’t buy an air purifier if your goal is to remove excessive moisture from the air. On the other hand, a dehumidifier excels at removing humidity from the air but doesn’t do anything about germs, microscopic dust particles, or pollutant gases dissolved in the air.
To put it simply, an air purifier is best for removing allergens and disease-causing pathogens from the air. An air dehumidifier is better for combating spores, mold formation, dust mites, and preventing wood/ walls from decaying due to excessive moisture. Neither appliance can replace the other, but why not own both? That way you will enjoy the freshest and cleanest air possible, while also making sure that your property stays safe from mold and mildew.
Just to clarify things a bit further, we shall briefly overview how each of these appliances work-
The Air Purifier
An air purifier’s primarily role is to remove pollutants and unwanted material from indoor air. It accomplishes this task by blowing air through a series of physical filters, each designed to capture a specific kind of pollutant. The first filter layer is usually called the pre-filter, and is designed to capture the largest objects floating around in the air such as pet hair, or large grains of dust. The next stage is usually a HEPA (High Efficiency Particulate) filter which catches objects as small as 0.3 micrometers in size.
The HEPA filter is responsible for filtering out allergens, certain kinds of harmful pathogens, pollutant gas molecules, etc. Then, you might have a charcoal or activated carbon filter which removes all the hydrocarbon based pollutants, or organic stuff. The activated carbon filter removes foul odor from the air. Finally, the cleaned air passes out through the front grill for everyone to breath. This is the most common type of air purifier found in most homes, some air purifiers may also UV radiation to kill disease causing pathogens, while other models also generate ozone alongside clean air.
Advantages (relative to a dehumidifier)
- Better at filtering out odors which are not related to excessive humidity (such as cooking smells, cigarette fumes, emissions from nearby factories or vehicles, etc.)
- Directly targets the asthma causing allergens that float in the air, thus it is more effective at preventing specific health problems related to suspended allergens in the air.
- Effectively filters out pollen and pet hairs from indoor air
Disadvantages (relative to a dehumidifier)
- Doesn’t help with the musty smell that is caused by excessive humidity
- Cannot combat the spread of mold and mildew in the house
- Doesn’t relieve you from the skin irritation and sweating that occurs on a hot, humid day
Air Dehumidifier — Facts
Like we explained before, the primary goal of a dehumidifier is to remove excess moisture content from the air. Most dehumidifiers are refrigerant/ compressor based, and we shall discuss how they work in the next section. Right now, all you need to know is that the air dehumidifier only contains one layer of air filtration, and that is to prevent large dust particles/ pet hair from accumulating on the coils inside the unit. Dehumidifiers are also larger, heavier, and consume more electricity than most air purifiers, because of the fact that they use compressors. While air purifiers can be easily integrated into your home HVAC system, it will cost much more to install an air dehumidifier into the HVAC system. Which is why, most homes utilize standalone air dehumidifier units, especially portable models.
Advantages (relative to an air purifier)-
- Much more effective at dealing with the musty odor caused due to excess humidity and molds/ mildew
- Better suited to protecting wooden furniture/ furnishing from decaying in a humid climate (for example, if you live nearby the coast)
- Doesn’t remove mold and mildew spores from the air, instead it removes the condition necessary for them to breed (aka humidity), thus destroying the menace at its root
- Improves comfort levels during the summer, especially on hot and humid days
Disadvantages (relative to an air purifier)-
- Cannot deal with odors that are not related to humidity
- Doesn’t aid with dust or pollen
- Will not filter out disease causing pathogens, or pollutant gas particles
Of course, certain situations will arise because of which you have to invest in both a purifier as well as dehumidifier. For example, if you live along the coast and have pets in your home along with family members who suffer from respiratory tract related issues such as asthma. Or, if you live in a tropical climate, and in close proximity of a busy highway or large factory, the air in your home will be dirty as well as humid. In these scenarios, you will have to combine the powers of a dehumidifier along with an air purifier.
4 Distinct Types of Dehumidifiers — How They Work
Until now we have talked about what a dehumidifier does, the benefits of owning a dehumidifier, and the differences between it and an air purifier. But before we proceed further, it is necessary for you to understand how a dehumidifier works. Don’t worry, we are not going to attack you with mathematical formulas and advanced technological jargon.
