I thing what you might have is, Acanthosis Nigricans, it's a skin pigmant disorder, that usually occures in obese people, I have acanthosis nigricans, under my arms, on my inner thies, on my elbows and knees, and behind me knees, and on my arm where my elbow bends.
Dear Angie: I want to hire a reputable air duct cleaning company. Dear Barbara: Weâve seen a lot of reports from Angieâs List members in which they were quoted prices anywhere from $49 to more than $1,000 for the cost of air duct cleaning.
I would stay with your central AC system since you already have the infrastructure installed for it. Even if a ducted system has not been used in years, a good cleaning would cost very little ($400-$800). For standard house, the duct are galvanize steel/aluminum and does not have liners. Unless you see a lot of rust or the ducts are falling apart, it is perfectly usable.