I read this article (link) but I'm having trouble seeing how a tiny impeller like this (link) can actually move water up my seven-story building. I understand it's connected to an electric motor, which spins it.
But does the spin on that impeller (at a high velocity) really create enough momentum to move water up seven or eight stories?
Are there other impellers or pumps along the way that help it? Or is it just that one pump attached to the boiler? (I live in an apartment complex with around 100 units.)