The most important thing is to know the size and place of installation before buying an air conditioner. A small bedroom with a large living room is different from a big house which has many rooms, so it’s necessary that you consider where you will be installing the air conditioner before purchasing it.

Another important point would be the energy consumption. There are many energy efficient models available in the market which consume less power and don’t heat up the environment. Also, some models come with a remote that helps reduce your electricity bills.

You can either choose between window or split ACs depending on the size of your room. Window air conditioners are cheap but take up more space. Split ACs are expensive but provide more coverage. You can also consider inverter ACs which automatically adjust the speed of cooling depending on how much you need it.

Once you install an air conditioner, make sure it is regularly checked by professional technicians for any problems. A good quality air conditioning system should last at least 8-10 years with proper maintenance.

Regular inspections of your air conditioner will allow technicians to detect early signs of problems and fix them before they become major problems, saving you money and time. Here are some steps you should take to ensure that your air conditioning system is always in good operating condition:

Regularly change the filters and clean the dust catcher. It will improve efficiency and durability of the machine.

Once a month turn on the fan for about 10 minutes to dry moisture in your humidifier so it won’t grow mold or mildew.

To keep mineral deposits from building up, add white vinegar during fill up instead of tap water (about one cup for every full tank).

When there’s a power failure, throw away water in the tank (It can be used again after you boil it).

When you leave for vacation make sure someone is responsible enough to turn ac off at set point before leaving home (or turn ac on if needed). If not, you could end up with hundreds of dollars in water damage when ac freezing up! You can use a thermostat or programmable time switch like this one.

Do not place a humidifier on carpet or rug – this will cause deterioration of surface and it can become moldy.

Keep pets away from the humidifier, especially when it’s on.

 It is recommended to descale the humidifier every 3-6 months (depending on water hardness). Fill the water tank with vinegar and let it work for 10 minutes, then rinse thoroughly with clear water and leave open to dry completely.

Do not touch hot surfaces – the exterior of your unit and its heating element can be very hot and may cause burns.

Do not add oils, perfumes or glycerin to the water tank.

Unplug the humidifier before you clean it!

Be careful not to spill water on the ac unit – this can damage it or cause an electrical shock.

If you have pets, keep them away from ac units because they will play with the fan and can injure themselves! They can also dig stuff under an ac unit causing problems with your ac system. Make sure the ac is off before you clean anything around it!

Keep ac units away from exterior walls of the house (at least 2 feet) – it should be more than 3 feet above the ground if possible. Basically, don’t put ac right next to any opening in your home!

Never let your ac unit run 24/7 (turn on and off according to need). This will seriously degrade ac performance and shorten its lifespan.

Make sure ac unit is always plugged into grounded circuit, otherwise it will cause ac fuse to blow out or ac breaker to trip! Keep ac fuses away from flammable objects so they won’t be damaged by fire.

In winter, place a unit on a heat resistant mat so it doesn’t melt anything under it (like carpet).

Learn more from https://en.wikipedia.org/wiki/Air_conditioning