Bob Bird
Bird Family HVAC & Insulation
July 24, 2026
Are you using your AC system to control the humidity inside your home?
Not your best idea!
Here’s four quick reasons why:
- Your AC is the most expensive appliance in your home.
- Your AC compressor is the biggest electric energy hog in your home.
- Your AC system is the most expensive appliance to repair in your home.
- Your AC system is the most expensive appliance to replace in your home.
Here’s a better idea for managing indoor humidity: use a Whole House Dehumidifier.
What is a Whole House Dehumidifier?
A whole-house dehumidifier is a dehumidifier attached to your central HVAC system. It uses the network of supply and return air ducts to manage the humidity inside your home.
The advantages of a whole house dehumidifier vs using your central AC system.
- You’re not running the AC all the time. Fewer hours = longer equipment life.
- Your whole-house dehumidifier is more efficient at removing moisture from the air inside your home.
- A whole-house dehumidifier uses far less energy to do its job, vs your central AC system.
How does a whole-house dehumidifier work?
A whole-house dehumidifier is a rectangular box about the size of a full size kitchen trash can. It operates on 120v electricity.
It pulls air in from one end of the unit, and exhausts dryer air out the opposite end. Inside the box is a small AC compressor and exchanger (looks like a small car radiator). The air is pulled by a fan, through the filter, and through the exchanger where refrigerant is flowing. The refrigerant removes heat from the air, and causes condensate (water) to accumulate and drain from the cabinet. It’s a very simple operation.
When installing these whole-house dehumidifiers, we attach an 8” air duct to the intake side of your dehumidifier, and attach the opposite end of that duct into your Return-air plenum of your home’s HVAC system. So you see, the whole-house dehumidifier is pulling all its airflow from your Return-air duct system.
On the opposite end of the whole-house dehumidifier, we attach another 8” air duct, and connect it to your Supply-air plenum of the same HVAC system. The dryer air exiting your dehumidifier is blown into the living space through the HVAC Supply-air vents.
We normally set the machine to maintain 50% relative humidity.
Once every hour, the fan inside the dehumidifier is energized for fifteen minutes while it “samples” the airflow moving through the unit. Remember, this airflow is being sourced from your HVAC Return-air vents, so it is testing the moisture levels in every room that has a Return-air vent! This is why we refer to this type of dehumidifier as a “whole-house” dehumidifier.
When the dehumidifier finds the humidity level above your set-point (50% in this example), it energizes the small compressor in the dehumidifier, and activates your HVAC fan to move more airflow.
Inside the house, you may think the AC just kicked on, but it’s only the fan motor while your whole-house dehumidifier removes moisture from the house.
When the indoor humidity drops below your set-point (50% in this example) the little machine turns off your HVAC fan, and shuts itself off. And it waits for an hour, when it starts the 15 minute test sequence again.
Our Whole House Dehumidifiers are fully Automatic and Integrated
Here’s another beautiful thing about the make and models that we install: These whole-house dehumidifiers operate regardless if the AC is running . In other words, if your AC is cycled on, cooling the house, your whole-house dehumidifier continues to test the air every hour, and when needed, turns itself on and off independent of what your HVAC system is doing!
Here’s What Savvy Atlanta Homeowners Are Doing
Use your HVAC AC to manage the temperature inside your home.
Use a Whole-house dehumidifier to manage the humidity inside your home.
On average, you should plan to spend around $5000 to have a quality, whole-house dehumidifier completely installed and set-up. Here at Bird Family HVAC & Insulation we normally install these in less than half a days time.
Dryer air is more comfortable air for our bodies. Those of you who have migrated to Atlanta from dryer regions understand this.
The average year-around relative humidity in Georgia ranges from 55% to 70%. So you see, we are completely surrounded by water! Your home is a little island surrounded by water in the form of vapor that is constantly being drawn into your living space.
The sweet spot for humans is 45%-50% relative humidity. When it drops below that, we get cracked lips, static electricity, and in extreme cases, wood floors and furniture can be negatively affected.
When the air has greater than 50% relative humidity, we feel clammy, and the air feels sticky. I’ve had homeowners also describe it as a musty feeling inside their home.
Houses on Vented Crawlspaces Beware!
In extreme cases of high indoor humidity I’ve seen wood floors buckle and warp!
Is your house built over a vented crawlspace? That humid, damp environment is irresistibly drawn upwards into your house. Do yourself a big favor: consider a whole-house dehumidifier! Second, hire us to spray your subfloor with a layer of closed-cell spray foam insulation. Your floors will dry out, and your Indoor Air Quality will dramatically improve! Your home will be Healthy & Fun to live in!
When Beau evaluates your house for a whole-house dehumidifier, tell him to BUNDLE closed cell spray foam floor insulation into your price. Tell him, “Your Dad told me to tell ya!”
Whole-house Dehumidifier Is Your AC’s Best Friend!
Even though the thermostat shows (for example) 72 degrees inside the house, and isn’t turning on the AC – you feel clammy and stuffy – and walk over to manually activate the AC because it just feels better. Although it’s getting colder inside and costs hard dollars to run that 3 ton (36,000 BTU) AC equipment.. It’s what everyone does.
After a while, it’s 92 degrees outside, and your AC struggles to keep the house at your set-point of 74 degrees. It runs all afternoon and deep into the evening.
If you had a whole-house dehumidifier, although the temperature inside your home may be a little higher than the set-point, the dryer air tricks your body and you feel much more comfortable!
In fact, our homeowners who have whole house dehumidifiers often find they can comfortably raise their thermostat setting a degree or two. Because the air is drier and more comfortable, they no longer need to run the AC as frequently to combat a “sticky” or “clammy” feeling, resulting in less strain on the equipment.
Are you ready for a professional opinion? Ready to feel good inside your home, regardless of how wet it is outside?
Call or text Nicole at 404-538-9168 and ask her to schedule Beau Bird to your home for your complete evaluation. Beau started installing whole-house dehumidifiers with me while he was still a teenager, and understands the science. Best of all, because Beau has walked the talk, he knows how to talk and explain building science in everyday, 6th grade comprehension levels so you always feel trusted and comfortable in your conversation.
Thanks for reading.
God Bless You!
