Can the Penetration Rate of Air Conditioning Indicate the Urban Heatwave Vulnerability?

In recent years, the heatwave had occurred frequently across the globe. 2024 is one of the hottest years in meteorological record, as many cities had a temperature of more than 40℃ for continuous days. Under such extreme weather conditions, the use of air conditioners rises up sharply. But in the meantime, it also exposed an interesting phenomenon: the more popularized the air conditioners of the city, the "weaker" it would be when facing the heatwave. 

So, can the rate of air conditioning use indicate the urban heatwave vulnerability?

I. Contradiction between surface cooling and systematic heating

The air conditioners truly mitigated the threat from heatwaves individually. For civilians, lowering down the indoor temperature relates to the insurance of life and health, but for the urban system, the popularization of air conditioners will lead to opposite effects:

Cumulative effect for heat emission

When cooling, the air conditioner will exhaust the interior heat to the exterior, making the city temperature higher and higher at night. Research shows that in densely air-conditioned urban areas, nighttime ground temperatures can be 1–2°C higher than in the surrounding areas.

Surged energy burden

During the heatwaves, the electricity demand surges and the city grid shoulders a great burden. Once the power outage occurs, it will lead to "temperature backlash"—the areas that deeply rely on air conditioners will be the most dangerous.

Unbalanced spatial distribution

In high-profile and commercial districts, there are complete cooling systems, while for low-income groups or old districts with a lack of air conditioning or stable electricity supply, these are the heat wave vulnerable areas.

So, the air conditioning penetration rate seems to show the ability of heat resistance; in fact, it may reveal the city's degree of reliance on heatwaves and the risk imbalance.

II. The gap from "own air conditioners" to "withstand heatwaves"

1. Air conditioning penetration ≠ heatwave safety

The higher popularization rate means citizens rely more on mechanical cooling. Once the extreme conditions occur (such as power cuts, appliance malfunctions, and insufficient water supply), the whole city will face a high-temperature crisis. For example, during a power outage in some Indian cities in 2022, there were numerous cases of heatstroke in hospitals and senior citizen communities.

2. Enlarged fragility of the energy system

During the heatwaves, the peak demand of air conditioning units is usually 40%~50% higher than normal. If there is no redundant design of the city grid or the support of new energy, such peak value will increase the system risk.

3. The superposition of urban heat island effect

When the emitted heat from the air conditioners accumulates among the dense buildings, it will strengthen the heat island effect. As a result, people use air conditioners to cool in the daytime and are surrounded by the exhausted heat at nighttime. Such circulation makes cities more passive regarding climate.

III. Air conditioner penetration rate: a sign of "vulnerability"

It's better to regard the air conditioner penetration rate as a vulnerability signal of the climate rather than an index of anti-heat. In high-income and high-penetration-rate cities, it represents an excessive reliance on the cooling system; once it fails to work, the risk increases manyfold. In low-income and low-penetration-rate regions, it exposes the lack of basic means of cooling among citizens and a higher risk of heatstroke, dehydration, etc.

So, there is a "bimodal relationship" between the air conditioning penetration rate and heatwave vulnerability. Too low a rate means a lack of heat protection, and too high a rate reflects the excessive reliance. A really safe city should be equipped with diversifiable mechanisms except for the air conditioning.

IV. Redefine the standards of the "anti-heat city."

It's not enough only to improve the air conditioner penetration rate to reduce the urban heatwave vulnerability from the basis, but also to optimize the structure:

Passive cooling design of the buildings:

Wall insulation, ventilation optimization, reflective roof materials, green roofs, etc.

Diversified energy structure:

Solar air conditioners, energy storage systems, intelligent power grids, and other ways can reduce the burden of the city grid.

Temperature balance in public spaces:

Add cooling centers and shade facilities to old districts, schools, bus stations, and so on.

Climate-monitored urban management:

By timely supervising heat wave exposure and power load to preview the conditions, cooling resources can be scheduled in advance to form a dynamic defense system.

V. KRG's perspective: convert "cooling demand" into "climate adaptation"—a prolonged mindset

As a brand focusing on high-efficiency air conditioning solutions, KRG believes that air conditioning will not only provide cold air but also help cities cope with heatwaves in a more intelligent and more sustainable way.

· We are now developing high-efficiency air conditioning products with low emissions, aiming to contribute to the urban heat islands.

· We are now pushing intelligent control systems with load management technologies to make cooling devices with flexible operation.

· We are now focusing on solutions against heatwaves in developing countries, hoping to reduce the reliance on energy for cooling.