Wow ! Sorry to hear Bud , I just finished removing and replacing my domestic fce from oil and wood conversion to a new high efficiency gas unit . I had to replace the heating plenum and branch ductwork and all cold air returns to provide proper static operating pressure to provide optimism (balanced) heatng efficiency . My Son and I did all the work . The original piping was 20 yrs old and resembled a Chia pet farm inside . Even with religious filter change out there always is some residual bypass of dirt. mold and other bacteria . Presently looking into adding a hepa multistage air filtration unit along with ultraviolet purification unit . We both wire dusk masks and white disposable coveralls , messy job at best ! Hope all goes well within your recovery friend , take care and thanks for the heads up , us oldies have to look after each other ! lol.

Hope that you get better soon.

I work rehabbing apartment complexes and houses. Basically what I do is go in and strip a place to the studs and floor joist and then rebuild everything back up to date with new materials, fixtures and the works. Once I get finished everything in a unit is brand new. . . We run into some nasty stuff in some of them that has been neglected for many years. Everything from roaches, bedbugs, mold to meth labs. We never enter a unit to do a wreck-out without wearing full protective gear. We have had a few guys that thought they were to cool or tough to gear up. They paid the price for it.