Narrative:

En route at FL370; the flight attendant called to advise us the cabin was very cold. We had made various temperature adjustments for them on the preceding flight. On the environmental control system page; the cabin indicated 15 degrees C; with 25 degrees selected. The pack output temperature was amber dashes. The right pack was indicating normally; with a green outline on the environmental control system page. The point here is; the automatic temperature controller had been deferred; but not rendered inoperative. In the MEL; the maintenance procedures call for the deactivation of the related circuit breakers; and collaring of the circuit breakers. This is in addition to selection of the manual temperature controller. Neither had been done. I believe what happened is the automatic temperature controller was indeed not working correctly. I believe that the automatic temperature controller allowed a lot of cold acm air into the cabin; and not enough hot bypass air. I believe this caused the temperature control valve to freeze in position. Our first flight in this plane was from ZZZ to ZZZ1 the automatic temperature controller worked perfectly fine. I didn't think about it; and should have. I did not select manual temperature control for the right pack while on the ground in ZZZ. In hindsight; I should have verified this. I was a bit rushed. I'd like to mention that I did comply with the operational procedures of the MEL which clearly state 'none.' well; now we are FL370; and the cabin temperature is getting painfully cold for people wearing shorts and t-shirts. I selected manual control of the temperature for the right pack; and got a pack fail amber message on the EICAS. I deselected the manual control; and the message went away. Pressurization was normal; and all indications were normal. I believed at this point the problem is with both temperature controllers. I contact our dispatcher and maintenance to try to address the problem and also to get guidance as to what is too cold for passenger comfort/safety. I received no guidance on temperature. I suggested a divert to ZZZ1; which was fairly close. The dispatcher suggested ZZZ2. I complied. After turning to ZZZ2; I realized it was not close enough to make a significant difference in time versus ZZZ. I then called the dispatcher again; and said we needed to go to ZZZ3. He helped me facilitate this. We landed safely with plenty of fuel. Upon arrival; a female passenger broke out in hives; apparently an allergic reaction to something she had eaten. We called for medical attention. Customs came to facilitate because we were an international flight; although we had been pre-cleared. The passenger was given the ok to board by the medical personnel and station personnel. We departed ZZZ3 and had an uneventful flight into ZZZ. So; had the mechanic that did the deferral actually deactivated the automatic temperature controller; I don't believe we would have had such uncontrolled cold air flowing into the cabin. Also; had I verified that the manual switch was selected for the right temperature controller; the cold air would have been ctlable. I did not react to the pack fail because I believed it was a direct result of the selection of manual mode on the right temperature controller. I eventually ended up diverting an international flight because of cabin temperature. This was a result of both the mechanic and I making errors.

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Original NASA ASRS Text

Title: A CRJ700 IN CRUISE AT FL370 DIVERTED DUE TO THE DEFERRED R PACK PUTTING OUT FULL COLD AIR AND UNCTLABLE. MEL SPECIAL PROCS NOT ACCOMPLISHED.

