Dehumidifier vs Air Conditioner: Which Do You Really Need?

DEC 21, 2025

Last updated: DEC 21, 2025

925 views, 4 mins read

Imagine walking into your home after a long, sweltering summer day. The air feels heavy, sticky, and uncomfortable. You want instant relief—but should you turn on an air conditioner or invest in a dehumidifier? While both appliances are commonly associated with indoor comfort, they serve very different purposes.

Many people assume they are interchangeable, but that misconception often leads to higher energy bills and unmet comfort needs. In this guide, we’ll break down the real differences between dehumidifiers vs air conditioners, explain how each works, compare costs, comfort, health benefits, and help you determine which solution—or combination—is truly right for your home.

In this article

1. What is a Dehumidifier? 2. Dehumidifier vs Air Conditioner, Side by Side Comparison 3. Dehumidifier vs. Air Conditioner, Which One Should You Choose? 4. Can an Air Conditioner Replace a Dehumidifier? 5. When to Use Both a Dehumidifier and an Air Conditioner? 6. Frequently Asking Questions

What is a Dehumidifier?

To make the right choice, you first need to identify the enemy. Is it the heat, or is it the water in the air? A dehumidifier is a specialized appliance designed with one singular focus: moisture removal.

A dehumidifier is an electrical appliance that removes excess water vapor from indoor air. It works by drawing moist room air over cold coils, causing the water to condense into droplets that collect in a tank or drain away. The now drier air is then reheated slightly and returned to the room. Unlike an air conditioner, a dehumidifier does not primarily cool the air; it focuses on maintaining a comfortable humidity level. Lowering humidity improves comfort (air feels less “sticky”) and health: high humidity can fuel mold and allergy triggers, while dry air prevents structural problems in the home.

For example, modern dehumidifiers often come with smart features. The Newentor ND-25L is a 25 L/day portable dehumidifier (suitable for ≈80 m²) that uses only 330 W of power. It has a built-in humidistat to automate operation, a 24-hour timer, child-lock, and even a continuous drain hose so it can run unattended. Such models can remove over 25 L of water per day (from wet laundry or a steamy bathroom) while costing only a few cents per hour to run. In short, a dehumidifier is ideal whenever indoor humidity is the problem – for instance, in damp basements, bathrooms, laundry rooms or in humid climates.

Newentor Portable Dehumidifier

$294.40 $920.00 Save $625.60

In stock, delivery in 3-5 days

Quantity

Powerful Dehumidification With Brilliant.
3-Fold Noise Reduction Technology.
Sleek and Portable Moisture Terminator.
Small Air Dehumidifier for Mould, Bedroom, and Bathroom.
Two Ways to Drain.
10-Year Warranty.

Learn More

Dehumidifier vs Air Conditioner, Side by Side Comparison

While both units use similar refrigeration technology (compressors, coils, and refrigerant), they are engineered for different outcomes. Here is how they stack up against each other:

Feature	Dehumidifier	Air Conditioner
Primary Function	Removes moisture (lowers humidity).	Lowers temperature (cools air).
Air Output	Dry, slightly warm air.	Cold, crisp air.
Water Removal	High efficiency. Water is collected in a tank or drained via hose.	Moderate efficiency (as a byproduct). Water drains outside.
Energy Consumption	Low to Moderate. Uses less electricity.	High. Requires significant power to move heat outdoors.
Best Environment	Damp basements, crawl spaces, humid bathrooms.	Hot bedrooms, living rooms, sweltering climates.
Maintenance	Emptying water tank, cleaning filter.	Cleaning filters, checking refrigerant, professional servicing.

Dehumidifier vs. Air Conditioner, Which One Should You Choose?

The decision ultimately comes down to your primary discomfort: Heat or Humidity?

Choose a Dehumidifier If:

You have a moisture problem, not a heat problem. If your basement is cool but smells musty, or if your laundry room is always damp.
You are budget-conscious. Dehumidifiers generally cost less to buy and significantly less to run than AC units.
You have allergies. If you are sensitive to mold spores or dust mites, controlling humidity is the most effective way to stop them from breeding.

Choose an Air Conditioner If:

The temperature is high. If the room is above 75°F (24°C) and you are sweating, a dehumidifier won't help—in fact, it might make the room slightly warmer.
You need better sleep. High temperatures disrupt sleep cycles. An AC provides the cool environment necessary for rest.
You live in a hot, dry climate. In areas like Arizona or Nevada, a dehumidifier is rarely needed, but an AC is essential.

Can an Air Conditioner Replace a Dehumidifier?

An air conditioner will reduce humidity only as a byproduct of cooling, and only under certain conditions. While cooling, the AC’s indoor coil condenses water (like a mini dehumidifier). However, once the room reaches its set temperature, modern inverter AC compressors will back off and stop removing moisture. In heating mode, an AC removes virtually no humidity at all.

