Hot Room? It Could Be Your Dehumidifier!


A malfunctioning dehumidifier can sometimes making your room hot. But why?

Low refrigerant, corroded coils, a faulty humidistat, faulty fan, loose screws or a burnt capacitor can cause a dehumidifier to make a room hot. A dehumidifier that is the incorrect size for the room may also result in an increase in ambient temperature.

To fix the problem, it is important to understand how the system works. In the following article, we will talk about how a dehumidifier works and the potential reasons it could be blowing out hot air. We will also provide some easy troubleshooting tips to fix the problem.

How Do Dehumidifiers Work?

Here is how a dehumidifier works:

  • The humid air from the surroundings is brought into the device by a fan. A refrigerant like Freon absorbs the moisture, and in the process, the air cools down.
  • Warm/hot refrigerant gas is cooled by the coils, creating condensation.
  • Now the cool air left behind is passed through a reheating coil, and the hot, dry air is then blown out.

Dehumidifiers naturally release warm air due to the second set of coils, i.e., the reheating coils. However, the temperature is generally not too hot for you to notice.

Additionally, the appliance comes with a humidistat. You can set it at the level of your choice. So once the dehumidification reaches that point, the appliance starts cooling down and releases cold air for a bit.

Reasons Why Your Dehumidifier Is Making Your Room Hot

To identify the exact fault in the dehumidifier, use the elimination rule.

So we will recommend you go through the following reasons step-by-step.

1. Humidity Settings

The first thing you should check is the humidity settings on the humidistat. It allows you to maintain the relative humidity levels in the room. Once the moisture content reaches that limit, the appliance will switch off.

During this brief period, no moisture will be absorbed to bring the level back to normal. Hence, cold air is normally released. Thus, if you set this level too low, then the temperature of the room will naturally increase.

Generally, it is ideal to set a humidistat between 30% and 50% of relative humidity.

2. Low Refrigerant

Dehumidifiers require refrigerants to absorb moisture from the air. This is crucial for the dehumidification process. In case refrigerant levels are low or the chemical you are using is not compatible with your model, the device won’t absorb adequate moisture.

Without sufficient refrigerant the coils will not be cold, and the water will not condensate and be removed. Thus, low refrigerant is one of the potential causes behind dehumidifiers making your room hot.

The only way to go about it is to check the coolant levels in the system. To do so, plug in the appliance, wait a few minutes and then touch the first set of coils. If it does not feel cold to touch, then refrigerant is likely low.

When there is a refrigerant leak, ice will likely build up on the coil at the point of the leak.

If you find this is likely the case, you’re best bet is to contact the manufacturer to see if they can fix it or if it’s possible to refill the refrigerant.

3. Corroded Coils

A dehumidifier has two sets of coils; cooling ones and reheating ones. Over time, these coils can corrode or accumulate dirt. This impairs their performance and could be a reason for your dehumidifier blowing out hot air.

If you find your system to have dirty coils, cleaning can help.

To clean a dehumidifier:

  • Unplug and turn it off for safety.
  • Remove the water collection bucket and wash it with soapy water.
  • Clean the air intake and exhaust grills with a vacuum or brush.
  • Gently clean the evaporator and condenser coils with a soft brush or cloth.
  • Check and clean the air filter, replacing if necessary.
  • Use a mixture of bleach and water to clean the interior surfaces.
  • Ensure the drainage system is clear.
  • Let all cleaned parts dry completely before reassembling and turning it back on.
  • Regular maintenance improves efficiency and air quality.
  • Follow the manufacturer’s instructions and safety guidelines.

4. Faulty Humidistat

A humidistat is important to keep the humidity levels in check. If the sensor says the humidity is high (incorrectly) then it will keep running and will never turn off.

In this case, replacing the sensor is the only option. Once you remove the air filter, front grille, back panel, and case, you will see the sensor. Take the old one out and place a new, good-quality one that’s compatible with your dehumidifier model.

