Savings: varies, as much as $800 a year.
This seems so simple, but so hard to do!
The number one cause of problems with your air conditioning system is dirty filters. Having a dirty filter in your return grill will reduces the flow of air into the system. To make up for it the fan inside the unit will run harder using more electricity and wearing itself out.
Eventually this will cause your air conditioning system to ‘freeze up’, ice will build on the lines and the compressor (most expensive part of the system) might go out.
Savings: $144 a year
I always forget the change my filter, which is why I have an AprilAire whole house filtration system. The techs change it for me once a year during our Comfort Society membership check and it only costs around $50. That means it cheaper than those $12 a month filters you get from Walmart..