How To Avoid Health Risks Associated With Air Conditioning

Given that the majority of people in the United States spend about 90% of their time indoors, the quality of indoor air can have a significant impact on overall health and well-being. Unfortunately, many people overlook one common contributor to indoor air quality: air conditioning, which is widely used in U.S. homes.

Air conditioners can actually improve air quality by regulating temperature, reducing humidity levels, and enhancing filtration. However, a poorly maintained system can degrade air quality.

Research has shown that bacteria and other pathogens can accumulate in air conditioning units, potentially leading to illness in people who are exposed to them. For example, contaminated air-cooling systems can spread Legionnaires' disease, a type of pneumonia caused by bacteria. Additionally, dirty air conditioning systems can trigger hypersensitivity pneumonitis, an allergic reaction that causes lung inflammation in response to irritants like bacteria and fungi. 

A study conducted in 2023 compared healthy adults in India who spent at least six hours per day in air-conditioned environments with those who spent the same amount of time in naturally ventilated buildings. The study found that individuals in air-conditioned environments experienced more health issues, including respiratory symptoms, headaches, and lethargy. These health issues may be attributed, at least in part, to the accumulation of contaminants in air-conditioned buildings.

To avoid health risks associated with air conditioning and improve the air quality you breathe, here are some recommendations:

Choose the right air conditioning filter: Look for a filter labeled with a minimum efficiency reporting value (MERV) that rates its ability to trap airborne particles. Filters with higher MERV values, such as MERV 11 or MERV 13, are more effective at catching particles like dust, pet dander, smog, and mold.

Consider using a separate HEPA filter: If your air conditioning system is not compatible with high-quality filters, especially window units, you may want to invest in a separate HEPA filter to improve air quality. HEPA filters are known for their superior filtration capabilities.

Regularly clean or replace the filter: This is crucial to prevent the accumulation of mold and contaminants in your air conditioning system. Follow the manufacturer's instructions regarding the frequency of filter cleaning or replacement. As a general guideline, clean or replace the filter every month or two during periods of peak use. Reusable filters can be vacuumed, washed with water and a gentle detergent, and thoroughly dried before reinserting.

Ensure a proper fit for the filter: Gaps around the filter allow air to bypass it, rendering it less effective. If you have central air conditioning, consider having an upgraded filter slot installed to improve the fit.

Utilize the fan function: If you have central air conditioning, running the fan for about 20 minutes every hour (approximately 33% of the time) can improve filtration, particularly during seasons when there is a high presence of pollen or other irritants in the air. However, this technique may not bring significant health benefits with window units due to the lower-quality filters typically used.

Introduce outdoor air: Industrial HVAC systems often bring in outdoor air to enhance ventilation, but residential air conditioning units generally do not mechanically introduce fresh air. To improve indoor air quality, open windows for a few hours a day when weather conditions permit. If your air quality outdoors is poor, it is best to keep your windows closed.

Maintain your air conditioning system regularly: Regular maintenance by HVAC technicians is essential to ensure that your system is functioning correctly and that hard-to-reach components are clean and free from potentially harmful build-up.

By following these recommendations, you can mitigate AC-related health risks and improve the quality of the air you breathe indoors.