The only way to know if there is asbestos is to have it tested. If asbestos is left undisturbed and is encapsulated, then it is fine. For peace of mind, you might want to get the asbestos test done. Asbestos is one of those things you have to sign off on when you list the house for sale.
Asbestos wrapped ductwork was done before 1970. I know its asbestos because we had to sign off on it when we bought the house (built in 1968). There was one small tear that I could see, so I slapped on some duct tape (carefully) and haven’t disturbed it since.
Asbestos wrapped metal pipe may appear to have a thin layer of “cardboard-looking” material on the outside that covers the metal. It usually provides some insulating properties to the ducts and some sealing qualities as well. However, having asbestos ducts creates an exception status for Title 24 requirements, which will mean that you won’t be able to have a pressure test done when you install a new HVAC system. Some asbestos covered pipes remain hidden in walls of older homes or under a fiberglass wrap coating the pipes in your home.
For more information contact McDonald Plumbing, Heating and Air at (916) 233-4194.