Verify if the duct cleaner takes care to protect the duct work, including sealing and re-insulating any access holes that the service provider may have made or used so they are airtight.
Verify if the duct cleaner follows NADCA's standards for air duct cleaning and NAIMA's recommended practice for ducts containing fiberglass lining or constructed of fiberglass duct board.
Verify if the duct cleaner installs access doors in sheet metal ducts attached with more than just duct tape, e.g., screws, rivets, mastic, etc.
What is a duct cleaning service?
Air duct cleaning companies are a professional service. which traditionally will come to wherever to clean the ductwork in a residence or a professional building.
Why do you look for one?
If you need duct cleaning service:
» To help your furnace run better.
» To get the most of your central air.
» To keep the air in your home clean.
» To keep the dust level down in your home.
» To create a cleaner work environment.
then you consider air duct cleaning companies.
Where do you find good duct cleaning service?
Cleaningmall.com will help you to find the best air duct cleaning companies providing professionalefficient . and complete services. Check our listings to find the best duct cleaning service close to you. Whether a small home or a large building. you should prefer licensed air duct cleaning companies.
Verify if the duct cleaner takes care to protect the duct work, including sealing and re-insulating any access holes that the service provider may have made or used so they are airtight. 
