I hope you mean ventilation ducts, or is there something else about what such a wing phrase is mentioned?)) Are you looking for a service for a car or some kind of housing or maybe a unit that has begun to work poorly? In general, to clean the ventilation systems, you need to partially disassemble them. I was offered this service thecarparkman.co.uk at thecarparkman.co.uk and the guys quickly coped with the installation. To be honest, I like this kind of thing when you can entrust the work to someone, but as far as I know, to clean the air ducts in the car (filters and oil gaskets), you need to change and clog them for cleaning by blowing.