Hi,
I recently stumbled on a nice empty house at the fringes of my city. The homeless people are generally treated like shit under capitalism.
The house had a trapdoor, to a cellar. If it had been closed, maybe with a carpet no urban explorer would find it. Now all stuff I am writing is purely hypothetical, and I don’t intend on doing any of this.
The cellar is pretty empty, It has an empty shelf, where you could store can food, a mattress is very easy to come by, batteries can provide electricity which can be swapped out every week or something like that. So a homeless person could easily live there.
The only real challenge, which could really destroy the whole operation is ventilation. The air is pretty stale, and if the trapdoor is closed I only really see one small window which is blocked by leaves. Leaving this unaddressed could be really fcking dangerous. No questions that CO2 sensors have to be installed, but that is not enough. There needs to be ventilation. But there are 2 constrains:
- it has to be quiet. Urban explorers cant hear a constant humming
- major changes can only really happen in the cellar, and shouldn’t be clearly visible to the outside.
Fortunately I can work with micro-controllers enough to do some stuff. I thought that I run 2 pipes out of the window, roughing them up and covering them with a camouflage net and then leaves (making it look like it belongs seems better but idk how). Then I put two computer fans on it, one sucking one pulling, and they run pretty quickly at the day, when no movement is detected, turn of if movement is detected and don’t run / run very slowly at night.
I have no expertise on ventilation at all, maybe someone can share their ideas and expertise, providing an alternative plan, or improving upon my ideas.
Also for which gasses should I buy sensors? Safety is important, and it is important that no mold forms (no mold formed in 20 years when the trapdoor was open and noone was in there so that’s good.)
You can test for mold using an air quality monitor that has a PM1.0. That means it detects particles <1 μm in size which is good for bacteria. Combine that with an air purifier suitable for the size of the cellar.
Windows to cellars should already have trickle vents otherwise it could get damp pretty quickly. Look carefully at the frame of the small window. If no trickle vent, look to install one.
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?
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.
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.
For gasses, you should monitor co and gas, carbon dioxide alarms are uncommon outside of industries where we have a lot of carbon dioxide stored. Without a better idea of the space it’s hard to suggest a ventilation solution.
They make large diameter vent fans for buildings that are designed to run on a widely varied DC source like a solar panel, those can be really useful.
As the other reply says, you need a large volume of air slowly so a large diameter slower fan is good. You can get flexible duct work anywhere they sell construction supplies :3
oh, smoke alarm and fire extinguisher too! people are always smoking in abandoned buildings, burning them down
people are always smoking in abandoned buildings, burning them down
wtf??? Why would you do stupid shit like this ;-;
but yes this is essential then. It’ll be sooo much work to get that to the place of a save shelter, while remaining stealthy omg ;-;
I think this is critical. People are going to cook and heat in there, and may use fossil fuels rather than electricity. I’d be more concerned about having a CO sensor than CO2.
Never Forget: https://old.reddit.com/r/legaladvice/comments/34l7vo/ma_postit_notes_left_in_apartment/
Electricity is safer to cook with if the building has access to it. Small counter top induction hobs and electric pressure cookers are pretty safe these days especially in comparison to anything with an open flame.
I don’t disagree, but I also wouldn’t make assumptions on what people might choose to use.
Worse still, the electricity might get shut off, which will kill the sensors and powered ventilation and electric cooking & heating. I don’t have a quick & easy answer to that.
Worse still, the electricity might get shut off, which will kill the sensors and powered ventilation and electric cooking & heating. I don’t have a quick & easy answer to that.
I’ve seen a letter on the fence that says, the electricity will be shut down for a couple of hours at xx.xx.xxxx. So I assume that it has electricity. However, I don’t know how safe to use the electrical wires inside the house are. Its been abandoned for 20 years after all.
Is there any way I can check this? Because supplying batteries would be possible, but continuous work (bad because I might move at some point). Else I might be able to wire up something myself Idk.
Hey, a question I’m weirdly able to answer as a maintenance guy and grower.
You want a quiet ventilation system that runs on little power as possible?
Well, I grow marijuana [legal state] and you should consider something like this:
Yes, I know, Amazon. I don’t recommend buying from there if you can; search around online for small shops or even a “hydroponics store” located next to the local seedy smoke-shop for something similar. Explain your situation and they will absolutely help you; even if you live in a “bougie” area you can just phrase it that you’re looking for something to control humidity, provide proper ventilation to an attic area for “herbs” if you have to be so discreet. If you live in a red area; Amazon has that one use, then. Sometimes a sacrifice has to be done while you’re spiting the system ultimately if you know what I mean.
Any small ventilation system for a grow tent should be stealthy, have cheap filters and some even have humidity control. The maintenance man side says that if you are in the attic you should see if any of the ventilation runs from room to room. In the attic in my apartment there are grey, shiny metallic-looking tubing that is flexible and runs in connection to each vent in the apartment. You could splice right into one of those with your ventilation kit and not even have to physically modify anything externally/hide anything. All you’d need is a knife and duct-tape.
Being able to set up two systems to pump in at the top and pump out towards the bottom would be perfect. Seconding a Co2 sensor if you can.
