Shelter Room Lab Blender 5.2

A basement room used as a public shelter, cut open so you can see the air. Set the floor area, the number of people, the air supply and the weather, then run hours of shelter time in seconds and watch CO₂, oxygen, temperature, humidity and light. Drag to orbit, wheel or pinch to zoom, right-drag to pan. This is an engineering lesson with abstract mannequins: practical numbers only. Real shelters: follow local authority guidance.

Scenarios

Readout and verdict

Room and people

Ventilation and air supply

Weather and ground

Light, battery, water and open flames

Display

Live graphs

CO₂ (ppm, left) and O₂ (%, right) with a dotted projection if nothing changes. Dashed lines: 1000, 1500 and 5000 ppm

Temperatures (°C): room air, wall surface, soil shell, outdoors and deep ground

Relative humidity of the air and of the wall surface (%), liquid water condensed on the walls (g/m², right)

Battery energy left (Wh, left) and average illuminance (lux, right)

Experiment: how many people fit?

Question: for this room and this kind of activity, what is the largest number of people for whom CO₂ stays under the limit for the whole stay, as a function of the fresh-air flow? Every point is found by integrating the CO₂ balance numerically (RK4, bisecting on the number of people); the curve is the closed form N = dC Q / (g (1 - exp(-Q T / V))) and the dashed line its steady-state limit N = dC Q / g. The floor-area rule is shown as a horizontal limit: the smaller of the two is your capacity.

CO₂ limit Stay Space rule

Numerical checks

The science