Air filters seem pretty efficient; it's just a fan and a filter. If you exchange the air as well, you're sending clean air to the environment. (Though it has mo

Air filters seem pretty efficient; it's just a fan and a filter. If you exchange the air as well, you're sending clean air to the environment. (Though it has more CO2.) For oxygen, fast-growing indoor plants might help a little, but apparently you'd need a lot of them. [1] > Plants produce 22 L for every 150 g of growth (ref 2). They would need to increase in weight by 3.75 Kg (8 pounds), each day, to produce the oxygen used by one person. > Keep in mind that plants grow slowly. Adding 3.75 Kg to your houseplants every day would require a huge number of plants. Carbon capture: not as easy as it sounds. You'll need plenty of sunlight. Grow lamps? What would you do with eight pounds of plants per day? Hopefully some parts are edible, closing the cycle a little. I've heard that people growing cannabis will buy CO2, so if there were some other way to capture it then they'd probably take it. [1] https://www.gardenmyths.com/houseplants-increase-oxygen-levels/ https://www.gardenmyths.com/houseplants-increase-oxygen-leve...