Modern environmental control aims for high standards of living and working conditions. Improving fitness of body and mind places more demands on the breathable atmosphere, whilst acceptable pollutant levels have reduced with science and improved understanding. To support large numbers of people for extended periods in confined spaces, TPG faces many challenges:
- Respiration consumes oxygen and produces carbon dioxide.
- Charging batteries generates hydrogen.
- Running machinery produces carbon monoxide, hydrocarbons and fumes.
- Cooking produces vapours and odours.
These submarines are large with a high crew complement and require regenerative systems for extended duration underwater. Compared to conventional submarines, management of power consumption is less critical.
Space and power are at a premium on these submarines - a lower energy requirement being equivalent to a longer range. A small crew complement requires a high level of equipment automation. As dive durations become longer, regenerative atmosphere control equipment is increasingly common.