Airconditioning is so much more commonplace these days. We hardly see offices without it. Most restaurants are willing to spend money to boast of this facility. Shops and showrooms beckon more business, and command a superior image if they offer airconditioned comfort to their customers. More and more bedrooms boast of an airconditioner to stave off the oppressive heat of summer.

Don’t you wish you had the pleasure of airconditioning wherever youare? With the progressive reduction in excise duties, what was once part of the life styles of the rich has now fallen within the grasp of many of the middle class segment.

But wait. It is not as easy as 'lets aircondition our shop !'

Since it still is a fairly expensive price of equipment and the running cost of electricity is not cheap, it is necessary that one pauses and reflects on two major issues.

First, how much airconditioning does a room- whether an office cabin, a shop or showroom, a restaurant or any public area need ?

This is very important because too much capacity is an avoidable waste. And insufficient capacity is also waste anyway.

The capacity of the airconditioner is determined not just by the size of the room. Since an airconditioner primarily extracts the heat that exists or is being generated at the site, the length and breadth of the premises are only one of the factors. Every human being in the room generates "heat". Have you not noticed that your shop or restaurant is much colder when there are fewer customers ? It is because each customer adds to the load requirement. Each time the door opens, a bit of the outside warm air is drawn in.

Apart from people, the amount of light bulbs and electrical equipment add to the heat sources and the load requirement goes up.

The capacity calculations also must take into account the surroundings. Large window panes facing south and west radiate the outside heat of the sun into the room. A room on the top floor, under the hot open terrace will be warmer than one below an already airconditioned space.

Given below is a thumb rule for calculating the estimated airconditioning capacity.

The table and calculations are only indicative, based on 960F Outside/760F Inside DB conditions with proper insulation and shading.

Supplementary Factors:
For every extra person :            0.06 TR
For every extra 100 watt lighting : 0.05TR
For every extra 1 KW equipment load:0.4 TR
For floor above/below non A/C area : 0.06 TR/100 sq. ft.
Secondly, once required capacity is determined, decision over the type of equipment should follow.

Window Airconditioners : These are the lower end of the scale. Those most popular sizes are 1.0 and 1.5 tons. 0.5 and 0.75 ton capacity airconditioners are also available, suitable for very small rooms with a negligible heat load.
These can be easily fitted on window openings.

Split Airconditioners : The basic difference between a window and a split airconditioner is that the compressor of the latter is placed away from the room to be cooled and connected with the room cooling unit with insulated piping. The main advantage is that the noise levels are minimized. The sound you hear from a window airconditioner is 90% the humming of the compressor. Split airconditioners are recommended when noise levels do matter. For example if a jeweller’s showroom needs say 15 tons of air conditioning, and the showroom owner fits 10 nos of 1.5 ton window airconditioners, his customers may feel uncomfortable with the noisy background.

Within split airconditioners, there are three distinct types. These can be placed on walls, floors or ceiling. And they can generally be located according to the shape and requirement of the room- not necessarily constrained by the location of windows.

The VERTICOOL Split Airconditioner :
These are vertical indoor units that can be placed near the corners of the room so that the cold air can be evenly distributed.
Called VertiCool because of being ‘Vertical’ and 'Cooling', these machines are available in 3 Ton Capacities and are ideally suited for shops, showrooms. restaurants and ‘open plan’ offices and medium sized public areas.

The Ducted Splits: These are designed to give the ultimate comfort and style of "Central Airconditioning". The cost of installing these are comparatively higher because of the need to build false ceilings and ducting. These units are completely hidden away from view. Only the cooling comfort is felt.
Yet, to those who want to have the best , ducted units are the natural choice.

Packaged Airconditioners: These are in the same category as the ducted splits, except that the unit is placed in a separate room and the cooling is carried through ducting to the required areas. Packaged Airconditioners are available in 5, 7.5, 10 and 15 ton capacities and are recommended for medium offices, larger restaurants, shops and showrooms.

Central Airconditioning :
These are suitable for very large applications such as 5 star hotels, 0airports, huge offices of large corporations etc. The two most popular types of equipment used for such large central airconditioning plants are Centrifugal Chillers and Reciprocating Chillers.
Absorption Chillers are also useful in locations where steam or gas is readily available.

Ducted Splits, Packaged and Central Airconditioning systems allow for proper "air conditioning", i.e. inclusion and circulation of fresh air, exhaust of stale and contaminated air and should therefore be the ideal choice in public areas like shops, showrooms and offices where there are many people adding to the carbon dioxide content, and in hotels and restaurants where the need to expel odour and smell is very important.
Customers are advised to consult the airconditioning company's engineers on their authorized representatives before settling for one.