Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP)
Situational Awareness; Troubleshooting; Time Pressure
Aircraft Equipment Problem Less Severe; Inflight Event / Encounter Weather / Turbulence
Air Traffic Control Provided Assistance; Flight Crew Requested ATC Assistance / Clarification; Flight Crew FLC complied w / Automation / Advisory; Flight Crew Diverted; Flight Crew Overcame Equipment Problem
Aircraft
Flt level 240 we recognized we were in and out of icing conditions with one pack MEL'd. We noticed while flying that the anti-ice system came on. Then the cabin started to rise. We descended to FL220 in order to get out of ice conditions. We donned our masks. That wasn't low enough so we continued to 18000 ft but we received a Master Cabin Warning. As we descended the cabin pressure was still rising. The Captain called the Flight Attendant and we continued down to 11000 ft to stabilize the cabin. Still in ice we further went down to 9000 ft. We worked on the diversion items and diverted to ZZZ. No emergency was declared.Our crew communications was great. We constantly were sharing for a shared mental model. The Captain had everything seem seamless and did a fantastic job!
[Report narrative contained no additional information.]
EMB-145 flight crew reported being unable to maintain cabin pressurization due to one air conditioning pack being inoperative and the anti-ice system in use.