What is a Window Air Conditioner?
It comes in the form of a single box. It is easy to fit on a window or wall frame. This costs lesser than Split AC system, but is slightly noisier than Split AC. Not much scope for aesthetics – internally and externally for the building. They are cheapest last resort solutions mainly.

How does a window air conditioner work?
Window air conditioners work on exactly the same principles as a refrigerator or dehumidifier. They have a cooling system that refrigerates the air entering the unit. The moisture in the air condenses on the cold coils and drips into the bottom tray of the air conditioner. The warm air in the room is drawn over the evaporator coil, which collect heat. The heat is conducted into a refrigerant gas. The gas is then circulated to the condensing coils on the back of the unit where it is dissipated to the outside.

Are window air conditioners expensive to run?
Yes. They use a considerable amount of electricity. A standard single room air conditioner will cost approximately 7-12 cents per hour to operate. If you run the air conditioner for 8 hours per day it will cost you approximately $24.40 per month at $.10 per kilowatt hour.

Why use a window air conditioner?
Window AC's have many benefits such as reduced space requirements, better efficiency and ease of use. Plus, they work in almost all environments: dry or wet. They cool effectively and keep moisture levels down too. Many options offer adjustable thermostats for cooling control, quiet operation for nightttime cooling, and most models include either an Energy Star rating or economy setting to save you money on your energy bill.

What if Water leaking from the rear of a window air conditioner?
Water leaking from the rear of a window air conditioner is not unusual, especially when humidity levels are high. If water is being dumped outside then the machine is operating properly. Its primary job is to remove moisture from inside the home and dispose of it outside. If in an apartment building then a bucket under the rear of the air conditioner can stop it from leaking onto your downstairs neighbours.

Should I buy a Split AC or a Window AC?
It is possible that the circuit breaker for the compressor unit is thrown (switched to "off"). Go outside to the compressor unit and follow the big cable up to the circuit breaker panel on the wall. If it is off, throw the switch to "on." If that is not the problem, something is probably wrong with the compressor unit. Turn off the breaker panel and call a repairman.

To what distance will a Window AC or Split AC throw air?
A normal Window AC or split AC will throw air upto 15 feet. However, special Split units are available to throw air upto 30 feet.

What is the ideal location for a Window AC?
At a height of 5 feet behind you. Ensure that the AC air from the airconditioner does not hit you directly.

What part of the house or apartment would be most efficient for placement of a window unit air conditioner?
shade side of largest room And on the upper level if you want cool two floors. But in that case, "most efficient" would require two units, one upstairs and one downstairs. In fact, greater efficiencies (your question did ask about efficiency, not initial cost or practicality) can be gained with multiple smaller units in various rooms, than with one big unit.

What causes the compressor of a window air conditioner to come on for a few seconds then shut off then back on in a short period of time no mater what the temperature setting?
Could be very dirty and the lack of air flow is tripping the limit, could be the comp is seizing. This situation could be due to the cold air output gets sucked back immediately into the unit causing the thermostat to cut out. Make sure that the sponge seal between the outlet air and the return air is in place, it is just behind the front cover.

What causes a window air conditioner to freeze?
You either have a dirty air filter or the unit is leaking refrigerant and is undercharged. The first answer is the best bet, but also make sure the out side coils are not covered up with vines.

Why does a one-year-old window unit have a small amount of red oily substance showing up in the drain pan?
It may be lubricating oil leaking from the compressor. Have the unit serviced before any futher use.

Which Air conditioner is preferable – Window or Split AC?
Both types of ACs offer different features and advantages to the users.

My bed room doesn’t have the window provision; is it possible to use a window AC?
You can easily make a small opening in the wall and install the AC. Make sure that the supporting metal brackets, interior angles, etc. are structurally fastened to the building envelope and are strong enough for the size and weight of the AC unit.