Here is a perfect example of a homeowner not replacing their HVAC filter often enough and installing the filter incorrectly. As you can see this filter is almost entirely clogged with dust which makes your system run less efficiently and much harder. 70% of equipment damage is due to lack of maintenance and dirty HVAC filters. During peak heating and cooling months your system is running more often and therefore you need to change your filter more often. If you have an active home with children and pets we recommend changing your 1 and 2 inch filters monthly. If you have a less active home you can get away with changing your filter every other month as needed (regular visual inspections are a good idea).
You can see in the image to the left this filter was installed incorrectly so the pressure from the air flow pulled the filter inwards.