Google heating and air, followed by the city and state you live in. This should bring up several ac companies in your area.
You can find a Freon leak in a home Ac unit by using a leak detector. These instruments are capable of detecting trace amounts of Freon and pinpoint leaks.
There is no set amount required by different AC units, it may be listed on the mfg. tag on the unit but that is just the factory charge and may be different for lines over 25 feet. The freon in older home units is R-22 and isn't avilable to non licensed people. If your unit needs freon, it leaked out. someone should find the leak and give a quote on fixing it. If you are not licensed, it is illegal to sell you freon for private use. It is best to pay someone to take care of this task and then you will be more certain of having a working air conditioner. They have the training and tools to do a proper job.
4 pounds
It a word, no. Without a leak, the freon level in your unit should stay the same for years and years.
Yes you can if you have the tool, knowledge, and of course the freon. Youtube has instructional videos to help you.
$100
Depends on the size of the unit and when it was built. Modern A/C units contain no Freon (R12). It was banned in 1996. Call a home A/C professional.
it depends on the size of the unit and how many pounds of freon it takes r-22 is going for 10 to 15 dollars a pound
If your window unit is low on freon, the unit will not cool sufficiently or blast out warm air. To find out what kind of gas is used in this type of unit, look on the rear panel for a label which should specify what type is required.
Either the t stat is way out of calibration or it is not level.
A little oil will escape with the refrigerant. Look for a blackish oily stain on the tubing. A service tech might use electronic sniffing equipment.
No easy way of doing this. These units do not come with service valves.