The Cullen Report into the Piper Alpha disaster (Cullen, 1990) recommended that a temporary refuge (TR) should be provided on all offshore installations. The TR is required to have a defined performance standard related to its survivability when exposed to a major accident that includes, but is not limited to, ingress of smoke, flammable and toxic gas. HVAC forms an essential part of this. As the TR is the last space for the crew before abandoning the vessel, rig or platform, the HVAC system should create and maintain a comfortable and safe indoor condition free of any explosive and/or toxic gas-air mixtures. The air quality and pressure inside the TR-zone is than of top priority. This can be created by our special TR pressurization unit (TR-unit).