The Union Ministry of Power has proposed a move to restrict the temperature range of new air conditioners (ACs) between 20°C and 28°C. 

Why Regulate AC Temperature?

• Energy Efficiency and Conservation: Every 1°C increase in AC temperature setting reduces energy use by ~6%.
  • If India adopts a 24°C default setting, it could save 20 billion units of electricity annually (BEE data).
  • With AC demand projected to create a 200 GW load by 2030, controlling temperature is crucial for grid stability and energy security.
• Public Health and Thermal Safety: Settings below 18°C can increase blood pressure, trigger asthma, and worsen respiratory infections.
  • Vulnerable groups — infants, the elderly, and those with chronic diseases — face higher risks in excessively cold environments.
  • Studies link low indoor temperatures with mental health issues, including anxiety and depression.
• Climate and Environmental Responsibility: The rise in AC usage is fueling energy demand and emissions.
  • Promoting a standardized temperature range supports India’s climate goals under the Paris Agreement.
  • Efficient cooling reduces the carbon footprint, helping India balance development with environmental sustainability.

How does AC work?

• An air conditioner (AC) works by transferring heat from inside a room to the outside, cooling the indoor air in the process. 
• It operates using a refrigeration cycle, most commonly the vapor-compression cycle, which involves a refrigerant circulating through a closed loop of components. 
• Heat Transfer: Heat naturally flows from warmer to cooler areas. An AC reverses this by using energy (electricity) to pump heat from a cooler indoor space to a warmer outdoor environment.

Key Steps in the Cooling Process (Vapour-Compression Cycle)

• Evaporation (Cooling the Room): The AC uses a special fluid called a refrigerant, which evaporates at low temperatures. The evaporator inside the room holds the refrigerant just below its boiling point.
  • A fan blows warm room air over the evaporator.
  • The refrigerant absorbs heat and boils, cooling the air.
  • Moisture in the air also condenses on the evaporator and drains away, helping dehumidify the room.
• Compression (Raising the Temperature): The now warm, gaseous refrigerant moves to the compressor, where it’s compressed 3–4 times, raising its temperature to around 90°C. 
  • This step uses most of the AC’s power.
• Condensation (Releasing Heat Outside): The hot, high-pressure gas flows into the condenser, located outside the room.
  • Here, it releases heat to the outside air and turns back into a liquid.
• Expansion (Cooling the Refrigerant): The liquid refrigerant passes through an expansion device, dropping its pressure and temperature.
  • It becomes a cold liquid-vapour mix, ready to absorb heat again as it returns to the evaporator.

Efficiency of the ACs

• The AC works best when the temperature difference between indoors and outdoors is moderate.
• The refrigerant is most efficient at specific temperatures — within this range, the AC cools better and uses less energy.
• Heat transfer is more efficient at higher temperatures, which is why condenser coils are placed outside.

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