Written The AC's power consumption depends on its star ratingListed below is the BEE star rating chartThe EER is calculated by the following formulaEER= amount of heat removed in W/ power consumed in WEvery 1 ton of cooling power (commonly known as heat removed by a 1 ton AC in one hour) is also expressed as 3516 wattsHence 1.0 ton AC will be rated at at least 3516 WattsA 5 star AC will have a EER of at least 3.5 according to BEE guidelinesHence input power wattage = Heat removed (watts) / 3.5Hence input wattage rating = 3516/3.5 = 1005 watts (5 star rating)Ratings for various Star ratings1 star - 1302 Watts2 star - 1212 Watts3 star - 1134 Watts4 star - 1065 WattsThus if 5 star split ac with 1 tons cooling capacity is rated for 3516 Watts, it will consume 1005 watts per hour1000 watts per hour is one unit of power consumedThus the AC will consume 1.005 units per hourBut compressor runs only 70 percent of the time during normal use. Hence adjusted power consumption will be 0.7 units per hourFour 8 hours usage per day it will consume 5.6 units (Approximately)On a monthly basis it will consume around 168 units (5 Star 1 ton AC)You can apply the above calculation for any AC - but only for non inverter compressorsCool...

Be the coolest !!!Written There is no definitive answer as it depends on a lot of variable factors. Indoor - outdoor temperature differential, kind of insulation of walls, number of windows and glass / curtains, outdoor humidity, number of people in the room, how often the door/s to the room are opened just to name a few. You can consider the figures quoted by the manufacturer as conservative as the minimum.how to dispose of old ac unitWritten Approximately 1200 watt of electricity.so accordingly multiplying it with your running hour you can calculate total units .best split unit air conditionersWritten Ranges from 0.99 (5 star) to 1.47 (1 Star) Units per Hour, with different specifications.electric furnace ac unitWritten On average AC will consume 1205 Watts per hour when Temperature is set at 25 degree CelsiusThe AC's power consumption depends on its star ratingListed below is the BEE star rating chartThe EER is calculated by the following formulaCOP = amount of heat removed in W/ power consumed in WEvery 1 ton of cooling power (commonly known as heat removed by a 1 ton AC in one hour) is also expressed as 3500 wattsHence 1.5 ton AC will be rated

at at least 5275 WattsWe can calculate input wattage using the above chart for various star ratingsThus if 5 star split ac with 1.5 tons cooling capacity is rated for 1507 watts it will consume 1507 watts per hour1000 watts per hour is one unit of power consumedThus the AC will consume 1.507 units per hourIn real life usage AC compressor will run for only 70 percent of time normally. But since you are using Ac @ 4 degree Celsius above recommended Temperature the compressor will run 80 percent of the timeThus on average AC will consume only 1205 WattsThe AC will consume 1.205 Units in an HourAssuming eight hours usage per day it will consume 9.64 units per dayAC power consumption in a month (30 days) will be 290 units approximately14 percent increased power as compared to usage @ 24 degree CelsiusYou can apply the above calculation for any AC - but only for non inverter ACsIdeally the Ac must be run at around 25 degree CelsiusPlease refer to below links for more info on energy efficiencyVivek Ravindranath's answer to How can I use the air conditioner in an environment-friendly manner?

Air conditioners have evolved a lot over the years. The models produced in the year 2000 used 30 to 50 percent less energy than the ones that were manufactured in 1970s. Nowadays, the newer models are designed with better energy efficiency features. Before going into the details about the energy consumed by air conditioners, it is essential to know how the device works. Air conditioners work on the same principle as a refrigerator, where circuit of pipes and a pump form the cooling system. The room is cooled by the indoor cold evaporator coil, and the hot coil expels the heat outside the rooms. The cost of running an AC depends on various factors like: Energy Consumption of Air Conditioner Presently, AC models with 1 to 5 energy star rating are available in the market. A 5-star model saves maximum energy, and the 1-star rated model consumes more electricity. A regular AC used for residential purpose has a 5,500 - 14, 000 BTU/hour range. If the climate is hot, it is recommended to purchase an AC with higher start rating.

