General Dumbwaiter FAQ
Why is a dumbwaiter called a dumbwaiter
The word dumbwaiter is a funny name but dates back to the very beginning of the inception of the helpful device. Derived from the elevator world dumbwaiters in the beginning were all manually powered with a rope and pulley system. Today the manual dumbwaiter system is still available and being produced. However most dumbwaiter lifts are powered by a electric motor and they have a number of different systems that make the lifting take place.
The term dumbwaiter was first used to describe a small freight elevator or lift whose purpose was to carry objects between floors. It was called that because it carried food and other objects between floors of large houses with many staff members trying to run a smooth household. The “dumbwaiter” was not seen nor heard, and thus the term was born.
How much does it cost to put in a dumbwaiter?
The cost on dumbwaiters can vary greatly. Depending on the use being for residential or a commercial application. Also the lifting weight category will be a significant factor in the cost of the system. The number of floors served and amount of openings at each floor also contributes to the complexity of the dumbwaiter system cost. Most residential dumbwaiters today moving between two floors will cost between $3,600 – $6,500 for the equipment only. Other costs associated with the installation of a dumbwaiter system are the construction of the dumbwaiter hoist-way and the installation cost. The installation cost of a residential system can also vary greatly depending on your geographical location. Some states require the systems to be installed by a C-11 licensed elevator contractor. When this is the case the cost will soar to 2-3 times the cost of the dumbwaiter equipment, and will require a state inspection from the elevator division to pass the unit into service. The $3,600 versions are the low end / lower quality systems with limited customization and single phase electric motors with a chain, belt or rack and pinion track drive system. They also have a very industrial look and feel to the dumbwaiter car. The higher end units have many more options available and are fully customizable. Cars available in every wood species as well as mild steel with a durable powder coat finish and solid stainless steel. The stainless steel option is great for coastal communities where the salt air takes it’s toll on everything made from mild steel. Eventually the mild steel will begin to show signs of rust over time. The stainless steel and custom colored powder coated mild steel cabs suit the needs of higher end multi floor homes as well. The high quality dumbwaiter systems will run three phase electric gear motors and variable frequency drives (VFD) for complete motor control and protection. The three phase motor is best suited for the forward and reversing action required in a dumbwaiter lift system. With this type of motor and VFD drive system the system can have a soft start and soft stop. The VFD allows the ramp up and ramp down control of the motor that is not only much more forgiving on the motor system but is a very smooth take off and landing for the dumbwaiter car. This can be especially important for the restaurant industry when moving things such as a bowl of soup to mixed drinks. But it also works in favor of every system by being very easy going on the motor drive system.
Commercial dumbwaiter systems installed with equipment, installation, permitting and inspection also can vary greatly in price. Depending on the use and requirements of the installation as well as the number of floors served and load capacity. These commercial dumbwaiters can range in price from $20,000 to over $100,000. This will include all of the fire rated door systems required by code for these types of machines. Once again the above costs on the commercial rated dumbwaiter systems do not include the cost of building the hoist-way. A dumbwaiter in a commercial setting can greatly reduce the chance of an injury to an employee traveling stairs like in a restaurant for instance. Less injuries = less claims filed = less risk to the owners of said business. So in the long run it is a wise business decision to install a quality dumbwaiter system.
How does a dumbwaiter work?
Dumbwaiters of the past were all manually operated with ropes and pulley systems. These types of systems are still available today although not nearly used as much as fully automatic electric motor dumbwaiters. A dumbwaiter system basically operates very similar to an elevator. But instead of getting in the cab and selecting a floor to travel to you call or send the system via the call / send station at each floor outside of each entrance. The motion control of these different type of systems also varies in design. Some units use a winding drum and cable system on higher end systems with guide rails and pulley systems. For high speed and a high number of floors served the drive system will be very similar to a high rise elevator system know as a traction system. This system incorporates the use of several lifting cables attached to the dumbwaiter car on one side, cables go up to the top of the hoist-way and wrap around the traction drum machine and back down the opposite side of the hoist-way to a set of counter weights that also ride on a track system. This is a very efficient multi floor (usually over six floors) system derived from the elevator world.
Lower end basic dumbwaiters use several different modes of operation. Some run on rack and pinion gear and track system. These are slow and transfer more noise into the structure due to the drive system. Some run on chain and sprocket systems also creating a bit more noise due to the drive chain and sprockets. Some run on a gear and rubber belt system keeping the noise down but eventually wearing out the belt. The belts are also susceptible to skipping gear teeth if not properly tensioned or due to stretching. The electronics also vary from simple old school relay logic controller systems to very complex micro controller digitally controlled devices.