5. Fan

The compressor fan draws the surrounding air into the dehumidifier. Any fault with the fan will lead to inadequate airflow. If this happens in summer, then the chances are that high humidity in the room will make the temperature feel hotter than normal.

If the fan does not move freely and feels like it’s rubbing against something, then that likely explains the inadequate airflow.

However, if the fan blade is not rubbing against anything, the problem probably lies with the motor. A faulty fan motor can result in it overheating (i.e. generating heat). This can be confirmed by placing a hand on the unit as it will be hot itself (not just the air).

If either of them, the blade or the motor, is defective, contact the manufacturer and get them fixed or replaced.

6. Screws

If your dehumidifier is making the room hot, and you notice a rattling noise every time the device starts, it indicates that the mounting screws of the system are loose.

These screws control the movement of the fan and affect the performance of the compressor, coils, blower wheel, and other integral parts of the system. Therefore, any issue with the screws can cause the entire system to malfunction, eventually making your room hot.

In order to fix loose screws, use the manual guide and check where they are located. Then carefully tighten each one, and your dehumidifier should start functioning properly again.

7. Burnt Capacitors

Burnt capacitors are another reason for a malfunctioning dehumidifier. Capacitors are part of the compressor circuit, and compressors need them to start.

Compressors are essential for the condensation of air and eventual dehumidification. The burnt capacitors can impair their function and can potentially cause a short circuit. Hence, the appliance releases hot air in the room.

You’ll have to contact the manufacturer if you suspect this is the problem.

8. Dehumidifier Vs Room Size

One possible reason for your room getting too hot could be a disproportionate dehumidifier. The appliance comes in various sizes, and that affects the level of dehumidification.

A dehumidifier too small for the room will not remove enough moisture, and the room will still feel hot. So if everything else is fine with the system, consider if the size of your appliance is suitable for the room.

Can I Use A Dehumidifier As A Heater?

Although dehumidifiers naturally produce warm and dry air, it does not make a significant difference in room temperature. A dehumidifier is not an alternative for a heater.

The main use of dehumidifiers is to reduce the moisture content. They do not produce enough heat to warm a room during cold temperatures.

Additionally, using a dehumidifier in winter can disrupt the whole system due to frosting. The built-in defrost mechanism will come under stress in the winter. Therefore, using dehumidifiers in place of a heater is out of the question.

Will A Dehumidifier Cool A Room?

Dehumidifiers do not directly cool down a room. But they reduce the moisture content in the surrounding, which makes the room feel cooler.

In hot and humid summers, dehumidifiers don’t only keep bacteria and mold away by absorbing moisture but also make the environment comfortable. Moisture holds in warmth and can make the temperature feel higher than it is, which is a common problem in summer.

So a reduction in the moisture content actually cools down the room.

Do You Need A Dehumidifier For Winter Or Summer?

You primarily need dehumidifiers in a humid environment. So they are important in summer and spring, when humidity is naturally high. In winter, the air is already dry, so we advise not to plug in a dehumidifier.

Experts suggest that the ideal relative humidity is between 30%-40%. In winter, this level can fall even lower, so using a dehumidifier can actually cause extreme dryness.

Additionally, leaving the appliance plugged in when the weather is cold can lead to frozen coils. The defrost system won’t be able to sustain the load, and the dehumidification process won’t be efficient enough.

Therefore, we advise against using the dehumidifiers in winter.

Final Thoughts

In this article, we shed light on various reasons your dehumidifier can be making the room hot. Some degree of hot air blowing out of the system is not worrisome, but a significant change in room temperature indicates that the system is not performing optimally.

If the fault is because of a faulty party, replacing it can be expensive, and therefore, make sure you’re taking proper maintenance steps and identifying the cause as soon as the problem starts.

 

Theresa Orr

Theresa Orr holds a PhD in Earth Science and specializes in determining past climates from rocks using geochemistry. Her passion for clean water, soil and air drives her to provide easy to understand information for everyone to read.

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