Avoid Gimmicks: Ads for “$79-$99 whole-house specials” are scams. At most a few ducts will get a very cursory vacuum; and at worst, you’ll end up talked into a much more expensive package.
Cheap Service: High-quality duct and HVAC cleaning should cost upwards of $600-1200. A technician wil have an assortment of sophisticated equipment, brushes and tools to do a thorough cleaning.
Quick Service: Don’t settle for simple duct vacuum cleaning, make sure the cleaning service is a full scale scrub and clean. A typical full service cleaning is a full day event and can take 5-8 hours with sophisticated equipment.
Avoid Steam Cleaning: Any kind of duct cleaning involving steam or moisture should be avoided.