Did Thomas Jefferson invent the Dumbwaiter?
To improve the lives of him and his workers, Jefferson invented the Great Clock. Thomas Jefferson also treated the dumbwaiter as a more efficient way to transport wine form the cellar to the main floor. Servants controlled the dumbwaiter by using a pulley system. So yes this is a true statement and we owe the initial development of the dumbwaiter to Thomas Jefferson.
Are dumbwaiters illegal?
When did they become illegal? There are some illegal dumbwaiters in use today. People have converted machines such as a garage door openers into a vertical shaft transportation system like a dumbwaiter. However these types of home made systems will not pass any codes and are very dangerous. They do not posses the safeties of modern day dumbwaiter systems. This leaves the door open for the possibility of injury or death. They do not have emergency safety switches or more importantly door locking devices tied into the dumbwaiter controller. This allows the make shift systems to run with the hoist-way doors open creating a great safety hazard especially for children. While many dumbwaiters have either been walled up or converted into pantry nooks or decorative spaces, they are still legal, according to Buildings Departments, provided they have kept up-to-date with building codes, which specify fire resistance and proper venting of the shafts and the use of an approved safe dumbwaiter system. It is best to choose a dumbwaiter system that has a third party recognized certification based on current elevator codes for your jurisdiction.
How much weight can a dumbwaiter hold?
The weight categories of dumbwaiter systems usually range from 75 pounds – 500 pounds. The weight of a system is based on the cubic inches on the inside of the dumbwaiter cab. The maximum size for a dumbwaiter is 500 pounds. This equates to a 36” wide x 36” deep x 48” tall dumbwaiter cab. Width x Depth x Height = cubic inches, divided x 1728 (cubic inches in a square foot) x a factor of 13.9 give you the lifting capacity. Most residential dumbwaiters are in the 75- 250 pounds range. Although some homes do install the largest cabs available to move larger items, this being the 500 pounds units. Above 500 pounds the systems are categorized a a freight elevator and can lift up to 10,000 pounds such as a vehicle lift.
What is the difference between a residential and a commercial dumbwaiter?
A residential dumbwaiter is really just a stripped down version of a commercial lift. This version will be missing some required devises such as car gate monitoring or commercial grade industrial door locking devices. Usually the residential versions will have a much lighter duty drive system and cab for transporting the materials used in a household environment. A commercial dumbwaiter will have all the required bells and safety whistles allowing the machine to meet all the commercial codes for safe operation in a commercial environment. It will also have a very heavy duty car and gate system ready for the punishment of personnel in the industrial setting. Also the guide rails, drive machines and trolley or car slings will be made of industrial grade components designed for years of constant use and abuse.
Is it called a food lift or a dumbwaiter?
When it comes to the elevator industry it is important to remember that it spans far and wide which means that each type of elevator will have its own different origin story. For example, Elisha Graves Otis may be credited with inventing the emergency break for residential and commercial elevators however the dumbwaiter is an entirely different contraption although todays systems are required to have a very similar emergency braking system. Here is everything you need to know about the origins of the dumbwaiter…
Many people are unaware that the dumbwaiter has actually been around since the age of the Romans! After all, they may have lived during 200BC but they still had to move things between different floors. The term ‘dumbwaiter’ itself was coined because the lifts were first used in large rich houses where the kitchen was found in the basement or servants quarters so the waiters were silent and never seen. Plus, since dishes and food had to be transported between the different floors, it was more practical to use a dumbwaiter.
Of course, the dumbwaiters that were used hundreds of years ago were more practically designed than aesthetic as they were often operated by a rope and pulley in order to lift the dumbwaiter to the required floor and lower it back down again. Of course, the introduction of an electric motor in the 1920’s and other modern 21st century adaptions now means that a simple press of a button can do all the work for us.
Interestingly the dumbwaiter has also creeped out of the kitchen during its lifetime and in 1957, a play write called Harold Pinter wrote a play that was called ‘The Dumb Waiter’ which takes place in a basement kitchen and focuses on a dumbwaiter which delivers mysterious food orders.
Although the dumbwaiter may seem like an old fashion addition you may only find in Buckingham Palace, it is actually an integral part of the service industry. In fact, whilst the days of rope hauling may be behind us, modern adaptions mean that heated cabins, safety locks and contamination prevention is something that dumbwaiters can provide.