Why Does Dehumidifier Blow Hot Air: Detailed Guide

Understanding The Problem Why Does Dehumidifier Blow Hot Air

You’re not alone if you’ve ever wondered why your trusty dehumidifier suddenly starts to blow hot air instead of providing the cooling comfort you expect.

We’ll uncover the factors that might contribute to your dehumidifier’s hot air-blowing emissions, equipping you with the knowledge needed to troubleshoot and potentially resolve the issue.

From the impact of a dirty air filter to the consequences of extended operation, we’ll address the most prevalent reasons for this curious operation.

By the end of this article, you’ll not only comprehend the underlying ”dehumidifier blowing hot air” problem but also possess practical tips to keep it running optimally.

Understanding how dehumidifiers work

We will explore the fundamental principles of how dehumidifiers operate and what constitutes their normal functioning.

How do dehumidifiers work?

At the heart of every dehumidifier lies a key component called the refrigeration system. This system consists of a compressor, condenser coils, evaporator coils, and a fan.

When you switch on the dehumidifier, the compressor starts working, pressurizing the refrigerant gas, typically Freon or a similar substance, and starts to suck moist air into a given room.

The pressurized refrigerant gas then flows through the hot condenser coil, where it releases its heat, transforming into a high-pressure liquid.

The liquid refrigerant now moves through the evaporator coil, encountering a significant drop in pressure.

As a result, the liquid turns into a cold mist, absorbing moisture from the air coming from the surroundings.

The moisture-laden air passes over the chilled evaporator coils, causing moisture condenses into water droplets.

This process continues until the desired humidity level is reached, at which point the dehumidifier will shut off to conserve energy.

Why Does Dehumidifier Blow Hot Air
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Dehumidifier components

Compressor. The compressor serves as the heart of the dehumidifier, responsible for pressurizing the refrigerant gas.

Condenser coils. Once the refrigerant gas leaves the portable compressor dehumidifier, it moves into the condenser coils.

Evaporator coils. The high-pressure liquid refrigerant then enters the evaporator coils.

Fan. The fan plays a crucial role in the dehumidification process. It draws in moist, warm air coming from the surrounding environment and directs it over the cold evaporator coils making blow-cold air.

Drainage system. In some dehumidifiers, there is a built-in drainage system that allows the collected water to be automatically pumped out through a hose.

Water collection pan/reservoir. As the water droplets condense on the evaporator coils, they drip down into a collection pan or reservoir located within the dehumidifier.

Why Does Dehumidifier Blow Hot Air
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Normal operation

A dehumidifier’s normal operation involves removing excess moisture from the air conditioner through its refrigeration system.

As the device cycles, it cools the warm air coming to condense moisture into water droplets, which are collected while the dehumidified exhaust air is reheated before being released back into the room.

Regular maintenance ensures efficient and effective performance, providing a comfortable and healthy indoor environment.

How to turn off your dehumidifier’s hot air blower

When its blows hot air maybe a hot air blower is in operation, it can sometimes lead to discomfort or unnecessary too much heat generation.

Here’s a step-by-step guide on how to turn off your dehumidifier’s hot air blower.

  • Locate the Control Panel on your dehumidifier.
  • Find the Blower Setting, usually labeled “Blower” or “Fan.”
  • Adjust the Setting to “Off” or select the lowest fan speed (e.g., “Low” or “Auto”).
  • Monitor the dehumidifier to ensure that the dehumidifier is blowing hot air.
  • Opt for this setting in warm climates to save energy and prevent unnecessary heat.

Dehumidifier blowing hot air: common causes

Discover the common reasons behind this unexpected occurrence as we explore factors like a dirty evaporator coil and prolonged operation.

Why is your dehumidifier blowing hot air?

Understanding these factors will help you troubleshoot the problem and take appropriate steps to rectify it.

Dirty air filter. One of the primary culprits behind a dehumidifier is blowing hot air if a clogged or blow-air filter is dirty.

The dehumidifier’s evaporator coil is dirty. The evaporator coil is a crucial component responsible for extracting moisture from the air.

The dehumidifier has been running too long. Extended operation of compressor dehumidifiers, without periodic breaks can cause the dehumidifier’s compressor to overheat.

Faulty compressor. A malfunctioning compressor dehumidifier can produce too hot air and also be responsible for the excess heat issue.

Ambient temperature of the air. In some cases, the surrounding blow-warm air temperature can impact the cool air expelled by the dehumidifier.

The dehumidifier’s evaporator coil is dirty

One of the common culprits after that a dehumidifier is blowing hot air is a dirty evaporator coil.

The evaporator coil is responsible for cooling the incoming blow-warm air and extracting moisture from the air blowing through it.

When dirt accumulates on the coil’s surface, it acts as an insulator, preventing the coil from efficiently absorbing heat and moisture from the air passing over it.