Our goal is to provide you with a simple explanation that is easy to understand and comprehend, such that you will be able to appreciate the technology that most of us take for granted and can make better purchase decisions for yourself. Knowing about the distinct types of dehumidifiers and how they work, will also give you an insight into which design is best for your specific needs. Even so, 99% of you will probably end up buying a mechanical/ compressor based dehumidifier since they offer the highest moisture removal rates and cover the largest areas, making them a no-brainer for basement dehumidifying applications.
Mechanical / Compressor Based Dehumidifiers
These are the most common type of dehumidifiers, as well as the most highly performing kind. The mechanism inside one of these is very similar to that of an air conditioning unit – there are hollow metal coils encased within fin arrays, and connected to a compressor pump. There is also a fan and fan motor assembly which drives air through the inlet and outlet grills of the air dehumidifier. Finally, you have a bucket or “bin” that collects all of the condensate.
The basic principle behind a compressor based dehumidifier is actually really simple, it uses the phenomenon known as condensation to separate water from air. If you have ever woken up during a really chilly morning, you probably have experienced the formation of dew. This dew is generated when humid air containing water vapor is cooled below the dew point, aka the temperature at which water changes from vapor to liquid form through the process of condensation. Condensation occurs all around us, and is the result of heat transfer from a hot to cold region. Example – a can of cold drinks when taken out of the refrigerator will begin to collect water droplets.
Inside the dehumidifier, there is a process of heat exchange going on between the evaporator coil and the hot, humid air of your room. The entire cycle starts when a little sensor in the humidistat of your dehumidifier detects humidity levels that are higher than the settings which you have enabled via a control panel. Then, it turns on a switch that causes 120V of AC current (from the wall outlet) to pass into the compressor and fan motor, which begins a cycle of events.
The compressor pumps refrigerant fluid through a long, winding metal tube called the condenser coil. The compressors job is to take gaseous refrigerant at one end, and squeeze it through a tiny area to compress the fluid and convert it into a liquid. This process generates heat, and the heated refrigerant flows through the condenser coil. It then enters the evaporator coil where rapid expansion of the compressed liquid refrigerant results in an extremely cold gaseous phase transformation, and the evaporator coils temperature falls below the dew point.
Incoming humid air, which is being sucked in by the fan assembly flows over the cold evaporator coil, and water is separated through condensation. This water drips down into a bucket or containment tank which is removable. The now dry but chilly air passes over the condenser coil, and gets reheated to slightly above its original temperature, and is then thrown back into the room.
Medium to large – sized dehumidifiers are often equipped with rear side drain ports which allow you to connect them directly to a floor drain. In some advanced models, there is a pump in the condensate chamber, also known as a “condensate pump”. You can connect a hose to the outlet port and the dehumidifier will automatically pump out the water whenever its reservoir is full. Some commercial and industrial grade models give you the option of connecting an external drainage pump to the dehumidifier.
- Best suited for living areas and basements/ crawlspaces because of their high moisture extraction
- Can dehumidify large halls, entire homes, offices, etc. Industrial grade units are often used for post storm/ flood dehumidification duties
- Capable of covering areas as large as 3500+ sq. feet, although the smallest ones are optimized for spaces as small as 300 square feet
- Remove the most amount of moisture per watt of energy consumed as compared to any other design
Most of them are designed to work at standard room temperatures only, up to a minimum of 65°F (18°C). Any lower, and the coils will freeze, stopping the compressor. If you plan on using the dehumidifier in an extremely cold or highly insulated environment such as a garage, then you might want to look for one that is optimized to operate at extra low temperatures. These specialized models will cost more, since they are equipped with higher quality components and specially designed coils/ compressor pumps.
Refrigerant based dehumidifiers have two noise-generating components – the compressor pump and fan. As a result, these units can get pretty loud depending on the specific model and its size (some industrial units generate 75-80 decibels of noise, which is harmful to the human ear).
You will need to make sure that the condensate bin is emptied on time, or else the compressor will stop working. If you use the dehumidifier in an extremely humid part of the house (bathroom, basement, etc.) the bin might need to be emptied every 8-10 hours (depending on the size of the bin and the moisture extraction rate of the unit.
The efficiency of these units can vary based on the relative humidity of air, and performance drastically falls off below 35% relative humidity.
