Will a dehumidifier get rid of the musty smell in basement

This article discusses the efficacy of an air dehumidifier to get rid of the musty smell which is commonly present in basements. We discuss the causative agents behind the musty smell, and how air dehumidifiers play a role in the mitigation.

Will an air dehumidifier get rid of the musty smell in the basement?

Air dehumidifiers do not get rid of the musty smell in the basement. However, these devices keep in check the sources that cause musty smell in the basement.

Dehumidifiers dry out the air. This is essential in general, in certain seasons such as summer and spring, when the ambient humidity levels rise up to 60%. 

Basement areas are defined as enclosures placed directly under the building. These rooms are usually built below ground level, so they are prone to leakage problems, and usually lack adequate ventilation and heat. 

These factors play a major role in increasing the relative humidity of the room, which favours the growth of mold and mildews. 

Air dehumidifier types and working mechanism

There are mainly four different types of dehumidifiers, which include:

  • Refrigerative
  • Electronic
  • Desiccant
  • Ionic

A refrigerative dehumidifier operates by using a fan to suck warm air currents into its coils. Warm air condenses when it passes through the machine’s chilled coils, leaving condensation inside the dehumidifier.

As the condensation gathers, one droplet of water at a time, it falls into a dehumidifier-connected storage tank. Through the opposite side of the machine, cooler, drier air is sent back into the house.

The other common type of dehumidifier is a desiccant dehumidifier. This is a considerably more powerful dehumidifier, however it’s mostly used in commercial storage for medicines, food, and chemicals. 

It can lower humidity levels by 45 percent to 1%, however it does so by relying on thermal energy (natural gas or steam) rather than electrical outlets. 

Desiccant dehumidifiers employ chemical attraction instead of condensation to reduce humidity levels.

What is a musty smell?

Musty smell refers to the characteristic indoor air which is not fresh, due to which the air has an odor, and feels stuffy. This can happen due to the buildup of certain chemicals as well as humidity in the indoor environment.

As a result, the ratio of air contaminants responsible for making the air smell musty to the oxygen levels decreases, making it harder to breathe as well.

Factors that favour formation of musty air?

There are a few chemical species as well as biological components that are responsible for making the air seem musty. These include:

  • Water vapour
  • Mold and mildews
  • Tight packed houses
  • Poor ventilation system

Let us discuss these in more detail

Water vapour

In certain areas of the house, such as the kitchen, bathroom, and basements, the humidity levels can be much higher in comparison to the other rooms of the house.

Sometimes, in cases such as leakages or floods, when water manages to infiltrate the basement, the musty smell becomes more prominent than ever. 

This is primarily due to the presence of water in the vapour form. In higher humidity levels, water vapour promotes the growth of microorganisms such as bacteria, mold, and mildew.

We talk about them in more detail in the next segment.

Mold and mildew

Mold and mildew are fungal species that grow favourably under conditions such as presence of organic material, high humidity, low sunlight, and low temperatures.

These conditions are found in certain areas of the house, such as basements, bathrooms, cupboards, air conditioners, and so on.

The spores generated from mold and mildew, alongwith their odor, make the air feel stuffy and produce a musty or musty odor. 

In some cases, these spores can also cause serious health issues, especially in people suffering from a comorbidity, or ailing from respiratory illnesses such as covid.

Tight packed houses

Tight packed houses refers to the modern day construction of houses which utilises windows and doors that pack tightly i.e., have no gaps within.

This helps to prevent the infiltration of outdoor air pollution in the indoor environment, or the infiltration of toxic radon gas in the basements from the surrounding rocks, as well as limits the heat exchange rate with the surroundings, especially in the winter season.

However, such features also limit the air exchange rate of the basement with the outdoor sources as well as the other rooms quite significantly.

Due to poor air circulation, the amount of free oxygen available starts to decline, while the humidity levels as well as the concentration of pollutants responsible for the musty air smell start to rise.

This effect is more pronounced especially in winters and monsoons, when the relative humidity levels are high and the temperatures are comparatively lower than the other seasons.

Poor ventilation system

Ventilation is an important feature in every house. Apart from the fact that adequate ventilation keeps the air fresh and prevents musty air smell, it also removes the indoor air pollutants by bringing in fresh outdoor air, while carrying the indoor air away.

However, some places lack adequate ventilation, which can happen due to various reasons. In such cases, the indoor air pollution keeps aggregating, and growth of mold and mildew can also take place.

