Furnace filter ratings
Furnace filter ratings refer to the efficiency with which a furnace filter can capture airborne particles and impurities. The most commonly used rating system for furnace filters is the Minimum Efficiency Reporting Value (MERV) scale.
The MERV scale ranges from 1 to 20, with higher numbers indicating greater filtration efficiency. Here’s a breakdown of what each MERV rating typically means:
- MERV 1-4: These filters provide minimal filtration and are typically made of disposable fibreglass or synthetic materials.
- MERV 5-8: These filters can capture smaller particles than lower-rated filters, such as pollen, dust mites, and pet dander.
- MERV 9-12: These filters provide even higher filtration levels and can capture smaller particles such as mould spores, fine dust, and some bacteria.
- MERV 13-16: These filters are considered high-efficiency filters and can capture particles as small as smoke, cooking oil, and even some viruses.
- MERV 17-20: These filters are typically used in clean rooms and hospitals and can capture the smallest particles, including bacteria and viruses.
It’s important to note that while higher-rated filters are more efficient at capturing particles, they can also restrict airflow and put more strain on your furnace. Choosing a filter with a MERV rating appropriate for your furnace and your needs is important.