One of the most important components of your home’s HVAC system is the AC air filter. Make sure you know where these are located in your home. There may be only one, or there may be more depending on how large your system is, or if you have multiple units.

How often do I change the filters out?

A general guideline is to change your filter each season or every 3 months. A dirty air filter can cause issues with your central heat and air unit and its performance. Dirty filters can cause the following problems:

1. Evaporator coils to freeze
2. Extra strain on the blower
3. Increased energy consumption
4. Low air flow through the system
5. No longer effective filtering

What’s the best type of filter?

The choices for AC air filters have significantly increased over the past decade and deciding which one is best can be daunting. Gone are the days of simply grabbing the old standard, cheap fiberglass filter. So, what do you really need? That depends on what you want to get out of the filter. Factors like having pets, allergies, and general air quality where you live should be taken into consideration.

MERV Rating

One number you should become familiar with is the MERV rating of air filters. MERV stands for Minimum Efficiency Reporting Value and is a scale from 1 to 20 with 20 being the highest efficiency. The higher the rating, the tighter the filter mesh and thus the more particles the filter will catch. The older style fiberglass AC air filters have a MERV rating of 2 and are still an effective option. The higher MERV filters are actually a pleated material.

Keep in mind that a higher MERV rating also correlates to a more restricted air flow, so while your air may be cleaner, you may also be putting more strain on your HVAC system. The tighter mesh will filter out more particles but will also hinder air flow. If you use a filter with a higher MERV rating, you will want to change these more often to ensure adequate air flow through the system. No matter the filter you use, keeping it clean is the key to a healthy HVAC system.