Air Purifiers

Interest in HEPA air purifiers are gaining traction among people wanting to protect themselves against the Covid-19 pandemic. Earlier in 2020, AO Smith even donated 2000 air purifiers to hospitals in China to help contain the outbreak. How do HEPA air purifiers capture airborne contaminants and can it really protect you against Covid-19?

UV Air Purifiers are being marketed as being a better alternative to standard HEPA air purifiers but are they really more effective?

Some manufacturers claim numerous benefits regarding ionizing air purifier's ability to improve indoor air quality but how does a negative ion air cleaner actually work? Is it really effective at removing gasses and particles from the air as it claims to be? Is this technology safe to use?