A vapor deposition apparatus for coating an item has a cleanroom side that is accessible from inside a cleanroom and a service side that is not accessible from inside the cleanroom. The apparatus has a vaporizer for vaporizing solid coating material and a pyrolysis furnace for heating the vaporized coating material to form a pyrolized gaseous coating material. A deposition enclosure defines a deposition chamber for receiving an item to be coated. The deposition enclosure has an inlet for flow of pyrolized gaseous coating material into the deposition chamber, an outlet for flow of pyrolized gaseous coating material from the deposition chamber, an access door for accessing the deposition chamber from the cleanroom side of the apparatus, and a service door for accessing the deposition chamber from the service side of the apparatus.