Humidity, the amount of moisture in the air around you, plays an extremely important role in controlling the number of airborne allergens in your home. The two most common indoor allergens, dust mites and mold, thrive in warm, humid conditions. Allergens, such as mold and fungus are present though dormant in nearly all materials, but in the presence of a food source and moisture, they can rapidly proliferate. By keeping your relative humidity in the air below 50 percent, you can control the dust mite and mold spore populations in your home. The easiest and simplest way to do this and to increase the overall comfort level in your home is to control humidity levels with a dehumidifier.
Dehumidifiers remove water vapor from the air and lower the relative humidity in your home. There is a wide variety of brands and styles out there, and sorting through the clutter can be time consuming and difficult. Make this task easier with our Dehumidifier Buying Guide. Here we go explain how a dehumidifier can help, what different styles and types have to offer, and provide you with the key features to look for before you buy.
How Dehumidifiers Work
Dehumidifiers regulate humidity by removing moisture from the air and creating living conditions that are inhospitable to dust mites, mold and other allergenic organisms. Home dehumidifiers, like Danby or Soleus, work much like air conditioners--warmer, moist air enters the dehumidifier and then crosses refrigerant cooled coils, causing the moisture in the air to condense on coils within the machine. The moisture then collects in a drip pan or bucket for disposal while the air is slightly reheated before being discharged. The reheat process is done by capturing and using heat generated from the energy spent to cool the air. By being slightly warmed, the air exiting the dehumidifier is dry and warm - which means it will attract moisture like a magnet and maximize the dehumidifier's efficiency. Of our residential units, our line of Aprilaire dehumidifiers are some of the largest units we offer. Aprilaire is the only dehumidifier manufacturer that offers both excellent whole home as well as top notch basement/crawlspace dehumidifiers, including the very popular Aprilaire 1850F.As the newest addition to our offering, Santa Fe crawlspace dehumidifiers are a popular line for basements, attics, and crawlspaces. While some models can be worked to tie into HVAC systems, this isn't as easy as with AprilAire whole home models. With steel construction, unmatched efficiency and a range of models to meet your size and drying needs, Santa Fe dehumidifiers are a preferred choice for many homeowners with moisture controls problems.
Commercial and industrial units, like our Ebac dehumidifiers and Dri-Eaz dehumidifiers, work exactly the same way, but they have features like internal pumps and powerful fans that make them ideal for cleaning, water damage, and restoration projects. Another key feature to the Ebac line is that most are constructed of steel. This makes them heavier, but also lends itself to increased durability and longevity. Dri-Eaz dehumidifiers are constructed of a rugged plastic that is extremely resistant to dings, dents and cracking.
If you are allergic to dust mites or mold--or if you smell a musty, mildew-like odor in your home, or see condensation on windows, walls, or floors, then you should seriously consider using a dehumidifier to improve your indoor air quality. Some allergens, such as mold, can turn into a serious and difficult problem to solve if allowed to grow unchecked in your home. In addition to health concerns, excess moisture speeds the natural process of oxidation. From metals to wood, every material found on this planet is subject to the process of decay and deterioration through oxidation. In bedrooms and spaces where there are carpet, indoor humidity levels under 55% or so can help to reduce dust mites. They, like mold, need a certain level of moisture in the air to survive. Another common household problem that relies upon humidity to live is household pests, like roaches, spiders, and other insects. By keeping relative humidity levels low you can make your home inhospitable to these common insects. While researching a dehumidifier, there are some important factors to keep in mind before you make your purchase.
Moisture Removal Rate
How much water does the dehumidifier remove from the air in a given amount of time? Some Ebac industrial dehumidifiers can remove a whopping 50 gallons of water per day! One of our Dri-Eaz commercial models can remove 140 pints of water a day at 80° and 60% relative humidity, while the top end Santa Fe dehumidifier, the Max Dry, can extract up to 155 pints per day from your crawlspace or basement. Because your particular situation may not call for a unit this powerful, a standard room dehumidifier is the most common type of dehumidifier sold today. Depending on the specific models, Danby dehumidifiers, Soleus dehumidifiers, and the Santa Fe Rx are all room-sized dehumidifiers that can remove between 30 and 74 pints of moisture per day.
