Your heating and air-conditioning vents, more accurately called registers, can become clogged from dust and lint. If your registers are located in the floor, debris can fall down into the ductwork. Sometimes draperies, furniture, toys and other items may block a vent. Periodic inspection and cleaning is easy to to do and will result in a more comfortable environment and a reduction in airborne particles.
Using a vacuum hose and attachment will be the easiest way to clean the vents. If you have to clean out the in floor ducts, you will want to use the extension or "wand" attachment.
Locate the ventilation ducts in each room. Nearly every room should have at least one. Make sure the vent is not blocked by furniture or draperies. While it is okay for a vent to be located under a sofa, make sure there is still clearance for air flow and that the sofa does not have a skirt to trap the air.
In most cases the register should readily lift up and out of in-floor ducts. For wall and ceiling it is necessary to unscrew the register. Use the vacuum with the upholstery or drapery brush to clean the vents. If you remove the vent, then use the extension along with the brush to clean out accumulated dust and debris.
These simple steps will help to reduce the particles blown around by your home's heating system. The reduction in allergens will make for better air quality while unblocking vents will improve the heating and cooling in your home.