Few things to know abt Eco-Inverter Air Conditioner

After surviving last year super hot and humid summer in Kolkata, I finally decided to go for Air Conditioners which are day by day becoming important equipment at homes today. With increasing demand and widely available EMI schemes, it has mooted variety of brands and products availability in the market. Some of the brands that can be found in the market are Mitsubishi, Hitachi, Daikin, Panasonic, Sharp, LG, Carrier, O-General, Toshiba along with several indigenous brands like Voltas and BlueStar. Every brand offers non-Inverter air conditioners with variety of functions such as antibacterial air purifiers, anti-odour, energy efficiency where as the best offers of them offers newer and advanced technology like Inverter air conditioners.

In India room air conditioners are generally available from 0.8 to 2.5 Ton range denoting their cooling capacity class. Internationally the air conditioners are rated as 0.5, 1.0, 1.5, 2.0, 2.5 and 3 HP (Horse Power).

Below is a chart of the cooling capacity class:

0.5 HP = 6,000 BTU/Hr = 0.5 Ton
1.0 HP = 9,000 BTU/Hr = 0.8 Ton
1.5 HP = 12,000 BTU/Hr = 1.0 Ton
2.0 HP = 17,100 BTU/Hr = 1.5 Ton
2.5 HP = 24,000 BTU/Hr = 2.0 Ton
……..

As a consumer it became very difficult for me to determine which air conditioners to go with, I mean Inverters or non-Inverters, the one that provides the best bang for the buck and is also extremely energy efficient?

One way was to go the non-Inverter route where air conditioners are rated from 1 ~ 5 stars in terms of efficiency by Bureau of Energy Efficiency (BEE), a statutory body under the Indian Union Ministry of Power. Affixing BEE star label has been made mandatory by BEE to all the manufactures for the benefit of general public, showing the level of energy consumption by the non-Inverter air conditioner both in terms of absolute values as well as equivalent number of stars varying from one to five, in accordance with BEE stipulation. The greater the number of stars on the label, higher the appliance energy efficiency and lower its electricity consumption. While selecting the non-Inverter air conditioner refer to the BEE Star Rated Label affixed is must.

Energy Efficiency of Air Conditioner

Efficiency of an air conditioner is normally measured as Energy Efficiency Ratio (EER), which is the ratio of the cooling output, measured in British thermal units (BTU) per hour, to the power input (in Watts, and includes all inputs to compressor, fan motors and controls) to operate AC at standard rating conditions. This means a higher the EER, the more efficient the air conditioner is.

At times, EER is defined a little differently. The cooling capacity instead of being denoted in Btu/Hr is also denoted in Watts (1 BTU/Hr = 0.293 Watts). Thus EER is represented as Watts/ Watts or as a number without any units and will be assumed from now on.

EER Calculation of non-Inverter Air Conditioner

Non-Inverter Model: Hitachi i-Clean (RAU518ITDA)
Tonnage: 1.5 Ton
Star Rating: 5
Rated Cooling Capacity: 5274 watts
Total Power Drawn: 1524 watts
Rated EER: 5274/1524 = 3.46 

So the higher the EER number better is its efficiency and more costly it’s going to be, due to the use of more advanced technology.

BEE Chart of star ratings applicable to air conditioners for 2012 ~ 2013

1 Star -> 2.5 to 2.69 EER
2 Star -> 2.7 to 2.89 EER
3 Star -> 2.9 to 3.09 EER
4 Star -> 3.1 to 3.29 EER
5 Star -> 3.3 and upwards EER

And for 2014 ~ 2015

1 Star -> 2.7 to 2.89 EER
2 Star -> 2.9 to 3.09 EER
3 Star -> 3.1 to 3.29 EER
4 Star -> 3.3 to 3.49 EER
5 Star -> 3.5 and upwards EER

Lets assume someone buys a 5 star rated non-Inverter air conditioner in 2011 with COP of 3.1. By 2012 the same AC becomes a 4-star since 5-star requirement is 3.3 and by 2014 the same AC becomes a 3-star since 5-star now requires 3.5. By 2016 the same AC becomes a 2-star since 5-star now requires 3.7. So we find EER star rating of non-Inverter air conditioners to be an ever moving target and its star rating is respective to the year a particular model was released. This is very important to keep in mind while going for non-Inverter air conditioners.

