Is my air filter causing black grime on my walls?

I have a home air filter, and I have noticed a layer of black grime collecting on the walls near the air filter. Any ideas why this is happening and what I can do to stop it?? I have changed the actual filter part, no change. The filter is HEPA style with a carbon layer inside to filter out smell.
Is my air filter causing black grime on my walls?
do you smoke? do you have central air and heat? could it be mold from the inside of the wallboard? what is the humidity level?



whatever the problem, it's not CAUSED by the air filter. it's some kind of particulate matter in the air. smoke. dust, whatever. your air filter will cause a draft towards and away from the filter because of the fan(s) in the filter and whatever is in your air is gathering on the walls near the filter. BUT the filter is taking more of it out than is gathering on the walls! right?



i assume you are talking about a stand alone air filter system. if you are talking about an electrostatic or other filter system in your central air and heat, well you need to have your mechanical room sealed possibly. i would need more info to go farther.
Is my air filter causing black grime on my walls?
Change the filter every three months, and have all the ducts cleaned out. When was the last time you have had this done.?
The dust laden air is being pushed against the nearest surface, walls or ceilings, where is creates dirt streaks. The inside of your duct work remains clean due to the electronic air cleaner and filters doing their job.
If you burn alot of cheap candles, that will do it. You may want to have your furnace inspected to be sure the heat exchanger is still in good condition. (which should be done annually) Also over time with air constantly moving over a surface in the same direction(i.e. toward filter) dust that is in the air will start to show up on surfaces.