Desiccative dehumidifiers are cheaper, compact, and contain very few moving parts. They rely on a special humidity – absorbing material known as a desiccant (like the one found in shoe boxes) to squeeze moisture out of the surrounding air. The downside? Low extraction rates. Like, really low – even the best consumer grade models can manage a meager 15-20 pints per day, and that is still lower than the smallest compressor based dehumidifiers. However, unlike their compressor based counterparts, desiccant dehumidifiers can work in extremely cold temperatures. And, the efficiency of a desiccative dehumidifier does not vary with changes to the relative humidity or temperature of the surrounding air. It is also much quieter and consumes less power than a compressor based dehumidifier.
- Performance is stable irrespective of changes to relative humidity (these can work at low temperatures, and low humidity)
- Quieter and consume less power
- Usually they are smaller and lighter than their compressor based counterparts
- Extraction rates are very low (15-20 pints a day even on the most powerful consumer-grade desiccant dehumidifiers)
- Less value, since you are removing much less moisture per dollar spent
- The desiccant material used in these dehumidifiers gives off an odor whenever it is heated in order to relieve the stored moisture
Instead of using compressors, coils, and fans, these units use semiconductor plates to transfer heat.
Thermoelectric dehumidifiers use Peltier Heat Pumps to cool a surface and condense water vapor from the air. The overall design is extremely compact as well as lightweight. However, the moisture extraction rate is very low and energy efficiency is terrible. This design is used to make extremely portable dehumidifiers (battery operated or USB charged).
- Very compact and lightweight
- No noise is produced
- No maintenance needed
- Extremely low moisture extraction rate
- Extremely energy inefficient when implemented on larger scale
Ionic Membrane Dehumidifiers
These consist of a single ionic membrane which moves humidity inside or outside a sealed enclosure without the formation of visible water particles. Water vapor is removed through the process of electrolysis; hence this type of design is completely maintenance free. It is used to dehumidify sealed-off areas that typically don’t contain a whole lot of moisture to begin with, since this process can only remove a few grams of moisture per day from an area of up to a few hundred cubic feet. The ionic membrane requires very little electricity to operate, is completely noise and odor free. Ionic membrane dehumidifiers are utilized to protect sensitive electronic components, medical appliances and equipment, museum specimens, or scientific apparatus.
- Maintenance free
- No noise, waste, or odor is produced
- Requires very little electricity in order to operate
- Low moisture extraction rate
- Only applicable in completely sealed-off spaces
- You will never use one of these
Humidity Management Tips for Homeowners
While dehumidifiers are great for maintaining healthy levels of moisture in the air, there are several steps that you can take in order to maintain a healthy humidity level within your home. Dehumidifiers are the first step when it comes to humidity management, but running a dehumidifier in a home that is full of leaking pipes and has zero insulation is like eating a tub of ice cream right after a workout – your goal is to remove moisture from the interiors faster than it is generated, not the other way around.
Humidity is supposed to be in moderation, too little humidity can cause almost as many issues as too much humidity. The ideal humidity level is obtained after taking into account both people and property. Humans, furniture, electronics, and metal tools all have their own ideal humidity ranges. Fortunately for us, these ranges overlap with each other. But before we talk about the importance of maintaining humidity levels and how you can do it, the concept of relative humidity must be understood. Relative humidity is the ratio of water vapor currently present in the air, to the maximum amount of vapor that the air can hold at that temperature.
As you might know, gases expand upon heating and contract upon cooling. Hotter air has the capacity to hold more water vapor, hence it will have a lower relative humidity assuming that the quantity of water vapor is kept constant. Colder air holds less water vapor, so it will have lower relative humidity. Relative humidity may drop significantly in the winter because heating systems warm up the air without adding any moisture to it, hence the air feels dry.
But how is humidity introduced into your home? Well, it can happen from both interior and exterior sources. Interior sources of moisture include cooking, bathing, indoor drying of clothes, sweating, etc. Exterior sources include the moisture contained naturally in outdoor air which seeps through windows and doors, as well as rain water and underground water which can flood into the basement or crawlspace.
Why it is so important to regulate the humidity levels?
