machineroomless

Machineroomless, often abbreviated as MRL, is a term used in elevator technology to describe systems that do not require a dedicated machine room to house the primary hoisting machinery and control equipment. In an MRL installation, the drive motor, drive electronics, and related controls are located in a compact cabinet within the hoistway or in a small adjacent compartment, rather than in a separate above-ground room.

In typical MRL designs, a gearless traction machine with a permanent-magnet motor drives the elevator car. The control system is integrated into the same cabinet or nearby cabinets, enabling a reduced footprint and closer integration with the building structure. The absence of a large machine room can simplify architectural planning, save space, and lower construction costs, particularly in mid-rise and high-rise buildings where space above the shaft is limited.

Advantages commonly cited for MCs MRL systems include space savings, reduced construction requirements for a dedicated machine room, and compatibility with modern, compact control architectures. Disadvantages or considerations include the need for careful vibration and noise management, specialized maintenance access to the hoistway-side equipment, and strict adherence to local safety codes and standards.

MRL elevators must meet applicable elevator safety standards and codes, such as ASME A17.1 in the United States or EN 81 in Europe, along with jurisdiction-specific requirements. The technology has become widespread in modern residential and commercial buildings, offering a compact alternative to traditional machine-roomed designs.