On June 10, 2025, Union Minister of Power and Housing and Urban Affairs Manohar Lal Khattar announced that India will soon introduce new regulations to standardise air conditioning temperatures nationwide, limiting how low or high they can go. The temperature standardisation for ACs will be set between 20 degrees Celsius and 28°C. The upcoming regulation will not only apply to home air conditioners but also to those in commercial spaces and vehicles.
Currently, air conditioners can be set as low as 18°C or even 16°C. Once implemented, the new provision will restrict the minimum temperature to 20°C. The main aim is to reduce electricity consumption.
Pankaj Agarwal, a senior official from the power and housing ministry, told newspaper The Times of India that air conditioners use about 50 gigawatts of electricity, which is around 20 per cent of the country’s total power demand.
The Bureau of Energy Efficiency (BEE) estimates that each additional degree in AC temperature can yield approximately 6 per cent energy savings; hence even a 2°C increase could potentially save around 12 per cent electricity in some cases.
This is particularly relevant during the summer months, when demand is at its highest and can lead to electricity blackouts during heatwaves. The nation’s power use hit a record 250 gigawatts last summer, and it could rise to 270 gigawatts this year. So far, heavy rains in May have kept demand lower, but with heatwaves returning in June, usage has spiked again — with peak power demand reaching 241 GW on June 9, 2025.
Changing user behaviour can greatly boost energy efficiency efforts. However, monitoring and regulating temperature settings for every individual household, office, hotel room, or commercial vehicle is a difficult task and presents significant challenges in implementation and enforcement. Hence, defining limits within the device itself can help keep temperatures in check.
Imagine entering a cab, hotel, or office where the temperature is uncomfortably cold, often due to management setting the thermostat to the lowest possible level to ‘play it safe’. This new regulation seeks to correct such practices.
While changing user behaviour is essential, setting predefined temperature limits within the devices can ensure that temperatures remain within a reasonable, energy-efficient range without relying solely on user discretion.
According to the adaptive thermal comfort theory, people’s thermal comfort is not solely determined by fixed temperature levels, but by their ability to adapt to a wider range of thermal conditions, influenced by factors like environment and past experiences. This means indoor comfort levels can vary based on outdoor temperatures, building design, and individual behaviour. In essence, this means that people adjust to the temperatures they are exposed to over a period of time.
In a country like India, where summer temperatures frequently rise above 40°C and even can exceed 45°C, residents naturally adapt to higher ambient heat. The National Building Code of India, which includes sections based on adaptive comfort models, suggests that in most Indian cities, air-conditioned indoor temperatures between 24°C and 27°C are suitable for nearly 90 per cent of occupants.
Research even suggests that temperatures of 28°C can be acceptable when combined with adequate air circulation, such as a ceiling fan. Setting a minimum of 20°C, therefore, needs reconsideration. Lowering the AC setting to 20°C is often unnecessarily cold, uncomfortable, and leads to excessive energy use without added benefits in comfort or productivity.
The guidelines will apply to future AC stock, but there is a need to address existing systems. In hotels, offices, commercial complexes and public buildings, regulating air conditioning temperatures can lead to significant energy savings. In 2018, BEE issued recommendation guidelines stating that the ideal indoor temperature range is 24-25°C. Instead of recommendations, such guidelines need to be brought in as mandates. These spaces typically have centralised cooling systems, making them ideal cases for temperature regulation.
Other countries have already taken similar steps. Spain, Italy, South Korea and China have successfully implemented mandatory temperature regulations, which have proven effective and yielded positive results in energy conservation.
In 2022, Spain required offices, shops and government buildings to maintain cooling at no lower than 27°C to reduce reliance on imported fuel. Similarly, South Korea’s Seoul Metropolitan Government mandated a 26°C minimum during summer. Italy’s ‘Operation Thermostat’ in 2022 enforced a 27°C minimum in public buildings. China’s 2018 guidelines recommend not setting ACs below 26°C to conserve energy and promote environmentally responsible behaviour.
Tightening the lower operational limits of air conditioning can also prompt building operators to carry out minor retrofits to improve energy efficiency. These may include simple shading devices to reduce heat ingress, films over glass to cut solar heat gain, or sealing off points where air leakage occurs, essentially wasting energy.
Uncontrolled inward air leakage through cracks and crevices in the external surfaces of buildings and around windows and doors due to pressure differences is a key contributor to energy wastage in air-conditioned buildings.
The Energy Conservation and Sustainability Building Code 2024 also mandates that, to ensure better energy efficiency and minimise air leakage, all parts of a building envelope — except in naturally ventilated buildings or spaces — must be properly sealed, caulked, gasketed or weather-stripped. This includes sealing joints around windows, skylights and doors; gaps between walls, foundations, roofs and wall panels; openings for utility penetrations; site-built windows and doors and building assemblies used as ducts or plenums.
Additionally, exhaust fans must be fitted with a sealing device such as a self-closing damper, and operable windows should be designed to prevent air leaks between the frame and shutters.
Prolonged exposure to low air conditioning temperatures can reduce a person’s natural heat tolerance and make it harder for the body to adapt to rising outdoor temperatures. When someone remains in a cold indoor environment for extended periods and then suddenly steps out into the sweltering summer heat, their body may experience thermal shock due to the abrupt temperature shift. This rapid change, often a difference of 15-20°C, can cause the body’s temperature to rise quickly within 10-15 minutes.
Although the body’s natural cooling system maintains internal temperature between 36.3°C and 37.3°C by sweating and increasing blood flow to the skin, this mechanism can become overwhelmed by such a sudden and large temperature difference. As a result, thermal shock can lead to various health issues, especially in children, such as sneezing, dry eyes and skin, respiratory infections and muscle spasms. Maintaining moderate indoor temperatures can help the body adjust more gradually to outdoor heat, reducing these health risks and supporting overall well-being.
Hence, a higher low-operational point for air-conditioned buildings will reduce the temperature difference a person experiences when moving between conditioned and unconditioned spaces, thereby lowering the risk of thermal shock.
The government has previously conducted awareness campaigns to educate people about the energy-saving potential of maintaining air conditioners at 24°C. These need to be revived to encourage a change in user behaviour. Similar measures have already been taken by other countries.
Japan launched the “Cool Biz” campaign in 2005 to cut electricity use and carbon dioxide (CO₂) emissions from air conditioning. It encouraged offices to set air conditioners at 28°C and promoted lighter clothing instead of formal wear. After the 2011 earthquake, it evolved into the “Super Cool Biz” campaign to further reduce energy use. These efforts led to an estimated reduction of 1.56 million tonnes of CO₂, according to Japan’s Ministry of the Environment.
In Singapore, the ‘Go 25’ movement urged households, businesses and buildings to set their air conditioning at 25°C or higher. The government-backed initiative is part of the broader “Go Green SG” campaign, aimed at cutting energy usage, supporting sustainable cooling practices and strengthening long-term climate resilience. In the United States, the Department of Energy under a campaign called Flex Alert urged citizens to voluntarily conserve electricity by setting air conditioners to around 25°C when at home.
A similar campaign in India can promote responsible and sustainable cooling habits. Public outreach through television, digital platforms and community programmes can effectively change user behaviour. Highlighting the environmental benefits, health impacts and long-term cost savings can further motivate adoption.