When an oxygen concentrator, is not being used (for example, when the unit is turned off, being shipped, stored, or the like), the gas separation adsorbent may be detrimentally affected and/or deactivated, and thus, the life of the device (gas separation adsorbent) may be affected. In order to at least partially mitigate this issue, a method and an apparatus capable of performing said method are provided. The method includes the steps of assessing the pressure of at least one canister of the oxygen concentrator while the oxygen concentrator is in an off state and subsequently enabling the compressor at a speed sufficient to pressurise the canister to a predetermined pressure based on the assessed pressure of the oxygen when the oxygen concentrator is in an off state.
