Roel, I think it would all depend on the size of this heater and how much meat was being cooked. As stated in NFPA 96 4.1.1.”Cooking equipment used in processes producing smoke or grease-laden vapours shall be equipped with an exhaust system that complies with all the equipment and performance requirements of this standard”. It also states 4.1.1.1 ” Cooking equipment that has been listed in accordance with ANSI/ULC 197 or an equivalent standard for reduced emissions shall not be required to be provided with an exhaust system. Due to the fact it is not open and is closed makes it somewhat of a dilema. I would check to see if there are any labels on this equipment. You have to determine the amount of vapours escaping once the doors are open. I definitely would ask for a K extinguisher available. Good luck and please keep us posted with the outcome.