A good friend of mine owns a Vrs that is over 3 years old but still within its 1 year used warranty. He went to use the climate control with A/C when the weather improved and no cold air.

A trip to the dealer and 1 A/C unit required.

So, what is the issue with the Octavia A/C unit as there seems to be a problem at about 3 years old.

Is it poor design or cheap unit?

Poor Design - very common

Lack of use I guess, never had an issue with 2005 Octavia which I sold in 2010 with 99K miles on it with the original compressor and fully functional air conditioning. It was left in Auto all the time, never used in Econ, so it was running pretty much the whole time the car was.

Aircon does not just cool air, its possible during winter to have heated air conditioned air. This is much drier and as such prevents the car steaming up when its cold and damp.