Well, yeah, you could use the dumbwaitor to lift your stuff up to your room Zack. But like I said, the dumbwaitor's not in your room, it's tucked into the antique yet spooky furnace in the back right corner of the common room, which is next to your room on your left if facing the common room.
Here's how it works. You enter through the dorm house's main doors and you have the lobby in front of you. Set 1 of the internal doors takes you into a small alcove with two doors in front and to your right. The door to the right has a sign marked "Stairs" and leads to the spiral staircase. The door in front of you, Set 2, leads to the corridors with the rooms. In front you have the spacious common room, and two hallways of rooms to both sides. After talking to Scooter (MC) who approves the design of the dorm house and draws up the plans to show everybody on her wwebsite, the two hallways each have a total of eight rooms lined up in two rows of four rooms each facing each other. The hallway with dormrooms to your right would be the West Wing, and the hallway to your left would be the East Wing. On Floor 1, the West Wing has the following rooms: You turn to your right in a 90º angle and you see to your left four rooms. In order, they are, Room #1 occupied by the Count (MC) and Mokey Fraggle, Room #3 occupied by FireImps87 and Johnny Fiama and Sal Manilla, Room #5 occupied by Squigiman and Gonzo the Great, and Room #7 occupied by wockaocka (Rachael) and Fozzie Bear. On your right, there's Room #2 occupied by SkeeterMuppet (Kim) and Red Fraggle, Room #4 occupied by Scooter (MC) and Scooter, Room #6 occupied by Dr. Bombay and Kermit The Frog, and a laundry room. You turn back to face the common room and turn in a 90º angle to your left and have the same two rows of rooms. On your right, there's Rooms #8, 10, 12 and 14, all unoccupied at the moment; and Rooms #9, 11, 13 and the Floor 1 Bathrooms on your left.
Then you walk back up the stairs to Floor 2 and see the same setup. Facing the newly furnished Floor 2 common room, differing from the decorations of the common room below, you turn to your right in a 90º angle and find two rows of rooms. On your left, there's Room #15 occupied by Janice & Mokey's Man (Byron) and Rowlf The Dog, and Rooms #17, 19 and 21, all unoccupied at present. On your right, there's Room #16 occupied by Fozzie Bear (Kevin) and Floyd Pepper, the dorm house managers, Room #18 occupied by Anathema (Alex) and Janice, Room #20 occupied by HeraLirambar and Zoot, and Room #22 currently vacant. Turning back to face the Floor 2 common room and then turning to your left in yet another 90º angle, you'll find the following rooms: Room #23 vacant as of right now, Room #25 occupied by Crazy Ernie and Big Bird, Room #27 occupied by Daffyfan2003 and Bert, and Room #29 occupied by Don'tLiveinMoon (Aaron) and Ernie on your right; and Room #24 occupied by AaronLikesRowlf and the Newsman, Room #26 occupied by Erine81981 (Kyle) and Cookie Monster and Grover Monster and Herry Monster, Room #28 left without a resident, and the Floor 2 Bathrooms on your left. In the Floor 2 common room there's a trashcan occupied by Oscar the Grouch in the back left corner and an antique yet spooky furnace in the back right corner when facing the common room again. This same furnace was bought in duplicate and you'll find its mate down in Floor 1's common room. And I suspect there'll be a third such furnace installed into the Floor 3 common room's back right corner once Scooter (MC) comes back to this thread and sees that you've taken up your quarters in Room #30 up on the third floor. It is inside these furnaces where you'll access the dumbwaitor; and according to the explanation laid out for you in this post, you'll see that your room is next to the common room to maintain numeric consistency with the other two floors.
Hope this helps and have a good day Zack and Pepe.