According to the EPA (Environmental Protection Agency) and American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), the recommended relative humidity range for human beings can range between 30 and 60%. It is recommended not to raise the relative humidity above 50% if there are people with respiratory disorders in the home. Anything below 30%, and the air will feel too dry and can cause various skin issues. Conversely, if the relative humidity exceeds 60%, your home could potentially become a breeding ground for mold and mildew. Neither of these outcomes sound pleasant, so what can you do to keep humidity in check?
The first step is to invest in a good air dehumidifier. You might also want to keep a hygrostat handy, as it will monitor the levels on humidity inside your home. Whenever the humidifier is not running, it is recommended that you open the windows to let in some fresh air (especially during spring season). Stagnant air is moist and hot, and loaded with impurities. Humidity rises when the temperature falls, or when moisture is added to the air. You need to make sure that there are no leaks in the walls or ceilings, as the inside layers of walls tend to be colder and act as surfaces for moist air to condense upon.
One way to make sure that the humid air doesn’t pass through pores and cracks in the walls, is by installing ventilation ducts in the home, especially for the kitchen and bathroom. Air will always look for the easiest way to escape, and a ventilation duct is a much better route for air to pass through as opposed to tiny cracks and pores in the walls. You can install air seals around leaks and cracks in the wall, and you can also insulate walls to make them warmer on the inside which will prevent moisture from condensing. So how to know if the humidity levels are too high or low without using a hygrometer? Well, here are a few basic tricks that you can uses to get a rough idea of the humidity level.
Signs of High Humidity
- Condensation on the inside surface of windows
- Wet stains on ceilings and walls
- Mold and mildew growth around damp areas
- Air feels damp and smells musty
Signs of Low Humidity
- Sore throat and dry skin
- Occasional static shocks when you touch a metal or synthetic object
Valuable tips to prevent formation of excessive moisture
- While cooking, cover steaming pots and turn on the kitchen exhaust fan
- Make sure the clothes drier duct is connected to the vent without any clogs or leaks
- While showering, run the exhaust fan (if present) and open the windows, wipe off excess water from the shower door and bathroom walls
- Apply a waterproof coating to your basement wall
- Check plumbing for leaks and condensation
- If rain water is collecting too close to your home foundation, clean the gutters and make sure that down spouts lead at least 3 feet away from your house
- There are several indoor plants that can aid in maintaining a healthy amount of humidity within the house – Peace Lily, Reed Palm, English Ivy, Boston Fern, Tillandsia, certain small cacti, etc.
- Always clean and repair the roof gutters on a regular basis, especially after storms
- Keep relative humidity between 40 to 55 percent for a mold-free home
- Cover the crawl space floor with a plastic vapor barrier – 6 mil polyethylene (landscaper’s plastic) will prevent groundwater from seeping into your crawlspace. If you crawl down there frequently, trying using a heavier 20 mil plastic covering since it won’t rip as easily
- Eliminate clutter lying nearby the vents of your HVAC system since it will disrupt airflow.
- Always check for stagnant water around sump pumps, freezers, basement doors, and inspect crawl spaces for foundation leaks.
What characteristics separate a basement humidifier from a regular dehumidifier?
A typical basement dehumidifier is just like any other standalone compressor based dehumidifier, but it is optimized for performance in extremely damp and cold situations. Yes, there are desiccant type basement dehumidifiers as well, but those models are used only basements which are both extremely small and colder than usual. A good basement dehumidifier must have a gravity drain or condensate pump so that you don’t have to run up and down the stairs every 8 or 10 hours in order to empty the bin.
Basement dehumidifiers must also be more powerful than standard models, because the basement is usually where air is most humid in the entire house. But there are a few things to note before you go out and purchase a basement dehumidifier – first of all, you need to check your basement humidity levels and if the results indicate excess humidity, try to search the place for probable causes. Leaking pipes, cracks or faults in the HVAC system, dysfunctional or clogged vents, seeping groundwater, stagnant pools of water, etc. are the primary reasons behind excessive humidity in basements.
Once these issues have been identified, try to fix or control as many of them as you can. Then and only then, should you introduce a dehumidifier unit into the basement. Like we said before, working out doesn’t help if you eat a bunch of fast food right after the exercise. Eliminate or at least minimize the root causes behind excess humidity, then bring in a dehumidifier. Try monitoring the temperature average inside your basement, as long as it is above 70°F any decent condenser based dehumidifier will get the job done. But if you are noticing temperatures below 70°F on a regular basis, you must get a model that is specially designed for low temperature operation, preferably one with built-in defrosting systems.
