| Dehumidifier Buying
Guide
See Our Dehumidifiers
Dehumidifier Comparison Chart
In addition to being uncomfortable, humid indoor
air also causes damage to your home and furnishings, and promotes the
growth of mold and dust mites. Thankfully, purchasing a
quality dehumidifier is the perfect solution to excess household
moisture. Learn how to purchase a dehumidifier and see a
comparison chart of some of most popular models below:
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Do You Have a
Household Moisture Problem? |
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If you notice creaking floors, condensation developing
on windows, or exacerbated allergy symptoms, your home's
humidity levels may be out of whack. Low humidity levels can
cause problems such as increased static electricity;
respiratory problems; and cracking and peeling of furniture
and paint, but purchasing an inexpensive humidifier for your
home is an easy solution. However, high humidity levels are
often a more challenging problem. If your home is too wet, it
can be a breeding ground for mildew growth; stained ceilings
and walls; and excess condensation on windows and mirrors.
Those living in hot, humid climates may also find that their
homes provide the optimal environment for pests such as
termites. The chart below illustrates how humidity
levels can affect your health and home:
|
Common Symptoms |
High
Humidity (Use Dehumidifier) |
Low
Humidity (Use Humidifier) |
|
Allergic Reactions |
Chapped Lips and Skin |
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Musty Odors |
Respiratory Problems |
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Mold Growth |
Static and Sparks |
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Stains on Ceilings and Walls |
Scratchy Nose and Throat |
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Condensation on Windows and
Mirrors |
Damage to Electronic Equipment |
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Long Term Effects |
Damage to Home and
Furnishings |
Damage to Home and
Furnishings |
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Ongoing Allergies |
Continued Respiratory
Discomfort |
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Other Health Problems |
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All About
Humidity Levels |
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We hear about humidity daily in weather reports, and
humidity is often likened to that muggy, steam-room feeling
you experience on a summer day. Humidity is usually expressed
in ways such as absolute humidity and relative humidity.
Absolute humidity refers to the mass of water vapor divided
by the mass of dry air in a volume of air at a given
temperature. As such, the hotter the air, the more water it
contains.
On the other hand, relatively humidity refers to the ratio
of the current absolute humidity to the highest possible
absolute humidity. If an environment has 100 percent
relative humidity, this means the air is saturated with
water vapor and can hold no more moisture. As a result, this creates the
possibility of rain. Overall, humans are quite sensitive to
humidity because the skin relies on air to get rid of
moisture. Sweating is your body's way of keeping cooling and
maintaining its current temperature. This is why you feel
much hotter than the actual temperature when humidity levels
are high. Conversely, when there is low relatively humidity,
you feel much cooler than the actual temperature because
sweat is quickly evaporating and cooling us off. In other
words, if the air temperature is 75° F with zero relative
humidity, the temperature will feel like it's 69° F.
However, if the relative humidity is 100 percent at the same
air temperature, it will feel like it's 80° F.
With that in mind, according to the American Society of
Heating, Refrigerating and Air Conditioning Engineers (ASHRAE)
Standard Environmental Conditions for Human Occupancy, it is
recommended that relative humidity be kept between 30% to
50% in the summer, and 30% to 40% in the winter. In
order to measure humidity levels, you can purchase a small,
inexpensive hygrometer (often called a humidity sensor or
relative humidity indicator). This device measures the
humidity level in your home and will confirm whether there
is too little or too much humidity. Once you are aware of
the humidity levels in your home, you can then decide if you
need to take action. To get an idea of the human perception
of humidity, look to the chart below:
|
Human
Perception |
Relative Humidity at 90° F |
|
Extremely Uncomfortable |
62% |
|
Very Humid and Uncomfortable |
52 - 60% |
|
Somewhat Uncomfortable for
Most People |
44 - 52% |
|
Acceptable for Most; Some May
Perceive it as the Upper Limit |
37 - 46% |
|
Comfortable |
31 - 41% |
|
Very Comfortable |
31 - 37% |
|
May Feel Slightly Dry to Some
People |
30% |
Again, if your air is too dry, you can
regulate moisture levels with a humidifier. However, if your
air is too moist, a dehumidifier can help maintain the
indoor relative humidity at the desired level, control musty
odors, and protect furniture from water damage.
Dehumidifier Tip: |
| Excess humidity
not only causes discomfort, but it can also add to your
air conditioner's load. Therefore, a dehumidifier
not only keeps you comfortable, but it can also help
you save money on your AC bill. |
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What is a
Dehumidifier? |
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Dehumidifiers are household appliances
that help reduce the humidity levels in the air. There are
primarily two types of humidifiers - desiccant and mechanical.
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Desiccant |
Desiccant dehumidifiers (or
passive dehumidifiers) are named for their use of a
desiccative substance to dehumidify the air.
This substance has an affinity for water vapor, and
the dehumidifying process involves exposing the
desiccant matter to an air stream with high relative
humidity. These dehumidifiers do not utilize
compressors and are best used in areas with low
temperatures and relatively low humidity levels.
Desiccant dehumidifiers can also be used instead of
mechanical units or in combination with them.
Although not as efficient as mechanical models, they
are usually very inexpensive to purchase.
