Should I buy a split air conditioner or a window air conditioner? This is a question that many air conditioner buyers thinks of, before making a purchase. And we keep getting this question quite regularly at Bijli Bachao. It is not just about split or window, but about a whole lot of things that should be considered while buying an air conditioner. Air Conditioner is an appliance that can significantly blow up your electricity bills and utmost care should be taken while buying one. With this article we would try to provide you some guidelines on things to take care of before making a purchase decision for an air conditioner. Please note an air conditioner bought once will go on for next 10 years at least and thus it is important to make a right decision.
Split vs Window
Buying a split or a window is something that worries a lot of people. But from energy efficiency perspective there is no preferred choice. Both split and window can be equally efficient. What matters is EER or Energy Efficiency Ratio of the air conditioner. EER represents the amount of cooling an air conditioner can provide per watt of electricity it consumes. Bureau of Energy Efficiency rates air conditioners on its star rating based on EER of air conditioners. Higher the EER of air conditioner higher the star rating it will have. So a 5 star rated air conditioner provides more cooling per watt of electricity used.
Both split and window can have high EER ratios. But it is observed that Split air conditioners have more number of models in BEE 5 star rating as compared to Window air conditioners (check our research on air conditioners at this link: link). So if you are looking for high efficiency air conditioners then split air conditioners can provide you more options.
The main difference between the two is that window air conditioner has a single unit whereas split air conditioner has 2 units (indoor and outdoor). Split is lot more silent in operation as compared to window and looks aesthetically pleasing, but is relatively more complicated to install and requires more space as compared to window air conditioner.
Right sizing an air conditioner is very important
The most important thing that one should figure out before buying any air conditioner is the right size of the air conditioner. This can significantly impact your electricity bills. And from size we mean tonnage of air conditioner. Every room that is cooled has a certain amount of heat that depends on:
- Size of the room. This determines the amount of air in the room that needs to be cooled.
- Number of people in the room. Every human being emits heat and air conditioner needs to cool it.
- Amount of stuff kept in the room. Please note every item kept in the room will get cooled from the air conditioner, so lesser the stuff, lesser the electricity air conditioner will consume.
- Number of electrical appliances in the room (most electrical appliances emit heat, especially lights). Incandescent light bulbs can increase cooling load.
- Windows in the room. More the windows, more is the heat coming from outside. Well-insulated windows reduce cooling load. Check our insulation section for more details: http://www.bijlibachao.com/Save-Electricity/Insulation/
- Walls facing the sun can increase cooling load. Touch your walls and windows to check if they are hot or not and using the tips in insulation section to prevent heating of the room.
The amount of heat in a room and that coming in from walls and windows is represented in BTU (or British Thermal Unit). BTU is sum of heat from all the above-mentioned sources.
Every air conditioner has a cooling capacity, which is represented in BTU/hr. It is the BTUs of heat that it can remove in an hour. If the heat coming in the room (in BTUs) is more than the heat that air conditioner can remove, then the air conditioner will not be as effective. Thus an undersized air conditioner cannot remove heat effectively and the compressor of the air conditioner will continue running all the time thereby consuming more electricity.
With an undersized air conditioner, the compressor will keep running all the time and the temperature will not reach the desired level. They will not only be ineffective in cooling, but will also consume more electricity.
An oversized air conditioner will not only over cool your room but also will be ineffective in removing the humidity in a room. So if you set AC to 25, the extra energy that the compressor provides will cool it beyond 25. It will have shorter run cycles but all air conditioners are designed for optimum run cycles and if the cycle is shorter than that then the efficiency is reduced (source: energy star).
So every air conditioner is designed to run at optimum efficiency only if it is used as per the right size. So always size the air conditioner properly. You can use the calculator available at this link before buying an air conditioner: http://www.lg.com/in/support/ac-tonnage-calculator.
If you are not sure about what size to buy, you can always buy an inverter technology air conditioner, as it adjusts to the size and requirements of the room automatically, and thus makes optimum electricity consumption. To check more about inverter ac see our article: Air Conditioners with Inverter technology can help save electricity.
Look for the right options in the air conditioner
In a previous article (Various modes for running air conditioners and their impact on electricity bill) we discussed about various modes of air conditioners and their impact on electricity consumption. It is very important to figure out if the air conditioner has all the modes as per your requirement. If you live in humid area, a dry mode is important. Any air conditioner with energy saver mode and features should be preferred.
Star rating is for real
BEE Star rating of air conditioner does matter a lot. Any air conditioner would consume anywhere between 1-2 units per hour of usage based on tonnage, efficiency and size. Which means if it is used for 10 hours per day, it can consume about 10-20 units in a day or 300-600 units a month (for 10 hours of use daily). At an average rate of Rs 6-7 per unit (you can check your per unit rate using our calculator: Online Electricity Bill Calculator – For all states in India) it can be close to Rs 1800-4000 per month. If your usage is high then the yearly cost of an air conditioner can go very high. In case of high usage, incremental cost of buying a higher star rated air conditioner can easily be recovered in a few years. Please note that the air conditioner will work for at least 10 years and the electricity prices are on a rise. Buying an efficient one while buying a new air conditioner can prevent a lot of heartburn for you in future.
