If I only need a (three story) dumbwaiter an hour a week, is it so crazy to put a block and tackle in the air intake duct (typically wider than air delivery duct), and use it to transport books, laundry, garbage and occasionally food? In my old house, we use the air intake duct for communication (ie screaming at each other throught it).
Alternatively, should I consider 24-36" diameter duct (either rectangular sheet metal or some kind of tube) parallel to the air intake (on the grounds the carpentry there is probably easiest to work with and have the right empty width?
Now, I'm 62 and a food delivery back pack or even a cart with triple (stair) weheels would work for now, but I'm thinking of old age, and it is better to do this before I move in.
I'm thinking I'd like added HVAC ducting in the attic and basement so using the sheet metal fabricator on two projects would be synergistic.