CO2 concentrations are higher indoors, and they're affecting our cognitive ability. Atmospheric concentrations are going to be high for human cognition, especially in dense urban areas.
Better indoor ventilation will help, but if outdoor air already has higher than optimal CO2 concentrations, scrubbing that air is the only option left. Given the number of air changes needed (assuming 10X), a home unit would need to scrub CO2 from around 100,000 liters of air a day per person.
Small-scale removal is likely much more expensive than industrial BECCS or other carbon capture technology - but the value proposition would be fresher air for healthier, smarter workplaces and homes. Sell me cartridges of enzymes, and take spent ones with bicarbonate for reconditioning, and I can feel like I'm helping the planet a bit while making my life nicer.
https://thinkprogress.org/exclusive-elevated-co2-levels-dire...