A homeowner sitting on a couch points a remote control up towards a mini-split air handler on the wall above her head

You rely on your HVAC system to control the temperature in your home. But when things get too hot and humid, you need more than cool air to relax. 

This raises the question: will your home HVAC system dehumidify when it’s turned on?

This article will outline what your home HVAC system does to explain if it dehumidifies. We’ll also explore when your HVAC unit isn’t enough to dehumidify your home and what better solutions exist. 

So let’s get into it!

Does Your HVAC System Dehumidify When It’s Turned On?

Your home HVAC system will dehumidify your home due to its normal processes. While it lacks a specific dehumidifying function, its refrigeration process does reduce humidity. How much impact this has depends on the size of your home, the size of the HVAC system, and many other factors.

The Source of Humidity 

Humidity is a measure of how much water vapor is in the air. Water must first get heated to get there, causing it to release moisture. It then collects in the atmosphere, creating humidity.

Outside your home, the climate of where you live determines humidity. Arid lands, for example, experience less humidity than tropical regions. In your home, humidity builds where heat and moisture meet (kitchens and bathrooms are a good example).

But how does humidity affect your HVAC system? Humidity is naturally warm. By influencing the temperature in your home, humidity also affects how your HVAC functions.

How an HVAC System Works

HVAC stands for “heating, ventilation, and air conditioning.” While almost all of these functions are controlled with something as simple as a thermostat or remote, the HVAC system itself is complex, with many working parts. To achieve the desired effects, they work both independently and in unison.

The central and most significant part of your HVAC system is your furnace. Traditionally, the furnace is found somewhere in a home’s basement. It works by pushing warm air (generated with an energy source, such as oil) through connected ducts and vents spread throughout your home.

Closeup on a propane furnace in a basement

The evaporator coil is a component inside your furnace. It activates when you turn your thermostat down, quickly cooling the air sent through the vents. The liquid refrigerant is pulled through the coil to cool outgoing air by absorbing and condensing heat.

If your HVAC system has an outdoor component (usually a box-like structure with a visible fan), it contains a compressor. The compressor converts the refrigerant into a warm gas, which is then released into the outside air. The gas is then cooled, returning to a liquid form.

An outdoor unit for a ductless mini split HVAC system, mounted on a concrete plinth.

These are only the main components responsible for temperature change. Several other parts, such as fans, lines, vents, ducts, and containers help manage the system and push air into your home. 

The Dehumidification Process

Your HVAC system is designed strictly for temperature control. However, the cooling process naturally has the side effect of dehumidifying the air. It all comes down to the evaporator coil.

As the evaporator coil processes refrigerant, it also pulls heat out of the air in the surrounding room. When the refrigerant is eventually sent to the compressor, that heat is released. In essence, the cooling process removes hot air from inside your home, bringing it outside.

Moisture in the air is also removed, though it doesn’t travel quite as much. The cooling process causes condensation to form on the evaporator coil. When it drips down, it either collects at the bottom of your unit or runs through a drainage system.

A ductless mini-split condensate drain at the bottom of line near the compressor

This effect is automatic, but that doesn’t mean you’ll notice it with regular use. Just because you adjust your HVAC settings to reach a comfortable temperature doesn’t mean much condensation is taking place. For that to happen, you must drop the temperature considerably.

That means two things. First, you and everyone in your home may feel uncomfortable with the air temperature. Second, you’ll be spending much more on energy costs than you would under normal working conditions.

The number of units you have can increase the dehumidifying effect. For example, it’s easier to notice if you use in-window air conditioners in multiple rooms. However, you’ll run into the same problems.

The bottom line is this: your HVAC unit does dehumidify, but that’s not its designed purpose, and it’s not optimized for it. 

So if your goal is to dehumidify your home, relying on your HVAC system alone won’t achieve desirable results. Instead, you should use dedicated methods to dehumidify.

Better Ways To Dehumidify

Before you pick a technique, it helps if you understand how the dehumidification process works. The simple version is that something – be it a mechanical device or another method – removes the moisture from the air and transfers or traps it elsewhere. 

Any method you choose will have a limited area of effect. The fact that all dehumidifying techniques will have a limited range where it is effective is essential to understand—it means efforts to reduce the humidity in your home must focus on individual rooms. 

Unfortunately, there isn’t a single solution that will equally target all parts of your home. So, it’s helpful to know which rooms are the most humid and target them with a dehumidification method that works best for you. 

Here are a few ways to reduce the humidity in your home: 

Dedicated Dehumidifier

These devices are portable and easy to use. They utilize a condenser to pull moisture out of the air and deposit it in a container (usually a tray) inside the device. As a result, a dehumidifier has little effect on room temperature.

A homeowner emptying the tray of a dehumidifier

Dehumidifiers are commonly put in a home’s basement. Doing so not only eliminates airborne moisture, it helps stunt the growth of mold, mildew, and allergens. A single dehumidifier could affect every room if you live in a small apartment.

Repair Any Damaged Ductwork

As air travels to and from your HVAC system through ducts, it’s moist. So, if it has a point of escape before reaching the vents, that moisture joins the air in your home. Any such leak is constant while the system is in use, reducing your home’s air quality.

Repairing ductwork is a matter of spotting the damaged areas and sealing them with metallic tape. However, finding damaged areas can be difficult. So rather than do it yourself, it’s best to call an HVAC repair specialist.

A technician applying metal-backed tape to an cylindrical duct to prevent air duct leakage

Find the Right Size Air Conditioner 

If you run an AC unit in any room of your home, it could cause increased humidity. Spiked humidity levels aren’t a natural byproduct of an AC’s normal functions. Instead, it’s the result of the unit being the wrong size for the room.

“Size,” in this instance, refers to the AC’s cooling capacity rather than its physical dimensions. If it’s too small, it won’t collect enough moisture from the air. If too large, the machine will prematurely shut off after detecting the temperature change.

You can usually find the ideal room size for a unit listed somewhere on the box. Matching the AC to a room that best meets its specifications will ensure it removes as much moisture from the air as possible.


Your HVAC system will dehumidify your home somewhat thanks to its evaporator coil and condenser. However, this is a byproduct of how it works and not its primary function. 

Instead of relying on your HVAC system to dehumidify, you should  invest in a dedicated dehumidifier and ensure your HVAC is in working order. You should also ensure that your home’s AC is the right size to optimize its dehumidification. 


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