There is a cold coil that air passes over, as a result, the dehumidifier blows hot air and has to work harder to achieve the desired humidity levels, leading to increased energy consumption and the ”dehumidifier blowing hot air” problem starts.

Why Does Dehumidifier Blow Hot Air
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The dehumidifier has been running too long

As the dehumidifier runs, the compressor dehumidifier generates heat due to the compression of the refrigerant gas.

Under normal circumstances, the dehumidifier should cycle on and off to allow the compressor to rest and dissipate excess heat during the off periods.

However, if the dehumidifier runs continuously for prolonged durations, the compressor dehumidifier may not get enough time to cool down adequately and the dehumidifier blows hot air.

This can result in compressor overheating, which can have several adverse effects on the appliance:

The dehumidifier is set to fan instead of dehumidify

One common mistake that often leads to confusion and less effective dehumidification is when the dehumidifier is inadvertently set to the “fan” mode instead of the intended “dehumidify” mode.

While it might seem like a minor oversight, this setting can significantly impact the dehumidifier’s performance and the overall comfort of your living space.

If you find your dehumidifier continuously blowing room-temperature warm air and not reducing humidity levels, chances are it is set to “fan” mode.

To ensure your dehumidifier functions optimally, it’s essential to double-check the settings and confirm it is set to “dehumidify” mode.

Dirty air filter

As the air filter regularly becomes clogged with dirt and contaminants, it obstructs the airflow, causing the dehumidifier to work harder than necessary.

By keeping the temperature of the air filter stable, you not only ensure efficient operation and optimal humidity levels but also promote better indoor hot air quality.

As a general rule, it’s advisable to inspect the air filter at least once a month and clean or replace it as needed.

Maintenance and cleaning tips

We’ll explore the importance of regular maintenance, including cleaning and replacing the air filter, as well as preventive measures to ensure the longevity of your appliance.

How often should I clean o replace my dehumidifier’s air filter?

A clogged air filter can impede airflow and reduce the dehumidifier’s efficiency, resulting in less effective moisture removal and potentially causing the unit to blow excessively hot or cold air.

Clean washable filters every 2-4 weeks, especially in dusty areas. Replace disposable filters every 3-6 months.

A well-maintained filter ensures efficient operation and better indoor hot air quality.

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Preventive measures and maintenance tips

Keep it clean. Regularly cleaning the exterior of your dehumidifier helps prevent dust and dirt buildup, which can impact its performance.

Air filter maintenance. The air filter is a vital component that traps airborne particles and dust.

Mind the humidity level. Invest in a separate hygrometer or use the built-in humidistat if your dehumidifier has one.

Regular defrosting. If you’re using a refrigerant exhaust air-based dehumidifier in colder conditions, check and defrost the evaporator coils regularly.

Safe storage. If you plan to store the dehumidifier during seasons of low humidity, make sure it’s clean and completely dry before storing it in a cool, dry place.

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Thawing frozen evaporator coils

A frozen evaporator not only hampers the dehumidifier’s ability to extract moisture from the excessively hot air but also leads to reduced airflow and decreased efficiency.

To thaw the frozen evaporator coils, the first step is to turn off the dehumidifier and unplug it from the power source.

Allowing the unit to thaw naturally may take a considerable amount of time, but it is the safest option to avoid damaging the coils.

Checking for refrigerant leakage

Detecting refrigerant leaks early on is crucial to prevent potential damage to your dehumidifier and to ensure it continues to operate effectively.

Refrigerant leakage in your dehumidifier can compromise its efficiency.

Look for oil stains or abnormal performance, listen for unusual sounds, and monitor frost build-up.

If you suspect a leak, seek professional inspection and repair to ensure optimal performance.

Why Does Dehumidifier Blow Hot Air
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Do dehumidifiers make the air hot?

Yes, dehumidifiers can make the air feel hotter. They cool the air to remove moisture and then start blowing hot air to maintain room air temperature.

Is there a dehumidifier that doesn’t blow hot air?

Yes, there are dehumidifiers available in the market that do not blow hot air. These innovative devices are known as “desiccant dehumidifiers”. Unlike traditional compressor-based dehumidifiers that use refrigeration to condense moisture.

Why doesn’t a dehumidifier cool the air?

A dehumidifier doesn’t cool the air because its primary function is to remove excess moisture from the hot air coming from indoors, not to lower the temperature of the air.

How do I keep my room cool with a dehumidifier?

Keep your room cool with a dehumidifier by setting the ideal humidity level (around 45-50%), placing it strategically, using fans to produce hot air circulation, and considering an excessively hot air conditioner for more effective cooling.


Common causes, such as dirty air filters and evaporator coils, can lead to excessive heat emission.

Regular maintenance and cleaning, including replacing air filters and thawing frozen coils, play a vital role in preventing issues and ensuring your dehumidifier operates efficiently.

By familiarizing yourself with how dehumidifiers work and employing preventive measures, you can make the most of this essential appliance.

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