When considering what MERV rating you should select for your home, one factor that many people that don’t think about is the age of your home.
A common problem with older houses is outside air coming in. Building standards have changed quite a bit in the past few decades and were not as stringent as they are now. And unless your home has been refurbished since the time it was built, older homes typically have less insulation and more cracks in the walls, doors, and windows.
Anytime outdoor air enters your home, it directly affects the air quality in your home. Humidity and other pollutants enter your home which means you and your family are breathing them in. Plus, high humidity levels can cause your AC system to work harder than it should, which will make your monthly energy bill go up.
Installing better doors and windows and making sure all the cracks in your home are sealed up is something people who live in older houses can do to help improve the quality of their indoor air. But one of the most important things you can do to improve your air quality is to make sure that you are changing your air filters on a regular basis. Experts say that your air filters should be changed every 3 months. Changing your air filters regularly not only improves the air quality in your home, it can also protect your equipment, meaning a longer run life and fewer repairs.
Which MERV rating you choose is really up to you. Here’s a quick rule rundown of the different MERV ratings to help you discern which one is right for your home:
MERV 1 to 4 filters provides minimal filtration. These filters have to be replaced quite frequently and are typically made of disposable fiberglass or synthetic panel filters within a cardboard frame. These filters capture up to 80% of airborne particles as small as 10 microns.
MERV 5 to 8 filters are good for capturing dust and mold spores. These filters have to be replaced, depending on usage, every 3 months. MERV 8 replacement air filters will reduce pollen, pet dander, dust and other contaminants as small as 3.0 microns.
MERV 9 to 12 furnace air filters capture up to 95% of airborne particles and contaminants like pollen, dust mites and mold spores, as small as 1.0 microns. These filters come in a deep pleated, boxed media or bag filters, which are some of the most efficient filters used in homes and commercial buildings.
MERV 13 to 16 air filters will trap up to 98% of airborne allergens and pollutants such as bacteria, tobacco smoke, cooking oil and droplet nuclei, as small as 0.3 microns. Filtration should be applied to process both return and outside air that is delivered as supply air.