The kinetic energy of the mass of exhaust gas carries it along the exhaust pipe, and causes a pressure build up ahead of the mass of gas and a partial vacuum behind it. This principle is used in a tuned exhaust system.
Culligan - $2352 ($2053 w/o R/O unit) Culligan Gold Series (10), Good Water Machine. If I were to look at price only, I would go with either the cheaper Ecowater system w/R/O at $2698 or the Culligan system. At almost $4k, the Kinetico system seems greatly over priced.
1 Ion-exchange water softeners start around $400-$1,000 for a basic unit. 2  Installation costs range from $100-$500 (depending on the type of equipment, ease of access and whether you need to add new piping and a suitable drain for the unit) for a total cost of $500-$1,500 for basic water softener in an average-size home. The size of the water softener will depend on the amount of water to be softened (and some systems use more than one tank), but many water softeners are anywhere from 3-1/2 to 5-1/2 feet high and 12-26 inches across.