How can I tell if a duct is leaking?

[oldhome]

How can I tell if an air duct is leaking? My house seems unusually 'fuzzy' lately & it's not the dryer vent.

sue's house needs fixing

[imeduc]

Id start with the filter do you keep it clean . New one every 30 to 90 days? Do you use a good filter like pleated and about a MERV of 7. There are spray's that you can but on the filters when you put them in. It helps . Look at the cold air return any leaks there?

ED

My mistakes dont define me they inform me.

[HayZee518]

Home depot sells a smoke aerosol spray that you can use to check for leaks. Better if you take an old rope (cotton) get the end burning and blow out the flame, let it smoulder and move it near the duct joints. Air leaks will show up.

[LazyPup]

It is possible that dust could enter through a leak in a return duct, but that dust would then be caught by the filters. It is rather doubtful that it would happen on a supply duct because during normal operation the air in the supply duct is being driven by the fan and there is a constant positive air pressure in the duct. Any leak in the duct would result in air pushing out of the duct rather than in, so dust and dirt would not get in.

If it appears you are getting dust in the air begin by checking the air filters.

In most cases filters should be changed a minimum of once a month, however, most airborne dust is microfine and if you can see an aparent layer of dust on the surface of a filter it should be changed.