Changing out the air filter inside your home is one of the easiest jobs a homeowner can perform and should be a part of their regular maintenance. It takes less than five minutes to climb up a step ladder (or however you access your air filter), remove the old one, and replace it with a new air filter. It doesn't cost much, and according to professionals, it should be done at least once every two to six months, depending on the season.

But despite its simplicity, many homeowners hesitate to change the filter. The filter affects your home's HVAC system — which is tied into both the air conditioner and furnace — so failure to change the filter can rack up an enormous amount of bills in AC repair and heating repair in your home. Here's how not replacing your filter can hurt your HVAC system.

Overworked Unit

Contrary to popular opinion, air filters are mainly in place to protect your home's furnace and AC system, not to protect the homeowners from allergy issues (although they can certainly do that too). They're designed to filter out the pollen and dirt that is in the air to keep the ductwork and systems clean so that they're operating at peak efficiency. If they're clogged, the system will have to work harder, which will lead to premature breakdown, necessitating an AC repair call. 

Energy Inefficiency

Along with the overwork that will take place, you will most likely also notice a spike in your energy bills every month. Your furnace and AC units will have to work harder to deliver the air at the right temperature, so your thermostat will constantly read higher temperatures in the summer and colder temperatures in the winter. A heating repair technician may eventually have to come out and fix your furnace once the unit fails for good.

Dirty Ductwork

Air is going to be forced through your HVAC systems one way or the other, and if you've got a dirty air filter, that dirt can be pushed right through the filter and into your HVAC system where it collects along the walls of your ductwork. This will not only cause a gunky buildup that inhibits air flow and increases the wear and tear on your unit, it will also create a poorer quality of air that makes it harder for the people in your home to breathe. Although delivering quality air is not the primary job of the HVAC system, failure to replace your air filter will cause a greater than normal amount of AC repair bills and lower air quality in the meantime.