Environmental control

The environmental controls of a starship, space station, or even a colony were used to regulate atmospheric conditions including, but not limited to, the concentration of varying gases, lighting, temperature, humidity, and gravity.

Aboard Federation starships and space stations it was typical for there to be limited access to environmental control within crew quarters in order to meet the varied living requirements of these multi-species structures.

Typically, environmental controls for humidity were set to 37% in standard conditions on Federation starships. 

Environmental controls were often used to deploy certain chemicals ship-wide or station-wide. This was done for both benign purposes, such as the release of a retrovirus to cure a ship-wide epidemic, or for more aggressive purposes such as the release of a general anesthetic. 

On a larger scale, environmental controls could be integrated into a planet-wide network in order to regulate or moderate global weather. 

The Cardassians preferred warmer locations, thus their environmental controls were set very high. (Star Trek: Deep Space Nine)

The Starfleet crew of Deep Space 9 often had problems with the environmental controls soon after they took control of the space station. 

In 2369, Constable Odo contacted ops and asked if the environmental controls had broken down because it was snowing on the Promenade. 

In 2370, Miles O'Brien added a new subroutine to the environmental control for the habitat ring. 

An operative of the True Way attempted to assassinate Shakaar Edon in 2372 by attempting to sabotage the environmental controls. 

The environmental controls of Varro starships were completely regenerative, eliminating all waste. 

When chief engineer Geordi La Forge left the USS Enterprise (NCC-1701-E) to make repairs on Zefram Cochrane's Phoenix he named Lieutenant Paul Porter as being in command during his absence. He also ordered Porter to check the environmental controls as it was warm in engineering.