Dual mode hot water circulation apparatus

Abstract

A dual mode water circulation apparatus to provide instantaneous hot water to faucets remote from the heater in residential or small commercial building water systems. The apparatus comprises a cold water heat exchanger, a high sensitivity check valve, and an aspirator incorporated into a single unit. The heat exchanger is a chamber installed in the cold water supply line, containing a cooling tube exposed to the water. The check valve has a neutral buoyancy poppet and closes against an angular seat. The aspirator has a reduced cross section nozzle inside a tapered chamber connected to the water supply pipe, with a low pressure tap in the chamber bore. The apparatus is installed at an angle to the horizontal. The cooling tube is connected to a water return line from a tee in the hot water pipe at the remote faucet. The water circulation loop is from the remote hot water faucet to the heat exchanger portion of the apparatus, to the check valve, then to the aspirator and into the cold water supply to the heater. A continuous, low rate convective flow is induced in the loop by the heat exchanger, and a higher rate aspirated flow is present whenever water is used in the building. The apparatus is self regulating in response to user needs.

Dependencies are inferred from the claim text.