Narrative: ENRTE AT FL370; THE FLT ATTENDANT CALLED TO ADVISE US THE CABIN WAS VERY COLD. WE HAD MADE VARIOUS TEMP ADJUSTMENTS FOR THEM ON THE PRECEDING FLT. ON THE ENVIRONMENTAL CTL SYS PAGE; THE CABIN INDICATED 15 DEGS C; WITH 25 DEGS SELECTED. THE PACK OUTPUT TEMP WAS AMBER DASHES. THE R PACK WAS INDICATING NORMALLY; WITH A GREEN OUTLINE ON THE ENVIRONMENTAL CTL SYS PAGE. THE POINT HERE IS; THE AUTOMATIC TEMP CONTROLLER HAD BEEN DEFERRED; BUT NOT RENDERED INOP. IN THE MEL; THE MAINT PROCS CALL FOR THE DEACTIVATION OF THE RELATED CIRCUIT BREAKERS; AND COLLARING OF THE CIRCUIT BREAKERS. THIS IS IN ADDITION TO SELECTION OF THE MANUAL TEMP CONTROLLER. NEITHER HAD BEEN DONE. I BELIEVE WHAT HAPPENED IS THE AUTOMATIC TEMP CONTROLLER WAS INDEED NOT WORKING CORRECTLY. I BELIEVE THAT THE AUTOMATIC TEMP CONTROLLER ALLOWED A LOT OF COLD ACM AIR INTO THE CABIN; AND NOT ENOUGH HOT BYPASS AIR. I BELIEVE THIS CAUSED THE TEMP CTL VALVE TO FREEZE IN POS. OUR FIRST FLT IN THIS PLANE WAS FROM ZZZ TO ZZZ1 THE AUTOMATIC TEMP CONTROLLER WORKED PERFECTLY FINE. I DIDN'T THINK ABOUT IT; AND SHOULD HAVE. I DID NOT SELECT MANUAL TEMP CTL FOR THE R PACK WHILE ON THE GND IN ZZZ. IN HINDSIGHT; I SHOULD HAVE VERIFIED THIS. I WAS A BIT RUSHED. I'D LIKE TO MENTION THAT I DID COMPLY WITH THE OPERATIONAL PROCS OF THE MEL WHICH CLRLY STATE 'NONE.' WELL; NOW WE ARE FL370; AND THE CABIN TEMP IS GETTING PAINFULLY COLD FOR PEOPLE WEARING SHORTS AND T-SHIRTS. I SELECTED MANUAL CTL OF THE TEMP FOR THE R PACK; AND GOT A PACK FAIL AMBER MESSAGE ON THE EICAS. I DESELECTED THE MANUAL CTL; AND THE MESSAGE WENT AWAY. PRESSURIZATION WAS NORMAL; AND ALL INDICATIONS WERE NORMAL. I BELIEVED AT THIS POINT THE PROB IS WITH BOTH TEMP CONTROLLERS. I CONTACT OUR DISPATCHER AND MAINT TO TRY TO ADDRESS THE PROB AND ALSO TO GET GUIDANCE AS TO WHAT IS TOO COLD FOR PAX COMFORT/SAFETY. I RECEIVED NO GUIDANCE ON TEMP. I SUGGESTED A DIVERT TO ZZZ1; WHICH WAS FAIRLY CLOSE. THE DISPATCHER SUGGESTED ZZZ2. I COMPLIED. AFTER TURNING TO ZZZ2; I REALIZED IT WAS NOT CLOSE ENOUGH TO MAKE A SIGNIFICANT DIFFERENCE IN TIME VERSUS ZZZ. I THEN CALLED THE DISPATCHER AGAIN; AND SAID WE NEEDED TO GO TO ZZZ3. HE HELPED ME FACILITATE THIS. WE LANDED SAFELY WITH PLENTY OF FUEL. UPON ARR; A FEMALE PAX BROKE OUT IN HIVES; APPARENTLY AN ALLERGIC REACTION TO SOMETHING SHE HAD EATEN. WE CALLED FOR MEDICAL ATTN. CUSTOMS CAME TO FACILITATE BECAUSE WE WERE AN INTL FLT; ALTHOUGH WE HAD BEEN PRE-CLRED. THE PAX WAS GIVEN THE OK TO BOARD BY THE MEDICAL PERSONNEL AND STATION PERSONNEL. WE DEPARTED ZZZ3 AND HAD AN UNEVENTFUL FLT INTO ZZZ. SO; HAD THE MECH THAT DID THE DEFERRAL ACTUALLY DEACTIVATED THE AUTOMATIC TEMP CONTROLLER; I DON'T BELIEVE WE WOULD HAVE HAD SUCH UNCTLED COLD AIR FLOWING INTO THE CABIN. ALSO; HAD I VERIFIED THAT THE MANUAL SWITCH WAS SELECTED FOR THE R TEMP CONTROLLER; THE COLD AIR WOULD HAVE BEEN CTLABLE. I DID NOT REACT TO THE PACK FAIL BECAUSE I BELIEVED IT WAS A DIRECT RESULT OF THE SELECTION OF MANUAL MODE ON THE R TEMP CONTROLLER. I EVENTUALLY ENDED UP DIVERTING AN INTL FLT BECAUSE OF CABIN TEMP. THIS WAS A RESULT OF BOTH THE MECH AND I MAKING ERRORS.

Data retrieved from NASA's ASRS site as of January 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.