The controlled air exchange system in an elevator machine room designed to maintain the temperature and humidity within the limits required for safe and reliable operation of the traction machine, controller, and drive equipment.
Full Definition
Elevator machine rooms generate heat from the traction motor, drive inverter (VVVF), transformer, and controller electronics. EN 81-20 requires that the machine room temperature must not exceed +40°C (at ambient design conditions) and must not fall below +5°C. Typical heat dissipation from a modern gearless machine and VVVF drive system: 3–15 kW depending on rated power. Ventilation is provided by: forced-air extraction fans (most common); air conditioning units where ambient temperatures are extreme; natural ventilation via louvers where the thermal load is low and external conditions permit. Air change rates are calculated by heat load and permissible temperature rise. Air inlet must be positioned low (cool air entry) and exhaust high (hot air exit) for efficient natural convection. Filters on air inlets prevent ingress of dust and insects that can contaminate electrical contacts. Where MRL technology is used, the drive and controller in the hoistway or landing enclosure require equivalent thermal management provisions.
