Air Conditioning - Duct Lining

Help! I bought a house that was originally built in the early 40's. The original central A/C was an Arcla Servel that used ammonia. That unit has since been replaced but the old metal duct work is still in place.

My question is in regards to the inside lining of the ducts. It is brown and fibrous, kind of like a bad toupee. I don’t know what it is and if it is safe, especially considering the fact that my wife has a severe lung disease. One person told me it was horse hair. Someone else suggested it could be fiberglass or asbestos. I can’t imagine asbestos would ever be used on the inside of the a/c ducts.

Does anybody know what this material is and if it is safe? I’ve considered replacing the duct work, but it’s in great shape. I wonder if I can rip out the lining, but I am concerned about loosening dangerous material into the air.

No way of us knowing exactly what it is. It would be best to get an HVAC company out to look at it.

If it is fiberglass it can be coated.

Thanks for your replies.

Airman: what does that mean to coat fiberglass? Is that an expensive and difficult process?

Will be a lot cheaper than replacement.

Airman: sounds great. Do you have any referrals in the miami/ft.lauderdale area?

Ed was from FL don't know where? Maybe he knows somebody. Foster 40-20 is what we use.