A:AnswerAn inch or two is more than enough. This machine has a large air filter at the bottom that extracts heat and prevents high temperatures during working time. In addition, it has an insulating material inside that prevents the external surface from heating up. The equipment also has thermal sensors that constantly monitor the temperature and in case of any failure it is shown on the screen by means of an error code. It is important to read the manufacturer's specifications to avoid equipment damage, fire, or injury. In my opinion it is quite safe.