Honda Prelude 1990 Online Reference Owner's Manual page 109

System Maintenance
Run your air conditioner at least once a week for about ten minutes,
even during the off season, to lubricate the seals and the inside of
the compressor and, to verify that the system is functional.
If the air conditioner is not cooling properly, it may indicate an
undercharged system. Have your dealer check the system for leaks,
then evacuate and charge the system with refrigerant 12.
Charging quantity:
850-950 g(30.1-33.6 oz)
CAUTION:
Prolonged use of an undercharged system may damage the
compressor.