Having the right filter for your furnace is key to maximizing your heating efficiency. Learn the ins and outs of buying filters in this post.
For furnace filters, the first thing you have to understand is MERV. It’s short for “Minimum Efficiency Reporting Value.” In plain English, it tells you how effective your furnace’s air filter is.
With MERV, ratings range from 1-16, and the higher the rating, the less contaminants that pass through. The types of dust include things like pollen, carpet fibers, mold spores, pet dander, and bacteria.
Does a Higher MERV Mean the Filter’s Better?
Not necessarily. If it did, there’d be no sense in rating MERV from 1-16 because then you’d just get the #16 filter wouldn’t you?
A higher MERV has smaller pores for letting dust and other contaminants flow through. But, that also means lesser air gets through. If you have too much for your furnace, you can actually cut the air flow excessively and reduce air quality.
Some furnace manufacturers include the right MERV in your furnace’s manual, so you know which one to use for your furnace. Others don’t – ask an HVAC professional for a recommendation if that’s the case for you.
Whatever you do, the higher the MERV, the more often you need to change your filter. 3 months should be the minimum. And if it’s really cold out, you might want to do this every month.
Other Tips about Buying Filters with the Right MERV:
- A filter with a MERV of 7-8 generally gives you a good balance between cost and efficiency.
- Filters with a MERV of 4-12 are best for residential use
- If you have family members with weak immune systems or who suffer from allergy problems, shoot for a filter with a MERV of 11 or more
- Never ever switch from fiberglass filters to high-efficiency filters without speaking with an HVAC pro first. To get the maximum benefit from a high-efficiency filter, you must run your furnace’s fan more (which also costs you more). They’ll boost the fan’s speed to make up for the fan’s lower airflow.
- Always be very diligent about replacing your filter. A clogged one burns out your blower’s motor, while damaging your heat exchanger and wasting a lot of your money on unnecessarily used energy.
Those are the ins and outs of using the right furnace filter, and that’ll help you save hundreds on energy throughout the year!