The air conditioning industry needs to lift its game and increase the efficiency of units sold to consumers by at least 50 per cent by the year 2030, according to a new report released by the International Energy Agency (IEA).
The report warned that energy consumption for space cooling has more than tripled since 1990.
“Although space cooling equipment performance is improving continuously and electricity production is becoming less carbon-intensive, indirect CO2 emissions from space cooling are increasing rapidly; more than doubling to nearly 1 Gt between 1990 and 2021,” the report said.
“Space cooling demand experienced the highest annual growth among all buildings end uses in 2021 and accounted for nearly 16 per cent of buildings sector final electricity consumption (about 2 000 TWh).”
The IEA said efficiency standards are a key measure to avoid the lock-in of inefficient air-conditioning units in coming decades, together with passive, nature-based and alternative solutions to air conditioners, as well as improved design of buildings and districts.
While highly efficient air-conditioning units are available on the market, most efficiency standards – and consequently the units purchased by consumers – have two-to-three times lower efficiencies than the ones of best available technologies., the report said.
In the Net Zero Emissions by 2050 Scenario, indirect CO2 emissions associated with space cooling demand by 2030 fall to about one-third of those in 2021, with a decrease in emissions intensity per unit six times faster than over the past decade.
Energy demand for space cooling has risen at an average pace of four per cent per year since 2000, twice as quickly as for lighting or water heating.
The number of units in operation has more than doubled since 2000, reaching over 2.2 billion units in 2021.
Globally, space cooling energy demand rose over 6.5 per cent in 2021, with growth close to 8-9 per cent in Asia Pacific and Europe.
“Causes of growth vary across countries, but increased appliance ownership and rising temperatures are the main drivers,” the EIA said.
“The global average efficiency of air conditioners purchased by consumers has improved steadily in recent years. However, without moving towards the best available products, and improving the performance of the buildings in which they operate and their surroundings, electricity demand for space cooling in buildings could increase by as much as 40 per cent globally by 2030.”
To get on track with the Net Zero Scenario, the EIA said the average efficiency rating of new air conditioners would need to increase at least 50 per cent in all markets.
Buildings floor area has increased by more than 60 per cent in the past two decades and is set to increase by another 20 per cent over this decade, adding a total floor surface area of nearly 45 billion m2.
These floor area additions will mostly happen in regions that need space cooling. More than half of floor area additions are in regions with hot climates and mostly lack building energy codes covering the entire building sector, the report said.
Incorporating cooling-oriented design strategies into buildings energy codes and local planning, including passive and nature-based solutions, will be essential to reduce cooling needs and reduce the risk of heat islands in expanding urban areas while temperature rise. In the Net Zero Scenario, useful energy intensity (cooling service demand per square metre) declines by about 30 per cent in 2030 compared with 2021.
Global view
Despite increasing deployment globally, the penetration of space cooling solutions and air-conditioning equipment is not equally distributed across the globe.
The report found only around five per cent of households in sub-Saharan Africa are equipped with an air-conditioning unit, roughly 10 per cent in India and Indonesia, and around 30 per cent in Mexico and Brazil.
This compares with more than 85 per cent in Japan, Korea and the United States respectively. Globally, one in seven people (1.2 billion in total) in poor rural and urban areas are estimated to be at high risk due to a lack of access to cooling.
Rising temperatures, together with a growing population, urbanisation and improved living standards, are driving a sharp increase in the adoption rate of air conditioning, which is expected to jump from 35 per cent of the global population today to nearly 45 per cent in 2030.
Part-load operation
Data from air-conditioning product registries indicate that the units with the highest efficiency in some markets can be twice as efficient as the average unit sold – often at comparable prices, yet their deployment lags behind.
Achieving the best available energy efficiency during part load operation is an important area of ongoing research.
In addition, advanced vapour compression cycles – currently under demonstration – have improved design by integrating refrigerant control systems, sensors, renewable energy sources and combining the technology with others (membranes, evaporative cooling). In addition, they operate witth low GWP refrigerants.
Automated controls also enable the exploitation of cross-service synergies, such as recovering waste heat from cooling to heat water or, in the case of considerable loads, integrating the recovered heat into district energy networks.
Deployment of climate-friendly cooling equipment requires not only high-efficiency equipment, but also the use of natural refrigerants, or no refrigerant at all. The report found innovations are also emerging towards refrigerant free units or solid state cooling units.
“Renewable cooling technologies are also garnering more attention, particularly in countries where cooling demand is growing rapidly and the national electricity grid needs to be protected from overload,” the report said.
“District cooling can be an affordbale solution to providing electricity grid flexibility in warm areas with high building density and free source/waste heat availability.”
Building codes
Around 80 countries had building energy codes in force in 2021, the EIA report said.
Codes are principally lacking in emerging and developing markets – typically in regions with high cooling needs. More than 80 countries already have minimum energy performance standards (MEPS) for air conditioners, with additional standards currently under development in over 20 countries. MEPS now cover more than 85 per cent of global space cooling energy consumption in the residential sector, up from two-thirds in 2010.
These standards vary considerably from one country to another,
“As the first measure to reduce the amount of energy needed for space cooling, proper building design can improve natural ventilation, thermal insulation, reduce air leakage and improve internal and external shading by incorporating advanced envelope components such as reflective roofs, as well as passive-building design elements, integrated storage and renewables,” the report said.
Building energy codes have proven to be a highly effective instrument to improve building energy performance. Behavioural measures (for instance, higher air-conditioning set points) and awareness measures also play a critical role in reducing space cooling consumption.
“ Urban design, in particular the integration of green and blue areas, also contributes to reducing cooling demand.”
The EIA said countries can support R&D efforts to foster innovative air conditioning technologies. New business models, such as cooling as a service, are needed to reduce the upfront costs of the most-efficient technologies and accelerate their deployment.
“With proper support, manufacturers can deliver smarter and more responsive air-conditioning options (e.g. units with smart chips) to also provide electricity balancing services to the electricity grid,” the report said.