Furnace Filters and Air Filtration

Furnace Filters Explained

The furnace filter is an important part of your in-home heating system. The main purpose of the filter is to remove dust and debris particles from entering your furnace and blowing through your home. Air filtration helps with lowering allergy symptoms. The filtering of dust and debris also helps protect the mechanical components of your furnace system!

1) Check & change your filter on a regular basis – The length of time each filter is good for varies and depends on the exact filter you’re using. We recommend always following the manufacture guidelines. Generally speaking, a 1-inch thickness filter is good for 30 days and a 4-inch thickness filter is good for 3-6 months.

Here’s an example of a furnace filter that needed changing months ago. If your filter currently looks like this – consider having your furnace cleaned!

2) You need a proper fitting filter – Your furnace filter should fit JUST right in the filter slot – with no gaps on either side. Having a gap means not all the air circulating through your furnace will be filtered due to the fact that air takes the path of least resistance.

3) Should I pay attention to the MERV rating? – An air filter’s minimum efficiency reporting value (MERV) rating measures how effectively the filter stops dust and other contaminants from passing through the filter and into the air stream. A good Merv rating for residential use to balance filtration vs air flow is between 5 and 11. A higher MERVE rating and your furnace may not be able to handle the decrease in airflow. If your filter slot fits a filter size bigger than 1″, using a filter with a higher MERV rating isn’t as much of a concern due to the more surface area a thicker filter has (less resistance to air).

4) Run for your furnace fan, even when you’re not heating your home! – To keep continuous air flow and filtration in your home, have your furnace fan turned on. If you’ve never done this before, you’ll have to check on your state of your furnace filter more regularly as your filter will be pulling more air through it and filtering more dust and debris.

We carry a wide variety of filter sizes! If you’d like to stock up on replacement filters, just let us know. Prices will vary.