All About Bloomfield HVAC Filters: MERV and Changing Frequency

In part one of this two-part blog series, we went over some of the most common types of HVAC air filters available today, plus their general qualities. HVAC filters are a vital component of your system, helping trap contaminants and maintain proper air flow, and choosing the right option for your home or building is important — as are a few related concepts.

At FLAME Heating, Cooling, Plumbing & Electrical, we’re happy to provide a wide range of HVAC services to both homes and commercial buildings in Bloomfield, from air duct cleaning and thermostat services to numerous upkeep and maintenance themes — many of which may involve your HVAC filter or filtration system in some way. Today’s part two of our series will go over the general filter ratings you’ll see when choosing your filter, plus some basics on how often your filters should be changed.

Furnace Air Filter (MERV) Ratings

When it comes to how air filters are rated, “MERV” rating — short for minimum efficiency reporting value” — is the number to look at. The higher your MERV rating, the more efficient your filter is at removing contaminants from your air. Here are the general MERV rating ranges:

• MERV 1-4: Inexpensive pleated paper filters that do a decent job at removing airborne dust and larger particles.
• MERV 5-8: Higher-efficiency foam, slotted fiberglass, and “pleated media” filters designed for low to moderate HVAC uses. Good for homes with pets or smokers.
• MERV 9-12: Medium range pleated filters, usually made of micro-fiber materials. These are often used for residential HVAC systems with pets or smokers.
• MERV 13+: More expensive higher MERV filters designed to remove the smallest contaminants from the air — including pollen and dust mites. While these typically won’t hurt a home’s mechanical system, they’re usually too pricey for most residential uses.

When it comes to your HVAC system, you’ll typically want to choose filters with an MERV rating of at least 7 — this is the minimum efficiency reporting value that will help catch the most common contaminants in your area. For homes with pets or smokers — or less-than-perfect indoor air quality — you may need to look at higher MERV rated filters, especially for your air return system.

Filter Changing or Cleaning Schedule

How often should your HVAC filters be changed (or cleaned , for those homes or buildings that use non-replaceable types)? The answer here will vary depending on precisely which type of filter you purchase, and the best approach here is to check packaging — and perhaps the manufacturer website — for specific guidance on your specific model.

As a general rule, most high-efficiency air filters require changing every 1-3 months, depending on what you’re using them for — while lower MERV-rated filters can often last an entire HVAC season before needing to be changed. With some research and planning ahead of time, you can ensure you won’t ever leave your filters in too long, which leads to issues like growing contaminant numbers and potentially poor airflow.

For more on HVAC air filters, or to learn about any of our heating and air or plumbing services in Bloomfield or other parts of Michigan, speak to the staff at FLAME Heating, Cooling, Plumbing & Electrical today.