Why does the air feel heavy in my house?

This article discusses the various phenomena that take place in an indoor environment which can result in the air feeling heavy. Furthermore, we discuss the ways one can reduce as well as prevent this from happening.

Why does the air feel heavy in my house?

In an indoor environment, there are a lot of phenomena that take place, which can cause the air to grow stale. Stale air contains substances such as carbon dioxide (CO2), volatile organic compounds (VOCs), as well as excess humidity levels.

Furthermore, this air also contains less concentration of oxygen in it. All of these factors combined are the reason why the air feels heavy in the room.

Therefore, the main culprits to why the air feel heavy in the house are: 

  • Outdoor sources
  • Water vapour
  • Mold and mildew
  • Dust mites
  • Tight packed houses
  • Poor ventilation system

Let us discuss these in more detail

Outdoor sources

In a typical indoor setting, nearly 60% of the total dust arises from outdoors. This number can vary depending upon the location of the place, climatic settings, and other factors such as distance from road, combustion frequency in the area, etc.

Some of the main constituents of these are particulate matter (PM), which include pollen, soil, particulates from combustion activities and smoking, and other outdoor activities one can think of.

PM refers to particles, either solid or liquid, that are mixed and suspended in the air. They are a major part of air pollutants, and have a variety of natural and anthropogenic sources.

Some of these PM particles that are below 2.5 microns in size, known as PM2.5, have seriously adverse effects on human health, and long term exposures can cause serious health issues and even premature death.

The dust particles mainly act as allergens, and can also get trapped in one’s clothing and hair, from where they enter the home.

As the concentration of these pollutants start to increase, the air quality in an indoor environment starts degrading. Due to this degradation, the indoor air starts to feel heavy on inhalation.

For people living in urban areas, or places near a road, air purifiers are a must have, since the pollution generated from traffic can easily enter the house, and if not removed, can adversely affect the health of occupants.

Water vapour

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

This is primarily due to the presence of water in the vapour form. In higher humidity levels, the air becomes heavier than normal, making it harder to breathe.

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 feel heavy. 

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 heavy or stuffy, as well as produce a stale 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.

Dust mites

Dust mites are tiny pests that live in humid settings and flourish. Even if your home isn’t excessively hot or humid, dust mites are likely to be lurking in your beds, carpets, and curtains.

The more dust you have, the more dust mites you have, because dust is made up of things like animal dander and dead skin, which are two of dust mites’ favourite diets.

Dust mites and their waste products are relatively weightless. Therefore, they can stay suspended in the indoor air for a long time, and affect one’s health if inhaled.

These mites proliferate in an indoor environment, when the ideal conditions prevail. Their droppings act as allergens which cause shortness of breath and inability to deeply inhale, therefore making the air feel heavy.

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.

While this is good in certain conditions, since it prevents the infiltration of outdoor air pollution in the indoor environment, as well as limits the heat exchange rate with the surroundings, especially in the winter season, it also causes poor air exchange rate.

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 stale air smell start to rise, as well as the heavy feeling when inhaling.

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 stale 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.

Prevention and minimisation

There are multiple ways in order to minimise as well as prevent the indoor from feeling heavy while inhaling. Some of these are:

  • Opening windows and doors
  • Installation and regular maintenance of HVAC systems
  • Regularly cleaning your house
  • Investing in an air dehumidifier
  • Using an air purifier

Let us discuss these in more detail.

Opening doors and windows

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 indoor air quality will get further exacerbate, therefore making the air heavy.

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 stale, heavy air.

Regularly cleaning your house

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 the indoor air to feel heavy.

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

Invest in an air dehumidifier

As seen from above, high humidity levels play a major role in the generation of stale air, which on inhalation feels heavy. 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.

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 particulates associated with stale air 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.

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

What is meant by ‘stale air in lungs’?

Can poor air quality affect pregnancy?

Can poor Air Quality cause Allergies?


Indoor air can feel heavy on inhalation in numerous instances. These instances are mainly governed by two factors – high humidity, and lack of adequate ventilation.

In order to prevent this, it is important to improve the indoor ventilation, cleaning the house on a regular basis, and use an air purifier and an air dehumidifier.


Do humidifiers help in the case of mold and mildew formation?

No, humidifiers do not help in the case of mold and mildew formation. Rather, they can exacerbate the condition even more.

Mold and mildew only grow in humidity levels of more than 50 percent. However, using a humidifier will further provide the humidity levels required by the mold and mildew to proliferate, and also spread to other areas of the house.

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.

Can the air get heavy if there are more people in a room? 

Yes, the air can get heavy if there are more people in a room. This is because when there is a higher occupancy, the amount of carbon dioxide released in the air increases, while the amount of oxygen available in the air decreases.

This in turn causes the air to start feeling heavy. An example of such situations can be seen in areas such as classrooms and offices, where certain people report issues such as shortness of breath since the air feels heavy.


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