The Instant-Flow SR is an electric mini tankless water heater for point-of-use applications. Available for a wide variety of uses, the unit is 99 percent energy efficient and its small size makes it very versatile. It meets ADA requirements, delivers unlimited hot water, and can be used for bath lavatories, sinks, and showers. Cost: $350 to $450. Chronomite Laboratories. 800-447-4962.