Yes you can if you have the tool, knowledge, and of course the freon. YouTube has instructional videos to help you.
$100
Not by yourself, and not a window unit at all.
The refrigerant (freon) in any air conditioner should last the life of the unit. If not, you have a leak.
if you had the gauges,the know how,and the epa card to purchase freon.Then sure.
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.
No easy way of doing this. These units do not come with service valves.
actually this is a pet project of mine to produce a Freon-less A/C unit
Never. A properly operating AC unit will have no leaks, thus never need recharging.
The installer if the unit is still under warranty, which is usually one year after the installation. Otherwise the home owner.
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.
That sounds reasonable to me. I have in my home, a very large (22,000 BTU) through-the-wall air conditioner, designed to cool three large rooms. It uses 3.5 lbs of freon. A whole-house unit I can easily see using as much as 9 lbs.
To buy ac Freon you need to be certified and to add ac Freon to central air conditioning unit is risky.The air conditioner filters are normally located in return duct grills or in the air handler. Read how to change air conditioner filters.