A student, enters her house, exhausted, after a day out in the scorching sun.

She switches on the fan but the room only gets hotter, as the already warm air in the room is circulated. So, Prasanna decides to go in for an air conditioner.

Pleasant
"Though the climate is more pleasant now, I don't regret the purchase of the air conditioner. It is worth the buy, because it is a life-time investment," she says.

There are a lot of people out there trying to make up their minds about purchasing an air conditioner.

Why an AC?
Is an air conditioner a must-have or is it just for show-off? There are lots of people who have this query.

Even in a climate like Coimbatore's, air conditioners have become a necessity, because it has become difficult for people to tolerate even the three months of summer.

There are many reasons why people go in for air conditioners.

For example, Aravind is allergic to dust. He has air conditioned his house because he wants a dust-free atmosphere. For some others, it is the ambience of the house that matters a lot.

Temperature
The temperature, of course, plays a major role in determining the flow of your thoughts, feelings, creativity and imagination. Air conditioners, in addition to cooling down the room, help maintain a pleasant frame of mind.

If you are a person, who is careful about intellectual activity, air conditioners can assist you.

Types
Air conditioners come out in different types. It is up to you to choose from the wide range, each of which has its own features.

If you want to go along the trend, you can choose a split air conditioner, which is widely used. They can be fitted inside rooms and are noiseless.

They are priced at around Rs. 20,000. If what you want is a cost effective one, and if you don't mind the size and the appearance, window air conditioners are available at just Rs. 10,000.

As the name suggests, they can be fitted to the window. It is the old type, which is not as hushed as the latest ones. But ensure that your room has a provision for this.

Ductable air conditioners are those that are used to condition more than one room, in the same building.

Vertical standing air conditioners are used in bigger rooms, like conference halls, because of their higher throw speed and throw area.

Latest innovation
If you are in a mood to spend and if you can shell out Rs. 60,000 or more, there you have the latest innovation, the cassette type air conditioners.

It can be fitted to the ceiling. It throws air on four sides and sucks air in the middle, unlike the other types that throw air only at one side, sucking air on the other side.

It is very small and is not obviously seen. It is best suited for use in big halls like auditoriums.

Size of room
For a room with dimensions 10 x 10 x 10 (in feet), air conditioner of one tonne is used.

Air conditioner of 1.5 tonnes is used for a room of dimensions 10 x 14 x 10 (in feet); a room 16 x 22 needs a 2-ton air conditioner and it follows. So, check out the size of your room before planning for an air conditioner.

Maintenance
If you have already started using one, here are some ways by which your air conditioner can be well maintained.

The air conditioner has to be serviced once in three months.

It is better to get it done by the authorised dealer of the brand.

The room, which is air-conditioned, should have no gap, through which air can leak in.

Make sure to close the doors and windows of the room. This helps you get the best out of your air conditioner.

If you complain that your electricity bill goes too high because of air conditioners, try maintaining an average temperature. Why go for an air conditioner? This is the question for many of us.

"An air conditioner removes the moisture and makes the air fresh. In addition to cooling the room, air conditioners, condition the air, maintain it at the right humidity and prevent dust accumulation," says Ravishankar, Manager of Khaay-Zen Equipments. Some of us, who are very mindful of safeguarding the environment, could have heard that air conditioners damage the ozone layer.

Eco-friendly
When asked about it, Paramasivam who works in an air conditioner's shop explains, "the R12 gas which was used earlier is not used now. It has been replaced by the R22 gas, which is eco-friendly. So go ahead, air conditioners are not destructive."

Summer is the best time to buy an air conditioner.

"The sale of air conditioners reaches its peak from January to June. Some people buy air conditioners off-season to save on the cost," says Mr. Ravishankar.

If you have made up your mind on buying one, proceed.