Scheduling strategy and energy-efficient operation of hotel elevator group control systems
I am elevator expert Ethan Liu. In hotel projects, the scheduling strategy and energy-efficient operation of elevator group control systems are key factors that directly affect guest experience, operational efficiency, and long-term energy costs. Hotel elevators differ from those in office buildings: their passenger flow patterns show pronounced tidal characteristics (e.g., morning check-out, midday dining, evening check-in, and banquet periods), and they impose extremely high requirements on service response speed. Improper scheduling strategies not only cause passengers to wait for long periods but also increase energy consumption due to frequent starts/stops or empty-car operation. The following detailed analysis is based on GB 7588, GB/T 10060, and practical engineering experience.
I. Core Principles of Scheduling Strategy
Hotel group control systems usually adopt a combination of zoning dispatch and destination floor reservation, rather than simple "nearest-car response." According to Clause 5.3.2 of GB/T 10060-2011 *Code for Installation and Acceptance of Electric Lifts*, the group control system should be able to automatically adjust operating modes according to a preset passenger flow model. Specific strategies include:
1. Zoned service: Divide the hotel floors into a low zone (lobby to 3rd floor), middle zone (4th–10th floors), and high zone (11th floor and above), with each elevator fixed to serve a specific zone to reduce cross-zone travel. For example, a five-star hotel (32 floors, 6 passenger elevators) adopted a "two-zone, two-elevator" model, shortening the average waiting time during peak periods to within 25 seconds.
2. Destination floor reservation: Through reservation terminals in the lobby or guest rooms, passengers enter their destination floor, and the system assigns a designated elevator, avoiding unnecessary stops. This strategy can improve transport efficiency by about 20%, but attention must be paid to compatibility with fire linkage requirements (Clause 7.3.2 of GB 50016-2014 requires that fire elevators must be capable of manual control).
3. Dynamic scheduling algorithm: Based on AI prediction models, combined with historical passenger flow data (such as banquet hall dismissal times), the elevator distribution is adjusted in advance. For example, at a resort hotel, after the evening banquet ended, the system automatically dispatched 3 elevators to the 1st floor on standby, shortening evacuation time by 40%.
II. Key Technologies for Energy-Efficient Operation
Elevator energy consumption accounts for about 5%–10% of a hotel's total electricity use, mainly from traction machines, door operators, and control systems. Energy-saving measures must comply with the energy efficiency grade requirements of Clause 4.5 of GB/T 10058-2009 *Specification for Electric Lifts*. Specifically:
1. Energy feedback technology: Adopt variable-frequency drive + feedback devices (e.g., Vacon NX series) to convert braking energy into electrical energy and feed it back to the grid. Measured results show that feedback efficiency can reach 30%–40%. For example, after retrofitting at a hotel, a single elevator saved about 8,000 kWh per year.
2. Intelligent standby mode: During low passenger flow periods (e.g., 2:00–5:00 a.m.), the system automatically shuts down some elevators, keeping only 1–2 in operation, and sets a "dormant floor" (usually the 1st floor). Note that Clause 12.6 of GB 7588-2003 requires that elevators must still be able to respond to emergency calls during standby.
3. Lighting and ventilation optimization: According to Clause 10.3.1 of GB 50016-2014, the lighting power density in elevator cars should not exceed 7 W/m². Use LED lamps + human presence sensing control; when the elevator is idle for more than 3 minutes, automatically dim to 50% brightness; the ventilation fan automatically starts/stops according to car temperature (e.g., ≥28℃).
4. Traction machine selection: Give priority to permanent magnet synchronous motors (PM), whose efficiency is 15%–20% higher than that of asynchronous motors, and which require no gearbox, reducing mechanical losses. For example, a hotel selected KONE MonoSpace elevators, achieving a comprehensive energy-saving rate of 25%.
III. Practical Engineering Case
Case background: A city five-star hotel with 28 floors, equipped with 6 passenger elevators (load 1600 kg, speed 2.5 m/s) and 1 fire elevator. The original group control system used the traditional "nearest-car response" mode; the average waiting time during peak periods reached 45 seconds, the customer complaint rate was high, and the annual electricity cost was about RMB 180,000.
Retrofit plan:
1. Upgrade to the Otis CompassPlus group control system, adopting destination floor reservation and zoned dispatch (low zone 1st–10th floors, high zone 11th–28th floors).
2. Install energy feedback devices (Schneider Altivar Process) and LED presence-sensing lighting.
3. Set energy-saving mode: from 23:00 to 6:00, keep only 2 elevators in operation and put the rest into standby.
Results: After the retrofit, the peak-period waiting time dropped to 22 seconds, the annual electricity cost dropped to RMB 135,000 (25% energy savings), and customer satisfaction rose to 92%. Note that the retrofit must be reported to the local special equipment inspection institute and supervised inspection must be carried out in accordance with TSG T7001-2009.
IV. Implementation Recommendations
1. Preliminary assessment: Passenger flow simulation analysis must be carried out (e.g., using Elevate software) to clarify the passenger flow density of the hotel in each period. For example, the banquet hall floor needs high-capacity elevators (≥1600 kg).
2. Code compliance: The group control system must satisfy Clause 14.1.1 of GB 7588-2003 (emergency operation priority) and Clause 7.3.5 of GB 50016-2014 (independent control of fire elevators). If destination floor reservation is adopted, the manual floor selection function must be retained.
3. Operation and maintenance management: Establish an energy consumption monitoring platform (in accordance with GB/T 29186-2012), track single-elevator energy consumption in real time, and regularly (quarterly) calibrate the group control algorithm parameters. For example, through monitoring, a hotel found that the empty-car rate of the banquet hall elevators was as high as 60% during non-event periods; later, by adjusting the zoning strategy, it reduced the number of elevators serving that area by 2.
Summary: The optimization of hotel elevator group control systems requires balancing service efficiency and energy consumption. The core is to adopt a zoning dispatch + destination floor reservation strategy, together with energy feedback, intelligent standby, and high-efficiency equipment. In actual projects, it is recommended to entrust a professional elevator company to conduct passenger flow simulation and strictly follow GB/T 10060, GB 7588, and other codes to avoid energy-saving measures affecting safety or fire protection functions.
The above are reference opinions. The actual project situation still needs to be comprehensively evaluated and implemented in light of specific operating conditions, site conditions, and other factors.