Tankless water heater hot water return system

Abstract

A tankless return hot water return system to facilitate whole-house or whole-building hot water return recirculation used in conjunction with tankless water heaters. The system is designed to compensate for tankless head losses and to protect the tankless heat exchanger. The system has a hot water return by-pass for heat exchanger protection. The invention utilizes the tankless water heater as the heating source for the hot water return and eliminates the need and use of tank-type water heaters for tankless hot water return recirculation. The system is self-contained with built-in temperature sensing and does not require any auxiliary controls, sensors, switches, timing mechanisms or remote activation. The system is energy efficient and water conservative.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]The present utility patent application claims the advantage of provisional applications #60 / 914001 and #60 / 913998 both filed Apr. 25, 2007.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT[0002]Not Applicable.THE NAMES OF THE PARTIES TO A JOINT RESEARCH OR DEVELOPMENT[0003]Not Applicable.BACKGROUND OF THE INVENTION[0004]1. Field of the Invention[0005]The present invention relates to plumbing systems and particularly to a tankless water heating hot water return system which comprises a plumbing system having a hot water recirculating line which brings unused cooled “hot” water from the hot water supply lines back to the hot water heater so that it may be reheated and redirected to the hot water outlet, thereby conserving water.[0006]2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98[0007]Various hot water recirculating systems have been previously designed, some for boiler-tank systems as...

AI Technical Summary

Benefits of technology

[0043]The objective of the invention is to facilitate traditional hot water return in tankless water heating systems and eliminate the use of water storage tanks in potable domestic hot water recirculation systems. This eliminates the need for additional storage equipment in non storage applications, specifically designed to operate with various flow and pressure sensitive heating products such as tankless water heaters.

[0044]In brief, a tankless water heater hot water return system allows the use of traditional hot water return, pump sizing and piping methodology for tankless water heating applications. As water circulates through the unit's hot water recirculation line, the device senses that the system loop has fallen below the set point. The device then allows water to pass though the device and into the heat source heat exchanger. Once the system set point has been satisfied, the device will turn off until another demand for heating cycle. This is an energy efficient device due to low power consumption, electronic start and stop, low heating requirements and conservation of water.

Problems solved by technology

If the main water supply has insufficient pressure, the recirculating cooled hot water system is non-functional.

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