Narrative:

Climbing through FL220 for FL230 we received bleed air duct warning. Called for QRH; at same time I saw that we were depressurizing because all bleed air valves closed on us. As we did checklist I ask for descent to 10000 ft and declared emergency. At the point in checklist to land at suitable airport we decided ZZZ1 at first because it was 20 mi away. At that instance the warning went away; and we were already through 15000 ft going to 10000 ft. Cabin altitude was showing 5500 ft and climbing. We talked to the flight attendants let them know what was going on. We leveled at 10000 ft and the cabin was at 7500 ft and climbing. We then went to 8000 ft and the cabin met our altitude. We contacted dispatch and maintenance; told them what was going on and that the message went away. We decided to go back to ZZZ unpressurized. As we descended to 4000 ft cas message left duct mon caution came up. We ran the QRH; but at this point we were already unpressurized and checklist was of no help. We could not get any of the bleed valves to open. We made a shallow descent to the ZZZ airport and shot the visual. Then we saw that we had no more warnings and we descended to and below 10000 ft before the cabin pressure was above 8000 ft. We canceled our emergency with ATC. Duct mon warning shut the bleed air valves down and we could not get them to re open.

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Original NASA ASRS Text

Title: AN CRJ700 DUCT MONITORING WARNING SYSTEM CLOSED ALL BLEEDS CAUSING THE ACFT TO DEPRESSURIZED. ACFT RETURNED TO LAND.

Narrative: CLBING THROUGH FL220 FOR FL230 WE RECEIVED BLEED AIR DUCT WARNING. CALLED FOR QRH; AT SAME TIME I SAW THAT WE WERE DEPRESSURIZING BECAUSE ALL BLEED AIR VALVES CLOSED ON US. AS WE DID CHKLIST I ASK FOR DSCNT TO 10000 FT AND DECLARED EMER. AT THE POINT IN CHKLIST TO LAND AT SUITABLE ARPT WE DECIDED ZZZ1 AT FIRST BECAUSE IT WAS 20 MI AWAY. AT THAT INSTANCE THE WARNING WENT AWAY; AND WE WERE ALREADY THROUGH 15000 FT GOING TO 10000 FT. CABIN ALT WAS SHOWING 5500 FT AND CLBING. WE TALKED TO THE FLT ATTENDANTS LET THEM KNOW WHAT WAS GOING ON. WE LEVELED AT 10000 FT AND THE CABIN WAS AT 7500 FT AND CLBING. WE THEN WENT TO 8000 FT AND THE CABIN MET OUR ALT. WE CONTACTED DISPATCH AND MAINT; TOLD THEM WHAT WAS GOING ON AND THAT THE MESSAGE WENT AWAY. WE DECIDED TO GO BACK TO ZZZ UNPRESSURIZED. AS WE DSNDED TO 4000 FT CAS MESSAGE L DUCT MON CAUTION CAME UP. WE RAN THE QRH; BUT AT THIS POINT WE WERE ALREADY UNPRESSURIZED AND CHKLIST WAS OF NO HELP. WE COULD NOT GET ANY OF THE BLEED VALVES TO OPEN. WE MADE A SHALLOW DESCENT TO THE ZZZ ARPT AND SHOT THE VISUAL. THEN WE SAW THAT WE HAD NO MORE WARNINGS AND WE DSNDED TO AND BELOW 10000 FT BEFORE THE CABIN PRESSURE WAS ABOVE 8000 FT. WE CANCELED OUR EMER WITH ATC. DUCT MON WARNING SHUT THE BLEED AIR VALVES DOWN AND WE COULD NOT GET THEM TO RE OPEN.

Data retrieved from NASA's ASRS site as of May 2009 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.