You can increase energy efficiency, your air quality, and the life of your equipment by checking your vents and 
changing your furnace filter on a regular basis.
In addition to annual service for your heating equipment, checking vents to ensure there are no obstructions and cleaning or replacing your furnace filters every three months can also help you use natural gas more efficiently.
If you are concerned about air quality you should learn more about duct cleaning.
Do you need a new high quality furnace filter, or a maintenance plan so that your comfort is guaranteed?