If the condensing unit is underneath (I think it is), pull the louvered grill off the front and have a look around. It probably needs the condenser coil cleaned anyway. While you're under there, look to see how the refrigerant lines are routed into the cabinet. They probably go up to the evaporator either along the back wall (protected by a sheet metal cover) or they may be inside the wall. You can generally see them in the evap area be using a mirror and a light in the rear of the evaporator area and see how they routed from that end too. I'm pretty sure the sidewalls are clear on this model, but a quick call to True tech support may help if you can't see for sure....