The acronym MERV stands for "Minimum Efficiency Reporting Value." MERV ratings are used to rate the ability of an air cleaner filter to remove dust from the air as it passes through the filter. MERV is a standard used to measure the overall efficiency of a filter. The MERV scale ranges from 1 to 16, and measures a filter's ability to remove particles from .30 to 10 microns in size. To give you an idea of the scale of a micron, 100 microns is about the thickness of a piece of paper or a human hair. Filters with higher ratings not only remove more particles from the air, they also remove smaller particles.
MERV rating of 1 to 4filter are inexpensive
Typically inexpensive 1/2" or 1" disposable panel type filters.
MERV rating of 5 to 8 filters are a better choice
Standard Trion Air Bear filters, MERV 8
Standard Skuttle filters for DB-25-16, DB-25-20 and DB20-20, MERV 8
3M Dust & Pollen filters
MERV rating of 9 to 12filters are often used to help control air born allergens.
Standard Honeywell FC100 series filters MERV 10
Nordyne Partners Choice MERV 11
3M Filtrete Ultra Allergen Purple label, MERV 11
Micro Allergen MERV 10
MERV rating of above 12 are often used in commercial applications such as clean rooms.
We do not stock these, but we can order them from Purolator
How often should you change your filter.
Normally at least twice a year.
More often my be necessary depending on many factors. and example of some are
How often your Furnace / Air conditioner runs
Dusty environment (Such as living on a dirt road)
Not changing you filter often enough reduces your Furnace / Air conditioner efficiency by reducing air flow.