By contrast, a dehumidifier is designed for moisture removal. It runs its refrigeration cycle specifically to pull water out of the air, regardless of the room temperature. Mitsubishi’s comparison highlights this: air conditioners have no published moisture-removal rate, whereas dehumidifiers specify litres per day. In other words, an AC is not guaranteed to hit your humidity target, whereas a dehumidifier is.

In practice, trying to use an AC as a dehumidifier is inefficient. You’d have to run the AC at a low temperature for a long time, wasting cooling energy, and it may still leave humidity above comfortable levels. Commercial HVAC experts confirm this: pumping cold air through reheat coils (to force dehumidification) is “never efficient” compared to simply using dedicated dehumidifiers alongside fewer AC units.

So no, a standard air conditioner generally cannot fully replace a dehumidifier if removing humidity is your main goal. You need a true dehumidifier to handle persistent dampness or mold risk.

When to Use Both a Dehumidifier and an Air Conditioner?

There are many situations where running both an air conditioner and a dehumidifier makes sense. For example:

Humid Hot Summers: On a sweltering summer day, use the AC to cool down quickly, and let a dehumidifier pull extra moisture out of the air. This makes the room feel even more comfortable (dry air feels cooler) and can allow you to set the AC a bit higher (saving energy).
Coastal or Rainy Conditions: In coastal cities like Brisbane, Cairns or Darwin, summer rain or sea breezes can keep humidity high even if the heat isn’t extreme. Here, the AC alone may not keep mold at bay. Running a dehumidifier in bathrooms, bedrooms or living areas complements the AC by preventing condensation.
Indoor Laundry Drying: On wet or cool days, or when air-drying clothes inside, an air conditioner won’t efficiently dry air. A dehumidifier excels at clothes drying without overcooling. Some modern models even have a Laundry Mode that adjusts airflow and shuts off once clothes are dry.
Mold and Health Protection: If you have allergies or mold problems, running a dehumidifier continuously (even if the AC is off) can keep humidity around 40–50%. When the AC kicks in, you still benefit from the drier baseline air. This protects wooden furniture, musical instruments, and reduces asthma triggers.

In short, using both appliances lets each do what it does best. The AC handles temperature, the dehumidifier handles moisture. Together they keep your home “cool and dry” year-round. For most Australian homes in humid regions, this combined approach gives the health, comfort and energy-efficiency benefits that one alone cannot.

Frequently Asking Questions

Do dehumidifiers work better than AC?

Yes, if the goal is moisture removal. Dehumidifiers are built to strip humidity and have much higher moisture-removal capacity (often 10–25 L/day). Air conditioners only remove a small amount of humidity while cooling. So for controlling dampness or mold, a dehumidifier is far more effective.

Does a dehumidifier cool a room in summer?

No. A typical refrigerant dehumidifier actually warms the air slightly as it runs. After condensing water from the air, it releases that now-drier air warmer than before (the compressor heat goes back into the room). You might feel the room is more comfortable because it’s less humid, but the actual air temperature won’t drop. Only an air conditioner provides a true cooling effect.

What is cheaper to run, AC or dehumidifier?

Generally, a dehumidifier is much cheaper per hour of use. Dehumidifiers often run on a few hundred watts (for example ~0.3–0.5 kW), while an AC unit may draw 1 kW or more. Mitsubishi notes inverter dehumidifiers use “far less power” than a continuously running air conditioner. For instance, the Newentor 25 L dehumidifier runs at 330 W – roughly 0.33 kWh – so at 30¢/kWh that’s only about 10¢ per hour. An equivalent-sized split-system AC could be several times more. In practice, you’ll save electricity if you run a dehumidifier instead of an AC whenever cooling is not needed.

Conclusion

In conclusion, don’t fall for the myth that an AC can fully substitute a dehumidifier. Use each where it excels: AC for cooling, dehumidifier for drying. In Australian homes (especially humid coastal regions), pairing them wisely will give the best comfort, air quality and energy savings.

For example, many homeowners choose a unit like the Newentor 25L Portable Dehumidifier – it’s affordable, energy-efficient, and designed for high Australian humidity loads – alongside their air conditioning. This way you tackle both heat and humidity without compromise.

Newentor Portable Dehumidifier

$294.40 $920.00 Save $625.60

In stock, delivery in 3-5 days

Quantity

Powerful Dehumidification With Brilliant.
3-Fold Noise Reduction Technology.
Sleek and Portable Moisture Terminator.
Small Air Dehumidifier for Mould, Bedroom, and Bathroom.
Two Ways to Drain.
10-Year Warranty.

Learn More

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