Differences Between Hydraulic & Traction Elevators

Hydraulic and traction lifts are among the two most commonly used lifts in both residential and commercial buildings. Hydraulic lifts are powered by electronic pumps which transmit the hydraulic fluid to the jack. The lift has a piston at its base which will push it up. On the other hand, traction lifts use ropes, sheaves and counterweight for moving up and down. Both systems have their own set of pros and cons. So you should consider their advantages and disadvantages before choosing the right system. Hydraulic Lifts Hydraulic elevator require lesser amount of space because their hoistway doesn’t require as much space. These units are much more effective when it comes to lifting higher loads. The hydraulic systems have long been known to provide higher lifting power compared to traction ropes. On the other hand, hydraulic systems have their unique set of disadvantages. They are not as quick as their traction counterparts. The maximum speed the best hydraulic units can achieve is 150 fpm. When oil is used as the hydraulic fluid, its performance will depend on the temperature. Therefore, these units require a highly efficient machine room system. Another thing about these units is that they produce high amounts of heat. It is also possible that the oil may leak from the base. It can also contribute to pollution if the oil reaches the ground water. Thus, regular maintenance and care is required to keep it in peak form. Traction Elevators Traction elevators are faster compared to their hydraulic counterparts. This makes the traction units much more suitable for higher-rising, modern buildings. They also offer smoother and more comfortable rides compared to hydraulic systems. Another advantage is that these units are much more energy efficient. This is because they use counterweight for balancing the cab’s weight. On the other hand, the hydraulic unit requires pushing the cab. But the traction system also has its cons too. They can be a harder to provide maintenance and care because the controls are installed within the shaft headroom, which is not easily accessible. But this problem is addressed in traction units that use magnetic synchronous motor in place of the machine room. Comparisons Factors The differences between hydraulic and traction elevators can be simplified further depending on the following factors: - Price – Price is a clear factor of difference between the two types of elevators. Usually, hydraulic elevators are cheaper compared to their traction counterparts. - Energy Efficiency – Traction lifts may be costlier but they are much energy efficient. The difference is because of the difference in the two systems’ working mechanism. When it comes to hydraulic units, the pump creates force against gravity for pushing and lifting the cab up. The energy gets lost when the cab comes down. On the other hand, traction units use a counterweight for the same purpose. Because the weight of the cab is counterbalanced and lesser force is required. - Speed – As already indicated above, hydraulic elevators are slower compared to traction lifts. Hydraulic units can reach top speeds of 1 meter per second, but traction units can reach 2.5 meters per second. This is one of the main reasons why traction lifts are more commonly used in high-rises. - Space – The space required for installing the lifts is also a major difference between the two. Because of this reason, hydraulic units are suited more for some types of uses. Traction elevators mostly require more space and are bulkier. But new traction system called machine room less lifts require much lesser space. So make sure to consider all these factors before choosing the right elevator between hydraulic and traction systems.