While I’ve consistently been conscientious about air filters and seasonal repair for the furnace and air conditioner, I neglected the air duct. Because the plan is mainly concealed inside the walls, ceilings and crawl space. I never gave it a thought. Over the years, dust in addition to other contaminants gradually built up inside the pipes. This debris restricted airflow and made it more hard for the heating and air conditioning to match the temperature control setting. The equipment needed to run longer, consumed more energy, and lead to higher energy bills. Plus, whenever the furnace or air conditioner started up, those pollutants became airborne and were spread throughout the house. I noticed an excess of particles floating around in the air and on surfaces. I needed to dust and vacuum a lot more often. My family complained of headaches, congestion and sore throat. My friend and I all coughed and sneezed frequently. When I googled our complaints, I realized that the duct plan required cleaning. I found a local heating and air conditioningbusiness that specializes in the process. They brought in a machine that looked a lot like an industrial-sized vacuum cleaner, with a long hose and a brush liniment. While the repair was fairly expensive, it was completed fast and it caused no mess or disfigure. It also gave a huge improvement. The furnace and air conditioner are now able to maintain ideal, consistent indoor temperature. I’m spending a lot less on temperature control. I’m hopeful that the shortened run times will reduce wear and tear on the furnace and air conditioner.I hope it adds up to a greater reliability and longevity.