Can A Dirty Air Filter Make You Sick?

Yes! A dirty air conditioning filter can make you sick. The purpose of having a clean AC or furnace filter is to filter out all of the dust, germs and bacteria that is floating in the air. A clogged air filter will slow down the filtration in the home or workplace. The last thing you want are germs circulating in the air you breathe. Another reason to have a clean filter is to draw the warm or cool air out of the space and filter clean, cold or hot air, depending on how the thermostat is set. This will keep the air conditioner or furnace unit running at maximum efficiency and ultimately lowering the electric bill.

of course it can

More than you know.

i would like to point out however though as a air filter becomes dirty it actually becomes harder for anything to pass through the filter this includes more dirt the reason we replace them is eventually they become so clogged that the air flow is reduced to the point that it needs replacing.

Also unless you have serious allergies to anything in the air then as long as nothing mold like is growing on the air filter then its not going to get you sick. however if its not installed properly or it is pumping a lot of dust and dirt into the air in your house it can cause irritation to the respiratory track which can lead to infections because of micro tears from inhaling an excessive amount of coarse materials that the bodies natural defenses couldn't keep up with but you would probably be able to see that amount of dust and dirt in the air on any given day so its doubtful that would go unnoticed

It probably depends on what the dirt is. Like "plain" dirt will not, but say mold or anything like that sure could.