Confused?

If you have carbon filter it is suppose to stop odor correct?

The filter is attached to the exhaust fan which extracts the air
containing the odor.

So if i were to check on my plants, by opening the grow room
even with the carbon filter
wouldn't the odor escape through the opened door?

yes, but that's a lot less "dirty" air than you would have to deal with by just blowing the air inside your grow room out to another area. much less stinky air to deal with means that it's easier to deal with