Welcome to Aliens World
The low mechanical complexity of hydraulic elevators in comparison to traction elevators makes them ideal for low rise, low traffic installations. They are less energy efficient as the pump works against gravity to push the car and its passengers upwards; this energy is lost when the car descends on its own weight. The high current draw of the pump when starting up also places higher demands on a building's electrical system. There are also environmental concerns should the lifting cylinder leak fluid into the groun.
A hydraulic lift system does not use overhead lifting machines. Instead, these elevators use fluid compression to generate motion. The elevator car is lifted by an electric motor that pumps the oil into the cylinder to move the piston.
Hydraulic lifts also incorporate electric valves to control the release of oil for a smooth ride. The fluid needed to power a hydraulic lift must be oil-based. Hydraulic elevators have been rated the safest option for home elevators. They boast superb user friendliness and easy access machine room located at the basement.