Air Conditioning - Frozen coil help

My AC condenser? the unit outside recently froze up on me and it worked ok all summer. A cool day came and my wife suggested turning the AC off and opening the windows. When I turned the AC back on again it did not cool the house well and I looked at the condenser? outside and the line was frost covered. The filters have been changed twice this year............I don't know if it needs freon or whatever. What do you think it is? Any thoughts would be appreciated.

Only two things will cause a freeze up. Low air flow & low refrigerant. If the indoor blower seems to be ok, I suggest you call a service person to check the refrigerant charge. If it is low, make sure the tech either injects dye or finds the leak while he/she is there.

If this is a split system and frost is forming on the outside lines at the condensor the evaporator inside the house is probably a solid block of ice I would not run this unit untill it has been professsionally serviced, you will loose the compressor very shortly. Low airflow across the evap or low charge level either one could cause your problem, proffesional service is recommended, your favorite tech may be in need of some cash, brand name beer and cigs cost money don't you know

The EXACT same thing happened to us in Atlanta. Meaning, why did it all of sudden develope the leak? We also had A/C on all summer - no problem. Then, after turning thermo up and opening windows, everything freezes.

Thanks to all..............I kind of suspected the refrigerant was low as it never was cold in the house throughout the summer. I have shut the system down and will call in the pros now. Appreciate the help.