Matching the right size dehumidifier with the space you need to dry is key to getting the most from your dehumidifier while keeping your home in the ideal, 40-50% relative humidity range. Many dehumidifier manufacturers rate their machines by square footage, but this can sometimes be misleading considering the height of a space can vary from a crawlspace to basement or room in your home to commercial warehouse space. Other manufacturers use cubic footage, but this is not universal.
Coverage of particularly large areas is also dependent on airflow within a given space and the current humidity levels. In large spaces, if airflow is good, this can make the job of a dehumidifier easier. However, even if airflow is aided by things like ceiling fans or climate control/HVAC systems, high levels of humidity may still warrant the use of more than one dehumidifier.
In most homes, 50-70 pint dehumidifiers typically have a powerful enough fan to adequately dry any single room. For open basements, Santa Fe and AprilAire models are excellent options in the vast majority of homes. For crawlspaces, even the smallest Santa Fe (the Compact2) and all of the Ebac and Dri-Eaz models will dry sufficiently. You can do some tailoring when selecting your model by comparing CFM (cubic feet per minute) or air moved by each dehumidifier to give you a better idea between models when one lists square footage while another may list cubic footage.
For areas of the country where humidity is a more persistent or severe problem, it may be worth considering the use of a whole house dehumidifier. These units tie directly into the existing HVAC and can help to reduce moisture levels throughout the entire home. Not sure if a whole model is right for you? Check out our differences between single room and whole home dehumidifiers page.
If your dehumidifier is for a basement, garage, crawlspace, or any other area that might get cold during the winter, you will want to make sure that it can operate at lower temperatures. Ebac dehumidifiers are industrial strength and have different temperature ranges depending on the model, but they all work well in low temperatures--most, like the Ebac CD35 Dehumidifier, work all the way down to 33°F! The Ebac Desiccant Dehumidifiers work at even lower temperatures. The Dri-Eaz line of low grade refrigerant (LGR) dehumidifiers are engineered to work in temperatures from 33°F to 100°F. Danby models work in temperatures down to 44°F, while Santa Fe dehumidifiers have a temperature range down to 49°F. Soleus units will typically function in temperatures as low as 41°F. At this point, it is worth noting that below 50° or so, the efficacy of a refrigerant based dehumidifier drops significantly. So while all models will actually run, starting from just above the freezing point, their efficiency is dramatically reduced until the temperature gets up to around 50. For most of these basement/home/crawlspace models, low end temperature is not a major concern as these spaces typically stay above 50° F.
On the high end of this scale are the Dri-Eaz 2800i and 3500i dehumidifiers, which can operate in temperatures ranging from 33°F to temperatures as high as 125°F.
Choose a dehumidifier keeping in mind not only the temperature range, but also the overall climate of the region in which you live. For instance, in the Northeast a dehumidifier would be particularly useful since humidity remains high from May to October, while the temperature may remain mild. An air conditioner, which also removes some moisture in the air, would not run enough (due to the lower temperatures) to adequately control the moisture levels in your home. In this case, a dehumidifier would be an excellent fit.
Humidistat - Setting Your Humidity Goal
Similar to a thermostat, a humidistat indicates the relative humidity and allows you to adjust it to the desired level. Most dehumidifiers generally come with built-in, adjustable humidistat controls. Sometimes it may also include a digital readout, and in others it may simply be a dial to adjust from wetter to drier. In the smaller, portable dehumidifiers and in many water damage restoration models, there is only on/off functionality. If you need to monitor the relative humidity in your home, we offer an affordable, high-quality humidity gauge, the Acu-Rite Digital Humidity Gauge.
