About 10,000 public housing households face eviction unless they fix their air-conditioners. Housing Department assistant director Lee King-chi said unauthorised installation of air-conditioners could threaten public safety. 'Those air-cons installed outside premises are especially dangerous. The frames can easily rot because of the weather. It's lucky there have been no fatal injuries already,' he said. The Housing Department estimates half of the 660,000 public housing families have installed air-conditioners. Of these, at least 30 per cent do not follow official regulations on installation.