You should plan to change your AC unit's filter every one to three months, depending on the manufacturer's recommendations. You should also clean the coils at least once per year, but if you have pets or someone in your household has allergies, you might need to clean them more often. Fortunately, many pros will clean the coils and change the filter for you during an inspection, which you should schedule once or twice per year.

Sometimes, you can clean an HVAC filter rather than replace it. If you have a washable filter, also known as a permanent or semi-permanent HVAC filter, wash the filter once per month. However, if you have filters that are not labeled as washable, do not attempt to clean them and reuse them. Many HVAC filters are disposable, and you’ll need to buy a whole new filter to replace dirty disposable filters.

If you don't regularly change your HVAC air filter, it will become clogged with dust, dirt, and other contaminants. This blockage forces the system to work harder to circulate air, leading to several negative consequences. You may experience higher energy bills, poor temperature regulation, reduced air quality, and slower system performance. Over time, this added strain can cause parts to break more frequently, lead to system failure, and ultimately shorten the lifespan of your entire HVAC unit. In some cases, it can also contribute to health problems. It's recommended to change the filter at least every three months.

Most services take 2-5 hours, though full unit replacements or extensive repairs may take longer.