I have to be honest, I'm not a traditional prepper per say, but I am building a bunker under my shed, partly because I can, and partly because I need a storage area.
The initial plan was just a secure area for expensive equipment, but it has now become almost an obsession when I am still digging out the steps (in clay and siltstone) and I'm already down 5 meters below the concrete base of the shed, when I get to the optimal level which I think for now will be another meter I will start breeze blocking and casting the steps in concrete.
At that point I will start considering the 'room element' and what I actually want to do, and this is why I'm here.
I keep telling my neighbours and friends it's going to be an anti zombie bunker, and the more I think about it the more I'd like to carry on the ruse as I think its extremely funny, and also its a really good project and gets you thinking literally and laterally.
I have just completed a 'proof of concept' and a fully working model of a Carbon Dioxide scrubber that with staggered chemical replacement, could make a room breathable for 5 times longer without external ventilation, and the device is capable scubbing CO2 from a contained area with 3 occupants for 10 days before running out of chemicals (about 20KG)...
Also I am thinking about how to create a blast door and deterrants (smoke, Smell, electrification, light, sound and fear) already got the HHO generator to split the Hydrogen and oxygen, so I could A: produce oxygen and B: pump hydrogen beyond the door to create a bubble that could be ignighted (again I have a fully working model as a PoC), it actually can also be used as a small plasma cutter, but those thinking it can save money by plugging into your car and venting into the air inlet, no chance it pulls 30amps when running and would drain you car battery very quickly.... admittedly, for a short time you'd get one hell of a boost in performance and economy.
anyway.... thats me saying hello
Farnet