Lifts

Save Energy

There are already over 5 million lifts installed in the EU-28. Their energy consumption adds up to 3 to 5 % of the overall consumption of a building.


 

Simulations indicate that on average a lift at low load, running 20,000-30,000 starts a year, would use less that 1,000 kWh / year for travel. On the other hand, power consumption in standby can get a lift to 1 kW, which would translate into 5,000 kWh / year for 5000 hours of standby time in a year. This represents a substantial share of the total annual electricity consumption of the lift and should be considered when purchasing a new lift for a residential building.

The lift systems have been designed individually for each specific application. Each of its parts contribute differently to the overall efficiency of the lift. All lift systems have common elements, regardless of their principle of operation, including: a cabin, doors, lights and ventilation systems, a motor and a control device (said control panel) with shaft (an enclosed area where the car travels). There are two main classes of systems: hydraulic lifts and electric traction. Electric traction can be further divided into two categories: motor with gearbox (geared) and gearless.

 

The hydraulic lifts have no counterweight and they are the most inefficient. The energy is dissipated as heat when the hydraulic lift goes down. Hydraulic lifts also travel at low speeds, typically less than 1 m/s. The maximum stroke for this type of plant is about 20m.

Electric traction lifts use rope guided by pulleys driven by a motor and are fitted with a counterweight that reduces the weight to be lifted.

The hydraulic lifts dominate the market for buildings that are not very high, because they have substantially lower prices. The higher buildings traditionally make use of the lifts with electric motor (geared), while those without a direct electric motor (gearless) are predominant in skyscrapers.

Technological development in the lift industry was mainly driven by factors other than energy efficiency. Travel speed, acoustic noise, ride comfort and space are the main concerns of the lift design. However, the demand for energy efficient and greener buildings has increased in recent years and the lift industry has responded accordingly, presenting its customers with solutions to meet these growing needs.

The energy consumption of the installation of a lift is a significant percentage of the total electrical load of the building. Estimates range from 5 to 15% depending on other services installed in the building. Therefore, it is necessary to predict, with reasonable accuracy, the use of energy in a new installation and modernization of already existing plants.