The ratings are awarded by BEE (Bureau of Energy-Efficiency). The electricity charges are based on the units of consumption (1 unit = 1 kWh) For example: 10 numbers of 100 W bulbs when switched on for 10 hours will consume: Similarly, An AC with 2,000 Watt power input if operated for about 8 hours per day will consume: Energy Efficiency Ratio for AC: You can lower the energy consumption by following these simple steps: Use Portable or Window Units: If you are not cooling the entire house, then use a portable AC to cool only the area where the cooling is required. They use 50% less energy as compared to a centralized air unit to cool the same space. It is advisable to go for a programmable thermostat. This helps you to switch the AC on and off as per the program set by you. It avoids excessive utilization of power and saves almost 15 percent on electricity bills. Although your air conditioner requires only basic maintenance, it should be kept clean and free from dust, particularly if you live in areas where there is a lot of pollution.  

The seeds or pollen may stick to the air filters, which will make the device work harder, thereby decreasing the energy efficiency. Make sure that the space in your house, where the ducts run through without air conditioning are properly insulated. This will help in keeping the air cool. Although we rely on ACs to keep the area cool, having a few fans around is helpful too. Fans are useful in circulating the air around. Moreover, the energy consumed by fans is lesser than an air conditioner unit. Therefore, it is always a great idea to have fans as a backup.Air conditioning is cool, but fans are cheap. When Willis Carrier invented the air conditioner in 1902, he sparked a national love affair with conditioned air that grows stronger every year. According to a decade of research conducted by a Florida state energy agency, only 1 percent to 2 percent of the population today would prefer to live without air conditioning. Of course, that’s just what people did for centuries. During the latter half of the 19th century, fans, particularly ceiling fans, were the creature-comfort technology of the era.

Once the air conditioner came along, though — along with initially cheap electricity to run it — the populous was hooked. Today fans continue to provide home cooling -- and without sapping the large amounts of electricity needed to run air conditioners. The High Cost of Chilling Out Air conditioners, even the most efficient, newest models, occupy the top of the home energy consumption pyramid. In a typical household on a normal summer day, no other single appliance consumes as much electricity as the air conditioner or comes close. During cooling season, fully one-quarter of the utility bill goes to fund the sole function of keeping cool. An average single family residence will consume just over 2,800 kilowatt-hours of electricity per year to run air conditioners. In the United States, air conditioning alone consumes 5 percent of all electricity generated in the nation and costs homeowners $11 billion per year. Truth In Numbers At the average national electricity cost of 12 cents per kilowatt-hour, a typical window air conditioner running 12 hours per day uses 335 kilowatt-hours per month and costs around $40 monthly to operate.

A 2.5-ton common residential central air unit uses around 1,300 kilowatt-hours per month and costs just over $150. Now consider the humble fan. A midsize ceiling fan set on high for 12 hours per day costs just over a penny per hour in electricity or just about $3.50 per month. A higher revolutions-per-minute box fan adds just about $4.40 to your monthly electrical bill. In many homes, the cost of powering either fan for half of each day can be offset by the savings gained from simply switching incandescent light bulbs to compact fluorescent bulbs. Circulation Vs. Cooling Consuming mass amounts of electricity to run an air conditioning compressor isn’t required for home comfort -- up to a point. Moving air in the home with a fan can keep occupants acceptably comfortable at temperatures up to 85 degrees. The effect of increased air circulation on a hot day is based on the same principle as chill factor on a cold, windy winter day. Fans augment the action of both convection and evaporation to cool humans.

Moving air dissipates the heat of metabolism, convecting it away from the body. Meanwhile, the evaporative effect as perspiration dries cools the skin. The Combo Approach Fans and air conditioners are not necessarily mutually exclusive in today’s home. In fact, using a ceiling fan in conjunction with an air conditioner has a place in a strategy for both energy conservation and home comfort. Although a thermometer will show that the room temperature is not actually decreased by the action of a ceiling fan, the perception of coolness for human occupants is increased. A room that “feels” cooler to occupants allows you to nudge the air conditioning thermostat slightly higher, saving more electricity than the energy-stingy fan consumes and reducing net utility costs. Just be sure to turn off the fan when the room is unoccupied. References New York Times: Bringing In the Big FansMichael Bluejay: Saving Electricity 101U.S. Department of Energy: Air Conditioning Photo Credits Polka Dot Images/Polka Dot/Getty Images Suggest a Correction