Air Conditioners

The first modern air conditioner (AC) was invented in 1902¹ in Brooklyn, New York. Since then, the technology has become a fixture in many parts of the world.

How do air conditioners work?

ACs pull air from indoor spaces, then use chemicals called refrigerants to extract its heat. The newly chilled air is then sent indoors while the unwanted heat is directed out of the building.

Most people don’t realize it, but many air conditioners can heat as well as cool buildings—in fact, ACs are technically a type of heat pump. In some parts of the world, “air conditioning” refers to both heating and cooling.

Where are ACs used?

Today, only a relatively small percentage of the world’s population has air conditioning. In most countries, ACs are used almost exclusively by middle- and upper-income households, businesses, and institutions. With their relatively steep purchase price and high energy needs (in warm climates, they typically use more energy than any other residential appliance), these appliances are out of reach for many. In fact, as of 2018, ACs were present in more than half of all households in only a few countries:² China, Japan, Korea, Saudi Arabia, and the United States.

• Making ACs more energy efficient will cool or heat buildings while using less electricity, generating fewer planet-warming emissions, and reducing demand on energy grids. Higher efficiency also lowers users’ energy bills, helping more people afford ACs.
• Switching to climate-friendly refrigerants will keep more greenhouse gases out of the atmosphere.
• Getting high-quality ACs to more people who need them will save lives, keep people comfortable, and improve productivity during heat waves.

Governments

• Develop, promote, and incentivize the production and/or import of efficient ACs and those using low-global-warming-potential (GWP) refrigerants.
• Set policies to phase out the production, trade, and sale of inefficient ACs and those that use refrigerants with high global warming potential.
• Increase national awareness of the net benefits of efficiency of ACs and other appliances.
• Use labels to indicate and promote the most efficient and climate-friendly AC models.
• Reduce the need for air conditioning by supporting cooling-friendly design and construction practices, such as by ensuring that building standards and codes include effective insulation and triple glazing as the default option.

AC manufacturers

• Invest in research and development to improve the efficiency, affordability, and climate-friendliness of air conditioners to match global best practice.
• Abandon the production and export of inefficient models and challenge competitors to do the same.

Building professionals and urban planners

• Reduce the need for air conditioning by optimizing the design of buildings and cities, employing strategies like well-insulated walls and windows, cool roofs, natural ventilation, and green space.
• Lobby governments for cooling-friendly building standards and codes to minimize the need for ACs.

Consumers and consumer groups

• Choose the most efficient air conditioner you can afford to lower your energy bills and reduce your carbon footprint.
• Choose ACs with low-global-warming-potential refrigerants.
• Increase the wall insulation, shade, and layers of window glazing in your homes and businesses to reduce the need for air conditioning.
• Contact government representatives to request ambitious efficiency policies for all appliances.