Please send questions that I should ask for duct cleaning.
Answer:
You want to know if the machine moves 20K cubic feet of air per minute, a modest bungalow (1200 sq. ft.) takes roughly three hours so you want to know how long they'll be there, is the company doing it locally owned or have they had to travel a couple of hundred miles to get to the job - that too, has to be paid for, etc.