It is important to make a right decision while buying an air conditioner, as it is a long-term utility for you. Do not let lucrative deals, discounts and persuasion by a sales person impact your decision to buy an efficient appliance. A wrong decision on an appliance like air conditioner can significantly impact your electricity bills. We are trying to work out a calculator that can help you choose the right air conditioner for you and hope to release it soon. Till that time you can check the list of top ten most efficient air conditioners at: Top Ten Air Conditioners in India by electricity consumption and size.
Here is a short video for tips to buy the best air conditioner in India
Check this link to see Top Ten Air Conditioners in India for Electricity Savings: http://wp.me/p4hAhQ-4I
FAQs on AC Buying:
Size of an AC is a very important aspect that one should evaluate before buying an AC. Oversized AC can significantly increase electricity consumption while undersized may not cool properly. You can use the calculator given on the bottom of this page to evaluate your needs: AC Calculator Link
The choice of star rating depends on the hours that you use your AC for and the electricity tariffs in your area. Typically we do not recommend going for anything less than BEE 3 star rating. However your exact need can be evaluated using the calculator given on the bottom of this page: AC Calculator Link. You can input your daily and yearly consumption values and the calculator will suggest you the right star rating based on your use. It will also provide you approximate amount of money that you will pay for electricity if you choose a particular star rated AC. This can help you evaluate the benefit of a specific star rating.
Inverter AC is the latest energy efficient (electricity saving) technology which is available in the market. It has the potential to save 30-60% electricity depending on your choice of the model. You can read more about Inverter ACs on this link: Air Conditioners with Inverter technology can help save electricity
BEE star rating was not available for inverter technology till the year 2015. But BEE has introduced star rating for inverter ACs in 2016. It is not a mandatory rating so it is not necessary for all manufacturers to get their AC model rated, but some have started using the same as many consumers believe in star ratings. The ratings will become mandatory in 3 years.
However, the rating standards for inverter ACs and fixed speed ACs are different. A BEE 3 star rated inverter AC will still be more efficient than a BEE 5 star rated fixed speed AC. But BEE 2 or 1 star rated inverter AC may not be as efficient as BEE 5 star rated fixed speed AC.
It all depends on your usage of AC and tariffs. If your usage is high and tariff is also high, then it will be much better to go for inverter AC. For e.g. in places like Mumbai where tariff is already Rs 11-12 per unit for last slab, even a decent nightly use for 3 summer months would be better off with an inverter AC than a regular AC. But then it depends on your usage and tariff.
Most dealers are less equipped or trained on the technicalities and evaluation of ACs. Many a times they are not updated with latest information. Dealer training is one of the biggest challenges for energy efficiency. We would suggest that you use the calculator given on the bottom of this page to evaluate your needs: AC Calculator Link . You can see the numbers on right side of the calculator to see how much you will be paying for electricity if you go for a specific star rating.
Not really. In fact bigger tonnage ACs consume much more electricity. And they overcool. So if you set temperature to 25 degrees in thermostat, it will make the room cooler than that (more on this link: Oversizing ACs). A right sized AC is far better than oversized or undersized AC.
It is always better to right size an AC because oversizing increases electricity consumption and undersizing does not cool well. However undersizing can save electricity. Ideally sizing is done to assure that AC can cool well up to 25 degree centigrade. If you slightly undersize then it may cool only up to 27-28. And will save electricity as well. But then it cannot be equal to buying 1 ton AC when you need 1.5 ton (as that will be gross undersizing). It can be done if you buy 1 ton instead of 1.2 ton. Also sizing is done considering peak summer temperature in mind. If your usage is mostly at night (when temperature is much less) then you may consider buying an undersized AC as well.
Another situation where you can think of undersizing is if you plan to set up an AC in your living room which is huge. For a huge space cooling requirement is much high and if you try to rightsize the AC then you would need a huge AC. In such case you can undersize the AC and setup one close to the seating area (area where cool air is required). This will make sure that the seating area remains comfortable and you do not end up putting up a huge AC that can cost you a lot on electricity bills.
This is the most common question we get which is most difficult to answer. We have tried to answer this on our link: Which is the best brand to buy?. A lot of it is perception based on experience. However these are the brands that you will most likely find in our recommendations: Daikin, Hitachi, Sharp, Panasonic, General, Mitsubishi, Carrier, Blue Star, LG, Voltas, Samsung, Godrej. Not that other companies are bad, but these are top most. The only brands that we do not recommend to buy are the brands that used to be retailers and now have started selling ACs under their own brand names.
