My client asked, "What happens when the air filter is installed backwards?"
That was an excellent question!
And this filter gave her the perfect answer.
What a disaster!
The HVAC filter is constructed such that one side has a filter material and the other has some form of material to strengthen the filter's structure.
The filter in this photo has a metal mesh.
You can also see that this filter has not been replaced since they invented dust.
But that is another issue altogether.
Installing the filter the right way the structured side is intended to prevent the filter material from getting drawn into the unit.
As the filter gets dirtier it restricts air flow more and more.
If the filter is not installed the right way, the filter material can get sucked into the unit, and it can break off and get into the blower fins, and do damage.
The fins spin very fast and are a thin, delicate metal.
You can see in the red circle in this photo how the filter material is right to the edge of the entrance to the blower mechanism!
How often should you replace or clean the air filter?
During periods of heavy use it should be replaced or cleaned ONCE A MONTH!
How do you know which way to install an air filter? Which way would be backwards?
All air filters have an Air Flow arrow.
The Air Flow arrow should
ALWAYS FACE THE BLOWER!
That way you are sure to have the strong side where it needs to be.
Obviously there is a 50/50 shot at getting it right. And I don't know what percentage I see where it is installed backwards. My gut reaction is to say more than 50%!
My recommendation: filtration is a VERY IMPORTANT aspect of the HVAC system! The filter keeps the system clean and does filter some of the air. Don't believe the TV commercials that if you use their wondrous high-filtration filter your health and the health of your family will improve. I treated that subject in a previous blog here. Not that much volume of air flows through the filter to actually have much effect on the air quality of the entire house. Certainly good filters clean what air they filter! But overall, the purpose of the air filter is to keep the unit clean. So, replace that puppy regularly, and install it the right way!
Jay Markanich Real Estate Inspections, LLC
Based in Bristow, serving all of Northern Virginia.
Office (703) 330-6388 Cell (703) 585-7560