how to remove musty smell from stored items

This article discusses the various methods to get rid of the musty smell that emanates from items stored in the basement. We also discuss the reasons why these smells occur, the possible sources of smell, and ways to prevent it from happening.

Factors that favour formation of stale air in basements

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

  • Water vapour
  • Mold and mildews
  • Combustion processes
  • Poor ventilation
  • Household products

We shall discuss them in brief.

Water vapour

In higher humidity levels, the air becomes heavier than normal, making it harder to breathe. This can happen in basements where central boilers and heating systems are present.

Furthermore, water vapour also promotes the growth of microorganisms such as bacteria, mold, and mildew. These microorganisms further contribute to the odour, thereby making the air stale. 

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 basement, such as corners, carpets, drywall, old clothes, books and newspapers, furniture, and so on.

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

Poor ventilation system

Ventilation is an important feature in every house. Apart from the fact that adequate ventilation keeps the air fresh and prevents stale air, 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.

In the case of 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.

Sources of musty smell

Given that mold is the primary reason due to which musty smell occurs in the basements, there are certain household items that are prone to developing mold. These are:

  • Furniture
  • Clothes and carpet
  • Paper products and cardboard
  • Leaky places, such as pipes, walls, etc.

Mold usually requires dark and humid conditions, and a source of nutrition. Things made out of cellulose, such as clothes, paper products, furniture, etc. are excellent spots for mold to grow on.

Furthermore, leaky spots also provide the adequate moisture conditions required by certain mold colonies that can scavenge for food from the indoor air itself. Hence, it is noticed that places with water damage are usually associated with mold.

Ways to remove musty smell from basement

As we’ve seen so far, the musty smell is not only repelling in nature, it can also contain substances that can cause serious harm to human health if inhaled.

Therefore, it is important to get rid of the smell as well as the sources from which the musty smell arises from. The following methods can help:

  • Dry out the basement thoroughly.
  • Find spots where mold and mildew is present and eliminate them.
  • Use an air purifier

Let us discuss these methods in more detail.

Dry out the basement thoroughly

For big articles such as carpets, clothes, and other such stuff, it would be ideal to line dry them, and later wash them using baking soda and normal detergent.

Next, make sure you have fixed any area that has water damage, such as leaks or seeps. Any presence of water will provide the ambient conditions required for mold to develop.

While you are busy drying out the material present in your basement, it is also vital to dry out the air in your basement. This can be done using an air dehumidifier.

A refrigerant dehumidifier, the most common type of 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 your house.

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, in certain cases, if the humidity is too high, one should consider using a desiccant air dehumidifier. These devices use chemical reactions in order to dry out the air, and can reduce the humidity to anywhere between one to forty percent.

Eliminate mold and mildew

Based on what we’ve seen so far, as long as dark, humid, and cool temperature conditions prevail, mold and mildew will proliferate to  a point where it becomes a nuisance in other parts of the house as well.

Therefore, it is important to get rid of any existing colonies before they spread to other places, thereby wrecking more havoc.

For smaller spots, one can simply scrub them out using some detergent and water. However, one should not use bleach, as it only affects the surface of mold.

However, for bigger mold colonies, it would be ideal to hire a contractor who is trained in treating mold.

In the case of articles such as clothes, carpets, furnitures, using baking soda along with detergent and water to clean them out, followed by line drying in ample sunlight can help to get rid of mold from them.

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.

Air purifiers get rid of mold spores that can be suspended in the basement air, thereby reducing the chances of mold to spread to other parts of the house.

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.

However, it is important to note that air purifiers should not be used in high humidity conditions, as humid air is heavier than normal air, which causes overworking of the air purifier, thereby decreasing its efficiency.

Another reason for doing so is that the mold spores entrapped within the filters can start proliferating in there itself, which in turn can exacerbate the air quality.

How to prevent formation of musty smell in basement

It is vital to practice habits that would help to prevent the musty smell from forming in basements in the first place. This can be done by the following methods:

  • Improve ventilation
  • Use an air dehumidifier
  • Regularly cleaning the basement

Improve ventilation

Opening your doors and windows for some time during the day helps to increase the air exchange rate with the outdoor air. As mentioned earlier, this helps to remove the indoor pollutants as well as the odor, while introducing fresh air.

However, it is important to check the outdoor pollen and mold count, since on days of high concentration levels, the smell will get further exacerbated.

For places which do not have proper sources of natural ventilation, such as basements, HVAC systems are especially helpful. 

HVAC refers to Heating, Ventilation, and Air Conditioning. 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 stale air smell.

Use an air dehumidifier

As seen from above, high humidity levels play a major role in the generation of stale air smell indoors. Therefore, it is important to regulate the indoor moisture levels.

This is where air dehumidifiers come in the pictures. These devices, as the name suggests, lower the humidity of the indoor environment, therefore keeping the air dry and hampering the growth of mold.

Regularly cleaning your basement

It is important to keep your house clean, especially surfaces such as beddings, carpets, or places where people usually are present.

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 stale odor.

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

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

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Even in a dry basement, musty smell can originate from certain areas, which can happen due to leaks and seeps, or from high humid conditions in the basement, which leads to growth of mold in damp areas or on plant-derived products such as paper products, clothes, furnitures, and so on.

One can remove these smells by fixing any leaks and seeps, getting rid of mold, and by using an air purifier.

Furthermore, one can prevent the formation of musty smell by improving the ventilation, using an air dehumidifier to keep indoor humidity levels in check, and by routinely cleaning the basement on a regular basis.


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.


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