IBM Mainframe

An air conditioner is a device which cools the indoor air by removing heat and depositing it outside. It circulates indoor air and does not bring outside air into the home. A filter in the return air duct is required to keep the air conditioner clean and operating efficiently. Window A/C units are used to cool homes. But nowadays buying a Split Air conditioner is a fashion. AC units are rated in BTU?s of cooling capacity. As a rough rule of thumb, 1,000 BTU will cool 40 to 50 square feet of space with few windows and well insulated. An 8,000 BTU window unit should cool 300 to 400 square feet of space. In this guide, we will see the various features and options available in air conditioner systems.

1. What type you Need, Split or Window?

You may already have a budget in mind as to how much you would like to spend. Window Air Conditioners range from Rs. 9,900 to Rs. 45,000. Split Air Conditioners range from Rs. 15,000 to Rs. 2,75,000. The size and features affect the price.

And the decision also based on the facilities in your room where you are going to install. if you have enough facility to install a Window AC, then it's more affordable.

2. If it's Split AC, Where to Mount it?

DUCTABLE SPLIT:

A piping concealed within the walls or ceiling through which the cold air from the outdoor unit is sent indoors. Very good for large offices. Very good cooling capacity.

CEILING MOUNTED:

Are mounted on the ceiling. (Also known as Cassette Type Split Air Conditioners). Cools the room uniformly, useful if you don't have space for a wall mounted or a floor mounted air conditioner.

FLOOR MOUNTED:

Are placed on the floor. (Also known as Tower or Vertical Split Air Conditioners). Generally used when you do not have a wall, to mount a wall mounted unit or when you cannot use a ceiling mounted split air conditioner.

WALL MOUNTED:

The indoor unit is mounted on the wall. (Also known as High Wall Mounted. The indoor unit is mounted on the wall. Mainly used for rooms where the ducts cannot be concealed, and is generally preferred for small rooms where the air can be cooled uniformly.

Ductable split air conditioners are generally used where you can conceal the ducts and the indoor unit. They are generally preferred in big offices, shopping malls, etc.

Non-Ductables are used when you cannot conceal the ducts. Wall Mounted Air Conditioners are mainly used for rooms where the ducts cannot be concealed, and is generally preferred for small rooms where the air can be cooled uniformly. Floor Mounted Air Conditioners are generally used when you do not have a wall to mount a wall mounted unit or when you cannot use a ceiling mounted split air conditioner. The Floor Mounted split air conditioners have a good air throw so that the entire room gets cooled uniformly. Since ceiling mounted split air conditioners are sleek, they are generally placed in the centre of a hall especially if you want the cool air to come from the centre of the room and cool the room uniformly. Ceiling-Wall mounted air conditioners ensure automatic direction control, where the cool air is evenly distributed throughout the room. These ACs also have adjustable flaps that ensure distribution of air in all directions.

3. How Much TONs I needed?

The cooling capacity defines the price of an air conditioner. Most air conditioners are rated in BTU per hour (British Thermal Unit) or by tonnage. One ton is equal to 12,000 BTU per hour. It would be wise to analyze the exact unit size that you would need for yourself before accepting your dealer's estimates.

The cooling capacity that you need would depend on a number of factors:

The size of the room: The cooling capacity required is proportional to the area of the room you wish to cool.

Number of people normally present in the room: The cooling capacity of an air conditioner also depends on the number of people present in the room. The more the number of people present, the higher will be the capacity required

Exposure of the room to sunlight: Direct exposure of any of the walls of the room to sunlight, would lead to higher requirement of cooling capacity.

Proximity of the room to kitchen: If the room is nearer to the kitchen the cooling capacity required would be higher.

Now that you know what are the factors that affect the cooling capacity, you are ready to get into calculating the cooling capacity of the window air conditioner. Just follow these simple steps to arrive at the required tonnage of your window air conditioner. Here goes?.

Divide the square feet area of your room by 600 to arrive at the basic tonnage capacity required.

Add 0.5 tonnes for every 10 people occupying the room at the same time.

Similarly add 0.5 tonnes for every 1500 watts of appliances or lighting present in the room (A computer would consume about 300 watts and a regular bulb, 40 to 60 watts).

Always round off on the higher side However, this calculation is very subjective and each manufacturer has his own calculations for measuring required tonnage. Very often manufacturers' calculations suggest a number that is very high and your own discretion is required when you actually decide to buy. 

4. Which type of Compressor?

The compressor is the air conditioner's most important component and is often called "the heart of the refrigeration system" . It helps in the cooling process, by circulating the refrigerant through all the refrigeration parts. The compressors used in smaller capacity Air conditioners are of "hermetic" (fully sealed) type.

