Does air conditioning make you sick? Here is the truth.

Most Americans use air conditioning every day, whether in their office buildings or living spaces; 90% of the country has a home unit and AC accounts for about 10% of global electricity consumption.

But do we really need it?

A New York Times article put this question in perspective this week. The inhabitants of the world's warmest climates tolerate temperatures much better than Americans. Citizens of countries like Mexico, Brazil and India use much less air conditioning than us. The play led to a viral debate on Twitter to find out if AC is vital or even healthy for us.

In short: it will not do much harm to your health – but only if the system is closely watched and wisely. According to a study by the International Journal of Epidemiology, occupants of air-conditioned office buildings reported more symptoms of poor health than those working in buildings with natural ventilation.

"Much research has shown that air-conditioned office occupants tend to report more symptoms of unhealthy building syndrome than naturally ventilated office occupants," said William Fisk, Group Leader, Indoor Environment, Lawrence Berkeley National Laboratory. "Symptoms of SBS are self-reported symptoms, mainly irritation of the eyes, nose or throat and respiratory symptoms such as coughing."

According to Fisk, these symptoms are "probably due to the humidity of air conditioning units, which expose people to additional toxins, allergens or irritants". This moisture leaves the system open to tiny pollutants.

"Air conditioning systems are likely to collect infectious organisms and allergens, such as dust mites," said Dr. Wassim Labaki, professor of internal medicine and pulmonologist at Michigan Medicine. "Therefore, proper maintenance of these systems, including regular replacement of filters, is essential to prevent unhealthy air circulation."

There are also psychological effects. Productivity reaches its maximum when the temperature is pleasant and not under stifling heat or cold weather. This is especially true for women. (Are you listening, office managers?)

"A considerable body of research indicates that human performance in office work is optimized when temperatures are maintained at around 71 ° C. [degrees Fahrenheit] more or less a degree or two, "said Fisk," The CA can help us maintain such temperatures, but other technologies can also help. "However, the CA can also lead us in the opposite direction. an optimal temperature.

That being said, there are a few things to like about the AC in terms of our physical health; As long as it works properly and is well maintained, the machine usually eliminates air and particle pollution. According to a study by Yale researchers, the use of air conditioning also reduced the risk of hospitalization and death related to cardiovascular problems.

"Air conditioning can be expected to reduce the risk of heat stroke and heat-related mortality during heat waves, which are becoming more common with climate change," said Fisk. "Air conditioning also helps keep windows closed and air conditioning systems usually contain filters that remove circulating airborne particles. With the air conditioner and windows closed, concentrations of outdoor air pollutants such as particulates, ozone and allergens are reduced.

Especially if you have allergies, turning on the air conditioner to isolate the particles instead of opening your windows can help you reduce the annoying symptoms.

"For patients with allergies and other underlying respiratory diseases such as COPD / Emphysema, staying indoors with air conditioning and closed windows reduces exposure to pollen and external pollutants, "said Dr. Mark Aronica, an allergist-immunologist in Cleveland. Clinical.

Bottom line? There are some concerns about air conditioning, so proper maintenance (without overdoing it) is better for your well-being. Comfort and conservation are the two most important factors here, said Aronica.

However, "there can be significant differences in comfort, even between family members and spouses," he added. "And then, regardless of other factors that concern a person, energy efficiency, costs, etc. For window units, be sure to clean and maintain, and for central air conditioning, perform the appropriate maintenance and make sure air filters are replaced when recommended by the manufacturer. "

And remember, there are many ways to stay cool, including fans, cold roofs, energy efficient windows, and adequate shading. You do not always need to keep the air on. In order to conserve energy and seek optimal well-being, air conditioning should be more of a "last resort than first resort," said Nihar Shah, an energy and environmental policy researcher at Lawrence Berkeley National Laboratory.

"Some problems are that buildings are not designed to open windows, or with cold walls, cold roofs, awnings or curtains," he added.

Designers can change the orientation of a building, but you can not. However, you can move from different sides of the building without direct sunlight or with more shade. Do a creative conservation experiment before activating this alternative mode – you may be generally better off.