I tend to agree with Ertan. Buying a new aircon or getting the current one serviced will be the best if you want to remain cool (!)

OK if you want to use this as a means of learning remote controls then you can go ahead.

First I doubt if the remote uses RF as a link - most of the ones I see use IR. Here again it is not a problem to do it with 8052 - but the problem is to know what standard protocols they use for the commands - like the RC5 that is used for TVs and Audio equipments.

So getting that information is important rather than building the same with 8052 once you know that. Or else you have to change both Rx and Tx units and decide on your own protocol.

For RF remotes you get the small chip-on-board transmitters and receivers ( matched pairs ) that operate on FM and are kind of ready to use. Check out any source like RS components catalog. Or do a search on Google for "Radio controlled remotes " - will be fun or atleast it was when I did it the first time. First decide on the transmitter end keypad decoding and read it from the reciver end - maybe with a wired link. And once you are happy with the results, then it is a metter of using the RF as a link instead of the wired link. The readymade unjts that I mentioned above just modulate the FM carrier with your data input.

Raghu