Attic Furnace Filter

Merv means minimum efficiency reporting value merv and is an industry standard that measures the overall effectiveness of air filters.

Attic furnace filter.

The most common airborne contaminates that these filters are tested against tend to include pollen dust mites mold spores dust pet dander. Fire hazards can result if there are excess items pressed against the furnace. However both your furnace and a c share a single filter. Keep the area around your attic furnace clean.

As the merv rating increases the finer the filtration becomes. With forced air systems air gets sucked in through the return vents from all around your house goes through the air filter and then through the hvac system where the air is either heated or cooled depending on what you have your thermostat set to. You say you changed the two in the living areas suggesting that you have a dual zone system 2 floors. Astro guard attic replacement filters air filters inc.

Attic whole house replacement filters. The filter is probably at the air intake not in the furnace blower unit up in the attic.