This is again a very common question and extremely difficult to answer. Most of our analysis is purely technical based on the specifications of various models. Service levels depends on local service stations of various brands. It varies from city to city. Even within the city the service levels may vary. The best people to provide you suggestions regarding this are your local dealers and people who have used a particular brand.
EER or Energy Efficiency Ratio is a representation of how well an AC uses electricity. Higher the number, better the use of electricity by an AC. By no means is it a representation of actual electricity consumption. A 1 ton AC and 1.5 ton AC can have same EER but their electricity consumption will differ. And that is because 1.5 ton AC has to do more work than 1 ton AC. Same EER just means that they are equally good at using a unit of electricity.
However inverter technology is slightly different. Although usage of EER is not the right representation of an Inverter AC but many manufacturers do put the same for inverter ACs as well. If you want to do a right comparison then divide the EER of inverter AC by 0.8 (assuming it is just 20% more efficient than fixed speed AC .. however it can be more). So if you want to compare two ACs inverter and non inverter both of EER 3.3 then divide 3.3 by 0.8 to get comparison EER of inverter AC. Please note 20% is just pessimistic efficiency level for inverter AC. It can be more.
FAQ no 11 above gives a good answer for this. In most cases even a lower EER of Inverter AC will be better than higher EER of BEE 5 star rated fixed speed AC. But still we recommend that you go for an inverter AC of EER 3.2 and above (at least).
To explain this, first let us explain types of condensers that are available in the market:
a) PFC (Parallel Flow Condenser) or Multi Jet which is all aluminium. It is highly energy efficient but if it fails it need to be replaced. Although they come with anti corrosion coatings, but still fixing the small multi channels in case of clogging is difficult. Manufacturers specifically mention PFC or Multi Jet. PFC will look like this:
b) Coil and Fin type condenser, where coils are copper and fins are aluminium. Even in this the one with anti corrosion coating (also known as blue fin/gold fin) is better. Most brands have such type of condenser. You can ask the dealer to open the outdoor and indoor unit for you and you can check if it looks blue or not. Blue fin is the best for corrosion protection. Blue fin will look like this:
Now it is not that copper cannot corrode. What is important is to select a condenser that has anti corrosion coating. So ask for a condenser with copper pipes and pre coated aluminium fin. Even if it is aluminium then it should be coated with corrosion protection. When an AC spec says that it has pre-coated aluminium fins it is a coil and fin type condenser which is copper.
Window ACs have efficiency levels 1 level lower than split ACs. So a BEE 5 star rated window AC is equivalent in efficiency to BEE 4 star rated split AC. The reason for the same is that manufacturers have started reducing number of window AC models and have started solely focussing on split ACs. Most of the new technology is available only in split ACs. In fact only BEE 5 star rating is available only in 1.5 ton window ACs. 1 and 2 ton window ACs do not have BEE 5 star rated options. And even the 5 star rated 1.5 ton window ACs are equivalent to BEE 4 star rated split ACs. So our recommendation is to go for a split AC. However, if you are really tight on budget and you need 1.5 ton AC then you can go for BEE 5 star rated window AC. But if you need 1 or 2 ton AC then better go with split AC.
R410A, R32 & R290 are the most environment friendly refrigerants in ACs. R410A is non flammable, R32 is mildly flammable and R290 is highly flammable refrigerant. If you are planning to buy an AC with refrigerant that is flammable then we would recommend you to go for a good brand as better brands do take care of safety related issues with the refrigerants. For safe choice you can go with R410A. Daikin uses R32 but it is a very reliable brand.
Depends a lot on who is the seller. These days online websites are marketplaces which means they are not the direct sellers. One of the biggest issue with online buying is to get right warranty and support from the brand. If the seller is an authorised seller, you will get warranty as well as support. If seller is not authorised then the same becomes extremely difficult. Although portals do claim to sell original products, but it is extremely important to check seller reviews and confirm if you will get warranty on product or not.
Our suggestions are mostly based on energy efficiency of the model and the top brands (as listed in FAQ 9). We do not recommend any specific brand because everyone has a different experience with a brand. Also the service levels of various brands differs at various locations (as stated in FAQ 10). In fact many people who visit review websites like mouthshut get negative reviews of almost every brand. The reason for the same is that it is practically impossible for any brand to satisfy each and every consumer. The best thing that we can suggest you is to look at the list of top brands above, choose the brand that you like (or get a good feedback on from local dealers), then select the most efficient model of your tonnage requirement from this list: http://bit.ly/OpE1JR. If you do not find that model in the market, then just go for the model with highest EER in your preferred brand and suggested star rating.
