The system will require lube and it should be done in accordance with the manufacturers specifications you cannot have dampers especially spring activated thermal activation (mechanical trigger) ones running on dry slides, some of the auto units have motor controls outside of the unit and nothing penetrates into the vent part of the system. Hospitals usually use a food safe lube this type of lube can also be used on water systems. It won’t promote bacterial growth and gives off no smells, do not use old engine oil, any old grease or WD40 which is not actually a lube it’s water dispersant. The dampers are situated after the HEPA filters and these types of lube do promote bacterial growth and will contaminate your main theatres theatres will have to be done on planned shut downs due to the work carried out in there and restricted access, Your estates will sort this out and you will require deep cleaning of the theatres after the work with it being work on the HAVS system and opening the ceiling Aspergillus risk. The theatre vent system can be very complicated, it will run on a separate vent system to the rest of the hospital, be positively pressurised to the rest of the building and have so many air changes to prevent infection. The contractor will have to work on the system while it is operating for the commissioning after carrying out the maintenance, to check it is interfacing with AFD, to see if in the auto shut down systems the micro switches etc. are operating correctly, If he is carrying out pressure testing air flow metering it’s a bonus as that is far above the normal bi-annual check Make sure he provides good safe systems of work and method statements.