How To Use MERV Ratings To Choose An Air Filter
Posted on January 22, 2013
The air filter in your furnace prevents dust buildup inside your system, which can cause it to overheat and damage some of its components. Avoiding higher energy costs and expensive repair bills is often a simple matter of checking your air filter each month and replacing it when it’s dirty, especially in colder climates like ours in Wichita, where furnaces typically run 24/7 during the winter months. A clean air filter is essential to improving your indoor air quality, especially in the winter, when the bacteria and viruses are common.
Choosing a filter
Air filters are given a rating on the minimum efficiency reporting value, or MERV, scale. Higher MERV ratings mean your filter will remove more and smaller particles from your air and improve your overall indoor air quality.
- MERV 1-4 filters are very inexpensive and do little to improve your home’s air quality, trapping only particles 10 microns in size or larger. But they do protect your equipment, and if changed regularly, allow for clear airflow.
- MERV 5-8 filters trap particles 3 microns in size and larger. These filters are sufficient for most residential needs.
- MERV 9-12 filters trap particles 1 micron in size and larger. These filters are ideal for those suffering from allergies and asthma.
- MERV 13-16 filters are mostly used in commercial buildings, trapping particles 0.3 microns in size and larger.
Before upgrading your air filter, check the documentation that came with your system to determine what type of filter it will accommodate. Higher MERV filters can impede the flow of air to some systems, reducing efficiency and possibly overheating the system. Balancing optimum air flow with air-cleaning qualities is important when choosing a filter for your furnace.
Replacing your filter
To replace your filter, which is most likely located in the blower compartment between the cold-air return and the furnace, slide out the old filter and install the new one with the arrows on the frame pointing toward the furnace.
For more expert advice about choosing and replacing your furnace’s air filter, please contact us at Comfort Systems, serving the Wichita area with integrity since 1996.
Our goal is to help educate our customers in Wichita, Kansas about energy and home comfort issues (specific to HVAC systems). For more information about air filters and other HVAC topics, download our free Home Comfort Resource guide.