Why You May Need a Dehumidifier

What’s that musty smell? Why are my floors cupping and creaking? Why do pests keep invading my home? What is this fuzzy stuff growing on my shoes in the closet? Why do my allergies get worse when I’m inside my home?

If you find yourself asking any of these questions, your home may be suffering from high humidity.

Read on to find out why you may need a dehumidifier, how dehumidifiers work, why you can’t rely upon your AC system alone, and how to determine where to put a dehumidifier in your home.

Why Would I Need a Dehumidifier? 


Santa-Fe Compact70 Dehumidifier

First thing’s first: what’s the ideal humidity in a home? Home humidity levels should be kept between 

50-55%. When humidity levels creep above 60%, you’ll not only start to feel a bit sticky, but you may start to see some negative results. Too humid of conditions will increase your risk of bugs, bacteria, viruses, fungal growth, and other allergens.

High humidity doesn’t just impact your comfort levels. Controlling indoor humidity is crucial for preserving the long-term viability of any structure – including your home.

It’s time for a dehumidifier if you or your home are experiencing symptoms of high humidity.  

How Do Dehumidifiers Work?

There are two different types of dehumidifiers: refrigeration dehumidifiers and desiccant dehumidifiers.

Refrigeration dehumidifiers work by moving air over a coil that is cooled by a refrigeration system. When air hits the cold coil, the moisture in the air condenses on the surface of the coil and drains out of the dehumidifier. 

Desiccant dehumidifiers work by moving air over a wheel that is covered in an absorbent material. A stream of warm air is passed over the wheel to dry it so it can collect more moisture. The water collected is then drained into the unit’s collection tank. 

What Are The Benefits Of A Dehumidifier?

  • Reduce allergy symptoms caused by dust mites and mold
  • Prevent musty odors
  • Prevent microbial growth – including mold and mildew
  • Minimize pest issues
  • Protect household items from microbial growth
  • Minimize condensation
  • Improve your home’s comfort and air quality 


Wait… Can’t My AC Unit Help Dehumidify My Home? 

If you’ve been wondering, “Do air conditioners dehumidify?” the answer is yes. However, they are not dehumidifiers. When excess humidity is plaguing your home, the best course of action is to install a dehumidifier. Relying upon your air conditioner alone to dehumidify your home can result in excess strain on your HVAC unit – and result in excess condensation and water accumulation. Therefore, you shouldn’t rely upon your AC unit to solve all of your moisture issues. Doing so could result in a costly HVAC unit replacement down the line. 

Where Should My Dehumidifier Go?

You’ll need to look to your foundation when determining where to place your dehumidifier. The type of foundation your home rests upon will impact where you should place your dehumidifier. T 

These are likely the best approaches depending upon your foundation type:

  • Slab-on-Grade: ducting the dehumidifier into your existing HVAC system.
  • Basement:  installing the dehumidifier in-line with your HVAC system.
  • Crawlspace: encapsulation and independent dedicated crawlspace dehumidifier. 

Below we’ll get into specifics. 

Homes With a Slab-on-Grade Foundation

If your house is built on a slab-on-grade, the best approach when installing your dehumidifier is likely going to be ducting it into your existing HVAC system. This is called whole house dehumidification. When there isn’t an obvious moisture source, such as a crawlspace or basement, a whole house dehumidifier may be what you need. Whole house dehumidifiers work by ducting into the supply side of your existing HVAC system to supply dry air through the already existing HVAC pathways. 

Homes with a Basement Foundation

Basements may require a case-by-case approach – depending upon whether high humidity is affecting just your basement or your entire home. 

When high humidity levels are localized to your basement – often caused by high water tables, moisture diffusion through the foundation walls, or another moisture source.. If that’s the case, the best approach may be installing a dehumidifier dedicated solely to your basement that doesn’t impact the rest of your home but can help keep your basement dry.  Keeping the basement, the source of your home’s high humidity, within acceptable humidity levels will keep the rest of your house within an acceptable range as well. 

If humidity levels are consistently high throughout your home, you’ll want to duct your dehumidifier in line with your HVAC system – much like if you had a slab-on-grade home. 

Homes With a Crawlspace Foundation

If your home is built on a crawlspace, determining where to place your dehumidifier can get a little more complicated. The quick answer: your dehumidifier should go in the crawlspace, as centrally located as possible. But here’s the catch: you’ll need to make sure your crawlspace has been properly encapsulated before it’s ready for a dehumidifier. 

Why Does My Crawlspace Need to Be Encapsulated First?

Your crawlspace needs to be properly encapsulated in order for your dehumidifier to work as intended. Most crawlspaces already have a crawlspace vapor barrier, also known as a crawlspace moisture barrier. 

Crawlspace vapor barriers (or moisture barriers) are usually installed to satisfy the bare minimum requirement to pass inspections. Since crawlspace vapor barriers are not sealed, they are not enough to ensure that your dehumidifier only runs when it needs to.

You can think of a crawlspace encapsulation as a sealed crawlspace vapor barrier. The polyethylene barrier extends up the foundation walls (but not all the way to the sill plate as the bug guys need a space to inspect for termites) and is fastened to the wall permanently. This is accomplished using masonry anchors or double-sided butyl tape. The top edge of the barrier is then sealed using expanding spray foam. All of the overlapping polyethylene sheets get taped down the seams. Any piers should be wrapped and sealed. 

The idea is to make the polyethylene barrier as air-tight as possible. Creating an air-tight seal ensures that the dehumidifier will not run continuously, pulling up an endless amount of ground moisture. Once the crawlspace is properly sealed, the dehumidifier will run as necessary to keep ideal crawlspace humidity levels (50% – 55% relative humidity).

Hanging Crawlspace Dehumidifier

Santa-Fe Compact70 Dehumidifier – Hanger Kit Installation

The Mold Guys Can Help

Dehumidifiers can help keep you comfortable – and protect your home or business. Keep your crawl space, basement, and home comfortable and dry with The Mold Guys. We can help assess your indoor humidity levels by pinpointing the source of moisture and offering correctional services. Turn to us for expert moisture management in the Nashville area. We provide a number of services, including crawl space encapsulation, dehumidifier installation, and groundwater management.

Prevent costly moisture-related issues down the line by choosing the right dehumidifier and moisture control solutions today. We have plenty of high-quality dehumidifier options that will fit perfectly in your home. With expert installation and a 6-year manufacturer’s warranty, you can feel confident that you and your home are in great hands.

We hope this information has been helpful! We provide various services to keep you and your home safe. Reach out and get in touch if you have any further humidifier questions.