Dehumidifier Buying Guide
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:
Do You Have a Household Moisture Problem?
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:
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Common
Symptoms
|
High
Humidity (Use Dehumidifier)
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Low Humidity
(Use Humidifier)
|
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Allergic Reactions
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Chapped Lips and Skin
|
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Musty Odors
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Respiratory Problems
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Mold Growth
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Static and Sparks
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Stains on Ceilings and Walls
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Scratchy Nose and Throat
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Condensation on Windows and Mirrors
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Damage to Electronic Equipment
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Long
Term Effects
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Damage to Home and Furnishings
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Damage to Home and Furnishings
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Ongoing Allergies
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Continued Respiratory Discomfort
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Other Health Problems
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All About Humidity Levels
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:
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Human
Perception
|
Relative
Humidity at 90° F
|
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Extremely Uncomfortable
|
62%
|
|
Very Humid and Uncomfortable
|
52 - 60%
|
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Somewhat Uncomfortable for Most
People
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44 - 52%
|
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Acceptable for Most; Some May Perceive
it as the Upper Limit
|
37 - 46%
|
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Comfortable
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31 - 41%
|
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Very Comfortable
|
31 - 37%
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May Feel Slightly Dry to Some People
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30%
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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. |
|
What is a Dehumidifier?
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. |
|
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. |
|
Compressor Vs. Thermoelectric: 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.
|
How to Choose the Best Dehumidifier for You
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.
Brand: There are several
dehumidifier brands available, so if you're loyal to a
particular one, this may be something to consider.
Price: Dehumidifiers can range from
under $50 for mini units to upwards of $300 for basement
models. See a price breakdown of the different ones we
carry, see our
dehumidifiers organized by price.
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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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Shop for a Dehumidifier by Selecting One of the Categories
Below:
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Air & Water, Inc. serves
Orange County, Los Angeles County, Riverside County, San Bernardino
County. If you live in any of the following zip codes,
please feel free to come see our products in person: 92628,
90630, 92629, 92650, 92609, 92610, 92708, 92728, 92831, 92832,
and 92833.
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