Health Warning: Prolonged AC Use May Cause CO2 Poisoning
SingTao · 1 SOURCESabout 2 hours ago2 MIN
Summary
Hong Kong has recently endured extreme heat with record-breaking temperatures, prompting residents to rely heavily on air conditioning. An appliance retailer took to social media platform Threads to warn the public about the dangers of prolonged air conditioner use. Most air conditioning units operate on an internal circulation design, which continuously recycles indoor air without introducing fresh air from outside. This can cause carbon dioxide levels to accumulate dangerously over time, potentially leading to CO2 poisoning. Health experts recommend opening windows for ventilation every three to four hours to maintain safe air quality.
Key Points
- Most air conditioners in Hong Kong use an internal circulation design that continuously recycles indoor air without drawing in fresh outdoor air .
- A case from Heilongjiang documented a woman who developed CO2 poisoning symptoms after staying in a sealed, air-conditioned room for over 30 hours, experiencing dizziness, nausea, limb stiffness, facial numbness, and full-body convulsions due to brain hypoxia from elevated CO2 levels .
- The appliance retailer recommends opening windows every 3 to 4 hours for at least 10 minutes to allow proper air exchange and maintain indoor air freshness .
- Daikin, a major air conditioning manufacturer, advises opening two windows simultaneously to create effective cross-ventilation, with diagonal window placement providing the most efficient and comprehensive air exchange .
- Split-type air conditioning units, the most common type in Hong Kong, lack dedicated ducts or valves for fresh air intake, making ventilation particularly important for these systems .
Why It Matters
With Hong Kong experiencing unprecedented heat waves, residents face genuine health risks from well-intentioned efforts to stay cool. Carbon dioxide poisoning can cause serious neurological symptoms and, in extreme cases, can be life-threatening. This warning underscores the importance of balancing comfort with indoor air quality, especially in densely populated Hong Kong where many residents spend extended periods in relatively small living spaces with limited natural ventilation.
With Hong Kong experiencing unprecedented heat waves, residents face genuine health risks from well-intentioned efforts to stay cool. Carbon dioxide poisoning can cause serious neurological symptoms and, in extreme cases, can be life-threatening. This warning underscores the importance of balancing comfort with indoor air quality, especially in densely populated Hong Kong where many residents spend extended periods in relatively small living spaces with limited natural ventilation.