We have listed the power consumption of almost all ACs available in market on this link: http://bit.ly/OpE1JR. However, the number listed on this page is wattage of AC. To convert it into units per hour, you will have to divide the wattage by 1000 (so a 1450 W would convert to 1.45 units). Another point to note is that the actual consumption will not be just wattage divided by 1000. It will depend on temperature setting as well as various other factors. However, to get a ballpark number just multiple the unit per hour value that you have got in previous step by 0.8 (for fixed speed AC assuming compressor runs for 80% of the time) and 0.64 (for inverter AC assuming inverter AC to be 20% more efficient than fixed speed AC). So if an AC is rated at 1450 W, then if it is fixed speed AC then its power consumption would be (1450/1000) * 0.8 = 1.16 units per hour and if it is inverter AC then it would be (1450/1000) * 0.64 = 0.928 units per hour. Please note that these are just approximate values and power consumption of AC depends on several factors listed on this page: Things that impact electricity consumption in air conditioners
The calculation by the calculator is absolutely correct as per our knowledge. We have put in all the knowledge that we have about AC sizing in this calculator. We will provide you the same number even if you ask us personally.
If there are huge voltage fluctuations in your area then you must go for a stabiliser for your AC. It is more important if you go for a fixed speed AC. Inverter ACs can handle voltage fluctuations much better, however they have electronics that are prone to damage in case there is power surge (sudden increase of current as it happens in case of short circuits). So Inverter ACs should be protected from surges. A surge guard should be good enough for inverter ACs. If you still feel that you should put a stabiliser for inverter AC then you should go for one with surge protection feature.
Inverter ACs save much more electricity as compared to BEE 3 star rated ACs. They can save electricity even if you use AC for 1 hour. However what is important is to analyse how much money you can save by using inverter AC as compared to how much extra do you pay for buying it. The calculator on this link: AC Calculator Link can help you figure out the yearly electricity cost difference that you will incur if you go for a BEE 3 star rated AC as compared to Inverter AC. This can help you make a decision to go for right type of AC.
As we have mentioned in FAQ 13 above, Blue Fin and Gold Fin both are copper. Please refer to that FAQ to understand more about technology. You can also refer to this link: Air Conditioners: Copper Coil vs Aluminium Coil
The reason air filters are required in an AC is because ACs are meant to cool closed spaces. ACs do not take air from outside (unlike air cooler), they just cool the indoor air and circulate it. If the room (where AC is installed) remains closed for a long time, the quality of air deteriorates. It can result in accumulation of bacteria. Air Filters help improve the quality of air. However, it is important only if the room remains closed for a long time. It may be helpful even if you use it for 8-10 hours at night. Various brands have different kind of filters. It is more of a safety feature. Not absolutely necessary but good to have. You can choose the one that you feel you need.
It is absolutely fine if you go for an aluminium condenser if your area is not hot and humid. Biggest problem with aluminium condenser is corrosion. If the environment is not corrosive then it will not fail. And in fact Aluminium Condensers have high energy efficiency as well. Brands l like Samsung that have aluminium PFC condenser provide good enough corrosion protection for the condensers as well. In fact Samsung gives warranty on condenser too. People in many places have been using ACs with PFC condenser since quite some time and they have not failed. Their chance of failure is high only if the environment is corrosive, otherwise they can be a great choice.
Our data collection is based on data from BEE and models listed by brands on their website. We also try to check if the models are available in online stores. But it is possible that those models are not available in physical stores. Stores typically keep only those models that sell more (not necessarily energy efficient). You can try contacting authorised dealers of the brand and if you do not find any model with them, then the best bet is to go for the most energy efficient model that you get from your selected brands. We try updating our database every 2-3 months but it is possible that some of the models that we have collected are either very new or even discontinued ones.
Sizing an Air Conditioner involves taking a lot of environmental factors into consideration. A whole lot of things impact sizing as we have listed on our article Things that impact electricity consumption in air conditioners. As far as residential setups are concerned, things that are kept in a room and environment can be standardised (as we have done for the calculator) or can be assumed. But it is extremely difficult to assume or standardise a commercial setup or shop. A shop may be filled with a lot of products, or a commercial establishment can have a whole lot of people seated in it or equipments installed in it. Everything impacts electricity consumption. Thus it is very hard for us to evaluate or calculate requirement for a shop or commercial establishment. In fact the calculator that we have may not work perfectly for shop/commercial establishments. It is always better to get technical evaluation done by engineers from a reputed brand. If you want to install AC for your shop/commercial establishment, the best thing to do is to call a dealer of a brand that you want to go for and ask them to send an engineer to evaluate.
Air Flow is an important aspect for cooling a room. High Air Flow can result in cooling a larger area and even faster cooling. Air Flow depends on fan speed. In general if you keep high fan speed the air circulation would be more and thus air will cool faster. Increase air circulation also results in a farther reach of cooling. So if you have a choice then of for AC with higher air flow rate.