Furnace efficiency is one thing.
Best high efficiency air filter.
Finding the best hvac air filters for home for most homeowners a more expensive merv 7 or 8 pleated filter provides a good balance between cost and filtration efficiency.
The best air purifiers for such a task he says are high efficiency particulate air hepa filters which can pluck out particles that are as small as five micrometers or one millionth of a meter.
If you choose a purifier with a hepa filter or high efficiency particulate air filter it should remove about 99 96 percent of all airborne particles but there are other kinds of air purifiers.
Air filters also help keep your furnace s coils and heat exchangers clean which may prolong furnace life and keep it running efficiently.
These filters trap 80 to 95 percent of the particles 5 microns and larger more than enough filtration for most households.