50FIGURE 50FILTER LOCATIONSI528HORIZONTALI413DOWNFLOWAIRFLOWHORIZONTALMAINTENANCETHESE INSTRUCTIONS AREINTENDED AS AN AID TOQUALIFIED SERVICE PERSONNELFOR PROPER INSTALLATION,ADJUSTMENT AND OPERATIONOF THIS UNIT. READ THESEINSTRUCTIONS THOROUGHLYBEFORE ATTEMPTINGINSTALLATION OR OPERATION.FAILURE TO FOLLOW THESEINSTRUCTIONS MAY RESULT INIMPROPER INSTALLATION,ADJUSTMENT, SERVICE ORMAINTENANCE, POSSIBLYRESULTING IN FIRE, ELECTRICALSHOCK, CARBON MONOXIDEPOISONING, EXPLOSION,PROPERTY DAMAGE, PERSONALINJURY OR DEATH.TABLE 14FILTER SIZESUPFLOW FILTER SIZESFURNACE INPUT BOTTOM SIDE QUANTITYWIDTH MBTUH SIZE SIZE171/2" 45, 60, 75A 153/4" X 25" 153/4" X 25" 121" 75B, 90, 105 191/4" X 25" 153/4" X 25" 1241/2" 120 223/4" X 25" 153/4" X 25" 1DOWNFLOW/HORIZONTAL FILTER SIZESFURNACE INPUT QUANTITYWIDTH MBTUH SIZE171/2" 60, 75A 12" X 20" 221" 75B, 90, 105 12" X 20" 2241/2" 120 14" X 20" 2! WARNING