Remind Yourself to Regularly Inspect Your Home’s HVAC Air Filter

Any HVAC technician will tell you that the most common mistake homeowners make with regard to their forced-air heating and cooling system is neglecting to check and change the system’s air filter. The irony is that there’s nothing technical or difficult about this task – you pull the filter out of its slot and if it looks clogged or dust-covered, you replace it with a new one. If it’s a reusable filter, you clean it according to manufacturer instructions.

The job’s so basic that many homeowners end up taking it for granted and forgetting to do it. That’s why it’s helpful to have a simple reminder to check the filter on a regular basis, usually monthly. First, though, we’ll provide a refresher course on the important role an air filter performs in a central, forced-air heating and cooling system.

A Key Component of Your HVAC System

The air filter is typically located inside the furnace plenum or air conditioner/heat pump air handler, near where the return ductwork is connected to the equipment. A powerful fan circulates air through the system, including drawing it through the air filter before the air gets heated or cooled and recirculated through the house.

The filter’s job is to sift out dust, dirt and various constituent contaminants, to keep them from coating sensitive equipment and being circulated with conditioned air in the household. The consequences of not replacing a dirty filter on a regular basis can be serious, up to and including causing your HVAC system to break down. Usually, though, a clogged filter will have subtler negative repercussions.

One of the most serious impacts on your forced-air system’s performance and efficiency is impeded airflow. If air doesn’t have a smooth path through the equipment and ductwork, your blower motor will have to work harder and longer to do its job and satisfy the temperature setting on the thermostat. Additionally, if dust and dirt particles are falling onto sensitive components as a result of a clogged filter, that will increase friction in the equipment, reducing its efficiency.

How Do You Remember to Replace the Filter?

Now that we’ve established the importance of regularly inspecting and replacing your heating and cooling system’s air filter, it’s time to discuss how to remember to perform this crucial maintenance task. Following are some effective ways to remind yourself to check and change the filter.

• The most foolproof way (though also the most expensive) is to retrofit your HVAC system with a check-filter light. It glows when it’s time to change the air filter. Some WiFi/smart thermostats have this feature, sending the “change filter” message to your smartphone, tablet, laptop or desktop.

• Set reminders on your computer or smartphone. While these won’t alert you when the filter needs to be replaced, they will remind you that it’s time to inspect the filter. It’s a simple matter to pull the filter from its slot and detect whether it’s time to be changed. One tried-and-true test is to hold the filter up to a light, and if you have a hard time seeing the light through the filter, it’s time for a replacement.

• If you have a checklist you use to pay bills each month, add “inspect filter” to that list.

Other Helpful Air Filter Tips

• Write down the date when you install a new filter on the cardboard side of the filter, so you always have a way to determine how long it’s been doing its job.

• When you go shopping for a new filter, purchase several, to save yourself the trouble of schlepping to the home improvement store 12 times a year.

• For most systems, your best bet is a mid-efficiency air filter, one that’s not the very cheapest but also not the highest efficiency and most expensive. The cheapest filters will only sift out a relatively low percentage of airborne contaminants, doing little to improve your household air quality. However, high-efficiency filters, with their dense filtration media, may impede system airflow, forcing your blower or air handler to work way harder than necessary to circulate air in your house. This can lead to unbalanced air delivery, wasted energy, and system breakdowns.