The majority of HVAC units come with some sort of filter. The heating system has a furnace filter and the air conditioner possesses an air filter. Did you recognize that even a heat pump comes with an air conditioning filter? Most likely, the HVAC unit carries a filter to keep the air quality clean. The filter stops dust from going into the heater and air conditioner. So then dusty air does not pollute your indoor quality of air. Also not having dust go into the system is better for the HVAC equipment. Dusty HVAC solutions are harmful. The device goes longer and is less efficient. The dust can make it harder for the device to attain temperature control. A dusty unit is very likely to overheat. If you have a gas furnace, the system will catch on fire. The dust also puts strain on the unit and that means more HVAC repairs which can be expensive. So the HVAC filter is actually very important. However, a filter fills up with dirt quickly. About once a month the filter has to be taken care of. Check out exactly what HVAC filter you have. There are many options and each option is different. Washable filters allow you to clean them a few times before they need to be replaced. Fiberglass filters are more durable and may be used for a few months. Basically you can lightly dust them off. The filters also provide small holes that catch your dust. Smaller holes means you have to clean them more often. But they also are better for the air quality.