Air Duct Cleaning
Air Duct needs to be cleaned at least once a year, since it accumulates around 40lbs of dirt each year. These dusts are home for dust mites which causes allergies, fungi and mold. Which can cause indoor allergy and people with sensitive to dust and mold have difficulty in breathing.
The other reason is that it reduces your cost of running the equipment. A dirty Air Duct needs to work hard as compared to clean one to maintain the desired temperature inside the room. A clean Air Duct your indoor air quality and increases the life of your equipment.
It is best advisable to clean your duct once a year.