RETURN LAND BY FLC OF AN ACR TWIN JET WHICH HAD A LOSS OF THEIR CABIN PRESSURIZATION CONTROLLERS WHICH CREATED AN OVERPRESSURE SIT WITH A HIGH RATE OF CLB THAT MATCHED THE ACFT CLB; WHEN 20 MI NE OF DEN; CO.

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TKOF ON RWY 8 AT DENVER. CLBING UP TO 16000 FT MSL; CAPT NOTICED CABIN PSI PEGGED UP. BOTH PRIMARY AND STANDBY PRESSURIZATION CONTROLLERS HAD FAILED. THE ACFT WAS PRESSURIZED TO 8.5 PSI; OUTFLOW VALVE FULLY CLOSED; AND NOW CABIN ALT WAS MATCHING ACFT CLB RATE. DECIDED TO RETURN TO DENVER. MANUALLY OPENED OUTFLOW VALVE TO DEPRESSURIZE BELOW 10000 FT MSL. LANDED NORMALLY. AFTER DEPLANING; ONE FLT ATTENDANT COMPLAINED OF DISORIENTATION. SHE WAS TAKEN TO HOSPITAL. SHE WAS TESTED THOROUGHLY FOR EFFECTS OF RAPID ALT CHANGE. NO SIGNS OF PERMANENT DAMAGE FOUND. 2 OTHER FLT ATTENDANTS COMPLAINED OF 'TINGLING' SENSATION IN FINGERTIPS. THEY DECLINED GOING TO HOSPITAL. NO PAX COMPLAINED OF SYMPTOMS. NO OTHER CREW MEMBERS COMPLAINED OR SYMPTOMS. I ESTIMATE THE RATE OF CABIN ALT CLB THAT WE MANUALLY SELECTED TO HAVE BEEN BTWN 3000-4000 FPM. THIS ESTIMATION BASED ON TIME IT TOOK TO DEPRESSURIZE. THE CABIN VSI GAUGE ONLY GOES TO +/-1500 FPM. I BELIEVE WE SHOULD HAVE TAKEN MORE TIME TO DEPRESSURIZE THE ACFT. IF I WERE IN THE SAME SIT TOMORROW; I WOULD LIMIT TO 1000-1500 FPM CLB RATE; CONSIDERING POSSIBLE PHYSIOLOGICAL EFFECTS.