At the "Global Action for a Cooler Planet" seminar, organized by the Climate Change Department (Ministry of Agriculture and Environment) on 14/9, experts highlighted the significant downsides of air conditioners, which have become prevalent in Vietnam over the past two decades.

Associate Professor Nguyen Viet Dung, Vice Rector of the School of Mechanical Engineering at Hanoi University of Science and Technology, explained that these devices contribute to ozone layer depletion and the greenhouse effect. He stated that the overuse of air conditioning traps humanity in a cycle of "cooling indoors while heating the Earth".

Specifically, to reduce indoor temperatures, an air conditioner expels heat equivalent to 130% of the cooled amount into the outdoor environment, warming the air around the outdoor unit. This process leads to ambient temperatures being higher than usual.

"The hotter it gets, the more we rely on air conditioners, releasing even more heat outdoors," Dung remarked. "This, combined with increasing urbanization and concrete structures, causes urban temperatures to rise by 2-5 degrees C compared to surrounding areas."

Experts at the seminar. Photo: DCC

Another challenge lies in the direct relationship between cooling device electricity consumption and outdoor temperature. As outside temperatures rise, air conditioners consume more power. The Vice Rector estimated that a 1 degree C increase in outdoor temperature boosts air conditioner electricity consumption by 2-4%, perpetuating a cycle of "more use, hotter conditions, and increased usage."

Furthermore, air conditioners utilize refrigerant gases, which pose a risk to the ozone layer and contribute to global warming. The ozone layer is a vital atmospheric shield that absorbs most of the Sun's dangerous ultraviolet (UV) radiation. Dung noted that just one kilogram of older generation refrigerant gas has a global warming potential over 2,000 times that of CO2, severely impacting the climate.

According to the Climate Change Department, electricity consumption for cooling reached 71.4 TWh, accounting for 25% of the national total. Without effective control measures, the cooling sector could contribute nearly 10% of Vietnam's total greenhouse gas emissions by 2030.

This presents a critical need for sustainable cooling solutions that meet essential living and production demands while minimizing environmental impact. Experts emphasize that relying solely on air conditioners is not a viable long-term strategy.

To address this, Nguyen Cong Thinh, an independent expert in green building and construction, stressed the importance of reducing cooling demand from the initial planning and design phases. Key considerations include construction density, green spaces, and water bodies. Establishing green buffer zones can mitigate the "urban heat island" effect, where urban areas are several degrees C hotter than their surroundings.

Delving into design specifics, Phan Tuan Anh, founder and chief architect of GS Team, proposed solutions to reduce the need for air conditioning in buildings. He cited traditional practices, such as "ancestors" building south-facing homes to capture wind, incorporating courtyards, and using skylights. Another simple urban solution involves "sheltering buildings", where structures are strategically positioned to shade each other.

For standalone buildings, experts recommend prioritizing natural solutions. This includes designing spaces for optimal ventilation, creating buffer zones for direct sun exposure (east-west), and utilizing insulation and heat-reflective coatings.

Thinh clarified that sustainable cooling does not mean eliminating air conditioner use. Instead, it involves balancing two goals: reducing or using energy-efficient cooling equipment effectively, while still ensuring comfortable working and living conditions for users.

From a macro perspective, Vietnam has been a signatory to the Vienna Convention and the Montreal Protocol since 1994, working to control and eliminate ozone-depleting substances. The Kigali Amendment, adopted internationally in 2016, introduced a global phasedown of HFC refrigerants, commonly used in air conditioners and refrigeration equipment. Statistics from the International Ozone Secretariat indicate that from 1994 to 8/2025, Vietnam's compliance with these international commitments has prevented approximately 240 million tons of CO2e emissions.

Thuy Truong