Signs the air in your basement is too humid
- Humidity level higher than 55%, as measured on a portable hygrometer
- It feels damp to the touch
- An intense musty odor that is usually the result of mold or mildew formation/ damp rotten wood
- Your skin feels itchy, and you sneeze more often than usual (usually because of an increased concentration of dust mites in the damp basement air)
- Condensation on cold surfaces, such as the inside of your basement windows
- Peeling or cracking paint, and visibly rotten woodwork
Basement dehumidifiers typically have some, or all of the following features
Unless the area you live in sees warm temperatures throughout the year, it might be wise to invest a few extra bucks on a dehumidifier which will not frost and jam when temps drop too low. A refrigerant based dehumidifier extracts moisture from the surrounding air by passing the humid air on top of a really cold coil known as the evaporator coil. If the air in your room or basement is too cold (under 65°F), there is a high chance that the water will simply freeze into ice on the coils instead of falling down into the condensate tank.
Frozen coils shrink in size, impeding the flow of refrigerant fluid, increasing pressure on the compressor pump, and ultimately result in cracked tubing or fins. The amount of money that you spend on replacing the coil system or compressor is around half the cost (maybe even more) of the actual dehumidifier itself. A dehumidifier can be manually defrosted by blowing warm air on the frozen coils, or by simply leaving the compressor out in the sun. But constant frosting and defrosting will damage coils over the long run and reduces dehumidifier life.
The better thing to do is purchase a dehumidifier with an auto – defrost mode. These models are equipped with defrosting systems which will defrost the coils independent of user input, they do so by detecting ice formation through temperature sensors built into the coil systems. As soon as the sensor detects ice on the coils, it will instantly stop the compressor and the coils will no longer be cooled. The fan keeps running in order to speed up the defrosting process by blowing air over the iced-up coils. All this while, an indicator light should be on which tells you that the dehumidifier is currently in the process of defrosting.
When all the ice is removed, and coil temperatures are back to normal, the compressor will start pumping refrigerant once again. Dehumidifiers which are designed for operating in temperatures lower than 65°F always come with this feature, and their coils are constructed from high quality materials that can sustain this cycle of frosting and defrosting without reducing lifespan of the unit.
A wide operating temperature range
Climatic conditions can vary depending on where you live. Some places stay cold throughout the year, some places are more or less warm all the time, and then you have places where temperatures can vary wildly depending on the time of the year. If you live in a place that is mostly warm throughout the year, then you don’t have to bother with this feature. If you live in a place where temperatures can vary by huge margins, then we recommend that you look into dehumidifiers with a wide operating temperature range. If you live in a cold place, then you must buy a dehumidifier that is specially designed for low temperature operation, so that the coils don’t freeze.
A very useful feature to have, kind of like the timer on a microwave oven. You set it, and the dehumidifier will stop running after a certain number of hours. Or, you can make the dehumidifier start at a specific time during the day. This is an excellent feature to have on any dehumidifier, since you don’t have to be present around the machine in order to start or stop it. Timers are even more important on basement or crawlspace dehumidifiers, since that part of the home is rarely accessed by family members (generally).
The dehumidifier will automatically switch itself on after a power cut/ blackout, and will resume working at the same settings that it was set on prior to the power failure.
Gravity / Pump drainage
How do you feel about taking out the trash? Necessary, but unlikable. Just like that, the process of removing condensate from your dehumidifier is a process that must be carried out in order to keep the dehumidifier running, but nobody likes to do it. Especially if the dehumidifier is located in a basement or crawlspace. Which is why we recommend purchasing a unit that comes with gravity drainage or a built-in pump that lets the dehumidifier pump its water out through the window or into an overhead sink. Gravity drainage is cheaper, but you require a nearby floor drain to be located underneath the dehumidifiers drainage outlet for water to flow down freely. But if there is no such floor drain nearby, try getting a model with a built-in condensate pump. Attach a hose to the outlet port, and point it into a nearby sink or outside the window. Condensed water from the dehumidifier is not potable as it is stagnant, might contain microbes, has tiny metal bits floating in it, and contains no added minerals. You can definitely water plants with this water, however it is not a clever idea to water edible or fruit-bearing plants/ trees with dehumidifier water.