To Pump or Not To Pump - Removing the Condensate
Most, if not all, good dehumidifiers provide a small length of hose. This drain line allows condensate to flow directly out of the dehumidifier into a nearby sink or floor drain. Using only gravity, this process of "porting" your dehumidifier, eliminates the need to empty a water reservoir. In some instances, a gravity drain simply isn't plausible, and in crawlspaces, the supplied hose is rarely long enough to reach outside of that space. This is where a condensate pumps comes in handy.
This separate pump works much like a sump pump and collects condensate in a small reservoir. Once it reaches a certain point, it expels the water, often pushing it up to 25 feet, horizontally. Larger dehumidifiers and restoration dehumidifiers often have pumps integrated into them and provide 20-25 feet of hose, but even some smaller, room humidifiers have an integrated condensate pump, like the Danby dehumidifiers. Whether you need a pump largely depends on your specific circumstances, but almost anyone, the use of a pump that comes either as a basement package (the case with Santa Fe dehumidifiers) or integrated (as with many Ebac and Dri-Eaz models) can provide convenience.
Dehumidifier Buying Guide - Other Factors to Consider
Like all appliances, different dehumidifiers use different amounts of energy for operation. Typical dehumidifiers can use anywhere from 50 to 800 watts. (For comparison sake, a typical lamp uses about 60 watts, while a typical computer uses about 365 watts). Danby, Soleus, and Santa Fe dehumidifiers are all Energy Star compliant for lower energy costs. Santa Fe dehumidifiers, in particular, are the most energy efficient dehumidifiers available, with some exceeding Energy Star minimum requirements by as much as 50%. This can make a large impact on your yearly power bill. If you want a good comparison, particularly between larger dehumidifiers, look for the Energy Factor. The higher this number the better as it tells how many pints or liters of water are extracted per kilowatt hour of electricity consumed.
All the room dehumidifiers we offer are relatively quiet, with the Albert, by Stadler Form being the absolute quietest refrigerant-style dehumidifier we offer. For those who have owned older models of dehumidifiers, you will find that these new models are much quieter than their predecessors. Larger dehumidifiers (whole house or for commercial use) like Ebac are louder than room size units, but they are generally installed near or around your HVAC unit, on job sites, or outdoors. Whole home dehumidifiers are generally quiet, and if the noise of your HVAC running is not an issue, Dri-Eaz, Aprilaire, or an Ebac dehumidifier will likely not cause you any problems.
Most modern dehumidifiers were designed to be user friendly. For example, both Danby dehumidifiers and the high end Stadler Form Albert room dehumidifier feature electronic controls, fully adjustable humidity settings, auto defrost, auto-restart feature, removable and easy-to-clean air filters, and direct drain options for continuous operation. Look for these options that will make your life easier:
- Water level control to prevent overflow (typically a float)
- Full Tank Light that lets you know when it is time to empty the tank
- Drainage/Porting option so that you do not have to worry about repeatedly emptying the tank
- The easiest option would be an integrated condensate pump
- Anti-Frost Sensor (or Auto De-icer/auto defrost that keeps the dehumidifier from freezing up)
- Mobility--most of our room dehumidifiers come with wheels or casters for easy transport and nearly all come with built in handles. Even some of the basement/crawlspace models, like the Santa Fe Classic and most of the restoration models come with casters.
A manufacturer's reputation and the experiences of past customers deserve consideration in your decision. Certain manufacturers and products are highly respected in the industry for a reason--and the same goes for products which have garnered less respect. So whether it is a review or award issued by a nationally recognized magazine or simply an excellent review from someone just like you, it pays to do your research before buying.
A one-year warranty is the industry standard. A two-year warranty is even better! Take into account what the warranty covers--motor, fan, electrical components, the refrigeration system? Also, find out if certain customer actions will void the warranty. Warranties are your insurance policy against defect and malfunction, so it is prudent to take these into account when choosing a dehumidifier for your home.
Now that you've read through the Dehumidifier Buying Guide, when ready, you can shop all dehumidifiers or check out one of these helpful resources.