Many people have them installed right under a kitchen sink. We here are plumbing-impaired, so ours just sits on the laundry room floor next to the utility sink. It has an intake (simple screw on valve to the faucet) an output (pours into an 18 gal rubbermaid) and a waste line (just lays in the utility tub to drain). Believe me, if I could do this with just one visit to the hardware store (for that valve to screw on to the faucet) ANYONE can set these up. It is such a luxury not to be hauling gallons from the store.
Good Luck!