Any recommendations? Im looking for a vacuum to clean up deposits brushed from heat exchangers in domestic gas boilers. I assume given the potential for carcinogens in the deposits or potential for asbestos fibres in some older boilers that it should idealy be at least hepa filtered. I dont know if such a thing exists but is there a vacuum that have a bag with built in hepa filter so once the nasties are in the bag you dont have to expose yourself or any one else to them in order to empty it?