Three times last year, I ended up with a terrible sore throat & laryngitis. My dentist recommended doing something to help the indoor air quality in our home. I never thought the indoor air quality could affect our health so poorly. Since the air inside the cabin was dry & arid, it was having an adverse affect on our health, but during the night, I was sleeping with our mouth open. The dry air was irritating our throat & larynx. Even worse, the dry air was filled with contaminants that were causing myself and others to get sick. I had to spend our money a specialist to examine our indoor air quality. They carefully examined every square inch of our beach house for troubles. They found black mold inside our air ducting system, which was the likely cause for our distress. They performed a thorough cleaning of the air ducting system. They cleaned & sanitized each piece of air ducting equipment. They had a long brush that had an flexible head. The brush cleaned every square inch of the air ducting system. I could see the brush moving in & out of the air duct, because the crew used a special camera to view the interior areas of the air duct. It was absolutely interesting to see all of the odd & cool gadgets they used to clean the air duct. There was no way I could have reached all of the crevices inside. They were able to clean every nook & cranny with those specialty tools. The indoor air quality in our beach house is much better now, thanks to the task of our Heating & A/C team.