Will a Space Heater Lower Humidity?

A space heater can effectively lower the humidity in a room by warming the air, which allows it to hold more moisture. However, it’s important to understand the science behind this process and the factors that influence the effectiveness of a space heater in reducing humidity.

How Space Heaters Work to Lower Humidity

Space heaters work by heating a coil or element, which then warms the air around it. This warming of the air is achieved through the process of convection, where the warmer air rises and the cooler air sinks, creating a circulation of air within the room.

As the air temperature increases, its ability to hold moisture also increases. This is because warmer air can hold more water vapor before reaching its saturation point, which is the point at which the air can no longer hold any more moisture. When the air temperature rises, the relative humidity (the amount of moisture in the air compared to the maximum amount it can hold) decreases, making the air feel less humid.

Factors Affecting the Humidity-Lowering Capability of Space Heaters

will a space heater lower humidity

The effectiveness of a space heater in lowering humidity depends on several factors:

  1. Heater Size and Wattage: The size of the space heater and its wattage output will determine the area it can effectively heat and the extent to which it can lower the humidity. Larger heaters with higher wattage can warm a larger volume of air, resulting in a more significant reduction in humidity.

  2. Heater Type: Some space heaters are equipped with fans that help distribute the heated air more evenly throughout the room. These types of heaters can be more effective in lowering humidity compared to those without fans, as the even distribution of warm air can prevent the formation of pockets of high humidity.

  3. Room Size: The size of the room or area being heated also plays a role in the humidity-lowering capability of a space heater. Larger rooms will require more heating power to achieve the same level of humidity reduction as smaller rooms.

  4. Initial Humidity Levels: The initial humidity levels in the room will also affect the extent to which a space heater can lower the humidity. If the room starts with very high humidity levels, the space heater may not be able to reduce the humidity to a comfortable level on its own.

Limitations of Using a Space Heater to Lower Humidity

While a space heater can effectively lower the humidity in a room, it’s important to note that it does not actually remove moisture from the air. Instead, it simply changes the temperature, which in turn affects the relative humidity. This means that the space heater is not a substitute for a dehumidifier, which is specifically designed to remove excess moisture from the air.

In some cases, using a space heater to lower humidity may have unintended consequences, such as:

  1. Overly Dry Air: If the space heater is used excessively or in a small, well-insulated room, it can cause the air to become too dry, which can lead to discomfort, static electricity, and even respiratory issues.

  2. Increased Energy Consumption: Relying solely on a space heater to lower humidity can result in higher energy consumption, as the heater will need to run for longer periods to maintain the desired humidity levels.

Combining Space Heaters and Dehumidifiers for Optimal Humidity Control

To achieve the best results in lowering humidity, it’s often recommended to use a space heater in conjunction with a dehumidifier. The space heater can help warm the air, which reduces the relative humidity, while the dehumidifier can actively remove excess moisture from the air.

By using these two devices together, you can create a more balanced and comfortable indoor environment, with the space heater providing warmth and the dehumidifier ensuring that the air maintains an optimal humidity level.


In summary, a space heater can effectively lower the humidity in a room by warming the air, which allows it to hold more moisture. However, the effectiveness of a space heater in reducing humidity depends on factors such as the heater’s size, wattage, and type, as well as the size of the room and the initial humidity levels.

While a space heater can be a useful tool in managing humidity, it’s important to use it in conjunction with a dehumidifier for optimal results and to avoid the potential drawbacks of overly dry air or increased energy consumption.