Air Purifier vs Dehumidifier for Basement

This article discusses how air purifiers and dehumidifiers work in an indoor basement environment. We discuss each device’s effectiveness against certain problems associated with the air quality in a typical basement environment.

Why is basement air quality important?

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. 

The air quality in these rooms is primarily affected by factors such as 

(i) various items stored such as unused furniture, solvents and chemicals used for cleaning or hobby purposes, paints, and gasoline products 

(ii) moisture content 

(iii) presence of mold and mildew

(iv) presence of furnace or boilers; and 

(v) dust and dander.
 

Furthermore, these rooms usually have very limited air exchange, which causes a build-up of PM within these rooms. 

Certain products such as furniture release emissions more or less continuously, while other sources (e.g.: smoking, air fresheners) release emissions intermittently. 

Given the nature and origin of the emissions, they can be potentially harmful when inhaled and can cause serious respiratory issues in the long run.

These effects are more pronounced in certain groups such as children, older people, and people ailing from respiratory and cardiovascular diseases. 

Thus, it is important to ensure the air quality of the basement is well-maintained.

Air dehumidifiers

Types and working mechanism

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%. 

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.

How dehumidifiers help in basements

Rooms which are prone to moisture build up such as bathrooms, kitchens, and basements require an air dehumidifier.

The specific micro-climate conditions of high humidity levels and low temperatures in the basement directly contribute towards processes that lead to deterioration of indoor air quality. 

Elevation in humidity and temperature favours the growth of mold, which produce spores that act as biological air contaminants.

Mold and dust mites that grow in excessively wet air produce spores and droppings. These products can cause allergic responses and trigger severe asthma symptoms, especially in people prone to it.

An air dehumidifier has the ability 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.

Not only that, dehumidifiers also help to remove the suspended dust in the basement air, which can aggregate due to lack of proper ventilation.

However, dehumidifiers are not efficient in removing all dust particles present in the basement air. Furthermore, dehumidifiers can only keep in check the agents that cause musty odor in the basement, but not get rid of the odor itself.

How air purifiers help in the basement


A major component of basement air pollution is particulate matter (PM). These particles can originate indoors from various sources, or enter the basement from the outdoor air. 

PM has serious implications on health, depending upon its composition and abundance, and can also cause premature death in people ailing from respiratory and cardiovascular diseases. 

The best method for reducing PM concentrations is by using an air purifier. Depending upon the size of the basement, an adequate air purifier should be used. 

Air purifiers can remove particulate pollutants more than or equal to 0.3 microns with more than 99% efficiency. 

Furthermore, air purifiers can also get rid of musty smell and other gaseous pollutants that can arise from various sources in the basement, thereby making the air less repulsive in terms of odor.

Air purifiers can also get rid of mold and bacteria spores that can be suspended in the air, along with dust particles. This helps to keep the proliferation of mold in check, and also prevent increase in the number of dust mites as well.

However, it could be harmful to run an air purifier in humid conditions. This is because humid air is “heavier” in terms of adequately moist air, which can adversely affect the proper operation of the air purifier.

Furthermore, the dark and humid conditions that develop in the filter can serve as an excellent breeding ground for the mold and bacteria that were trapped earlier, thereby further exacerbating the efficiency of air purifiers.

There are different types of air purifiers that are commercially available in the market. Some of the most common air purifiers are:

  • HEPA filters
  • Air ionisers
  • Activated carbon filters

Air purifiers with HEPA (High-Efficiency Particulate Air) filters are best suited for indoor purposes. The presence of an activated carbon filter and a germicidal UV light chamber further increases the efficiency of the filters.

Other FAQs about Air Purifiers and Filters that you may be interested in.

Can a dirty air filter make your house smell?

Can air purifiers help with allergies?

HEPA Air Purifier Side Effects