The other way was to go for Inverter Air Conditioners which are sophisticated piece of equipment and expensive.

At the start up of an air conditioners operation, powerful cooling is required to reach the set temperature. After the set temperature is reached, less cooling is required to maintain it. A conventional non-Inverter air conditioner can only operate at a constant speed which is too powerful to maintain the set temperature. Thus, in attempting to achieve this, non-Inverter air conditioners switches the compressor ON and OFF repeatedly. This results in wider temperature fluctuations leading to wasteful consumption of electrical energy. 

The Inverter air conditioners on the other hand have a full-output operation mode to operate at maximum capacity as soon as they start thus reaching the targeted temperature faster than non-Inverter air conditioners and then drastically reduce energy consumption when the set temperature is achieved by going into energy-saving operation mode and varies the rotational speed of the compressor along with the indoor and outdoor fan motors for optimum performance at all times. This provides a highly precise method of maintaining the set temperature and drastically reduces wasteful cooling operation and energy consumption. 

Advantages of Inverter Air Conditioners

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Information from in-built sensors of both the indoor and outdoor units measuring temperature and humidity are processed at over 4000 times per second by Inverter air conditioners brain i.e. Digital Micro-computer Module which then maintains targeted room temperature and humidity by constantly controlling the voltage, current and frequency send to the compressors having highly energy efficient DC motor using magnetic force to operate the compressor rather than conventional AC motor used in non-Inverters in conjunction with the electronic pulse linear expansion valve to precisely control coolant pressure for more efficient heat exchange. High quality DC motors are also used in the indoor and outdoor fan units instead of AC motors to save energy, all being controlled by the same electronic digital micro-computer module.

'The Brain' of an Inverter Air Conditioner (Digital Micro-computer Module)



One has to understand that technology comes at a price. The hard earned money one pays for Inverter air conditioners are put in using much better quality components which never came with non-Inverters, reaping their benefits in terms performance and efficiency with significant reduction in power consumption. Also Inverter air conditioners produce no humidity when adjusting room temperature. This is very important since it is the moisture removed from the room which actually produces the feeling of cooling. If the air conditioners can effectively remove enough moisture from the room it will produce a feeling of comfort. 

'The Brain' of Inverter Air Conditioners are generally located on the Outdoor Units and their heatsinks are cooled by the ODU fan



Since I plan for extended use on a daily basis, I went for Inverter ones over cheaper non-Inverters. One will be astounded to learn in Japan almost all air conditioners are Inverter ones where as in India the same Japanese air conditioner companies sell normal non-Inverter 5 star rated air conditioners at same price of Inverter air conditioners since very few people know about the real benefits they offer in terms of cooling performance, efficiency and low power consumption under part load conditions. Thus they garner fat profit margins by selling 2~5 star rated age old technology.

Dokka Seethamma : Guest Is God': The Hospitality of a Hindu Saint

Guest Is God': The Hospitality of a Hindu Saint

The story of a holy woman who sacrificed her life's dream--and her dying wish--in order to serve the poor.

Considered a saint during her own life, Dokka Sitamma (1841-1909 C.E.) spent years feeding the poor and sick in her Indian village. After her death, the holy woman was lauded throughout India as "Apara Annapurna"- an incarnation of the goddess Annapurna. 

Everyone in Andhra Pradesh knew Dokka Sitamma, and everyone had an opinion about the elderly widow.

To the superstitious, Sitamma was an omen of bad luck because she, like all widows, was responsible for the death of her husband. To those blinded by caste and custom, she was an impudent old woman for refusing to remain confined to her house as a Brahmin widow should. But to the destitute and the devout, Sitamma was mercy personified, for she unfailingly fed the hungry.

With no children of her own to care for, and a heart overflowing with motherly love, Sitamma adopted the poor as her sons and daughters. "This illiterate moron is doing great harm by inviting those of a lower station into her home," sniffed the orthodox Brahmins, and when their condemnation failed to deter her, they took to humiliating her. Though the calumnies and threats and loneliness stung her, in the end they were little to one whose heart sung of compassion and love.

