This is a bit of a nonsense question. The CO2 diffuses away rather quickly and there is no reason to worry about this.
You clearly don’t have a CO2 monitor.
Ask HN: Best way to remove CO2 in a bedroom?
51–60 of 101 posts
Re: Ask HN: Best way to remove CO2 in a bedroom?
#52Have a fresh air intake installed on your HVAC system.
Re: Ask HN: Best way to remove CO2 in a bedroom?
#53Earlier quoted context omitted.
House plants
They are practically useless in reality. You’d have to live in a greenhouse for them to absorb your CO2 basically.
What about like a tiny cactus on my nightstand?
Will that help calm my anxiety and help me accept the inevitability of death and see it as the indivisible half of the miracle of life?
Re: Ask HN: Best way to remove CO2 in a bedroom?
#54I've found an in-window fan unit (blowing outward) is very effective at keeping CO2 levels down. Noisy, though.
Before that, overnight CO2 levels exceeded 2,600ppm. Now around 700 or so. Can go lower if I crank the fan up.
Now I have the new problem of poor thermal regulation. My window is directly above my HVAC duct, so cool air goes straight from my air conditioner through the fan and out the window.
I plan to wire up a microcontroller to turn the window fan on and off based on both CO2 levels and A/C activity, but I'm not really happy with the the setup. Too hacky, too much noise, and I need to seal the window screen better to keep bugs out.
I've tried just keeping a window open, with no fan, but my CO2 sensor indicated it wasn't super effective. Plus you have to make sure you close the window when it rains otherwise muggy air fills the bedroom.
Re: Ask HN: Best way to remove CO2 in a bedroom?
#55Breathing during sleep adds only little CO2 to the environment. Here's a calculator: https://www.omnicalculator.com/ecology/co2-breathing-emissio... .
My CO2 sensor shows up to 2,600 ppm overnight if we don't actively vent our bedroom. 500-750 if we do, depending on which in-window fan model and how high we set it.
Re: Ask HN: Best way to remove CO2 in a bedroom?
#56Not being snarky, but a window is one of the best options. Air conditioners can often be your worst option, as the air is recirculated more aggressively. We use a window fan that has multiple settings: circulate, ingress, egress. I find that no matter what setting you use, air is recirculated significantly well. On hot days, the fan is set on egress. This seems to do a really great job of removing excess CO2 while no…
Also if you live in an area with low humidity look into getting a swamp cooler. It won’t make the air as cold as AC but I personally prefer it
Swamp coolers can get really nasty and smelly due to being the perfect breeding ground for spores and other nasties.
Re: Ask HN: Best way to remove CO2 in a bedroom?
#57It’s typical for bedrooms to have a ACH (Air Changes per Hour) rate of between 0.35 and 1 So the CO2 is removed regularly.
This. I studied for like 12 years in the biomedical field and I don’t really understand why OP is worried about this.
He could have an unusually tight bedroom. Also, ACH on windless nights will be manyfold lower than on nights with even a 2-MPH breeze.
Re: Ask HN: Best way to remove CO2 in a bedroom?
#58Earlier quoted context omitted.
They are practically useless in reality. You’d have to live in a greenhouse for them to absorb your CO2 basically.
What about like a tiny cactus on my nightstand? Will that help calm my anxiety and help me accept the inevitability of death and see it as the indivisible half of the miracle of life?
It might take your mind off existential anxiety-related thoughts if you stab yourself on its spines in the dark.
Re: Ask HN: Best way to remove CO2 in a bedroom?
#59I have spent a considerable about of time on this question: and it really seems there is no practical way to remove it. You can let it out by ventilating, but that’s about it. This realization has made me quite anxious about the Keeling curve.
It is possible to remove it. If it weren't, then submarines full of people would not be able to stay submerged for months at a time like US Navy submarines routinely do. Right now it is pretty expensive like you point out, but if millions of people were to start wanting CO2-removal equipment, surely our civilization would find a way to get the price way down.
Re: Ask HN: Best way to remove CO2 in a bedroom?
#60For the kind of technology available to us, it could cost up to $100 a day to buy enough "soda lime" to filter out the CO2. You'd want the "color changing" type of product. You would also need HEPA filters to ensure the powder was not getting in the air. Temperature sensors would also be needed to ensure it wasn't releasing so much heat that it causes a fire.
The algae route is cheaper, but needs a lot of algae.