Do Dehumidifiers Cool a Room?

By: Evan Scoboria, Last updated: June 28, 2023

The primary role of these appliances is to decrease humidity levels in your home, something they do very well. Modulating temperature is not one of their roles, and it's important to note that dehumidifiers do not directly cool the air in a room. However, by reducing moisture in the air, dehumidifiers can create a perceived sense of coolness, as the air may feel more comfortable and less muggy. In this article, we'll take a deep dive into the functionality of dehumidifiers, their effect on room temperature, and other factors that contribute to the overall comfort of your indoor environment. 

Dehumidifiers: Function and Impact on Temperature

Dehumidifiers are appliances designed to reduce humidity or moisture in the air. They are commonly used in homes and other indoor environments to increase comfort, prevent the growth of mold and mildew, and reduce allergens associated with dampness. Here's a look at how they function and their impact on temperature.

The function of Dehumidifiers:

While bearing some similarities to air conditioners, the core operation of dehumidifiers primarily revolves around moisture extraction rather than air cooling. Initiated by a fan, humid room air is sucked into the dehumidifier. This air is then guided over coils filled with coolant, akin to those in refrigerators or air conditioners. The contrast in temperature leads to the condensation of moisture from the air, turning it into water.

This condensed water trickles into a collection tank within the dehumidifier often called the reservoir or bucket. For the dehumidifier to function uninterrupted, this water must be removed promptly. Most models have an automatic shut-off feature activated when the tank reaches full capacity. Some dehumidifiers also offer the option of continuous drainage via a hose connected to a drain or leading outside.

Finally, the dehumidified air, which is initially cooler post the condensation process, is re-heated as it passes over the warm section of the refrigeration compartment. This drier, warm air is circulated back into the room, completing the dehumidification cycle.

Impact on Temperature:

While dehumidifiers are not explicitly engineered to cool air like an air conditioner, their operational impacts change a room's temperature in several ways.

Firstly, the process of dehumidification inherently produces heat as a byproduct. The internal workings of the dehumidifier, including the compressor and other components, generate heat during their operation. This could result in a slight elevation of the room's ambient temperature. Nonetheless, this effect is typically minor and may not substantially alter your comfort levels.

Secondly, the dehumidification can lead to a perceived cooling effect. When a dehumidifier lowers a room's humidity levels, the air can subjectively feel cooler than at an equivalent temperature with higher humidity. This is attributed to the increased efficiency of sweat evaporation with less air moisture, which bolsters your body's natural cooling mechanism.

To sum up, even though dehumidifiers aren't designed to cool air directly, their capability to extract excess moisture can indirectly foster a more comfortable and perceptively cooler environment. However, if the primary objective is to reduce the actual temperature, incorporating air conditioning or other cooling strategies may be requisite in conjunction with dehumidification.

The Connection Between Humidity and Comfort

Humidity refers to the amount of water vapor in the air, which influences how we perceive temperature and our comfort level. Here's why:

  1. Impact on Body's Cooling Mechanism: Our bodies cool down primarily through evaporation. When we perspire, the sweat on our skin evaporates, which requires heat, cooling our bodies. However, the air is already saturated with moisture in high-humidity environments, which hampers evaporation. Consequently, our sweat doesn't evaporate as quickly - or at all - leaving us feeling hot and sticky. In contrast, making the same temperature feel more comfortable and cooler.

  2. Perceived Temperature or Heat Index: The heat index is a measure that combines air temperature and relative humidity to determine the human-perceived equivalent temperature - how hot it feels. High humidity can make the air feel warmer than it actually is. For example, if the air temperature is 85°F (29°C), with a relative humidity of 70%, the heat index—how hot it feels—would be 90°F (32°C). This phenomenon happens because the high humidity affects our body's ability to cool.

  3. Moisture and Air Quality: High humidity levels can promote the growth of mold, mildew, and dust mites, which can reduce indoor air quality and potentially lead to health issues, especially for people with allergies or respiratory conditions. High humidity can also make the air feel heavy and more challenging to breathe, contributing to discomfort.

  4. Comfort in Cold Weather: In contrast, during cold weather, very low humidity can make the air feel colder than it is, as moisture in the skin and respiratory system evaporates more quickly and draws away heat. Additionally, dry air can cause discomfort by drying out mucous membranes, leading to dry skin, irritated eyes, and exacerbating respiratory problems.

Therefore, balancing humidity levels in your home is crucial in maintaining comfort. The recommended indoor humidity level is between 30% and 50%. Dehumidifiers can help reduce high humidity, while humidifiers can add moisture to the air in low humidity conditions.

Alternative Cooling Solutions

If your primary goal is to cool a room, there may be more effective solutions than a dehumidifier. Instead, consider using air conditioners or fans to lower the room's temperature directly. Air conditioners cool the air and help remove excess moisture, serving a dual purpose. Fans can provide a cooling effect by increasing air circulation and promoting evaporative cooling on the skin.

  1. Air Conditioners: Air conditioners are the most effective way to cool a space. They use refrigerant to absorb heat from the air within a room and expel it outside. In addition to cooling, air conditioners dehumidify the air as a byproduct of their cooling process. This is because the refrigeration process naturally condenses moisture out of the air. This dual functionality makes air conditioning units particularly beneficial in hot, humid climates. However, they can be energy-intensive and increase energy costs if used extensively.

  2. Fans: Fans are a less energy-intensive alternative for cooling a room. They promote air circulation, which aids in evaporating sweat from the skin, creating a cooling effect. While fans do not lower the air temperature or reduce humidity, they can make a room feel cooler and more comfortable. Several types of fans are available, including ceiling fans, tower fans, table fans, and portable fans, each suited to different needs and room sizes.

  3. Evaporative Coolers: Also known as swamp coolers, evaporative coolers are another option, particularly effective in hot, dry climates. They work by evaporating water into the air, which cools and humidifies the room. They are more energy-efficient than traditional air conditioners but less effective in humid conditions since the added moisture can make the room uncomfortable.

  4. Heat Pumps: A more energy-efficient alternative to traditional air conditioners and heaters, heat pumps can cool and heat a room by transferring heat from one area to another. In cooling mode, they function much like an air conditioner, removing heat from inside the home and expelling it outdoors. In heating mode, they extract heat from the outside air—even in cold weather—and transfer it indoors.

  5. Insulation and Energy-Efficient Design: Finally, it's worth mentioning that good insulation and energy-efficient design can significantly impact a room's temperature. Proper insulation can keep a room cool in the summer by reducing the heat that enters. Energy-efficient design elements like shading, natural ventilation, and reflective surfaces can help maintain a comfortable indoor temperature.

Remember, the best cooling solution for you will depend on various factors, including the climate, the size of the room, the building's insulation, and your specific needs and budget.

Wrapping up:

While dehumidifiers do not directly cool a room, reducing humidity can make the space more comfortable. However, if your primary goal is to lower the room's temperature, consider alternative solutions, such as air conditioners or fans. By understanding the relationship between humidity, temperature, and comfort, you can make informed decisions about the best cooling solutions for your home.