How to Select the Perfect Dehumidifier for Your Basement?
When you want to purchase a dehumidifier, the first requirement that needs to be addressed is sizing. And by “sizing” we don’t mean the actual, physical size of the unit. No, we mean the ability or capacity of a particular dehumidifier model to remove moisture from the air. Units that are similar in terms of physical size might perform very differently when it comes to extracting moisture from the air. The rate at which a humidifier can extract humidity from the air depends on several factors, including external conditions such as air temperature. But most importantly, it is the compressor power and coil area/ size that determine how fast the dehumidifier can pull moisture from the air.
Fan speed and design also plays a key role, the more air a fan can pump across the coils, the more moisture the coils can collect. You will often see the sizing or capacity of a dehumidifier denoted in terms of pints, which basically refers to how many pints (1 pint = 0.473 liters) of moisture the unit can extract during a period of 24 hours with the fan running at maximum speed. But there is more to it than just that – remember how the efficiency of a refrigerant based dehumidifier can vary greatly depending on temperature and relative humidity?
For example, a compressor style dehumidifier might be able to extract 50 pints of moisture per day, at a temperature of 90°F, but drop the temperature to 70°F and its extraction rate decreases down to just 20 pints per day. This is because lower temperatures affect the rate at which water condenses on the evaporator coils, and increases the chances of frosting. If the unit has to defrost frequently, it means that less time is spent on extracting moisture.
Well, different manufacturers might test their models in different conditions (varying temperatures, varying humidity, etc.). You will also have to consider how damp your basement is, if the relative humidity in your basement sits at around 50 to 55% on average, then you can stick to the recommendations shown on most dehumidifier sizing charts and all should be good. But if your basement is extremely damp, you might need to up the compressor sizing by a few notches.
For example (comparative purposes only, does not pertain to actual scenarios or measurements), a 500-square foot basement filled with air at 65% relative humidity contains more moisture than a 1000-square foot basement filled with air at 30% relative humidity, assuming both basements are at equal temperatures. Which means, the 500-square foot basement will need a more powerful or “larger” dehumidifier compared to the 1000-square foot basement.
Here is a dehumidifier sizing guideline provided by the Association of Home Appliance Manufacturers (AHAM). This sizing guide correlates dampness levels with area (measured in square feet) to give you an approximate recommendation on what size of dehumidifier you should buy-
|Condition||500 sq. feet||1000 sq. feet||1500 sq. feet||2000 sq. feet||2500 sq. feet|
|Moderately Damp with Musty Odors in Humid Weather||10 pints||14 pints||18 pints||22 pints||26 pints|
|Very Damp with Odors and Damp Spots on Walls and Floors||12 pints||17 pints||22 pints||27 pints||32 pints|
|Very Wet with Sweating Walls and/or Seepage||14 pints||20 pints||26 pints||32 pints||38 pints|
|Extremely Wet with Wet Floors and High-Load Conditions||16 pints||23 pints||30 pints||37 pints||44 pints|
All of these measurements were made under a temperature of 80°F and at a relative humidity of 60%. These conditions can vary depending on where you live, what appliances you have placed in your basement (clothes drier or washing machine in the basement, how many fans you have etc.), as well as the weather in your area. It is important to understand that AHAM recommendations may not comply with the sizing charts provided my manufacturers. Many manufacturers (not AHAM certified) may test their machines in 100% humidity or saturation condition, and post those inflated results to make their products look better.
A refrigerant based dehumidifier will ALWAYS draw more moisture from the air at higher relative humidity, especially at 100% humidity which is also called saturation. If a dehumidifier is rated for 50 pints at saturation, it will barely draw 20-25 pints under AHAM testing conditions (80°F and 60% relative humidity). Keep these things in mind while checking out various models from different manufacturers. That chart shown above is not completely representative of all basement sizes and conditions, these tests were conducted in uninhabited spaces.
Add 5-10 pints depending on factors such as – how many people occupy the basement, do you have equipment in the basement that acts as a source of moisture (washing machine, clothes drier, plumbing, etc.). Consult a technician or support staff to obtain more specific sizing recommendations based on your needs. Feel free to research online if you are unsure about the performance of a certain model at varying humidity and temperature ranges.
