You need a lot of houseplants to make up for a human. Humans exhale something like 1 kg CO2/day where plants consume something like 0.2 kg/hr/100 m2. Figure natural light, maybe 6-8 hours of full sun in a day, and you'd need 60-80 m2 of leaf surface.

That kg/day of CO2 is enough to raise a 200 m2 home to 3000 ppm CO2. CO2 diffuses pretty well, but my 110 m2 house equilibrates around 1000ppm when it's sealed against the summer heat.