All air
conditioning systems require some routine maintenance. The
amount of maintenance required depends on the type of system,
usage, and age of the equipment.
Maintenance may be required for legal reasons, to ensure
safety, to minimise breakdowns (which generally occur in
extreme conditions when you can least afford to be without air
conditioning), to minimise energy cost, maximise equipment
life and to minimise the impact on the environment.
As requirements vary so much I can't give any definite
statements, except that cleaning filters is vital (refer the
relevant section). However the following questions may help
you decide if the frequency of maintenance should be reviewed.