Do you work in a tall building everyday? If you do, there’s a large chance that you encounter and use elevators on a daily basis. Do you live in an apartment building between say maybe, 3 and 20 stories? If so, This is probably the case for you as well. Even people not in these situations still manage to come across instances where taking the elevator is feasible very commonly. But what about all of the energy being consumed throughout this daily process? How much energy is actually being used and would it be better to just take the stairs?
Now this can be a bit of a complicated question. Elevators today have a large number of variables that could change the outcome of their energy output. Some examples would be: How many people are riding the elevator? What type of lighting is in the car? Is the elevator geared, gearless, hydraulic, or traction applied? Does the system have the most recent braking technology, which recaptures energy that would otherwise have been lost as heat, funneling it back to the grid? Does it use software that plots out the most efficient route possible for each car?
These are all important questions (but not all) that come into play when calculating if you specifically should take the stairs. Let’s jump in and look at some basic details.
The differences in elevators and their consumption can be very wide. According to the elevator calculator from Thyssenkrupp, a typical hydraulic applied elevator that uses LED lighting in a 3 story office building uses about 4,725 kilowatt-hours per year. That’s around how much the average American house uses in a little over 5 months. Traction elevators are used for taller buildings and a traction applied elevator in a 40 story apartment building uses about 14,130kilowatt-hours per year. That’s more than three times as much as the smaller building and as more than an American home uses in an entire year!
Another variable to consider is, not all elevator rides are equal. For example, a hydraulic elevator needs more energy to go up than it does to come down. These types of systems are typically used in buildings that are 7 stories or shorter. But the ride down isn’t totally free. When the elevator needs to come down, as it passes through the shaft at a controlled speed, the friction caused by oil passing through the hydraulic valves generates heat, which then has to be dissipated by the building’s cooling system.
In traction systems used in taller buildings, it is operated by counterweighted pulleys that help raise and lower the cars. The counterweight usually weighs about as much as the car when it is at around 40% capacity. So when it is loaded at full capacity, it needs a significant burst of energy to actually make it lift up. A full car traveling downward, on the other hand, is significantly much heavier than the counterweight so it can move without much help. So what does this mean? Essentially a full car going up uses more energy than a full car going down, and an empty car going down uses more energy than an empty car going up. The system turns out to be most efficient when the car is 40 percent full or when it’s perfectly balanced with the counterweight.
Elevators are even going to burn energy when not running. Some systems have automatic lights and fans that shut off while not in use, some don’t. The average standby power rating is between 0.8 and 2 kilowatts, which can eventually add up.
So, how does this apply to you? Would you consider taking the stairs if it was more energy efficient in your specific situation? Basically, if you have to navigate through tall buildings, it is more beneficial to try to minimize trips altogether and carpool with your co workers and neighbors if you HAVE to take the elevator to your floor. However, If you live in a small apartment building or work in a low rise office, or even if you don’t need to go that many floors up, it would be immensely more beneficial to the environment and your overall health to just take the stairs.
If you were to simply walk up and down 3 flights of stairs instead of taking the elevator, you would save about 15 kwh a day or 450 kwh a month. That’s enough to power an air conditioning system for a little over 4 hours, or even a 55″ tv for 78 hours! Now can you honestly say that you can’t abstain from taking a 20 second ride to save all of that energy? Try to do your part, when you can.
If you have any insightful information on this topic or other great ways to save power and energy, get the discussions started and comment to let us know!