In painting the ceiling we also painted the duct work and everything else. 

., insulation, sealed ductwork) instead of sexy (solar, granite countertops).

I had one home with a lot of rodents and one of them died in the ductwork so the owner paid to have the ductwork cleaned. it ended up being a waste because another rodent died in the ductwork!

However, it's not apparent that there *IS* anything more in the walls than that piece of ductwork by the louvers. 

They  also found some duct work that wasn't attached and blowing hot air in the basement that they reattached. 

There is currently NO heating in the house, just an AC with duct work under the flooring.

Here were my final numbers: 30 year fixed rate loan with no PMI$151,000 purchase price (I bumped it up to pay for new ductwork)$143,450.00 loan amount$8,800 down (as a credit from the seller)My out of pocket: $2,967.10 for closing costsMy mortgage is $781 + $166 a month for taxes and insuranceThe house currently makes $1,400-$1,900 a month on Air BNB (depending on how often I stay there)I estimate it would rent for $1,100 a month with a long-term leaseThis house paid for itself will continue to pay for itself, is in a neighborhood that is appreciating at a high rate, and has given me so much confidence in myself and my abilities to achieve my goals.

I called out the HVAC guys to see about a cleaning, but the ductwork is 48 years old and he didn't think it would hold up to a cleaning.

Also, HVAC--if it was running at the time of the fire the ductwork will be contaminated and will need to be cleaned at minimum, or replaced if bad enough. 

Side note, I just got a quote to replace the HVAC unit in a 1100 sf single family I own, and it was $4,500 but that doesnt include replacing the ductwork and electrical.