Always look for an Energy Star sticker on whatever dehumidifier model you plan to buy. This is a guarantee that the particular model will perform at least 10-15% more efficiently than one that is not Energy Star certified. Efficient models will also feature an automatic humidistat – this is going to ensure that the compressor starts only when humidity levels rise above the point that you set.
This way, energy is conserved and you might save a couple hundred dollars in electricity bills over the lifetime of your dehumidifier. To get an estimate of the running costs, multiply the unit’s wattage with the number of hours that you plan to run the dehumidifier each day. Then, divide the result by 1000, and you should get the number of kilowatt hours (kWh) that your dehumidifier consumes daily. Multiply this with the cost of electricity per kilowatt hour ($ per kWh) to figure out daily operating costs.
Highly Desirable Features:
- Digital display – allows you to program specific humidity levels
- Auto restart – Turns the dehumidifier back on after a power cut, with the same settings
- Fan Speed Control – allows you to set the fan speed based on the RH of your space
- External water level gauge/ viewing slot – Lets you conveniently monitor the water level of the bin
- Washable air filters – Help keep the evaporator/ condenser coils clean
- Timer – Allows you to run the dehumidifier when you are not in the house
- Wheels/ casters – great for moving a heavier model
- Easy to remove water bin – Preferably one with a handle
- Automatic defrosting
- Built-in humidistat
- Drain port or condensate pump
Refrigerant based dehumidifiers will produce noise, that is how they are designed. The noise is generated by two components within these dehumidifiers – one is the compressor, and the other is the fan. Some models with built-in condensate pumps will be slightly louder, depending on the size of the pump and the capacity of the dehumidifier. Well, since you can’t get rid of the noise, the next question you might ask is – how to reduce it? There is no set limit for what noise level is considered to be annoying or disruptive, but here are a few examples to give you an idea of how the decibel scale compares to noises and sounds that we experience in our daily life-
- 10 dB(A): a metal pin falling on the ground
- 20 dB(A): rustling leaves
- 30 dB(A): whisper
- 40 dB(A): cooling fans within a computer
- 50 dB(A): light traffic/ refrigerator
- 60 dB(A): face to face conversation at close range/ Air Conditioning system
- 70 dB(A): vacuum cleaner
- 90 dB(A): lawn mower
- 110 dB(A): chainsaw
- 130 dB(A): shotgun
Most modern dehumidifiers generate anywhere between 48 to 65 decibels of noise, depending on the design and size of the model. Desiccant based dehumidifiers are much more silent though (between 30 to 35 decibels), since they don’t really contain any big moving parts. Apart from the noise generated by the dehumidifier, you must also consider the environment in which you shall place it. If you plan on installing a dehumidifier inside your basement, then you might be able to get away with a slightly noisier model depending on how your basement is designed and whether it is usually occupied with people.
In a large and empty space, the noise will be more easily heard, but if your basement is loaded with things like a refrigerator, washing machine, clothes drier, etc. then the noise generated by each individual appliance will be somewhat drowned out. Let’s say you plan on installing a dehumidifier in your living room or master bedroom, that is when silence becomes really important.
You might be watching TV, interacting with your family, doing work, and you certainly don’t want to be distracted by the constant buzzing of a dehumidifier in the background. Different people use their basement for different purposes, it is up to you to decide how much noise is tolerable from the dehumidifier, while also taking into account where you shall place it and what other appliance are going to be active in its vicinity. Interestingly, the advantage to owning a larger than needed dehumidifier is twofold – you will dehumidify the room faster, and you can afford to run the unit at a lower fan speed to keep noise levels down without compromising too much on moisture extraction rate.
Smaller models will be quieter, but they will also feature low extraction rates. You need to find a nice balance between size (performance) and noise emission. Fortunately for you, modern technology and highly competent manufacturers have combined together to produce extremely efficient dehumidifiers which boast silent operation along with high-end performance. Some of the best dehumidifiers on the market have been reviewed in the next section. We have covered both portable as well as commercial grade dehumidifiers for home and office usage. Take a look at the models we have presented, and decide which one is the best option for you based on what we have learned so far.