Earth normal pressures are in the range of 40-200 kPa.
Pressure differences between the inside the CELSS and the outside environment impacts structural integrity considerations, requiring airlocks, and other pressure regulation measures.
An airtight home must have a flexible lung (see Biosphere II) to allow internal and external air pressure to remain equal, without actual exchange of air.
Airlocks
CELSS design within Earth's atmosphere
The pressure of the Earth's atmosphere is extremely dynamic, varying with the weather. In order to maintain structural and atmospheric integrity of the CELSS in these conditions, a pressure regulation mechanism must be included in the design. Biosphere 2 used a bladder system1. Such a mechanism can be as simple as a large trash bag on one end of a pipe that penetrates a wall. Typical atmospheric pressure changes due to weather may amount to 2-5% of the total CELSS volume, so for a 500m3 CELSS, the bladder should be 10-25m3. The device must account not only for the pressure changes due to weather, but from heating and cooling of the air inside the CELSS.
Because leaks are almost inevitable, it is usually advisable to manage the flow by creating positive pressure inside the CELSS, and replacing the lost air with intentionally filtered air from outside.
CELSS design in space
Since O2 is the active component (as far as animals are concerned), lower pressures can conceivable be tolerated if the percentage of O2 content is increased.
Pressure differences between the inside the CELSS and the outside environment impacts structural integrity considerations, requiring airlocks, and other pressure regulation measures.
An airtight home must have a flexible lung (see Biosphere II) to allow internal and external air pressure to remain equal, without actual exchange of air.
Airlocks
CELSS design within Earth's atmosphere
The pressure of the Earth's atmosphere is extremely dynamic, varying with the weather. In order to maintain structural and atmospheric integrity of the CELSS in these conditions, a pressure regulation mechanism must be included in the design. Biosphere 2 used a bladder system1. Such a mechanism can be as simple as a large trash bag on one end of a pipe that penetrates a wall. Typical atmospheric pressure changes due to weather may amount to 2-5% of the total CELSS volume, so for a 500m3 CELSS, the bladder should be 10-25m3. The device must account not only for the pressure changes due to weather, but from heating and cooling of the air inside the CELSS.
Because leaks are almost inevitable, it is usually advisable to manage the flow by creating positive pressure inside the CELSS, and replacing the lost air with intentionally filtered air from outside.
CELSS design in space
Since O2 is the active component (as far as animals are concerned), lower pressures can conceivable be tolerated if the percentage of O2 content is increased.