Ironically, one of the easiest actions you can take to enhance the performance and efficiency of your HVAC system is also one of the easiest to forget. As a rule of thumb, air filters should be changed quarterly but this can vary in either direction based on actual usage. So, if you’re not operating off of a fixed schedule, what are some of the things you should look for signaling it’s time for a refresh? 

1. The Filter’s Appearance

Ah yes, the old eye test. Air filters begin life with sparkly clean appearances, but after some usage, they’ll progressively get darker as the dust and allergens build up. Most filters are easily accessed, so take a peek directly at the source if you think you might be overdue for a change. 

2. Preventative Maintenance Agreements

If you have a preventative maintenance agreement for your HVAC, make sure air filter replenishment is included. This may only happen twice a year depending on the nature of your agreement, but it’s a nice back-up in case you forget to change it more frequently. 

3. Dirt Around Vents

A buildup of dust, dirt and other contaminants around the vent may be due to a clogged filter. A blocked air duct can cause a similar issue, but it’s easy to check the filter first as you diagnose the problem. 

4. Bigger Bills

Assuming rate hikes, abnormal temperature setpoints or extreme weather were not at hand, a bigger electricity bill could indicate your filters are overdue for changing. When clogged, the filters cause your system to work harder to maintain a set temperature and therefore consumers more energy. 

5. Slower Setpoint Achievement

Similar to the previous sign, you may notice it taking longer for your building to reach a desired setpoint. If you are scheduling earlier and earlier start times to reach the right temperatures, assess if filters are the problem. 

6. Hot AC Unit

If warm to the touch, the AC unit may be working harder than normal because of a clogged filter. Working harder not only means the unit is drawing more energy than should be necessary, its longevity is being reduced by the wear and tear.