The condo corporation hired Superior Air Quality Services to clean the dryer drums and vents, and bathroom exhausts in every unit in the building. I can only speak from my own experience but I found the 2-man crew (Barry and helper) to be extremely efficient and professional, providing excellent service in my unit. And they didn't leave a mess like many contractors do. Now the exhaust system is working better than it ever has. Whatever the cost agreed to by the condo corporation, it was well worth it.