A common example of this is seen in basements which typically do not have a natural source of ventilation. Articles such as clothes, furniture, and walls are more prone to mold and mildew than the other rooms of a  house.

How air dehumidifiers help

As we’ve seen, excess humidity levels are the major reason for creating a musty smell in basements. This is where air dehumidifiers come into play. 

An air dehumidifier should be able to reduce the humidity in the air to 30 to 50 percent relative humidity.

Many dehumidifiers come with a metre that monitors the relative humidity in the area where they’re installed, and you may adjust the humidity to the desired percentage.

However, air dehumidifiers do not get rid of the musty smell all by themselves. For this, one would need other alternatives, which are discussed below.

How to prevent musty air smell

There are multiple ways in order to minimise as well as prevent the buildup of musty air smell within a room. Some of these are:

  • Installation and regular maintenance of HVAC systems
  • Regularly cleaning your basement
  • Using an air purifier

Installation and regular maintenance of HVAC systems

HVAC refers to Heating, Ventilation, and Air Conditioning. Although in some places it is already present, it might be the case that certain places may not have it.

HVAC systems are especially helpful for places which do not have proper sources of natural ventilation, such as basements. They help to regulate the room conditions in a manner that prevents growth of mold.

However, one should also ensure that the HVAC systems are being maintained on a regular basis, since faulty systems as well as older units may sometimes contribute to the musty air smell.

Regularly cleaning your basement

In a typical setting, basements are commonly used as storage areas for things such as newspapers, books, old clothes, furniture, carpets and beddings, and so on.

It is important to keep the room clean, especially surfaces such as beddings, carpets, or places which are prone to accumulation of dust.

Studies have shown that nearly 60% of total dust accumulated in the indoor air originates from outdoors. Within these dust particles, mold spores and other substances can be present, which cause indoor musty odor.

By regularly dusting surfaces and cleaning the basement, there are lesser chances of accumulation of substances that give rise to musty air smell.

Use an air purifier

Air purifiers are devices that help to keep the air in an indoor environment clean. They not only remove pollutants that give rise to stale air smell, but can also remove the smell efficiently.

HEPA filters with an activated carbon filter as well as a germicidal UV light chamber are the best option for getting rid of the stale air smell in a relatively short amount of time.


Air dehumidifiers do not directly get rid of the musty odor that is commonly associated with basements. However, dehumidifiers adversely affect mold and mildew, the microorganisms that grow in high humidity conditions, and cause the musty odor.

Furthermore, there are alternatives to control the musty odor in basements by improving the ventilation of the room in order to get rid of the stale air often associated with such rooms, regularly cleaning the basement in order to prevent build up of mold spores which would eventually lead to formation of mold colonies, and by using an air purifier which removes the mold spores as well as the odor associated with mold from the basements.


Do air fresheners and essential oils help to get rid of bad smells in the house?

Yes, air fresheners and essential oils can help to get rid of bad smells in the house. However, this is only a temporary solution, since once the effect of these fragrance compounds fades away, the sources of odors are still persistent, thereby causing the bad smells to occur once again.

As a solution, it would be ideal to rather identify the sources of unpleasant odors in your house and take care of them, as this is a viable solution that would last for a longer time.

Can appliances that regulate physical parameters of the air cause stale smell in the house?

Yes, appliances that regulate physical parameters of the air can cause stale smell in the house. This can be seen particularly in appliances such as air conditioners as well as HVAC (HEating, Ventilation, Air Conditioning) systems.

If the filters are old, chances are that they are overloaded with pre-existing dust deposits. This causes a decrease in the air inflow rate for the device, due to which the air circulation gets impeded.

Furthermore, these devices can also develop dark and humid conditions, which help mold and bacteria to thrive. Therefore, these appliances may end up exacerbating the indoor air quality and will give rise to the unpleasant odor as well.

How long does it take for an air purifier to clean a room?

This depends mainly on the coverage area of the air purifier, as well as the size of the room. For small rooms, a typical air purifier will clean the air in about 30 minutes.

However, for larger rooms, it can take upto 2 to 3 hours to completely clean the indoor air. But, air purifiers also have an option to vary their flow rates, which could help in getting the job done even faster.

Other FAQs about Air Dehumidifiers that you may be interested in.

What is an air dehumidifier?

Will a dehumidifier help a stuffy room?


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