Examples of desiccant dehumidifiers would be the
Eva-Dry EH-500F and the
Eva-Dry
EDV300. |
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Mechanical |
Mechanical dehumidifiers (or active
dehumidifiers), however, are much more common,
efficient, and are simply air conditioners with both the hot and cold
coils in the same box. A fan draws the room's air over the
cold coil of the AC to condense the moisture, and this is
often collected into a bucket. Dry air
will then pass through the hot coil to heat it back up to its
original temperature. Therefore, mechanical dehumidifiers
will slightly raise the air temperature, as opposed to air
conditioners, which will cool the air as it dehumidifies it.
Examples of mechanical dehumidifiers would be
the
NewAir AD-400 and the
Soleus CFM40. |
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Compressors Vs. Thermoelectric Peltiers: What's the
Difference? |
|
While very small spaces may only
require passive dehumidifiers, rooms or larger areas
with moisture problems will require a mechanical
dehumidifier that either utilizes compressor or
thermoelectric technology. Here are the main
differences between the two different types:
Dehumidifiers with Compressors:
This is the most common technology utilized by
dehumidifiers. Like air conditioners,
compressor dehumidifiers have coils through which
compressed air or refrigerants move. In other
words, one set of coils is cooled by moving heat
to the other set of coils. A fan within the
unit pulls moist air from the room over the cool
coils, and this cools the air and causes water to be
condensed and to fall into a collection bucket.
Dehumidified air is then passed over the hot coils
where it is warmed back to room temperature and
passed back into the room. Although these
types of dehumidifiers are somewhat loud, they are
extremely effective. Examples of dehumidifiers
with compressors would be the
NewAir AD-400 and the
Soleus CFM40.
Dehumidifiers with
Thermo-Electric Peltiers: These types of
dehumidifiers utilize thermo-electric technology.
An electric current is passed through two dissimilar
metals which transfer heat, and this causes the same
effect that is used by compression technology.
The one benefit to this technology is that there are
no moving parts so the only noise that is emitted
from these units is produced by the fan that
circulates the air. Although less energy
efficient than compressor dehumidifiers, they are
effective for smaller areas and offer almost silent
operation. Examples of thermo-electric
dehumidifiers would be smaller capacity models such
as the
NewAir ADS-500 and
NewAir ADS-600. |
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How
to Buy a Dehumidifier |
When shopping for a
dehumidifier, there are several factors to consider
such as the size of the unit, dehumidification
capacity, and safety features. Below is
a list of some of the most common things to look for
when choosing a dehumidifier and what they mean to
you:
Size:
The size of a dehumidifier is generally based on the
amount of moisture extracted from the air in 24
hours, which is usually measured in pints. Purchase
a larger capacity model over a smaller one because
larger units can dehumidify more area in a shorter
amount of time. Furthermore, a dehumidifier with a
smaller capacity may run continuously and still not
lower the humidity to proper levels. The AHAM, or
Association of Home Appliance Manufacturers,
recommends the following dehumidifier size
guidelines:
|
AHAM Dehumidifier Sizing Guidelines - Match
Room Size to Current Humidity Conditions to
Find Minimum Size Ratings |
|
Condition Without Dehumidification |
500 Sq. Ft. |
1,000 Sq. Ft. |
1,500 Sq. Ft. |
2,000 Sq. Ft. |
2,500 Sq. Ft. |
|
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 |
Portability: If you're looking to
move your dehumidifier from room to room, look for a
unit that is compact, lightweight, and includes a
carrying handle or rolling casters.
Built-In Humidistat: If you'd like to be
able to adjust different humidity levels, finding a
dehumidifier with a humidistat is key. This feature
will automatically turn the unit on/off depending on
the humidity setting.
Automatic Shut-Off: This function will
allow you to turn the unit on or off without having
to unplug it, and it also prevents overfilling when the
storage tank is full.
Low Temperature Operation / Automatic Defrost:
If you may be using the dehumidifier in
temperatures colder than 65° F, look for a unit that
has an anti-frost sensor and can operate in cold
temperatures. This prevents quick cycling and frost
from accumulating on the sensor.
Storage Tank Capacity: Almost all
dehumidifiers have storage tanks for the collected
water. If you're not planning to purchase a model
with a continuous drainage port, you'll have to
empty the tank periodically. If the dehumidifier is
to be placed in an area where you may not be able to
empty it frequently, look for a tank size of at
least 15 pints.
Continuous Drainage:
Dehumidifiers with a continuous drainage port will eliminate
the hassle of emptying a condensation tank. Simply
attach a hose to the dehumidifier, and the moisture
will drain out through the hose.
Washable / Removable Air Filter: Dehumidifiers
that have washable filters trap airborne dust and
particles. If the filter is washable, this makes
maintenance a breeze: simply pull out the filter;
rinse it with mild soap and water; and replace it
back within the unit.
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Dehumidifier Tip: |
| When it comes to
dehumidifiers, placement is also important. If the
unit has an air vent on top, it can be placed against
the wall. If it doesn't, it will need to be placed
away from walls and furniture for proper circulation.
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Dehumidifier
Comparison Chart |
To make it even easier to choose a
dehumidifier, look to the comparison chart below to see all
of the models we carry and the features they have to offer:
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