What is a Dehumidifier

A dehumidifier is an appliance that removes moisture from the air in a room or building. It works by drawing humid air into the unit, condensing the moisture out, and releasing drier air back into the room. Dehumidifiers are commonly used to reduce humidity levels and help control mold, mildew, dust mites, and other humidity-related issues in homes, basements, offices, and other spaces.

In this comprehensive guide, we’ll cover everything you need to know about dehumidifiers including how they work, their benefits, where to place them, and frequently asked questions.

What Do Dehumidifiers Actually Do?

A dehumidifier removes excess moisture from the air through a refrigeration process. Here are the key steps:

  • Air is drawn into the dehumidifier through an intake grille by an internal fan. This brings the humid air in contact with cold refrigerated coils inside the unit.
  • When the warm, humid air hits the cold coils, the moisture condenses and accumulates in a bucket or drain tank.
  • The now dehumidified air passes back through the hot condenser coils which reheat it slightly.
  • The drier air is then circulated back out into the room through vents, lowering the relative humidity.


This refrigeration process continuously extracts and collects moisture from the air, helping to control humidity and reduce dampness.

What Is The Benefit Of A Dehumidifier?

There are several key benefits that a dehumidifier can provide:

  • Reduces humidity and eliminates dampness. This helps control mold, mildew, dust mites, and musty odors.
  • Prevents moisture damage to walls, floors, furniture, electronics and other possessions. Dampness can warp wood and encourage mold growth.
  • Improves air quality by reducing allergens like mold spores and dust mites which thrive in humid environments. This can help allergy and asthma sufferers.
  • Makes indoor spaces feel more comfortable. Humidity can make indoor temperatures feel hotter and stickier. Dehumidifiers help regulate this.
  • Protects basements, crawlspaces and other flood-prone areas by controlling moisture sources. This reduces the chance of water damage from flooding or seepage.
  • Helps laundry dry faster indoors by removing moisture from the surrounding air.


Overall, dehumidifiers are beneficial for controlling humidity, reducing allergens, protecting possessions and improving comfort.

What Are The Disadvantages Of A Dehumidifier?

While dehumidifiers provide important benefits, there are some potential drawbacks to be aware of:

  • Initial investment can be high for larger capacity dehumidifiers. However, this cost is usually recouped over time in energy savings and damage prevention.
  • Ongoing electricity costs for operation which can add up depending on usage time. Energy efficient models help save on electricity bills.
  • Noise from the internal fan and compressor. Look for quieter models rated for home use.
  • Regular emptying and cleaning is required. Dehumidifiers collect impressive amounts of water that needs to be emptied from the tank.
  • Refrigerant chemicals are used in the cooling process. Eco-friendly refrigerants like PURON are recommended.
  • Possible temperature increase. Dehumidifiers emit heat from the condenser coils which can slightly warm a room.


With proper use and maintenance, these disadvantages can be minimized while leveraging the benefits of a dehumidifier.

What’s The Difference Between A Humidifier And A Dehumidifier?

Humidifiers and dehumidifiers sound similar but perform opposite functions:

  • A humidifier adds moisture to dry indoor air to increase humidity.
  • A dehumidifier removes excess moisture from air to reduce humidity.


Here is a comparison:

Humidifier Dehumidifier
Increases humidity Decreases humidity
Releases water vapor Collects and condenses water
Best for dry air Best for damp air
Helps during winter Helps during summer
Prevents static electricity, dry skin Prevents mold, mildew, condensation

While they perform contrasting tasks, humidifiers and dehumidifiers are often used complementarily to maintain ideal humidity levels indoors. Humidifiers add needed moisture during dry winter months while dehumidifiers remove excess moisture in damp summers.

When Should I Use A Dehumidifier?

Here are the main situations when a dehumidifier is recommended:

  • During summer months when higher temperatures increase humidity indoors.
  • In damp basements and crawlspaces where seepage or flooding occurs.
  • When indoor humidity levels exceed 50-60% relative humidity.
  • If mold, mildew, condensation, or musty odors are present.
  • In rooms where laundry is dried to help remove moisture from the air.
  • In bedrooms, living rooms, and enclosed spaces where occupants spend a lot of time.
  • To supplement central air conditioning which can help control but not eliminate humidity.