There are 3 types of compressors - reciprocating, rotary and scroll. A window air conditioner will be factory fitted with one of the first two types of compressors. Split Air conditioners may have any one of the three types of compressor.

Reciprocating Compressor - It compresses the air by sliding the piston over the cylinder. Air conditioners fitted with a reciprocating compressor are generally less expensive and not as efficient and silent as the ones fitted with a rotary compressor. The Reciprocating compressor uses a connecting rod or scotch yoke mechanism to convert the rotary motion of motor in to reciprocating motion of the piston, which slides in a cylinder and handles the refrigerant gas. It has internal springs for low vibration and noise. Due to suction gas cooling, the motor temperature is low. They are generally less expensive and are not as power efficient and silent as rotary compressors.

Rotary Compressor - This is a superior type of a compressor over the conventional reciprocating type. It compresses air by centrifugal action of high-speed impeller in a confined space. This method reduces the loss in pressure of the refrigerator gas. Rotary compressors are more efficient and silent. The Rotary compressor uses a rolling piston (or) lobe moving in a cylinder to circulate the gas. This technology, though dominant in Asian market for close to 3 decades due to its low cost, is new to India. These have press fitted construction internally and have to be suitably applied to have low vibration and noise. Rotary compressors are silent and generate fewer vibrations as compared to reciprocating compressors.

Scroll Compressor- (Only for Split AC) Scroll compressors have a wide operating voltage, economical running and low sound and vibration as compared to reciprocating and rotary compressors. The Scroll compressor is the latest technology product and is imported. This uses a set of involutes called scroll flanks which work in an orbiting motion to handle the gas.

Rotary compressors are silent and generate lower vibrations as compared to reciprocating compressors. Reciprocating compressors are generally less expensive and not as power efficient and silent as the ones fitted with a rotary compressor. Rotary compressors are not repairable, when the failure occurs out of warranty period. Reciprocating compressors are repairable ? mostly by respective compressor manufacturers in India.

Scroll compressors have the highest efficiency and are very reliable. This is as such a better option to go for, if you are planning for a Split AC.

5. How much EER?

Energy Efficiency Ratio measures the cooling efficiency of the air conditioner compared to the power it consumes. It is the ratio of the cooling capacity in BTU/hr to its electricity consumption in watts. Models with a higher EER would be energy efficient and save on your electric bills but may be more expensive to buy. We consider an EER of 9 and above as a high EER. It is in your best interest to buy machines with higher EERs so that you can save on electricity consumption. 

6. What type of Filters?

A filter purifies the air that goes through the air conditioner. There are different types of filters that remove dust, germs, bacteria, odour, etc.

Anti-Fungus / Bacteria Filter:

The anti-fungus/bacteria filter cleans the air as it flows through the air conditioner and also removes the bacteria and fungus present in the air. A boon for people with respiratory problems and those who live in humid areas.

Deodourising Filter:

It absorbs smells and odour generating particles like tobacco smoke, etc from the room. Helps to keep the room odour-free thus keeping the air in it smelling fresh. If you smoke or live in an air-polluted area that is prone to dust, this would be an important feature to consider.

Electrostatic Filter:

It generates an electrostatic field and thus attracts and cleans the air by removing dust particles. It will extend the life of your air conditioner because the important parts, like the blower assembly, the cooling coil, and other inner parts will stay cleaner, operate more efficiently and last longer. Your family and you will enjoy breathing much healthier indoor air.

The body and chassis of air conditioners is prone to corrosion particularly since it is exposed to rain and humidity from the outside. However, if the body is made of galvanised steel or is powder coated it helps in protecting the unit from corrosion and extends the life of the body.

8. Auto Restart

If there is a power failure or if the air conditioner has been disconnected, you may have to reset and programme all the cooling functions and features that you originally had. An air conditioner with the auto restart facility starts automatically and restores the original settings when the power is restored. This feature is beneficial in areas where power supply is irregular.

9. Timer

Air conditioners may have a timer option, which allows the user to set the exact time when the air conditioner should switch off or switch on. This is useful to maintain the temperature in the room, particularly at night. It saves you the trouble of getting up to switch off the air conditioner when the room gets too cold. The timer lets you to set the air conditioner to begin cooling at any time, whether you are home or not.

10. Noise Level

Noise level is measured in decibels and is the level of sound generated by the appliance during operation. Air conditioners with rotary compressors generally make less noise than a reciprocating compressor. 60 decibels is the amount of sound created by two people in normal conversation. Therefore, a smaller decibel denotes less noise from your air conditioner.  

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