"Come in! Come in! I have just finished cooking and was hoping that you would join me for dinner tonight." Sitamma would quickly say this to those who came to her in need, thus sparing them the humiliation of having to beg for food.

Because of the chicanery of some unscrupulous neighbors who despised her ministry and prized her fertile fields, she found her large holdings reduced year after year until she was left with a small plot of land. A famine came and still Sitamma never turned away those in need, somehow managing to make her shrinking supplies feed a growing stream of hungry souls. And even when she had little to eat, she remained grateful for the opportunity to serve, for it gave her joy and feeding the poor was her chosen path to salvation.

One night after working in the kitchen for many hours, Sitamma thought: `I have served four decades and now my body has become worn out. I am nearing the end of my life. It is time for me to go to Varanasi. There I may pass away in peace with the Lord's name on my lips.'

For the last few years, Sitamma had dreamed of going to the holy city, for to die there was to be assured of liberation. Every time she set out, however, a desperate arrival or a traveling pilgrim prevented her from leaving. So she would return to her cooking and chanting, putting aside the only desire she had for herself, a desire that daily grew more powerful. But tonight she knew that the hours of her life were few and that only a handful of tomorrows remained.

When morning came, Sitamma gave away her last few possessions so as to bring her charitable works to a close. She hired a bullock cart for the first leg of her journey and set out for Varanasi. Though every rut and rock in the road jarred her old bones, and the sun was unmercifully hot, Sitamma was filled with a happiness that increased with each passing mile, for every turn of the bullock carts' wheels brought her nearer to the end of her earthly sojourn.

At eventide, Sitamma and the bullock-cart driver took shelter in a free roadside inn for traveling pilgrims. The hard day of travel weighed on her and she wearily lay down on a bed of rags. As she began to fall asleep, she was awakened by the cries of young children in the next room.

"I know that you haven't eaten today, but we don't have any food to give you, my love," she heard a father's voice consoling his daughter.

"Can't you ask for some? I'm hungry and my stomach hurts."

"It's not fit for us to beg. It would be better to starve. But don't worry. Tomorrow we will go to the home of Sitamma. She never sends away those who are hungry."

"Why is Sitamma the only one we can ask?"

"Because she treats her guests with respect and never expects anything in return for her charity."

Once the family had fallen asleep, Sitamma began to stir. "Get up, get up!" she whispered to the snoring cart driver. "We must leave right away!"

"What is the rush? If you have waited for 40 years to go Varanasi, you can surely wait one more day," the driver sleepily said. "We can't travel at night anyway. The road is filled with bandits and wild animals."

"I cannot wait." Sitamma firmly replied.

"Grandmother, do you want to die in a ditch tonight or die in Varanasi in a week?"

"Get up this instant! I have paid you to drive me and we are leaving!" And with that, the two travelers stole into the night.

With the first rays of dawn, the starving family awoke and set out eagerly in the direction of Sitamma's village, unaware that the one they were looking for had been lying but a few feet away.

The family traveled the same rough and wild road as Sitamma, the whole way the children crying from hunger, their mother and father struggling to soothe them despite their own wretched condition. By evening they reached Sitamma's village and after a few inquiries found the dirt path that led to her home.

Seeing the darkened little house, the father despaired: `Is that a candle light in the window or is it the reflection of the moon? Do I hear the clanging of a pot or is that the sound of a cowbell?'

The mother feared, `She's not home. If she is, will she receive us? Have we come all this way for my children to die of hunger.'

Before the father could knock on the door and end the family's suspense, it swung open. The fragrant smell of dal and rice greeted them.

"Come in! Come in! I have just finished cooking and was hoping that you would join me tonight," Sitamma cheerfully said.

If they had not tried to conceal their tears of gratitude, the family might have observed that Sitamma's sari was frayed and sullied from the dust of the road. If they were not so fatigued, the family might have noticed that Sitamma was trembling with exhaustion from having spent the night being bounced and bruised in the bullock cart and then having to cook this meal. If they were not so hungry, the family might have seen that Sitamma's cupboard and garden were bare, and that she had taken the shame of begging upon herself from her neighbors so that they could eat.

Sitamma did not die in Varanasi. It was reported, however, that upon her death, a great light burst forth from the roof of her house and shot up into the heavens.