A cabin air filter cleans the air that passes through the heating, ventilation, and air conditioning systems. An engine air filter keeps dirt, dust, sand, and other contaminants from getting inside the engine.

every 15,000 miles Are you wondering if it is time to change your cabin air filter? According to most of the experts in the automotive industry, it is a good idea to change the air filter every 15,000 miles. Be sure to take a look at your owner's manual to see if there are different recommendations from the manufacturer.

But these are two different types of filter with separate roles. Your vehicle relies on each, not only for best performance but also for safety. While your air filter cleans air before it flows into your engine, your cabin filter decontaminates air that flows into your cockpit.

And notice. There's an arrow. And usually it even says airflow. Direction how do you know which way the air is going to flow. Sometimes you get really lucky.

Engine Strain Surprisingly, having a clogged filter can actually impact your fuel efficiency because your engine is having to put out more energy than it should.

A clogged cabin air filter doesn't reduce engine performance or degrade your oil, but it does leave your interior dirtier than necessary. It also reduces the air flowing through it from the air conditioner, resulting in reduced cooling that you can't fix with a refrigerant refill.

A new cabin air filter will prevent pollen from making its way into a vehicle and causing its occupants to start sneezing, or even worse. HVAC system will run poorly: A cabin air filter left in place beyond its life span will make a vehicle's HVAC system work harder, which can cause the motor to burn up.

Poor Function of HVAC System - A cabin air filter left beyond its life span will make a vehicle's HVAC system work significantly harder, which can cause the engine to burn up. Dirty or clogged cabin air filters will restrict the amount of air flowing from the vents.

Decreased air quality is the most common problem when AC's are run without a filter. Dust will not settle down in a room with an AC running continuously without a filer. This will eventually lead to the clogging of the unit.

A new cabin air filter will prevent pollen from making its way into a vehicle and causing its occupants to start sneezing, or even worse. HVAC system will run poorly: A cabin air filter left in place beyond its life span will make a vehicle's HVAC system work harder, which can cause the motor to burn up.

You're going to see an arrow around the edges of it pointing one way so to answer the question the arrow just needs to point towards the return so my return is in the wall yours might be any more

Cold air flows downward according to hot air because it is more dense and sinks while hot air rises. In hot room the air will be much thinner thus reducing the pressure so the air flows from cold room to hot rooms.