alt Hacker NewsI think the error bars are too high to say more than that. I doubt they did a measure of the power the original consumed, just an analysis of the system. They likely only have whole building power consumption, where HVAC is the majority of the costs: 1 degree difference in the weather or a couple tenants taking a vacation will make a much larger difference than the elevator.
I wouldn't be surprised if most of the savings was the new lights are LED while the old only incandescent was available - this is just speculation though, I have no idea. Every gear and every stretch of the ropes cost a little bit of efficiency and the modern system has less of those.
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> I wouldn't be surprised if most of the savings was the new lights are LED while the old only incandescent was available
It’s definitely not the lighting, you only need a few thousand lumens to have bright elevator lighting. If you need 4000 lumens, that is (5) 60W incandescent lamps, switching to LEDs that do 100 lumens per watt (8W lamp) saves you 260 watts/hr.
The new elevator uses a VFD (they call it a VVVF) to control the motor which is where virtually all of the gains come from. Lowering the speed of the motor lowers the power usage, it’s a non-linear relationship but a motor spinning at 75% speed uses 1/4 to 1/3rd of the power that it would use at full speed.
> They likely only have whole building power consumption
You can easily measure the power of a single circuit or single panelboard using a submeter: https://www.shopemondirect.com/catalog/shop/Shop-E-Mon-Direc...
The reduction in cable weight probably was a big part of the savings, next to the vfd. Normally counterweights hang from the same sheave as the elevator. Its not clear to me from the sketch, but with the counterweight in different shaft the cable may have run three times the height of the building (the excessive length was noted) and that's a lot of mass to accelerate and brake.