A320 FLT CREW HAS THE CAPT WINDSHIELD HEAT FAIL DURING CRUISE.

Narrative

1 HR PRIOR TO LNDG A L WINDSHIELD AND L SIDE WINDOW HEAT FAIL ECAM WAS DISPLAYED ON THE LOWER ECAM SCREEN. A REVIEW OF THE FLT MANUAL VERIFIED THIS WAS A CREW AWARENESS ECAM ONLY. AT THE TOP OF DSCNT I NOTICED FROST FORMING ON THE CORNERS OF THE AFT L WINDOW. THE DSCNT WAS IN IMC AND ICING CONDITIONS FROM FL280 TO 2800 FT. ENG ANTI-ICE WAS ON THROUGH THE DSCNT. UPON BREAKING OUT AT 2800 FT I NOTICED THE L SIDE AFT WINDOW COMPLETELY OBSCURED; THE FORWARD L SIDE WINDOW PARTIALLY OBSCURED; AND THE LOWER ONE THIRD OF THE FRONT L WINDSHIELD PARTIALLY OBSCURED WITH FOG AND OR FROST. THE CONDITIONS WORSENED AS WE DSNDED LOWER. I XFERRED CTL OF THE ACFT TO THE FO AND A SUCCESSFUL APCH AND LNDG WERE COMPLETED. ONCE ON THE GND THE L SIDE WINDOWS AND WINDSHIELD WERE COMPLETELY OBSCURED. ATTEMPTS TO CLEAN THE WINDOWS WITH PAPER NAPKINS WERE UNSUCCESSFUL. THE REMAINDER OF THE TAXI TO THE GATE WAS ACHIEVED LOOKING OUT THE OPEN L SIDE WINDOW. THE FLT MANUAL PROC HAS NO MENTION OF FROST AND OR FOG FORMING ON THE GLASS SURFACES DUE TO COLD; MOIST AND HUMID CONDITIONS.