Monitoring humidity levels with a hygrometer is helpful to know when dehumidification is needed. The optimal humidity range for comfort and health is 30-50% relative humidity.

Where Is The Best Place To Put A Dehumidifier?

Strategic placement improves the effectiveness of your dehumidifier:

  • Living room, bedroom, basement – Areas where people spend a lot of time
  • Laundry room – Helps dry laundry by removing moisture
  • Crawlspaces or closets – Controls humidity in enclosed areas
  • Near humidity sources like bathrooms or kitchens – Absorbs moisture at the source
  • Upper floor in multi-story homes – Moisture rises so upper floor units help entire home
  • Near HVAC return vents – Circulates dehumidified air through ventilation system
  • Allow proper airflow around the unit leaving at least 12 inches of space


Testing different locations with a hygrometer can help determine the optimal dehumidifier placement for your home.

Is It Ok To Sleep In A Room With A Dehumidifier?

It is perfectly safe and often recommended to use a dehumidifier in bedrooms while sleeping. The drier air can help improve breathing and provide relief for those with allergies, asthma or respiratory congestion.

Here are some tips for using dehumidifiers in bedrooms:

  • Choose a quiet, low-decibel model to minimize noise disruption
  • Place near bedside within reach to adjust settings as needed
  • Direct air flow away from bed to avoid a chill while sleeping
  • Keep doors and windows closed so drier air circulates through the room
  • Use a hygrometer to monitor humidity levels, optimal for sleep is 40-50%
  • Empty water tank before bed so it doesn’t overfill overnight


Dehumidifiers can greatly improve quality of sleep when used properly in bedrooms. Just take measures to minimize noise and direct air flow for comfort.

Do Dehumidifiers Get Rid Of Smells?

Dehumidifiers cannot directly remove smells, but by reducing humidity levels they can help eliminate musty odors and improve overall air quality.

How dehumidifiers help with odors:

  • Lower humidity makes it harder for smell-causing mold and bacteria to thrive
  • Reduces off-gassing of moisture-loving allergens like dust mites
  • Improves airflow and ventilation which can dissipate trapped odors
  • Removes musty, dank smells caused by excess moisture
  • Makes air feel fresher by eliminating stagnant, humid air


For severe smells from smoke, pets, cooking or chemicals, additional air purifiers with activated carbon filters can help remove odors. But dehumidifiers play an important role in odor control by regulating humidity.

Will A Dehumidifier Stop Mold?

Dehumidifiers are an effective preventative treatment against mold growth. By maintaining relative humidity under 50%, mold spores cannot thrive and multiply.

However, dehumidifiers alone cannot eliminate mold once a severe infestation has taken hold. The mold must first be remediated using protective equipment, biocides, removal of contaminated materials and drying techniques.

Here’s how dehumidifiers help fight and prevent mold growth:

  • Creates a dry environment mold hates
  • Controls humidity to stop further mold growth
  • Removes dampness that allows mold to spread
  • Improves airflow to remove mold particulates
  • Prevents future mold issues by regulating humidity


Dehumidifiers are powerful tools for mold prevention when used properly. But existing mold requires professional mold remediation before a dehumidifier can be effective.


Dehumidifiers are invaluable appliances for controlling humidity and dampness in indoor spaces. They work by extracting moisture from humid air to create a drier, healthier environment. Strategic use of these units can prevent damage, improve air quality, reduce allergens and protect against mold growth.

With a better understanding of how dehumidifiers work and their key benefits, we are now equipped to use them effectively in our homes. Keep an eye on humidity levels with a hygrometer, select an appropriately sized and quiet unit, and find the optimal placement to maximize the dehumidification results.

With proper ongoing use and maintenance, a quality dehumidifier can provide years of dry air and improved indoor environmental conditions. Don’t resign yourself to damp, humid summers – take control with the power of dehumidification. Your home furnishings, possessions and most importantly your family’s health will benefit.

If you’re experiencing indoor mold around North and Central Georgia, contact Southeast Water Restoration immediately for professional mold remediation!