1. What is the objective of the BEE for recommending optimum temperature setting of air-conditioners?

Bureau of Energy Efficiency (BEE) has issued the guidelines to major commercial establishments with the objective of conserving energy through optimum temperature settings for the airconditioners, within the comfort zone or chart. It is estimated that changing the temperature from conventional 20-21 degree Celsius can result in approximately at 24 per cent of energy savings.

2. What is the estimated saving potential due to this initiative?

Overall potential for energy conservation through such measures is estimated to the tune of 20 billion units (worth Rs 10,000 crore) annually. If about half (50 per cent) the consumers adopt to such recommendations, this would result in about 10 billion units of electricity, which is equivalent to reduction of 8.2 million tonne of CO2 per year.

3. What does default setting at 24-degree C mean? Whether the consumers will be able to adjust their ACs to a lower temperature?

Default setting is the setting at which a machine comes from the factory. Therefore, when the machine is switched on then it will have a preset temperature of 24-degree C. However, a user can adjust or set the air-conditioner at a lower (or higher) temperature, as per her choice.

4. Why is it beneficial to preset the temperature of AC equipment at 24-degree C?

Normal human body temperature is between 36-37 degree C. It is generally observed that in large commercial establishments like hotels, airports and offices, the AC operating staff, try to set the lower temperature (around 18-21 degree C), believing that it indicates a better cooling performance of AC system. However, technically this is not true and the cooling action of compressor is same at other settings also. On the other hand, setting the temperature in the range of 18-21 degree C results into a very cool internal ambient conditions, which compels people to wear warm clothing leading to wastage of energy. As per the comfort chart, the temperatures upto 25-degree C are quite comfortable for human body, along with desired humidity and air movement values.

5. If there are more persons in the room, will it be possible to maintain comfort conditions?

The same temperature setting would enable AC equipment to provide sufficient cooling, even if there are more persons. The compressor will work slightly longer till such time equilibrium is reached.

6. What are the advantages of setting AC default temperature at 24-degree C?

It is estimated that by increase in temperature of room by 1 degree C, we can save about 6 per cent of electricity. Typically, room temperature is set between 20-21 degree C whereas, as per standard comfort conditions, ideal temperature is 24-25 degree C. Considering change from 20-degree C to 24-degree C, there is potential to increase at least 4 degrees C, which will lead to savings of about 24 per cent of electricity. Therefore, the users will be able to save significant amount of energy (and money) by running their air-conditioners at 24-degree C.

7. Which are the potential buildings or areas that BEE is targeting to implement the guidelines?

The guidelines have been recommended to the major commercial establishments such as airports, hotels, shopping malls, offices and government buildings (ministries and attached offices, state government and public-sector undertakings).

8. Is the advisory mandatory right now?

The advisory for the commercial establishments has been issued for voluntary adoption. The aim is to increase awareness and encourage consumers to adopt the guidelines. A public survey would be conducted after 4-6 months awareness campaign by the Ministry of Power/BEE.

9. Does setting the thermostat at 18-degree C cool the room faster than keeping it at 24-degree C?

No. The thermostat just checks the temperature of the air inside the room and stops the compressor when the temperature reaches the desired level. This means that the compressor will work longer if the temperature is set to a lower level, i.e. it will work more and use more electricity if temperature is set to 18-degree C than if it is set to 24-degree C. This is because it will take less time for air to reach to 24-degree C than 18-degree C, as the compressor is working with the same power or wattage.

10. Why is this move important for India?

BEE estimates that considering the current market trend, total connected load in India due to air-conditioning will be about 200 GW by 2030 and this may further increase as today only 6 per cent of households are using one or more air-conditioners. If the measures are followed by all consumers, India can save about 23 billion units of electricity. The total installed capacity of airconditioner is about 80 million TR, which will increase to about 250 million TR in 2030. 

(Source: PIB/Ministry of Power)