Before you choose an air conditioner (AC), first thing you need to do is to understand your room in terms of average people using them at a time, electrical equipment, furniture & appliances that are part of the room. A living room will be occupied by more number of people on an average & will probably have more appliances that may comparatively more emit heat. So, you'll be better off with higher capacity AC in a similar sized living room than a bed room, which probably will be occupied with in the evening & night hours. 

Exposure to direct sunlight is also another important factor for air conditioning. If you plan to use AC in a room that is exposed to direct sunlight, then the AC will have to put in more effort. Also, ceilings that are exposed to direct sunlight heat more resulting in higher ambient temperature & thus require higher capacity AC.

Split and Window ACs
Residential air conditioners are widely available in 2 physical forms - split & window.

  • Split ACs are made up of two parts - outdoor unit & indoor unit. As the moving parts like compressor along with condenser are outside the room (outdoor unit) split ACs are more silent compared to window ACs.
  • While window ACs are great for smaller rooms, Split ACs have following advantages: quicker cooling, easier installation, lesser noise, more suitable for rooms with lesser ventilation, energy efficient operation & ease of service.
  • Considering these advantages, its recommended to opt for split AC unless space for installing outdoor unit is a constraint.

Non-Inverter & Inverter ACs
Split ACs are available with fixed speed compressors and variable speed compressors (widely known as inverter ACs). In fixed speed compressor or regular AC, the compressor is either off or on. When it is on, it works at full capacity and consumes full electricity it is designed to consume.

When the thermostat reaches the temperature level set in the AC, the compressor stops and the fan in AC continues to operate. When the thermostat senses that the temperature has increased, the compressor starts again. The variable speed compressors in InverterAC on theotherhandhasabilitytoworkon variable speed. Hence it can meet the fluctuation in power demands.

When inverter compressor needs more power; it gives it more power. When it needs less power, it gives less power. With this technology, the compressor isalwayson,butdraws less power or more power depending on the temperature of the incoming air and the level set in the thermostat. The speed and power of thecompressorisadjustedappropriately.

Average daily usage shouldgovernselectionofeither fixed speed compressor AC or Inverter AC. if you plan to use ACforshorterdurationapproximately 3 hrs a day, 4 to 5 months a year you can opt for fixed speed compressor AC. If you plan to use AC for more hours daily than this or throughout the year, you should then consider investing in inverter AC.



Copper & Aluminium PFC Condenser

The material used for condenser coils used in AC affects their efficiency, their ease of cleaning and maintenance. Two types of condenser coils are used inACs -copperandaluminium.

Pros and Cons of both these condensers are:

 It's important to look for corrosion protective coating applied on condenser and higher warranty on condenser.

AC Tonnage = Length X Width X Height in feet

For example, if a room is 10 feet in length; 8 feet wide and 10 feet high, then - 10 X 8 X 10 / 1000 = 0.8. Hence recommended AC would of 1 Ton capacity.

However, you also need to consider capacity increment of approximately 0.5 Tr if any of the following conditions are also applicable for the room:

  1. Room has more than 2 windows or a bigger / full-sized window
  2. The ambient temperature of exceeds 38 degree celcius
  3. The room is situated on or above 3rd floor
  4. The room is on top-most floor or terrace is directly above the room


  • Bureau of Energy Efficiency Ministry of Power - Government of India has started standards and labeling program with the objective of consumer an informed choice about the energy saving and thereby the cost saving potential of the marketed household and other equipment
  • This is expected to impact the energy savings in the medium and long run while at the same time it will position domestic industry to compete in such markets where norms for energy efficiency are mandatory.
The Energy Efficiency Ratio of a cooling device is the ratio of output cooling energy in Watt W to input electrical energy in Watt - W at a given operating point. EER is generally calculated at standard conditions as per Indian standard IS1391.
Star rating valid for split Air Conditioners Non-Inverter fixed speed compressor Valid from 01/01/2016 to 31/12/2017
The Indian Seasonal Energy Efficiency Ratio is the COP Co-efficient of performance or EER expressed in Watt hour/Watt hour. Instead of being evaluated at a single operating condition like EER, it represents the expected overall performance over time - in this case - for a typical year's weather as per Indian conditions. ISEER is an energy efficiency ratio that represents the expected overall performance for a typical year's weather as per Indian conditions.
The ISEER is thus calculated with the same indoor temperature, but over a range of outside temperatures 24 – 43 degree Celsius based on national weather data for 54 cities across India and is the BEE approved measure.

Note that, the Seasonal Energy Efficiency Ratio is calculated with the same indoor temperature but over a range of outside temperatures from 21-degree celsius - 35-degree celsius. It is used in European climate, not representative of Indian Climate and hence not the BEE approved the measure.





  • Refrigerant is a fluid, gas that runs through condenser coils & compressor of an AC & takes out heat from room and disposes it in the atmosphere. There are various types are refrigerants available and are being used in ACs basis of their thermodynamic properties.
  • The most common refrigerant in the past was a CFC like R-12. In the 1990s and 2000s, the CFCs were replaced with hydrochlorofluorocarbon and the most common HCFC refrigerant being R22. More than 50 percent of Air Conditioners in India still use HCFCs. However, HCFCs are just marginally better than CFCs as they contain chlorine, which is harmful for the environment. As per Indian Government’s plan, HCFCs will be phased out from India by the year 2030.
  • HFC refrigerants like R-410A and R32 are ozone friendly that is they don't deplete the ozone layer however they still have global warming potential. India has also embraced HFC phase-out under Montreal Protocol.
  • Hydrocarbons or HC refrigerants like R290 are the most environmental friendly refrigerants available as of now and are completely halogen free, have no ozone depletion potential and are lowest in terms of global warming potential.