I’ll admit that I don’t think much about maintaining my air conditioning unit.  That is, until it doesn’t work.  Just a few months after my first daughter was born, our air conditioner quit working during a particularly warm week in May.  With temperatures climbing into the upper 80’s, we were living in a poorly insulated house at the time.  We had just past the 1 year warranty period on the unit, so we were out $800 bucks for the repair.  I’m not sure that an annual tuneup would have prevented my unit from going out, but regular maintenance of your A/C unit will help it run more efficiently and save you money in the process.  

Without regular maintenance an air conditioner looses about 5% of it’s original efficiency for each year of operation.  The good news is that you can recover most of that lost efficiency through regular maintenance. Studies show that with regular tune-ups a unit will maintain up to 95% of it’s original efficiency. This means that the cost of an annual tune-up is recovered very quickly in savings on your monthly electric bill and reduced repair costs. A properly serviced air conditioner will also do a better job of dehumidifying your home.

Below is a checklist of items your HVAC technician should do during an annual visit.

1. Cleaning the condensing unit coils, checking the amp draw of the compressor, 
2. Oiling the fan motors, 
3. Checking that belts are well adjusted, 
4. Checking the system operating pressures and temperatures against the manufacturers specifications. One of the most important items to check is the coolant level (commonly know as Freon) in the air conditioner. A system that is only 10% low on coolant will cost about 20% more to operate! The Air Conditioning Contractors of America (ACCA) recommends that coolant levels be checked every year.

There are some things in addition to yearly tune-ups that you can do to help ensure a high level of comfort and proper system operation. First, buy good filters and change them regularly. Next, keep bushes and other materials away from the outside unit of your air conditioner. Another good idea is to avoid closing supply air outlets in your house. In almost all cases, closing supply outlets is harmful to the operation of the overall system.

Source:  http://www.greenbuilder.com/general/articles/AAS.AC.html

Photo credit:  geri-jean