I am quite conscientious about official home repair.
Every year, I drain the water heater, service the refrigerator & hire vent cleaning for the clothes dryer.
I respectfully remove debris from the gutters & change air filters in the vacuum cleaner, heater & air conditioner. In the fall, I inspect the interior & exterior of the household for any areas that require caulk, weatherstripping or insulation. I have the shrubbery mower, heater & cooling system professionally inspected every year. It never occurred to me to include the HVAC duct in my job list. Because the network of pipes is largely concealed behind walls & ceilings, I forgot all about it. However, the conditioned air that my family breathes & I pay for passes through the system multiple times per day. It’s responsible for delivering heated & cooled air to the multiple rooms of the house. Any holes or gaps at the seams allows that air to escape. Those imperfections can also draw in unconditioned air & introduce VOCs, odors, dust & other pollutants into the living space. When the maximum amount of air fails to reach the intended destination, the heater & air conditioner are required to run longer & use more energy. Energy bills go up & there’s an increased opportunity of malfunction. When I hired a licensed Heating, Ventilation, & A/C supplier to test the operation of our home’s HVAC duct, she found that approximately 20% of air was leaking out. She commanded duct sealing. The process was not invasive, damaging or messy. It was completed in a few hours. The serviceman pumped pressurized air laced with polymer particles into the ducts that sealed up the holes as the air leaked out.