My HVAC system is approximately ten years old, and I have never had the duct system professionally serviced by an HVAC contractor. As my monthly energy bills have gradually risen and my home has become less comfortable, I have suspicion that the duct system is leaking. There are hot and cold spots in the house, and both my furnace and air conditioner are running longer and longer. I went online and did some research into common problems with HVAC air ducts and discovered that the typical system wastes up to 40% of heating and cooling energy. Ducts that leak just 20% of the heated or cooled air passing through will force the HVAC equipment to work 50% harder. That could result in malfunction and the furnace or air conditioner wearing out faster. I read that having the duct sealed could save me more than three hundred dollars each year. Holes in the ductwork not only allows conditioned air to escape, but welcomes outside air into the system. Problems with mold, polluted indoor air quality, and health issues can often be blamed on air ducts. I was worried that having the air ducts sealed would be an expensive and messy project. I spoke with my HVAC contractor, and he explained a process called Aeroseal, which accesses the entire duct system without damage or disruption. They blow adhesive particles into the duct system, and as the particles escape through leaks, they buildup along the edges. The adhesive particles are able to effectively seal holes that are up to an inch in diameter.