CO2 is heavier than O2 and naturally sinks to the bottom. So you'd need to install ventilation pipes around the room, connecting between cellar floor level and the ground level above. A computer fan is not big enough to cut it, and you are thinking about it the wrong way as well. You need to move large volumes of air, so the smaller the fan diameter, the more RPMs you need to achieve desirable movement of sufficient air volume, which means more sound produced by the movement of the fan.
What you could do is take a couple old stand or wall fans and weld them together to create a 6-blade double-sided fan. Then dig an S-tunnel for ventilation, and line it with aluminum or PVC to create a sterile surface. Install the fan somewhere in the middle, and connect it to a fan motor modified to work at slower RPMs for silent running, but running constantly.
You can camouflage the ventilation tunnel's exit by building a small structure around it that makes it look like a brick grill maybe. Whatever ventilation system you use, you'll need it to be covered to protect the fan's electrical system and the cellar itself from rain. You'll also need to install grills/filters to prevent critters from moving through, especially stuff like mice, snakes, or venomous insects/arachnoids.
As for mould, you need to make sure the place is not susceptible to humidity, so a simple dehumidifier should suffice.
Aside from a CO2 sensor, it wouldn't be a bad idea to also have a humidity sensor and maybe a carbon monoxide sensor as well. You don't need much else.
Very great advice, I don't want to kill people but help them after all. But if I remember correctly the cellar was about 10m².
Did you mean combining blades of fans?
Also have you done this already once or more? And if so, can you share pictures?
I have done something similar but not for living conditions. Rather for a room containing fermenters. I don't have pictures to share though, since I no longer work at that place.
If you don't have the knowledge to put together a make-shift fan, then I'd suggest to go out and buy something like the one that another commenter suggested. I only suggested something like that because it would cut down your costs significantly. If you have no experience in doing something like that though, it'd be a lot safer to buy something ready.
You need a carbon monoxide detector not carbon dioxide. I don't know if that's just a mistake but monoxide is the dangerous one that's more dense than oxygen and puts people to sleep.
I assumed his plan was to have a carbon dioxide sensor that would activate the fan. Humans don't breathe out carbon monoxide and it doesn't float in the atmosphere in large quantities, so while life-saving by itself, a CO sensor would be useless for activating the fan regularly. For purposes of ventilation, a rise in carbon dioxide concentration means a reduction in oxygen.
Carbon dioxide is heavier than carbon monoxide by the way.
CO2 is heavier than O2 and naturally sinks to the bottom. So you'd need to install ventilation pipes around the room, connecting between cellar floor level and the ground level above. A computer fan is not big enough to cut it, and you are thinking about it the wrong way as well. You need to move large volumes of air, so the smaller the fan diameter, the more RPMs you need to achieve desirable movement of sufficient air volume, which means more sound produced by the movement of the fan.
What you could do is take a couple old stand or wall fans and weld them together to create a 6-blade double-sided fan. Then dig an S-tunnel for ventilation, and line it with aluminum or PVC to create a sterile surface. Install the fan somewhere in the middle, and connect it to a fan motor modified to work at slower RPMs for silent running, but running constantly.
You can camouflage the ventilation tunnel's exit by building a small structure around it that makes it look like a brick grill maybe. Whatever ventilation system you use, you'll need it to be covered to protect the fan's electrical system and the cellar itself from rain. You'll also need to install grills/filters to prevent critters from moving through, especially stuff like mice, snakes, or venomous insects/arachnoids.
As for mould, you need to make sure the place is not susceptible to humidity, so a simple dehumidifier should suffice.
Aside from a CO2 sensor, it wouldn't be a bad idea to also have a humidity sensor and maybe a carbon monoxide sensor as well. You don't need much else.
Very great advice, I don't want to kill people but help them after all. But if I remember correctly the cellar was about 10m². Did you mean combining blades of fans?
Also have you done this already once or more? And if so, can you share pictures?
Yeah combining blades into one.
I have done something similar but not for living conditions. Rather for a room containing fermenters. I don't have pictures to share though, since I no longer work at that place.
If you don't have the knowledge to put together a make-shift fan, then I'd suggest to go out and buy something like the one that another commenter suggested. I only suggested something like that because it would cut down your costs significantly. If you have no experience in doing something like that though, it'd be a lot safer to buy something ready.
You need a carbon monoxide detector not carbon dioxide. I don't know if that's just a mistake but monoxide is the dangerous one that's more dense than oxygen and puts people to sleep.
I assumed his plan was to have a carbon dioxide sensor that would activate the fan. Humans don't breathe out carbon monoxide and it doesn't float in the atmosphere in large quantities, so while life-saving by itself, a CO sensor would be useless for activating the fan regularly. For purposes of ventilation, a rise in carbon dioxide concentration means a reduction in oxygen.
Carbon dioxide is heavier than carbon monoxide by the way.