If you shop at Home Depot for your furnace filters you’re going to be confused. Why? Because the filters The Home Depot sells have a rating system called “FPR,” which stands for Filter Protection Rating, and is exclusive to filters sold at The Home Depot.
The industry filtration rating standard is MERV (Minimum Efficiency Reporting Value), the system that virtually all filter manufacturers have used since 1960. MERV ratings vary from 1 (filters only the largest of particles) to 16 (filters ultra-fine particles like viruses and bacteria). Low MERV ratings don’t offer much filtration for your home or for protecting furnace components. Very high MERV ratings can reduce airflow far too much and are generally only used for filtering air in places such as operating rooms. The best choice for most homes is a MERV rating between 7 and 12. So what should you choose if you shop at The Home Depot?
Here is a comparison chart that will help you decide:
|13||10||Homes with in-house smokers or family members who have low-immunity or allergy issues.|
|11||7||Homes in dusty environments, with frequent open windows, and pet owners.|
|8||5||Perfect for the vast majority of homes. Does a fine job of filtering air while letting the air flow smoothly.|
The higher the MERV or FPR rating, the sooner your filter will clog and the more frequently it’ll need to be replaced. So, it’s not always best to choose a high-rated filter. In fact, high-rated filters can actually cause strain on furnaces because there’s not enough airflow to keep motors and components cool, especially if you don’t change the filter often enough. At the very least, filters should be inspected once a month. Visually compare the old filter to a brand new one, and you’ll know when it needs to be replaced.