Recently a friend of mine whose opinions and recommendations I value — on anything from movies to marriage to motor oil — told me he had just had his home’s air ducts cleaned. In fact, he couldn’t stop raving about it. He claimed he’s never breathed easier, the air is fresher and he regrets not doing it years ago. I politely nodded and tried to change the subject. Working in the HVAC industry, I’m no stranger to the debate on duct cleaning. Debate? Yes. The fact is, empirical

Chances are that if you talk to a friend who recently had the ductwork in their home cleaned out, they’ll babble incessantly about all the benefits to be recouped by undergoing the process. “I can breathe so much easier!” “The house smells fresher.” “My allergies have practically disappeared!” Etcetera, etcetera. Well, all those benefits could be figments of your friend’s imagination. In other words, there are opposing factions of HVAC professionals who debate the efficacy of