(KPIX 5) — Special filters for your furnace and air purifiers for selected rooms will certainly help your home feel more comfortable, but will it help protect you from the novel coronavirus?

Some doctors are suggesting that COVID-19 may be spread by much smaller particles than the droplets caught by some face masks. There are dozens and dozens of air purifiers on the market that claim to filter and remove dust, pollen, mold and even viruses from the air.

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Experts say they are better than nothing but retired Air Force colonel and Stanford Infectious Disease Specialist Dr. Dean Winslow is cautious.

“I would be concerned that by just putting a few ‘in-room’ air purifiers in a large crowded room with lots of people would give a false sense of security,” said Winslow.

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The virus is extremely small and isn’t likely to be captured in standard filters. “I think the most important place, if you’re going to incorporate filters would be part of a high-efficiency HVAC system,” said Winslow.

Your home heating and cooling system gives you options. There are filters that claim to remove viruses down to the 5-micron level. That’s one-tenth the average diameter of a human hair.

“Filters that are used for this purpose will generally work really well against 5-micron droplets but some of the viral material might be in droplets as small as 1 micron,” said Dr. William Nazaroff, Distinguished Professor of Engineering Emeritus at the University of California, Berkeley.

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Both doctors agree that the volume of air exchanged is equally as important as using the correct filter.