Is the air around you becoming polluted because of your air conditioner?

Air conditioners (ACs) have long been considered one of the most effective cooling solutions in hot and dry climates. However, behind that comfort, recent studies show that ACs can significantly degrade indoor air quality, in some cases making the air even more polluted than outdoors. This leads to a series of health issues that users often fail to recognize.

A 2024 field study in Kenadsa, Bechar (Algeria) - a region representative of hot, arid climates found that wall-mounted split air conditioners (SACs) continuously recirculate stale indoor air instead of supplying fresh air. This mechanism allows fine particles, allergens, microorganisms and harmful gases to accumulate over time.

This unfiltered air recirculation becomes the starting point of multiple risks.

The study recorded high rates of symptoms associated with AC usage:

• Headache: 65%
• Sneezing: 60%
• Runny or congested nose: 52%
• Dry skin: 40%

Additionally, 74% of participants reported fatigue and poor sleep - symptoms commonly linked to Sick Building Syndrome.

Notably, more than 20% of users set their AC temperature below 18°C, a level considered excessively low, leading to energy waste and increasing the risk of thermal shock when moving between environments.

Recirculated Air: The Reason Fine Particles Surge in Air-Conditioned Rooms

Dust accumulation inside AC filters rises significantly when:

• There are pets in the home
• Carpets or rugs are used
• The room has high activity levels
• Windows are opened while the AC is running
• The AC operates at high speed for prolonged periods

Since split ACs do not draw in outdoor air, they simply blow the same indoor air back into the room. If that air is not properly filtered, fine particles and harmful contaminants continue to circulate within the living space.

Where Do Pollutants Accumulate? The Answer: Inside the AC Filter

User maintenance behavior is a major concern. Most people do not clean their AC filters regularly. Only 32% do so for health reasons, while 54% clean the filter only when the AC “no longer feels cool.”

Consequences include:

• Heavy buildup of fine particles, dead skin cells, pet dander, pollen and organic debris
• Rapid growth of bacteria and mold inside the moist evaporator coil
• Indoor air becoming 2–10 times more polluted than outdoor air, according to multiple international studies

Air conditioners are designed to cool, not to filter fine particles or toxic gases. Expecting an AC to function as an air purifier is fundamentally incorrect.

High-Performance Air Filtration Solutions for Air-Conditioned Spaces

To address the inherent limitations of split ACs and ensure comprehensive indoor air quality, IQAir offers specialized filtration systems that work independently or integrate with cooling systems.

Perfect 16: Building-Wide Air Purification Through Central HVAC

Perfect 16 is a whole-building air filtration system integrated directly into HVAC infrastructure. It is rated beyond MERV 16 and captures ultrafine particles down to 0.003 microns, including:

• Fine particulate matter (PM2.5 and PM1.0)
• Allergens and pollen
• Pet dander and bioaerosols
• Bacteria and viruses
• Aerosols and ultrafine airborne particles

Its double-V design provides more than 170 ft² of filter surface area, increasing clean airflow while maintaining low resistance, enabling the HVAC system to operate smoothly and quietly. Clean, filtered air is then distributed to every room through the ductwork, forming a continuous clean-air circulation loop.

Perfect 16 operates silently without a dedicated motor and consumes no additional electricity. It is available in various sizes suitable for high-end residences, offices, hotels, schools and buildings with demanding air-quality requirements.

IQAir HealthPro 250 XE: Advanced Filtration for Rooms Using Split ACs

The HealthPro 250 is IQAir’s best-selling room air purifier, equipped with HyperHEPA technology that filters 99.5% of ultrafine particles down to 0.003 microns — far smaller than the capability of standard HEPA filters. The V5-Cell filtration stage adsorbs toxic gases, VOCs and odors, providing simultaneous purification of both particles and gases.

The upgraded HealthPro 250 XE features:

• Real-time PM2.5 monitoring
• Remote monitoring and control via the IQAir AirVisual app
• Three intelligent modes that auto-adjust filtration based on air quality
• Optimized fan performance for improved energy efficiency

With strong filtration performance against fine particles, allergens, bacteria, viruses, VOCs and odors, the HealthPro 250 XE is ideal for bedrooms, home offices, children’s rooms and spaces requiring high air-quality standards.

IQAir: A Complete Clean-Air Ecosystem from Single Rooms to Entire Buildings

A cool room offers momentary comfort. Truly clean air delivers lasting value: supporting health, concentration, sleep quality and overall well-being in homes, offices, hotels and large buildings.

Perfect 16 ensures whole-building air purification through central HVAC systems, while the HealthPro 250 XE elevates air quality in individual rooms where people spend the most time. Together, they form an integrated clean-air ecosystem that overcomes the inherent limitations of air conditioners and creates healthier, more stable and sustainable living and working environments.

A refreshing room brings comfort. Clean air creates lasting value.

Nguồn: Benyamine, M., Fezzioui, N., Alkhafaji, M. A., Kaid, N., Benti, N. E., & Menni, Y. (2024). Assessing indoor air quality and health risks of air conditioner usage in residential buildings under hot and arid climatic conditions: insights from field studies and questionnaire analysis. International Journal of Low-Carbon Technologies, 19, 2397-2408.